staging: mei: registering the MEI driver with the kernel watchdog core interface

Adding kernel watchdog interface (/dev/watchdog) to the MEI Driver to support AMT Watchdog feature.
This patch and the following one will replace MEI Driver self management of the AMT watchdog
with the standard kernel watchdog interface.

Signed-off-by: Oren Weil <oren.jer.weil@intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/mei/init.c

@@ -133,6 +133,7 @@ struct mei_device *mei_device_init(struct pci_dev *pdev)
 	init_waitqueue_head(&dev->wait_stop_wd);
 	dev->mei_state = MEI_INITIALIZING;
 	dev->iamthif_state = MEI_IAMTHIF_IDLE;
+	dev->wd_interface_reg = false;
 
 
 	mei_io_list_init(&dev->read_list);

drivers/staging/mei/interface.h

@@ -23,7 +23,9 @@
 #include "mei_dev.h"
 
 
-#define AMT_WD_VALUE 120	/* seconds */
+#define AMT_WD_DEFAULT_TIMEOUT 120	/* seconds */
+#define AMT_WD_MIN_TIMEOUT 120	/* seconds */
+#define AMT_WD_MAX_TIMEOUT 65535	/* seconds */
 
 #define MEI_WATCHDOG_DATA_SIZE         16
 #define MEI_START_WD_DATA_SIZE         20

drivers/staging/mei/interrupt.c

@@ -396,6 +396,18 @@ static void mei_client_connect_response(struct mei_device *dev,
 		dev->wd_due_counter = (dev->wd_timeout) ? 1 : 0;
 
 		dev_dbg(&dev->pdev->dev, "successfully connected to WD client.\n");
+
+		/* Registering watchdog interface device once we got connection
+		   to the WD Client
+		*/
+		if (watchdog_register_device(&amt_wd_dev)) {
+			printk(KERN_ERR "mei: unable to register watchdog device.\n");
+			dev->wd_interface_reg = false;
+		} else {
+			dev_dbg(&dev->pdev->dev, "successfully register watchdog interface.\n");
+			dev->wd_interface_reg = true;
+		}
+
 		mei_host_init_iamthif(dev);
 		return;
 	}

drivers/staging/mei/main.c

@@ -241,6 +241,10 @@ static void __devexit mei_remove(struct pci_dev *pdev)
 		mei_disconnect_host_client(dev, &dev->wd_cl);
 	}
 
+	/* Unregistering watchdog device */
+	if (dev->wd_interface_reg)
+		watchdog_unregister_device(&amt_wd_dev);
+
 	/* remove entry if already in list */
 	dev_dbg(&pdev->dev, "list del iamthif and wd file list.\n");
 	mei_remove_client_from_file_list(dev, dev->wd_cl.host_client_id);

drivers/staging/mei/mei_dev.h

@@ -18,6 +18,7 @@
 #define _MEI_DEV_H_
 
 #include <linux/types.h>
+#include <linux/watchdog.h>
 #include "mei.h"
 #include "hw.h"
 
@@ -36,6 +37,12 @@
 #define MEI_WD_PARAMS_SIZE             4
 #define MEI_WD_STATE_INDEPENDENCE_MSG_SENT       (1 << 0)
 
+/*
+ * AMT Watchdog Device
+ */
+#define INTEL_AMT_WATCHDOG_ID "INTCAMT"
+extern struct watchdog_device amt_wd_dev;
+
 /*
  * AMTHI Client UUID
  */
@@ -258,6 +265,8 @@ struct mei_device {
 	bool iamthif_flow_control_pending;
 	bool iamthif_ioctl;
 	bool iamthif_canceled;
+
+	bool wd_interface_reg;
 };
 
 

drivers/staging/mei/wd.c

@@ -19,20 +19,36 @@
 #include <linux/device.h>
 #include <linux/pci.h>
 #include <linux/sched.h>
+#include <linux/watchdog.h>
 
 #include "mei_dev.h"
 #include "hw.h"
 #include "interface.h"
 #include "mei.h"
 
+/*
+ * Watchdog Device structs
+ */
+const struct watchdog_info wd_info = {
+		.identity = INTEL_AMT_WATCHDOG_ID,
+};
+
+struct watchdog_device amt_wd_dev = {
+		.info = &wd_info,
+		.timeout = AMT_WD_DEFAULT_TIMEOUT,
+		.min_timeout = AMT_WD_MIN_TIMEOUT,
+		.max_timeout = AMT_WD_MAX_TIMEOUT,
+};
+
+
 /*
  * MEI Watchdog Module Parameters
  */
-static u16 watchdog_timeout = AMT_WD_VALUE;
+static u16 watchdog_timeout = AMT_WD_DEFAULT_TIMEOUT;
 module_param(watchdog_timeout, ushort, 0);
 MODULE_PARM_DESC(watchdog_timeout,
 		"Intel(R) AMT Watchdog timeout value in seconds. (default="
-					__MODULE_STRING(AMT_WD_VALUE)
+					__MODULE_STRING(AMT_WD_DEFAULT_TIMEOUT)
 					", disable=0)");
 
 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };