staging: comedi: drivers: use comedi_fc.h cmdtest helpers

Use the cfc_check_trigger_src() helper for Step 1 in all the
driver cmdtest functions.

Use the cfc_check_trigger_is_unique() helper for Step 2 in all
the driver cmdtest functions. Note that single source triggers
do not need to be checked, they are already unique if they pass
Step 1.

For aesthetic reasons, change the comments in the cmdtest
functions for steps 1 and 2 so that they are all the same.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/8255.c

@@ -82,6 +82,8 @@ I/O port base address can be found in the output of 'lspci -v'.
 
 #include <linux/ioport.h>
 #include <linux/slab.h>
+
+#include "comedi_fc.h"
 #include "8255.h"
 
 #define _8255_SIZE	4
@@ -229,39 +231,20 @@ static int subdev_8255_cmdtest(struct comedi_device *dev,
 			       struct comedi_cmd *cmd)
 {
 	int err = 0;
-	unsigned int tmp;
-
-	/* step 1 */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
 
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_FOLLOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2 */
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c

@@ -479,57 +479,26 @@ int i_APCI3120_CommandTestAnalogInput(struct comedi_device *dev, struct comedi_s
 	struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;		/*  divisor1,divisor2; */
 
-	/*  step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-		cmd->scan_begin_src != TRIG_FOLLOW)
-		err++;
-
-	if (cmd->convert_src != TRIG_TIMER)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
 
-	if (cmd->scan_end_src != TRIG_COUNT) {
-		cmd->scan_end_src = TRIG_COUNT;
-		err++;
-	}
-
-	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
-		err++;
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3200.c

@@ -2560,7 +2560,6 @@ int i_APCI3200_CommandTestAnalogInput(struct comedi_device *dev, struct comedi_s
 {
 
 	int err = 0;
-	int tmp;		/*  divisor1,divisor2; */
 	unsigned int ui_ConvertTime = 0;
 	unsigned int ui_ConvertTimeBase = 0;
 	unsigned int ui_DelayTime = 0;
@@ -2571,41 +2570,32 @@ int i_APCI3200_CommandTestAnalogInput(struct comedi_device *dev, struct comedi_s
 	int i_Cpt = 0;
 	double d_ConversionTimeForAllChannels = 0.0;
 	double d_SCANTimeNewUnit = 0.0;
-	/*  step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
-	/* if(i_InterruptFlag==0) */
-	if (s_BoardInfos[dev->minor].i_InterruptFlag == 0) {
-		err++;
-		/*           printk("\nThe interrupt should be enabled\n"); */
-	}
+
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
+
+	if (s_BoardInfos[dev->minor].i_InterruptFlag == 0)
+		err |= -EINVAL;
+
 	if (err) {
 		i_APCI3200_Reset(dev);
 		return 1;
 	}
 
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT) {
-		err++;
-	}
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(&cmd->start_src);
+	err |= cfc_check_trigger_is_unique(&cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(&cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
+
 	if (cmd->start_src == TRIG_EXT) {
 		i_TriggerEdge = cmd->start_arg & 0xFFFF;
 		i_Triggermode = cmd->start_arg >> 16;
@@ -2619,21 +2609,6 @@ int i_APCI3200_CommandTestAnalogInput(struct comedi_device *dev, struct comedi_s
 		}
 	}
 
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-		cmd->scan_begin_src != TRIG_FOLLOW)
-		err++;
-
-	if (cmd->convert_src != TRIG_TIMER)
-		err++;
-
-	if (cmd->scan_end_src != TRIG_COUNT) {
-		cmd->scan_end_src = TRIG_COUNT;
-		err++;
-	}
-
-	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
-		err++;
-
 	if (err) {
 		i_APCI3200_Reset(dev);
 		return 2;

drivers/staging/comedi/drivers/adl_pci9111.c

@@ -332,7 +332,7 @@ static int pci9111_ai_do_cmd_test(struct comedi_device *dev,
 	int range, reference;
 	int i;
 
-	/* Step 1 : check if trigger are trivialy valid */
+	/* Step 1 : check if triggers are trivially valid */
 
 	error |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
 	error |= cfc_check_trigger_src(&cmd->scan_begin_src,

drivers/staging/comedi/drivers/adl_pci9118.c

@@ -1102,7 +1102,7 @@ static int pci9118_ai_cmdtest(struct comedi_device *dev,
 	int tmp;
 	unsigned int divisor1 = 0, divisor2 = 0;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
 	err |= cfc_check_trigger_src(&cmd->start_src,
 					TRIG_NOW | TRIG_EXT | TRIG_INT);
@@ -1124,70 +1124,31 @@ static int pci9118_ai_cmdtest(struct comedi_device *dev,
 	if (err)
 		return 1;
 
-	/*
-	 * step 2:
-	 * make sure trigger sources are
-	 * unique and mutually compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->start_src != TRIG_NOW &&
-	    cmd->start_src != TRIG_INT && cmd->start_src != TRIG_EXT) {
-		cmd->start_src = TRIG_NOW;
-		err++;
-	}
-
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_INT &&
-	    cmd->scan_begin_src != TRIG_FOLLOW) {
-		cmd->scan_begin_src = TRIG_FOLLOW;
-		err++;
-	}
-
-	if (cmd->convert_src != TRIG_TIMER &&
-	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW) {
-		cmd->convert_src = TRIG_TIMER;
-		err++;
-	}
-
-	if (cmd->scan_end_src != TRIG_COUNT) {
-		cmd->scan_end_src = TRIG_COUNT;
-		err++;
-	}
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
 
-	if (cmd->stop_src != TRIG_NONE &&
-	    cmd->stop_src != TRIG_COUNT &&
-	    cmd->stop_src != TRIG_INT && cmd->stop_src != TRIG_EXT) {
-		cmd->stop_src = TRIG_COUNT;
-		err++;
-	}
+	/* Step 2b : and mutually compatible */
 
-	if (cmd->start_src == TRIG_EXT && cmd->scan_begin_src == TRIG_EXT) {
-		cmd->start_src = TRIG_NOW;
-		err++;
-	}
+	if (cmd->start_src == TRIG_EXT && cmd->scan_begin_src == TRIG_EXT)
+		err |= -EINVAL;
 
-	if (cmd->start_src == TRIG_INT && cmd->scan_begin_src == TRIG_INT) {
-		cmd->start_src = TRIG_NOW;
-		err++;
-	}
+	if (cmd->start_src == TRIG_INT && cmd->scan_begin_src == TRIG_INT)
+		err |= -EINVAL;
 
 	if ((cmd->scan_begin_src & (TRIG_TIMER | TRIG_EXT)) &&
-	    (!(cmd->convert_src & (TRIG_TIMER | TRIG_NOW)))) {
-		cmd->convert_src = TRIG_TIMER;
-		err++;
-	}
+	    (!(cmd->convert_src & (TRIG_TIMER | TRIG_NOW))))
+		err |= -EINVAL;
 
 	if ((cmd->scan_begin_src == TRIG_FOLLOW) &&
-	    (!(cmd->convert_src & (TRIG_TIMER | TRIG_EXT)))) {
-		cmd->convert_src = TRIG_TIMER;
-		err++;
-	}
+	    (!(cmd->convert_src & (TRIG_TIMER | TRIG_EXT))))
+		err |= -EINVAL;
 
-	if (cmd->stop_src == TRIG_EXT && cmd->scan_begin_src == TRIG_EXT) {
-		cmd->stop_src = TRIG_COUNT;
-		err++;
-	}
+	if (cmd->stop_src == TRIG_EXT && cmd->scan_begin_src == TRIG_EXT)
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/adv_pci1710.c

@@ -1046,7 +1046,7 @@ static int pci171x_ai_cmdtest(struct comedi_device *dev,
 	int tmp;
 	unsigned int divisor1 = 0, divisor2 = 0;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
 	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
 	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);

drivers/staging/comedi/drivers/amplc_dio200.c

@@ -210,6 +210,7 @@ order they appear in the channel list.
 
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
 #include "8255.h"
 #include "8253.h"
 
@@ -771,52 +772,24 @@ dio200_subdev_intr_cmdtest(struct comedi_device *dev,
 			   struct comedi_subdevice *s, struct comedi_cmd *cmd)
 {
 	int err = 0;
-	unsigned int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= (TRIG_NOW | TRIG_INT);
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= (TRIG_COUNT | TRIG_NONE);
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually
-		   compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* these tests are true if more than one _src bit is set */
-	if ((cmd->start_src & (cmd->start_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
-		err++;
-	if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
-		err++;
-	if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/amplc_pc236.c

@@ -56,6 +56,7 @@ unused.
 
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
 #include "8255.h"
 #include "plx9052.h"
 
@@ -313,39 +314,20 @@ static int pc236_intr_cmdtest(struct comedi_device *dev,
 			      struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
 
-	/* step 1 */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_FOLLOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: ignored */
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/amplc_pci224.c

@@ -720,53 +720,31 @@ pci224_ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 	int err = 0;
 	unsigned int tmp;
 
-	/* Step 1: make sure trigger sources are trivially valid. */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_INT | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT | TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_EXT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_INT | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_EXT | TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src,
+					TRIG_COUNT | TRIG_EXT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* Step 2: make sure trigger sources are unique and mutually
-	 * compatible. */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* these tests are true if more than one _src bit is set */
-	if ((cmd->start_src & (cmd->start_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
-		err++;
-	if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
-		err++;
-	if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
 
-	/* There's only one external trigger signal (which makes these
-	 * tests easier).  Only one thing can use it. */
+	/* Step 2b : and mutually compatible */
+
+	/*
+	 * There's only one external trigger signal (which makes these
+	 * tests easier).  Only one thing can use it.
+	 */
 	tmp = 0;
 	if (cmd->start_src & TRIG_EXT)
 		tmp++;
@@ -775,7 +753,7 @@ pci224_ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 	if (cmd->stop_src & TRIG_EXT)
 		tmp++;
 	if (tmp > 1)
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/amplc_pci230.c

@@ -193,6 +193,7 @@ for (or detection of) various hardware problems added by Ian Abbott.
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 
+#include "comedi_fc.h"
 #include "8253.h"
 #include "8255.h"
 
@@ -958,23 +959,11 @@ static int pci230_ao_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	unsigned int tmp;
 
-	/* cmdtest tests a particular command to see if it is valid.
-	 * Using the cmdtest ioctl, a user can create a valid cmd
-	 * and then have it executes by the cmd ioctl.
-	 *
-	 * cmdtest returns 1,2,3,4 or 0, depending on which tests
-	 * the command passes. */
+	/* Step 1 : check if triggers are trivially valid */
 
-	/* Step 1: make sure trigger sources are trivially valid.
-	 * "invalid source" returned by comedilib to user mode process
-	 * if this fails. */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_INT);
 
-	tmp = cmd->scan_begin_src;
+	tmp = TRIG_TIMER | TRIG_INT;
 	if ((thisboard->min_hwver > 0) && (devpriv->hwver >= 2)) {
 		/*
 		 * For PCI230+ hardware version 2 onwards, allow external
@@ -990,46 +979,23 @@ static int pci230_ao_cmdtest(struct comedi_device *dev,
 		 * scan_begin_src==TRIG_EXT support to be a bonus rather than a
 		 * guarantee!
 		 */
-		cmd->scan_begin_src &= TRIG_TIMER | TRIG_INT | TRIG_EXT;
-	} else {
-		cmd->scan_begin_src &= TRIG_TIMER | TRIG_INT;
+		tmp |= TRIG_EXT;
 	}
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, tmp);
 
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* Step 2: make sure trigger sources are unique and mutually compatible
-	 * "source conflict" returned by comedilib to user mode process
-	 * if this fails. */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* these tests are true if more than one _src bit is set */
-	if ((cmd->start_src & (cmd->start_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
-		err++;
-	if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
-		err++;
-	if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;
@@ -1610,75 +1576,45 @@ static int pci230_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	unsigned int tmp;
 
-	/* cmdtest tests a particular command to see if it is valid.
-	 * Using the cmdtest ioctl, a user can create a valid cmd
-	 * and then have it executes by the cmd ioctl.
-	 *
-	 * cmdtest returns 1,2,3,4,5 or 0, depending on which tests
-	 * the command passes. */
+	/* Step 1 : check if triggers are trivially valid */
 
-	/* Step 1: make sure trigger sources are trivially valid.
-	 * "invalid source" returned by comedilib to user mode process
-	 * if this fails. */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
 
-	tmp = cmd->scan_begin_src;
-	/* Unfortunately, we cannot trigger a scan off an external source
-	 * on the PCI260 board, since it uses the PPIC0 (DIO) input, which
-	 * isn't present on the PCI260.  For PCI260+ we can use the
-	 * EXTTRIG/EXTCONVCLK input on pin 17 instead. */
+	tmp = TRIG_FOLLOW | TRIG_TIMER | TRIG_INT;
 	if ((thisboard->have_dio) || (thisboard->min_hwver > 0)) {
-		cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_TIMER | TRIG_INT
-		    | TRIG_EXT;
-	} else {
-		cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_TIMER | TRIG_INT;
+		/*
+		 * Unfortunately, we cannot trigger a scan off an external
+		 * source on the PCI260 board, since it uses the PPIC0 (DIO)
+		 * input, which isn't present on the PCI260.  For PCI260+
+		 * we can use the EXTTRIG/EXTCONVCLK input on pin 17 instead.
+		 */
+		tmp |= TRIG_EXT;
 	}
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_INT | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, tmp);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_TIMER | TRIG_INT | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* Step 2: make sure trigger sources are unique and mutually compatible
-	 * "source conflict" returned by comedilib to user mode process
-	 * if this fails. */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* these tests are true if more than one _src bit is set */
-	if ((cmd->start_src & (cmd->start_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
-		err++;
-	if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
-		err++;
-	if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
-	/* If scan_begin_src is not TRIG_FOLLOW, then a monostable will be
-	 * set up to generate a fixed number of timed conversion pulses. */
+	/*
+	 * If scan_begin_src is not TRIG_FOLLOW, then a monostable will be
+	 * set up to generate a fixed number of timed conversion pulses.
+	 */
 	if ((cmd->scan_begin_src != TRIG_FOLLOW)
 	    && (cmd->convert_src != TRIG_TIMER))
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/cb_das16_cs.c

@@ -46,6 +46,7 @@ Status: experimental
 #include <pcmcia/cistpl.h>
 #include <pcmcia/ds.h>
 
+#include "comedi_fc.h"
 #include "8253.h"
 
 #define DAS16CS_SIZE			18
@@ -169,47 +170,26 @@ static int das16cs_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and
-	 * mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/cb_pcidas.c

@@ -803,58 +803,35 @@ static int cb_pcidas_ai_cmdtest(struct comedi_device *dev,
 	int tmp;
 	int i, gain, start_chan;
 
-	/* step 1: trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_NOW | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_FOLLOW | TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_TIMER | TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER &&
-	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
-	/*  make sure trigger sources are compatible with each other */
 	if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW)
-		err++;
+		err |= -EINVAL;
 	if (cmd->scan_begin_src != TRIG_FOLLOW && cmd->convert_src != TRIG_NOW)
-		err++;
+		err |= -EINVAL;
 	if (cmd->start_src == TRIG_EXT &&
 	    (cmd->convert_src == TRIG_EXT || cmd->scan_begin_src == TRIG_EXT))
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;
@@ -1079,43 +1056,24 @@ static int cb_pcidas_ao_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/cb_pcidas64.c

@@ -2108,74 +2108,50 @@ static int ai_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 		      struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
 	unsigned int tmp_arg, tmp_arg2;
 	int i;
 	int aref;
 	unsigned int triggers;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
 
-	tmp = cmd->scan_begin_src;
 	triggers = TRIG_TIMER;
 	if (board(dev)->layout == LAYOUT_4020)
 		triggers |= TRIG_OTHER;
 	else
 		triggers |= TRIG_FOLLOW;
-	cmd->scan_begin_src &= triggers;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, triggers);
 
-	tmp = cmd->convert_src;
 	triggers = TRIG_TIMER;
 	if (board(dev)->layout == LAYOUT_4020)
 		triggers |= TRIG_NOW;
 	else
 		triggers |= TRIG_EXT;
-	cmd->convert_src &= triggers;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->convert_src, triggers);
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_EXT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src,
+					TRIG_COUNT | TRIG_EXT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/*  uniqueness check */
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_OTHER &&
-	    cmd->scan_begin_src != TRIG_FOLLOW)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER &&
-	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT &&
-	    cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_EXT)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
-	/*  compatibility check */
 	if (cmd->convert_src == TRIG_EXT && cmd->scan_begin_src == TRIG_TIMER)
-		err++;
+		err |= -EINVAL;
 	if (cmd->stop_src != TRIG_COUNT &&
 	    cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_EXT)
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;
@@ -3466,55 +3442,33 @@ static int ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 		      struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
 	unsigned int tmp_arg;
 	int i;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_INT | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_INT | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/*  uniqueness check */
-	if (cmd->start_src != TRIG_INT && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+
+	/* Step 2b : and mutually compatible */
 
-	/*  compatibility check */
 	if (cmd->convert_src == TRIG_EXT && cmd->scan_begin_src == TRIG_TIMER)
-		err++;
+		err |= -EINVAL;
 	if (cmd->stop_src != TRIG_COUNT &&
 	    cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_EXT)
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/cb_pcidda.c

@@ -48,6 +48,7 @@ Please report success/failure with other different cards to
 
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
 #include "8255.h"
 
 /* PCI vendor number of ComputerBoards */
@@ -247,56 +248,26 @@ static int cb_pcidda_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* cmdtest tests a particular command to see if it is valid.
-	 * Using the cmdtest ioctl, a user can create a valid cmd
-	 * and then have it executes by the cmd ioctl.
-	 *
-	 * cmdtest returns 1,2,3,4 or 0, depending on which tests
-	 * the command passes. */
+	/* Step 1 : check if triggers are trivially valid */
 
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique and mutually
-	 * compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_TIMER
-	    && cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_TIMER && cmd->stop_src != TRIG_EXT)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/comedi_parport.c

@@ -85,6 +85,8 @@ pin, which can be used to wake up tasks.
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 
+#include "comedi_fc.h"
+
 #define PARPORT_SIZE 3
 
 #define PARPORT_A 0
@@ -176,39 +178,20 @@ static int parport_intr_cmdtest(struct comedi_device *dev,
 				struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
-
-	/* step 1 */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
 
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_FOLLOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: ignored */
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/comedi_test.c

@@ -231,44 +231,23 @@ static int waveform_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW | TRIG_TIMER;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW | TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique and mutually compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->convert_src != TRIG_NOW && cmd->convert_src != TRIG_TIMER)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/das16.c

@@ -402,62 +402,42 @@ static int das16_cmd_test(struct comedi_device *dev, struct comedi_subdevice *s,
 	int gain, start_chan, i;
 	int mask;
 
-	/* make sure triggers are valid */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
 
-	tmp = cmd->scan_begin_src;
 	mask = TRIG_FOLLOW;
 	/*  if board supports burst mode */
 	if (board->size > 0x400)
 		mask |= TRIG_TIMER | TRIG_EXT;
-	cmd->scan_begin_src &= mask;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, mask);
 
 	tmp = cmd->convert_src;
 	mask = TRIG_TIMER | TRIG_EXT;
 	/*  if board supports burst mode */
 	if (board->size > 0x400)
 		mask |= TRIG_NOW;
-	cmd->convert_src &= mask;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->convert_src, mask);
 
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/**
-	 * step 2: make sure trigger sources are unique and
-	 * mutually compatible
-	 */
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_FOLLOW)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER &&
-	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	/*  make sure scan_begin_src and convert_src dont conflict */
 	if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW)
-		err++;
+		err |= -EINVAL;
 	if (cmd->scan_begin_src != TRIG_FOLLOW && cmd->convert_src != TRIG_NOW)
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/das16m1.c

@@ -170,42 +170,24 @@ static int das16m1_cmd_test(struct comedi_device *dev,
 	const struct das16m1_board *board = comedi_board(dev);
 	unsigned int err = 0, tmp, i;
 
-	/* make sure triggers are valid */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/das1800.c

@@ -784,59 +784,35 @@ static int das1800_ai_do_cmdtest(struct comedi_device *dev,
 				 struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
 	unsigned int tmp_arg;
 	int i;
 	int unipolar;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_EXT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_FOLLOW | TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src,
+					TRIG_COUNT | TRIG_EXT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
-	/*  uniqueness check */
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT &&
-	    cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_EXT)
-		err++;
-	/* compatibility check */
 	if (cmd->scan_begin_src != TRIG_FOLLOW &&
 	    cmd->convert_src != TRIG_TIMER)
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/das800.c

@@ -609,44 +609,24 @@ static int das800_ai_do_cmdtest(struct comedi_device *dev,
 	int gain, startChan;
 	int i;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/dmm32at.c

@@ -41,6 +41,8 @@ Configuration Options:
 #include "../comedidev.h"
 #include <linux/ioport.h>
 
+#include "comedi_fc.h"
+
 /* Board register addresses */
 
 #define DMM32AT_MEMSIZE 0x10
@@ -258,47 +260,26 @@ static int dmm32at_ai_cmdtest(struct comedi_device *dev,
 	int tmp;
 	int start_chan, gain, i;
 
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER /*| TRIG_EXT */ ;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER /*| TRIG_EXT */ ;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER /*| TRIG_EXT */);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_TIMER /*| TRIG_EXT */);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually
-	 * compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/dt2814.c

@@ -45,6 +45,8 @@ addition, the clock does not seem to be very accurate.
 #include <linux/ioport.h>
 #include <linux/delay.h>
 
+#include "comedi_fc.h"
+
 #define DT2814_SIZE 2
 
 #define DT2814_CSR 0
@@ -129,42 +131,22 @@ static int dt2814_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are
-	 * unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->stop_src != TRIG_TIMER && cmd->stop_src != TRIG_EXT)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/dt282x.c

@@ -582,47 +582,24 @@ static int dt282x_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_FOLLOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique
-	 * and mutually compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;
@@ -862,44 +839,22 @@ static int dt282x_ao_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique
-	 * and mutually compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/dt3000.c

@@ -63,6 +63,8 @@ AO commands are not supported.
 #include "../comedidev.h"
 #include <linux/delay.h>
 
+#include "comedi_fc.h"
+
 #define PCI_VENDOR_ID_DT	0x1116
 
 static const struct comedi_lrange range_dt3000_ai = { 4, {
@@ -408,37 +410,19 @@ static int dt3k_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/gsc_hpdi.c

@@ -723,45 +723,24 @@ static int di_cmd_test(struct comedi_device *dev, struct comedi_subdevice *s,
 		       struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
 	int i;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually
-	 * compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/*  uniqueness check */
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/me4000.c

@@ -52,6 +52,7 @@ broken.
 #include <linux/list.h>
 #include <linux/spinlock.h>
 
+#include "comedi_fc.h"
 #include "8253.h"
 
 #if 0
@@ -895,18 +896,6 @@ static int me4000_ai_do_cmd(struct comedi_device *dev,
 	return 0;
 }
 
-/*
- * me4000_ai_do_cmd_test():
- *
- * The demo cmd.c in ./comedilib/demo specifies 6 return values:
- * - success
- * - invalid source
- * - source conflict
- * - invalid argument
- * - argument conflict
- * - invalid chanlist
- * So I tried to adopt this scheme.
- */
 static int me4000_ai_do_cmd_test(struct comedi_device *dev,
 				 struct comedi_subdevice *s,
 				 struct comedi_cmd *cmd)
@@ -923,81 +912,29 @@ static int me4000_ai_do_cmd_test(struct comedi_device *dev,
 	/* Round the timer arguments */
 	ai_round_cmd_args(dev, s, cmd, &init_ticks, &scan_ticks, &chan_ticks);
 
-	/*
-	 * Stage 1. Check if the trigger sources are generally valid.
-	 */
-	switch (cmd->start_src) {
-	case TRIG_NOW:
-	case TRIG_EXT:
-		break;
-	case TRIG_ANY:
-		cmd->start_src &= TRIG_NOW | TRIG_EXT;
-		err++;
-		break;
-	default:
-		dev_err(dev->class_dev, "Invalid start source\n");
-		cmd->start_src = TRIG_NOW;
-		err++;
-	}
-	switch (cmd->scan_begin_src) {
-	case TRIG_FOLLOW:
-	case TRIG_TIMER:
-	case TRIG_EXT:
-		break;
-	case TRIG_ANY:
-		cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_TIMER | TRIG_EXT;
-		err++;
-		break;
-	default:
-		dev_err(dev->class_dev, "Invalid scan begin source\n");
-		cmd->scan_begin_src = TRIG_FOLLOW;
-		err++;
-	}
-	switch (cmd->convert_src) {
-	case TRIG_TIMER:
-	case TRIG_EXT:
-		break;
-	case TRIG_ANY:
-		cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-		err++;
-		break;
-	default:
-		dev_err(dev->class_dev, "Invalid convert source\n");
-		cmd->convert_src = TRIG_TIMER;
-		err++;
-	}
-	switch (cmd->scan_end_src) {
-	case TRIG_NONE:
-	case TRIG_COUNT:
-		break;
-	case TRIG_ANY:
-		cmd->scan_end_src &= TRIG_NONE | TRIG_COUNT;
-		err++;
-		break;
-	default:
-		dev_err(dev->class_dev, "Invalid scan end source\n");
-		cmd->scan_end_src = TRIG_NONE;
-		err++;
-	}
-	switch (cmd->stop_src) {
-	case TRIG_NONE:
-	case TRIG_COUNT:
-		break;
-	case TRIG_ANY:
-		cmd->stop_src &= TRIG_NONE | TRIG_COUNT;
-		err++;
-		break;
-	default:
-		dev_err(dev->class_dev, "Invalid stop source\n");
-		cmd->stop_src = TRIG_NONE;
-		err++;
-	}
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_FOLLOW | TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src,
+					TRIG_NONE | TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE | TRIG_COUNT);
+
 	if (err)
 		return 1;
 
-	/*
-	 * Stage 2. Check for trigger source conflicts.
-	 */
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_end_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
+
 	if (cmd->start_src == TRIG_NOW &&
 	    cmd->scan_begin_src == TRIG_TIMER &&
 	    cmd->convert_src == TRIG_TIMER) {
@@ -1017,11 +954,7 @@ static int me4000_ai_do_cmd_test(struct comedi_device *dev,
 		   cmd->scan_begin_src == TRIG_EXT &&
 		   cmd->convert_src == TRIG_EXT) {
 	} else {
-		dev_err(dev->class_dev, "Invalid start trigger combination\n");
-		cmd->start_src = TRIG_NOW;
-		cmd->scan_begin_src = TRIG_FOLLOW;
-		cmd->convert_src = TRIG_TIMER;
-		err++;
+		err |= -EINVAL;
 	}
 
 	if (cmd->stop_src == TRIG_NONE && cmd->scan_end_src == TRIG_NONE) {
@@ -1032,11 +965,9 @@ static int me4000_ai_do_cmd_test(struct comedi_device *dev,
 	} else if (cmd->stop_src == TRIG_COUNT &&
 		   cmd->scan_end_src == TRIG_COUNT) {
 	} else {
-		dev_err(dev->class_dev, "Invalid stop trigger combination\n");
-		cmd->stop_src = TRIG_NONE;
-		cmd->scan_end_src = TRIG_NONE;
-		err++;
+		err |= -EINVAL;
 	}
+
 	if (err)
 		return 2;
 

drivers/staging/comedi/drivers/ni_6527.c

@@ -44,6 +44,7 @@ Updated: Sat, 25 Jan 2003 13:24:40 -0800
 #include <linux/interrupt.h>
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
 #include "mite.h"
 
 #define DRIVER_NAME "ni_6527"
@@ -224,40 +225,20 @@ static int ni6527_intr_cmdtest(struct comedi_device *dev,
 			       struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_OTHER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_FOLLOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_OTHER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and */
-	/*         are mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/ni_65xx.c

@@ -55,6 +55,7 @@ except maybe the 6514.
 #include <linux/slab.h>
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
 #include "mite.h"
 
 #define NI6514_DIO_SIZE 4096
@@ -486,40 +487,20 @@ static int ni_65xx_intr_cmdtest(struct comedi_device *dev,
 				struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_OTHER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_FOLLOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_OTHER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually
-	compatible */
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/ni_at_a2150.c

@@ -321,45 +321,23 @@ static int a2150_ai_cmdtest(struct comedi_device *dev,
 	int startChan;
 	int i;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique and mutually
-	 * compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/ni_atmio16d.c

@@ -40,6 +40,7 @@ Devices: [National Instruments] AT-MIO-16 (atmio16), AT-MIO-16D (atmio16d)
 
 #include <linux/ioport.h>
 
+#include "comedi_fc.h"
 #include "8255.h"
 
 /* Configuration and Status Registers */
@@ -246,45 +247,26 @@ static int atmio16d_ai_cmdtest(struct comedi_device *dev,
 			       struct comedi_subdevice *s,
 			       struct comedi_cmd *cmd)
 {
-	int err = 0, tmp;
+	int err = 0;
 
-	/* make sure triggers are valid */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_FOLLOW | TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique & mutually compatible */
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_TIMER)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/ni_labpc.c

@@ -979,55 +979,33 @@ static int labpc_ai_cmdtest(struct comedi_device *dev,
 {
 	int err = 0;
 	int tmp, tmp2;
-	int stop_mask;
+	unsigned int stop_mask;
 	enum scan_mode mode;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_FOLLOW | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_FOLLOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
 
-	tmp = cmd->stop_src;
 	stop_mask = TRIG_COUNT | TRIG_NONE;
 	if (thisboard->register_layout == labpc_1200_layout)
 		stop_mask |= TRIG_EXT;
-	cmd->stop_src &= stop_mask;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->stop_src, stop_mask);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT &&
-	    cmd->stop_src != TRIG_EXT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	/* can't have external stop and start triggers at once */
 	if (cmd->start_src == TRIG_EXT && cmd->stop_src == TRIG_EXT)

drivers/staging/comedi/drivers/ni_mio_common.c

@@ -2164,61 +2164,38 @@ static int ni_ai_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 {
 	int err = 0;
 	int tmp;
-	int sources;
+	unsigned int sources;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	if ((cmd->flags & CMDF_WRITE)) {
+	if ((cmd->flags & CMDF_WRITE))
 		cmd->flags &= ~CMDF_WRITE;
-	}
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src,
+					TRIG_NOW | TRIG_INT | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
 
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
 	sources = TRIG_TIMER | TRIG_EXT;
-	if ((boardtype.reg_type == ni_reg_611x)
-	    || (boardtype.reg_type == ni_reg_6143))
+	if (boardtype.reg_type == ni_reg_611x ||
+	    boardtype.reg_type == ni_reg_6143)
 		sources |= TRIG_NOW;
-	cmd->convert_src &= sources;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->convert_src, sources);
 
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->start_src != TRIG_NOW &&
-	    cmd->start_src != TRIG_INT && cmd->start_src != TRIG_EXT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_OTHER)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER &&
-	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;
@@ -3356,44 +3333,28 @@ static int ni_ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	if ((cmd->flags & CMDF_WRITE) == 0) {
+	if ((cmd->flags & CMDF_WRITE) == 0)
 		cmd->flags |= CMDF_WRITE;
-	}
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_INT | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
 
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_INT | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;
@@ -3643,51 +3604,21 @@ static int ni_cdio_cmdtest(struct comedi_device *dev,
 {
 	int err = 0;
 	int tmp;
-	int sources;
 	unsigned i;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	sources = TRIG_INT;
-	cmd->start_src &= sources;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique... */
-
-	if (cmd->start_src != TRIG_INT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_NONE)
-		err++;
-	/* ... and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/ni_pcidio.c

@@ -60,6 +60,7 @@ comedi_nonfree_firmware tarball available from http://www.comedi.org
 #include <linux/firmware.h>
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
 #include "mite.h"
 
 #undef DPRINTK
@@ -683,45 +684,25 @@ static int ni_pcidio_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually
-	compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->start_src != TRIG_NOW && cmd->start_src != TRIG_INT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/ni_tiocmd.c

@@ -48,6 +48,7 @@ TODO:
 	Support use of both banks X and Y
 */
 
+#include "comedi_fc.h"
 #include "ni_tio_internal.h"
 #include "mite.h"
 
@@ -237,61 +238,35 @@ EXPORT_SYMBOL_GPL(ni_tio_cmd);
 int ni_tio_cmdtest(struct ni_gpct *counter, struct comedi_cmd *cmd)
 {
 	int err = 0;
-	int tmp;
-	int sources;
+	unsigned int sources;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
 	sources = TRIG_NOW | TRIG_INT | TRIG_OTHER;
 	if (ni_tio_counting_mode_registers_present(counter->counter_dev))
 		sources |= TRIG_EXT;
-	cmd->start_src &= sources;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW | TRIG_EXT | TRIG_OTHER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	sources = TRIG_NOW | TRIG_EXT | TRIG_OTHER;
-	cmd->convert_src &= sources;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, sources);
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_FOLLOW | TRIG_EXT | TRIG_OTHER);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_NOW | TRIG_EXT | TRIG_OTHER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique... */
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+
+	/* Step 2b : and mutually compatible */
 
-	if (cmd->start_src != TRIG_NOW &&
-	    cmd->start_src != TRIG_INT &&
-	    cmd->start_src != TRIG_EXT && cmd->start_src != TRIG_OTHER)
-		err++;
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_OTHER)
-		err++;
-	if (cmd->convert_src != TRIG_OTHER &&
-	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_NONE)
-		err++;
-	/* ... and mutually compatible */
 	if (cmd->convert_src != TRIG_NOW && cmd->scan_begin_src != TRIG_FOLLOW)
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/pcl711.c

@@ -64,6 +64,7 @@ supported.
 #include <linux/ioport.h>
 #include <linux/delay.h>
 
+#include "comedi_fc.h"
 #include "8253.h"
 
 #define PCL711_SIZE 16
@@ -266,42 +267,24 @@ static int pcl711_ai_cmdtest(struct comedi_device *dev,
 	int tmp;
 	int err = 0;
 
-	/* step 1 */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/pcl812.c

@@ -117,6 +117,7 @@
 #include <linux/io.h>
 #include <asm/dma.h>
 
+#include "comedi_fc.h"
 #include "8253.h"
 
 /* hardware types of the cards */
@@ -533,49 +534,31 @@ static int pcl812_ai_cmdtest(struct comedi_device *dev,
 {
 	const struct pcl812_board *board = comedi_board(dev);
 	int err = 0;
+	unsigned int flags;
 	int tmp, divisor1, divisor2;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
 
-	tmp = cmd->convert_src;
 	if (devpriv->use_ext_trg)
-		cmd->convert_src &= TRIG_EXT;
+		flags = TRIG_EXT;
 	else
-		cmd->convert_src &= TRIG_TIMER;
-
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
+		flags = TRIG_TIMER;
+	err |= cfc_check_trigger_src(&cmd->convert_src, flags);
 
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are
-	 * unique and mutually compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/pcl816.c

@@ -41,6 +41,7 @@ Configuration Options:
 #include <linux/io.h>
 #include <asm/dma.h>
 
+#include "comedi_fc.h"
 #include "8253.h"
 
 #define DEBUG(x) x
@@ -458,48 +459,23 @@ static int pcl816_ai_cmdtest(struct comedi_device *dev,
 	      pcl816_cmdtest_out(-1, cmd);
 	     );
 
-	/* step 1: make sure trigger sources are trivially valid */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_EXT | TRIG_TIMER;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_EXT | TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
+	/* Step 2a : make sure trigger sources are unique */
 
-	/*
-	 * step 2: make sure trigger sources
-	 * are unique and mutually compatible
-	 */
-
-	if (cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_TIMER) {
-		cmd->convert_src = TRIG_TIMER;
-		err++;
-	}
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
 
-	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
-		err++;
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/pcl818.c

@@ -107,6 +107,7 @@ A word or two about DMA. Driver support DMA operations at two ways:
 #include <linux/io.h>
 #include <asm/dma.h>
 
+#include "comedi_fc.h"
 #include "8253.h"
 
 /* #define PCL818_MODE13_AO 1 */
@@ -1261,43 +1262,23 @@ static int ai_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 	int err = 0;
 	int tmp, divisor1 = 0, divisor2 = 0;
 
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
 
-	if (cmd->stop_src != TRIG_NONE && cmd->stop_src != TRIG_COUNT)
-		err++;
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/pcm_common.c

@@ -1,60 +1,30 @@
 #include "../comedidev.h"
+
+#include "comedi_fc.h"
 #include "pcm_common.h"
 
-/*
- * 'do_cmdtest' function for an 'INTERRUPT' subdevice.  This is for
- * the PCM drivers.
- */
 int comedi_pcm_cmdtest(struct comedi_device *dev,
 		       struct comedi_subdevice *s, struct comedi_cmd *cmd)
 {
 	int err = 0;
-	unsigned int tmp;
-
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= (TRIG_NOW | TRIG_INT);
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
 
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= (TRIG_COUNT | TRIG_NONE);
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and
-	 * mutually compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* these tests are true if more than one _src bit is set */
-	if ((cmd->start_src & (cmd->start_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
-		err++;
-	if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
-		err++;
-	if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
-		err++;
-	if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/quatech_daqp_cs.c

@@ -56,6 +56,8 @@ Devices: [Quatech] DAQP-208 (daqp), DAQP-308
 
 #include <linux/completion.h>
 
+#include "comedi_fc.h"
+
 /* Maximum number of separate DAQP devices we'll allow */
 #define MAX_DEV         4
 
@@ -456,51 +458,26 @@ static int daqp_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_TIMER | TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources
-	 * are unique and mutually compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_FOLLOW)
-		err++;
-	if (cmd->convert_src != TRIG_NOW && cmd->convert_src != TRIG_TIMER)
-		err++;
-	if (cmd->scan_begin_src == TRIG_FOLLOW && cmd->convert_src == TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/rtd520.c

@@ -106,6 +106,8 @@ Configuration options:
 
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
+
 #define DRV_NAME "rtd520"
 
 /*======================================================================
@@ -976,52 +978,25 @@ static int rtd_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique
-	   and mutually compatible */
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT) {
-		err++;
-	}
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/s626.c

@@ -1505,56 +1505,28 @@ static int s626_ai_cmdtest(struct comedi_device *dev,
 	int err = 0;
 	int tmp;
 
-	/* cmdtest tests a particular command to see if it is valid.  Using
-	 * the cmdtest ioctl, a user can create a valid cmd and then have it
-	 * executes by the cmd ioctl.
-	 *
-	 * cmdtest returns 1,2,3,4 or 0, depending on which tests the
-	 * command passes. */
-
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT | TRIG_EXT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT | TRIG_FOLLOW;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT | TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src,
+					TRIG_NOW | TRIG_INT | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT | TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->convert_src,
+					TRIG_TIMER | TRIG_EXT | TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually
-	   compatible */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT
-	    && cmd->scan_begin_src != TRIG_FOLLOW)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER &&
-	    cmd->convert_src != TRIG_EXT && cmd->convert_src != TRIG_NOW)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/skel.c

@@ -76,6 +76,8 @@ Configuration Options:
 
 #include <linux/pci.h>		/* for PCI devices */
 
+#include "comedi_fc.h"
+
 /* Imaginary registers for the imaginary board */
 
 #define SKEL_SIZE 0
@@ -349,60 +351,40 @@ static int skel_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
 	return n;
 }
 
+/*
+ * cmdtest tests a particular command to see if it is valid.
+ * Using the cmdtest ioctl, a user can create a valid cmd
+ * and then have it executes by the cmd ioctl.
+ *
+ * cmdtest returns 1,2,3,4 or 0, depending on which tests
+ * the command passes.
+ */
 static int skel_ai_cmdtest(struct comedi_device *dev,
-			   struct comedi_subdevice *s, struct comedi_cmd *cmd)
+			   struct comedi_subdevice *s,
+			   struct comedi_cmd *cmd)
 {
 	int err = 0;
 	int tmp;
 
-	/* cmdtest tests a particular command to see if it is valid.
-	 * Using the cmdtest ioctl, a user can create a valid cmd
-	 * and then have it executes by the cmd ioctl.
-	 *
-	 * cmdtest returns 1,2,3,4 or 0, depending on which tests
-	 * the command passes. */
-
-	/* step 1: make sure trigger sources are trivially valid */
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/* step 2: make sure trigger sources are unique and mutually compatible
-     */
+	/* Step 2a : make sure trigger sources are unique */
 
-	/* note that mutual compatibility is not an issue here */
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/usbdux.c

@@ -98,6 +98,8 @@ sampling rate. If you sample two channels you get 4kHz and so on.
 
 #include "../comedidev.h"
 
+#include "comedi_fc.h"
+
 /* timeout for the USB-transfer in ms*/
 #define BULK_TIMEOUT 1000
 
@@ -929,9 +931,9 @@ static int usbduxsub_submit_OutURBs(struct usbduxsub *usbduxsub)
 static int usbdux_ai_cmdtest(struct comedi_device *dev,
 			     struct comedi_subdevice *s, struct comedi_cmd *cmd)
 {
-	int err = 0, tmp, i;
-	unsigned int tmpTimer;
 	struct usbduxsub *this_usbduxsub = dev->private;
+	int err = 0, i;
+	unsigned int tmpTimer;
 
 	if (!(this_usbduxsub->probed))
 		return -ENODEV;
@@ -939,51 +941,23 @@ static int usbdux_ai_cmdtest(struct comedi_device *dev,
 	dev_dbg(&this_usbduxsub->interface->dev,
 		"comedi%d: usbdux_ai_cmdtest\n", dev->minor);
 
-	/* make sure triggers are valid */
-	/* Only immediate triggers are allowed */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	/* trigger should happen timed */
-	tmp = cmd->scan_begin_src;
-	/* start a new _scan_ with a timer */
-	cmd->scan_begin_src &= TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	/* scanning is continuous */
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	/* issue a trigger when scan is finished and start a new scan */
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	/* trigger at the end of count events or not, stop condition or not */
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique and mutually compatible
-	 * note that mutual compatibility is not an issue here
-	 */
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_TIMER)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;
@@ -1488,8 +1462,9 @@ static int usbdux_ao_inttrig(struct comedi_device *dev,
 static int usbdux_ao_cmdtest(struct comedi_device *dev,
 			     struct comedi_subdevice *s, struct comedi_cmd *cmd)
 {
-	int err = 0, tmp;
 	struct usbduxsub *this_usbduxsub = dev->private;
+	int err = 0;
+	unsigned int flags;
 
 	if (!this_usbduxsub)
 		return -EFAULT;
@@ -1500,69 +1475,46 @@ static int usbdux_ao_cmdtest(struct comedi_device *dev,
 	dev_dbg(&this_usbduxsub->interface->dev,
 		"comedi%d: usbdux_ao_cmdtest\n", dev->minor);
 
-	/* make sure triggers are valid */
-	/* Only immediate triggers are allowed */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
 
-	/* trigger should happen timed */
-	tmp = cmd->scan_begin_src;
-	/* just now we scan also in the high speed mode every frame */
-	/* this is due to ehci driver limitations */
 	if (0) {		/* (this_usbduxsub->high_speed) */
-		/* start immediately a new scan */
 		/* the sampling rate is set by the coversion rate */
-		cmd->scan_begin_src &= TRIG_FOLLOW;
+		flags = TRIG_FOLLOW;
 	} else {
 		/* start a new scan (output at once) with a timer */
-		cmd->scan_begin_src &= TRIG_TIMER;
+		flags = TRIG_TIMER;
 	}
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, flags);
 
-	/* scanning is continuous */
-	tmp = cmd->convert_src;
-	/* we always output at 1kHz just now all channels at once */
 	if (0) {		/* (this_usbduxsub->high_speed) */
 		/*
-		 * in usb-2.0 only one conversion it transmitted but with 8kHz/n
+		 * in usb-2.0 only one conversion it transmitted
+		 * but with 8kHz/n
 		 */
-		cmd->convert_src &= TRIG_TIMER;
+		flags = TRIG_TIMER;
 	} else {
-		/* all conversion events happen simultaneously with a rate of
-		 * 1kHz/n */
-		cmd->convert_src &= TRIG_NOW;
+		/*
+		 * all conversion events happen simultaneously with
+		 * a rate of 1kHz/n
+		 */
+		flags = TRIG_NOW;
 	}
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	/* issue a trigger when scan is finished and start a new scan */
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->convert_src, flags);
 
-	/* trigger at the end of count events or not, stop condition or not */
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique and mutually compatible
-	 * note that mutual compatibility is not an issue here
-	 */
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_TIMER)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/usbduxfast.c

