Input: add Philips UCB1400 touchscreen driver

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/Kconfig

@@ -144,4 +144,19 @@ config TOUCHSCREEN_TOUCHWIN
 	  To compile this driver as a module, choose M here: the
 	  module will be called touchwin.
 
+config TOUCHSCREEN_UCB1400
+	tristate "Philips UCB1400 touchscreen"
+	select SND_AC97_BUS
+	help
+	  This enables support for the Philips UCB1400 touchscreen interface.
+	  The UCB1400 is an AC97 audio codec.  The touchscreen interface
+	  will be initialized only after the ALSA subsystem has been
+	  brought up and the UCB1400 detected.  You therefore have to
+	  configure ALSA support as well (either built-in or modular,
+	  independently of whether this driver is itself built-in or
+	  modular) for this driver to work.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ucb1400_ts.
+
 endif

drivers/input/touchscreen/Makefile

@@ -15,3 +15,4 @@ obj-$(CONFIG_TOUCHSCREEN_HP600)	+= hp680_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)	+= touchright.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)	+= touchwin.o
+obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o

drivers/input/touchscreen/ucb1400_ts.c

@@ -0,0 +1,579 @@
+/*
+ *  Philips UCB1400 touchscreen driver
+ *
+ *  Author:	Nicolas Pitre
+ *  Created:	September 25, 2006
+ *  Copyright:	MontaVista Software, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
+ * covering the UCB1100, UCB1200 and UCB1300..  Support for the UCB1400 has
+ * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/ac97_codec.h>
+
+
+/*
+ * Interesting UCB1400 AC-link registers
+ */
+
+#define UCB_IE_RIS		0x5e
+#define UCB_IE_FAL		0x60
+#define UCB_IE_STATUS		0x62
+#define UCB_IE_CLEAR		0x62
+#define UCB_IE_ADC		(1 << 11)
+#define UCB_IE_TSPX		(1 << 12)
+
+#define UCB_TS_CR		0x64
+#define UCB_TS_CR_TSMX_POW	(1 << 0)
+#define UCB_TS_CR_TSPX_POW	(1 << 1)
+#define UCB_TS_CR_TSMY_POW	(1 << 2)
+#define UCB_TS_CR_TSPY_POW	(1 << 3)
+#define UCB_TS_CR_TSMX_GND	(1 << 4)
+#define UCB_TS_CR_TSPX_GND	(1 << 5)
+#define UCB_TS_CR_TSMY_GND	(1 << 6)
+#define UCB_TS_CR_TSPY_GND	(1 << 7)
+#define UCB_TS_CR_MODE_INT	(0 << 8)
+#define UCB_TS_CR_MODE_PRES	(1 << 8)
+#define UCB_TS_CR_MODE_POS	(2 << 8)
+#define UCB_TS_CR_BIAS_ENA	(1 << 11)
+#define UCB_TS_CR_TSPX_LOW	(1 << 12)
+#define UCB_TS_CR_TSMX_LOW	(1 << 13)
+
+#define UCB_ADC_CR		0x66
+#define UCB_ADC_SYNC_ENA	(1 << 0)
+#define UCB_ADC_VREFBYP_CON	(1 << 1)
+#define UCB_ADC_INP_TSPX	(0 << 2)
+#define UCB_ADC_INP_TSMX	(1 << 2)
+#define UCB_ADC_INP_TSPY	(2 << 2)
+#define UCB_ADC_INP_TSMY	(3 << 2)
+#define UCB_ADC_INP_AD0		(4 << 2)
+#define UCB_ADC_INP_AD1		(5 << 2)
+#define UCB_ADC_INP_AD2		(6 << 2)
+#define UCB_ADC_INP_AD3		(7 << 2)
+#define UCB_ADC_EXT_REF		(1 << 5)
+#define UCB_ADC_START		(1 << 7)
+#define UCB_ADC_ENA		(1 << 15)
+
+#define UCB_ADC_DATA		0x68
+#define UCB_ADC_DAT_VALID	(1 << 15)
+#define UCB_ADC_DAT_VALUE(x)	((x) & 0x3ff)
+
+#define UCB_ID			0x7e
+#define UCB_ID_1400             0x4304
+
+
+struct ucb1400 {
+	ac97_t			*ac97;
+	struct input_dev	*ts_idev;
+
+	int			irq;
+
+	wait_queue_head_t	ts_wait;
+	struct task_struct	*ts_task;
+
+	unsigned int		irq_pending;	/* not bit field shared */
+	unsigned int		ts_restart:1;
+	unsigned int		adcsync:1;
+};
+
+static int adcsync;
+
+static inline u16 ucb1400_reg_read(struct ucb1400 *ucb, u16 reg)
+{
+	return ucb->ac97->bus->ops->read(ucb->ac97, reg);
+}
+
+static inline void ucb1400_reg_write(struct ucb1400 *ucb, u16 reg, u16 val)
+{
+	ucb->ac97->bus->ops->write(ucb->ac97, reg, val);
+}
+
+static inline void ucb1400_adc_enable(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
+}
+
+static unsigned int ucb1400_adc_read(struct ucb1400 *ucb, u16 adc_channel)
+{
+	unsigned int val;
+
+	if (ucb->adcsync)
+		adc_channel |= UCB_ADC_SYNC_ENA;
+
+	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel);
+	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel | UCB_ADC_START);
+
+	for (;;) {
+		val = ucb1400_reg_read(ucb, UCB_ADC_DATA);
+		if (val & UCB_ADC_DAT_VALID)
+			break;
+		/* yield to other processes */
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(1);
+	}
+
+	return UCB_ADC_DAT_VALUE(val);
+}
+
+static inline void ucb1400_adc_disable(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
+}
+
+/* Switch to interrupt mode. */
+static inline void ucb1400_ts_mode_int(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
+			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
+			UCB_TS_CR_MODE_INT);
+}
+
+/*
+ * Switch to pressure mode, and read pressure.  We don't need to wait
+ * here, since both plates are being driven.
+ */
+static inline unsigned int ucb1400_ts_read_pressure(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
+			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
+			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+	return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
+}
+
+/*
+ * Switch to X position mode and measure Y plate.  We switch the plate
+ * configuration in pressure mode, then switch to position mode.  This
+ * gives a faster response time.  Even so, we need to wait about 55us
+ * for things to stabilise.
+ */
+static inline unsigned int ucb1400_ts_read_xpos(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
+
+	udelay(55);
+
+	return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
+}
+
+/*
+ * Switch to Y position mode and measure X plate.  We switch the plate
+ * configuration in pressure mode, then switch to position mode.  This
+ * gives a faster response time.  Even so, we need to wait about 55us
+ * for things to stabilise.
+ */
+static inline unsigned int ucb1400_ts_read_ypos(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
+
+	udelay(55);
+
+	return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPX);
+}
+
+/*
+ * Switch to X plate resistance mode.  Set MX to ground, PX to
+ * supply.  Measure current.
+ */
+static inline unsigned int ucb1400_ts_read_xres(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+	return ucb1400_adc_read(ucb, 0);
+}
+
+/*
+ * Switch to Y plate resistance mode.  Set MY to ground, PY to
+ * supply.  Measure current.
+ */
+static inline unsigned int ucb1400_ts_read_yres(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_TS_CR,
+			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+	return ucb1400_adc_read(ucb, 0);
+}
+
+static inline int ucb1400_ts_pen_down(struct ucb1400 *ucb)
+{
+	unsigned short val = ucb1400_reg_read(ucb, UCB_TS_CR);
+	return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
+}
+
+static inline void ucb1400_ts_irq_enable(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, UCB_IE_TSPX);
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+	ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_TSPX);
+}
+
+static inline void ucb1400_ts_irq_disable(struct ucb1400 *ucb)
+{
+	ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
+}
+
+static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
+{
+	input_report_abs(idev, ABS_X, x);
+	input_report_abs(idev, ABS_Y, y);
+	input_report_abs(idev, ABS_PRESSURE, pressure);
+	input_sync(idev);
+}
+
+static void ucb1400_ts_event_release(struct input_dev *idev)
+{
+	input_report_abs(idev, ABS_PRESSURE, 0);
+	input_sync(idev);
+}
+
+static void ucb1400_handle_pending_irq(struct ucb1400 *ucb)
+{
+	unsigned int isr;
+
+	isr = ucb1400_reg_read(ucb, UCB_IE_STATUS);
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, isr);
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+
+	if (isr & UCB_IE_TSPX)
+		ucb1400_ts_irq_disable(ucb);
+	else
+		printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
+
+	enable_irq(ucb->irq);
+}
+
+static int ucb1400_ts_thread(void *_ucb)
+{
+	struct ucb1400 *ucb = _ucb;
+	struct task_struct *tsk = current;
+	int valid = 0;
+
+	tsk->policy = SCHED_FIFO;
+	tsk->rt_priority = 1;
+
+	while (!kthread_should_stop()) {
+		unsigned int x, y, p;
+		long timeout;
+
+		ucb->ts_restart = 0;
+
+		if (ucb->irq_pending) {
+			ucb->irq_pending = 0;
+			ucb1400_handle_pending_irq(ucb);
+		}
+
+		ucb1400_adc_enable(ucb);
+		x = ucb1400_ts_read_xpos(ucb);
+		y = ucb1400_ts_read_ypos(ucb);
+		p = ucb1400_ts_read_pressure(ucb);
+		ucb1400_adc_disable(ucb);
+
+		/* Switch back to interrupt mode. */
+		ucb1400_ts_mode_int(ucb);
+
+		msleep(10);
+
+		if (ucb1400_ts_pen_down(ucb)) {
+			ucb1400_ts_irq_enable(ucb);
+
+			/*
+			 * If we spat out a valid sample set last time,
+			 * spit out a "pen off" sample here.
+			 */
+			if (valid) {
+				ucb1400_ts_event_release(ucb->ts_idev);
+				valid = 0;
+			}
+
+			timeout = MAX_SCHEDULE_TIMEOUT;
+		} else {
+			valid = 1;
+			ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
+			timeout = msecs_to_jiffies(10);
+		}
+
+		wait_event_interruptible_timeout(ucb->ts_wait,
+			ucb->irq_pending || ucb->ts_restart || kthread_should_stop(),
+			timeout);
+		try_to_freeze();
+	}
+
+	/* Send the "pen off" if we are stopping with the pen still active */
+	if (valid)
+		ucb1400_ts_event_release(ucb->ts_idev);
+
+	ucb->ts_task = NULL;
+	return 0;
+}
+
+/*
+ * A restriction with interrupts exists when using the ucb1400, as
+ * the codec read/write routines may sleep while waiting for codec
+ * access completion and uses semaphores for access control to the
+ * AC97 bus.  A complete codec read cycle could take  anywhere from
+ * 60 to 100uSec so we *definitely* don't want to spin inside the
+ * interrupt handler waiting for codec access.  So, we handle the
+ * interrupt by scheduling a RT kernel thread to run in process
+ * context instead of interrupt context.
+ */
+static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
+{
+	struct ucb1400 *ucb = devid;
+
+	if (irqnr == ucb->irq) {
+		disable_irq(ucb->irq);
+		ucb->irq_pending = 1;
+		wake_up(&ucb->ts_wait);
+		return IRQ_HANDLED;
+	}
+	return IRQ_NONE;
+}
+
+static int ucb1400_ts_open(struct input_dev *idev)
+{
+	struct ucb1400 *ucb = idev->private;
+	int ret = 0;
+
+	BUG_ON(ucb->ts_task);
+
+	ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
+	if (IS_ERR(ucb->ts_task)) {
+		ret = PTR_ERR(ucb->ts_task);
+		ucb->ts_task = NULL;
+	}
+
+	return ret;
+}
+
+static void ucb1400_ts_close(struct input_dev *idev)
+{
+	struct ucb1400 *ucb = idev->private;
+
+	if (ucb->ts_task)
+		kthread_stop(ucb->ts_task);
+
+	ucb1400_ts_irq_disable(ucb);
+	ucb1400_reg_write(ucb, UCB_TS_CR, 0);
+}
+
+#ifdef CONFIG_PM
+static int ucb1400_ts_resume(struct device *dev)
+{
+	struct ucb1400 *ucb = dev_get_drvdata(dev);
+
+	if (ucb->ts_task) {
+		/*
+		 * Restart the TS thread to ensure the
+		 * TS interrupt mode is set up again
+		 * after sleep.
+		 */
+		ucb->ts_restart = 1;
+		wake_up(&ucb->ts_wait);
+	}
+	return 0;
+}
+#else
+#define ucb1400_ts_resume NULL
+#endif
+
+#ifndef NO_IRQ
+#define NO_IRQ	0
+#endif
+
+/*
+ * Try to probe our interrupt, rather than relying on lots of
+ * hard-coded machine dependencies.
+ */
+static int ucb1400_detect_irq(struct ucb1400 *ucb)
+{
+	unsigned long mask, timeout;
+
+	mask = probe_irq_on();
+	if (!mask) {
+		probe_irq_off(mask);
+		return -EBUSY;
+	}
+
+	/* Enable the ADC interrupt. */
+	ucb1400_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
+	ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+
+	/* Cause an ADC interrupt. */
+	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
+	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
+
+	/* Wait for the conversion to complete. */
+	timeout = jiffies + HZ/2;
+	while (!(ucb1400_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VALID)) {
+		cpu_relax();
+		if (time_after(jiffies, timeout)) {
+			printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
+			probe_irq_off(mask);
+			return -ENODEV;
+		}
+	}
+	ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
+
+	/* Disable and clear interrupt. */
+	ucb1400_reg_write(ucb, UCB_IE_RIS, 0);
+	ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
+	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+
+	/* Read triggered interrupt. */
+	ucb->irq = probe_irq_off(mask);
+	if (ucb->irq < 0 || ucb->irq == NO_IRQ)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int ucb1400_ts_probe(struct device *dev)
+{
+	struct ucb1400 *ucb;
+	struct input_dev *idev;
+	int error, id, x_res, y_res;
+
+	ucb = kzalloc(sizeof(struct ucb1400), GFP_KERNEL);
+	idev = input_allocate_device();
+	if (!ucb || !idev) {
+		error = -ENOMEM;
+		goto err_free_devs;
+	}
+
+	ucb->ts_idev = idev;
+	ucb->adcsync = adcsync;
+	ucb->ac97 = to_ac97_t(dev);
+	init_waitqueue_head(&ucb->ts_wait);
+
+	id = ucb1400_reg_read(ucb, UCB_ID);
+	if (id != UCB_ID_1400) {
+		error = -ENODEV;
+		goto err_free_devs;
+	}
+
+	error = ucb1400_detect_irq(ucb);
+	if (error) {
+		printk(KERN_ERR "UCB1400: IRQ probe failed\n");
+		goto err_free_devs;
+	}
+
+	error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
+				"UCB1400", ucb);
+	if (error) {
+		printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
+				ucb->irq, error);
+		goto err_free_devs;
+	}
+	printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
+
+	idev->private		= ucb;
+	idev->cdev.dev		= dev;
+	idev->name		= "UCB1400 touchscreen interface";
+	idev->id.vendor		= ucb1400_reg_read(ucb, AC97_VENDOR_ID1);
+	idev->id.product	= id;
+	idev->open		= ucb1400_ts_open;
+	idev->close		= ucb1400_ts_close;
+	idev->evbit[0]		= BIT(EV_ABS);
+
+	ucb1400_adc_enable(ucb);
+	x_res = ucb1400_ts_read_xres(ucb);
+	y_res = ucb1400_ts_read_yres(ucb);
+	ucb1400_adc_disable(ucb);
+	printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
+
+	input_set_abs_params(idev, ABS_X, 0, x_res, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, y_res, 0, 0);
+	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
+
+	error = input_register_device(idev);
+	if (error)
+		goto err_free_irq;
+
+	dev_set_drvdata(dev, ucb);
+	return 0;
+
+ err_free_irq:
+	free_irq(ucb->irq, ucb);
+ err_free_devs:
+	input_free_device(idev);
+	kfree(ucb);
+	return error;
+}
+
+static int ucb1400_ts_remove(struct device *dev)
+{
+	struct ucb1400 *ucb = dev_get_drvdata(dev);
+
+	free_irq(ucb->irq, ucb);
+	input_unregister_device(ucb->ts_idev);
+	dev_set_drvdata(dev, NULL);
+	kfree(ucb);
+	return 0;
+}
+
+static struct device_driver ucb1400_ts_driver = {
+	.owner		= THIS_MODULE,
+	.bus		= &ac97_bus_type,
+	.probe		= ucb1400_ts_probe,
+	.remove		= ucb1400_ts_remove,
+	.resume		= ucb1400_ts_resume,
+};
+
+static int __init ucb1400_ts_init(void)
+{
+	return driver_register(&ucb1400_ts_driver);
+}
+
+static void __exit ucb1400_ts_exit(void)
+{
+	driver_unregister(&ucb1400_ts_driver);
+}
+
+module_param(adcsync, int, 0444);
+
+module_init(ucb1400_ts_init);
+module_exit(ucb1400_ts_exit);
+
+MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
+MODULE_LICENSE("GPL");