@@ -549,10 +549,10 @@ static int usbduxfast_ai_cmdtest(struct comedi_device *dev,
 				 struct comedi_subdevice *s,
 				 struct comedi_cmd *cmd)
 {
-	int err = 0, stop_mask = 0;
+	struct usbduxfastsub_s *udfs = dev->private;
+	int err = 0;
 	long int steps, tmp;
 	int minSamplPer;
-	struct usbduxfastsub_s *udfs = dev->private;
 
 	if (!udfs->probed)
 		return -ENODEV;
@@ -563,57 +563,31 @@ static int usbduxfast_ai_cmdtest(struct comedi_device *dev,
 	       "scan_begin_arg=%u\n",
 	       dev->minor, cmd->convert_arg, cmd->scan_begin_arg);
 #endif
-	/* step 1: make sure trigger sources are trivially valid */
-
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_EXT | TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	tmp = cmd->scan_begin_src;
-	cmd->scan_begin_src &= TRIG_TIMER | TRIG_FOLLOW | TRIG_EXT;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	tmp = cmd->stop_src;
-	stop_mask = TRIG_COUNT | TRIG_NONE;
-	cmd->stop_src &= stop_mask;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src,
+					TRIG_NOW | TRIG_EXT | TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src,
+					TRIG_TIMER | TRIG_FOLLOW | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_TIMER | TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique and mutually compatible
-	 */
+	/* Step 2a : make sure trigger sources are unique */
 
-	if (cmd->start_src != TRIG_NOW &&
-	    cmd->start_src != TRIG_EXT && cmd->start_src != TRIG_INT)
-		err++;
-	if (cmd->scan_begin_src != TRIG_TIMER &&
-	    cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT)
-		err++;
-	if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT &&
-	    cmd->stop_src != TRIG_EXT && cmd->stop_src != TRIG_NONE)
-		err++;
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
+	err |= cfc_check_trigger_is_unique(cmd->convert_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	/* can't have external stop and start triggers at once */
 	if (cmd->start_src == TRIG_EXT && cmd->stop_src == TRIG_EXT)
-		err++;
+		err |= -EINVAL;
 
 	if (err)
 		return 2;

drivers/staging/comedi/drivers/usbduxsigma.c

@@ -897,9 +897,9 @@ static int usbdux_ai_cmdtest(struct comedi_device *dev,
 			     struct comedi_subdevice *s,
 			     struct comedi_cmd *cmd)
 {
-	int err = 0, tmp, i;
-	unsigned int tmpTimer;
 	struct usbduxsub *this_usbduxsub = dev->private;
+	int err = 0, i;
+	unsigned int tmpTimer;
 
 	if (!(this_usbduxsub->probed))
 		return -ENODEV;
@@ -907,51 +907,23 @@ static int usbdux_ai_cmdtest(struct comedi_device *dev,
 	dev_dbg(&this_usbduxsub->interface->dev,
 		"comedi%d: usbdux_ai_cmdtest\n", dev->minor);
 
-	/* make sure triggers are valid */
-	/* Only immediate triggers are allowed */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
-
-	/* trigger should happen timed */
-	tmp = cmd->scan_begin_src;
-	/* start a new _scan_ with a timer */
-	cmd->scan_begin_src &= TRIG_TIMER;
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	/* scanning is continuous */
-	tmp = cmd->convert_src;
-	cmd->convert_src &= TRIG_NOW;
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	/* issue a trigger when scan is finished and start a new scan */
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
 
-	/* trigger at the end of count events or not, stop condition or not */
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources are unique and mutually compatible
-	 * note that mutual compatibility is not an issue here
-	 */
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_TIMER)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;
@@ -1558,8 +1530,9 @@ static int usbdux_ao_cmdtest(struct comedi_device *dev,
 			     struct comedi_subdevice *s,
 			     struct comedi_cmd *cmd)
 {
-	int err = 0, tmp;
 	struct usbduxsub *this_usbduxsub = dev->private;
+	int err = 0;
+	unsigned int flags;
 
 	if (!this_usbduxsub)
 		return -EFAULT;
@@ -1570,63 +1543,35 @@ static int usbdux_ao_cmdtest(struct comedi_device *dev,
 	dev_dbg(&this_usbduxsub->interface->dev,
 		"comedi%d: usbdux_ao_cmdtest\n", dev->minor);
 
-	/* make sure triggers are valid */
-	/* Only immediate triggers are allowed */
-	tmp = cmd->start_src;
-	cmd->start_src &= TRIG_NOW | TRIG_INT;
-	if (!cmd->start_src || tmp != cmd->start_src)
-		err++;
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
 
-	/* trigger should happen timed */
-	tmp = cmd->scan_begin_src;
-	/* just now we scan also in the high speed mode every frame */
-	/* this is due to ehci driver limitations */
 	if (0) {		/* (this_usbduxsub->high_speed) */
-		/* start immediately a new scan */
-		/* the sampling rate is set by the coversion rate */
-		cmd->scan_begin_src &= TRIG_FOLLOW;
+		/*
+		 * start immediately a new scan
+		 * the sampling rate is set by the coversion rate
+		 */
+		flags = TRIG_FOLLOW;
 	} else {
 		/* start a new scan (output at once) with a timer */
-		cmd->scan_begin_src &= TRIG_TIMER;
+		flags = TRIG_TIMER;
 	}
-	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
-		err++;
-
-	/* scanning is continuous */
-	tmp = cmd->convert_src;
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, flags);
 
-	/* all conversion events happen simultaneously */
-	cmd->convert_src &= TRIG_NOW;
-
-	if (!cmd->convert_src || tmp != cmd->convert_src)
-		err++;
-
-	/* issue a trigger when scan is finished and start a new scan */
-	tmp = cmd->scan_end_src;
-	cmd->scan_end_src &= TRIG_COUNT;
-	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
-		err++;
-
-	/* trigger at the end of count events or not, stop condition or not */
-	tmp = cmd->stop_src;
-	cmd->stop_src &= TRIG_COUNT | TRIG_NONE;
-	if (!cmd->stop_src || tmp != cmd->stop_src)
-		err++;
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
 
 	if (err)
 		return 1;
 
-	/*
-	 * step 2: make sure trigger sources
-	 * are unique and mutually compatible
-	 * note that mutual compatibility is not an issue here
-	 */
-	if (cmd->scan_begin_src != TRIG_FOLLOW &&
-	    cmd->scan_begin_src != TRIG_EXT &&
-	    cmd->scan_begin_src != TRIG_TIMER)
-		err++;
-	if (cmd->stop_src != TRIG_COUNT && cmd->stop_src != TRIG_NONE)
-		err++;
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= cfc_check_trigger_is_unique(cmd->start_src);
+	err |= cfc_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
 
 	if (err)
 		return 2;