hwmon: (sch56xx) Add support for the integrated watchdog (v2)

Add support for the watchdog integrated into the SMSC SCH5627 and
SCH5636 superio-s. Since the watchdog is part of the hwmon logical device
and thus shares ioports with it, the watchdog driver is integrated into the
existing hwmon drivers for these.

Note that this version of the watchdog support for sch56xx superio-s
implements the watchdog chardev interface itself, rather then relying on
the recently added watchdog core / watchdog_dev. This is done because
currently some needed functionality is missing from watchdog_dev, as soon
as this functionality is added (which is being discussed on the
linux-watchdog mailinglist), I'll convert this driver over to using
watchdog_dev.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[guenter.roeck@ericsson.com: Added missing linux/slab.h include]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

Documentation/hwmon/sch5627

@@ -16,6 +16,11 @@ Description
 SMSC SCH5627 Super I/O chips include complete hardware monitoring
 capabilities. They can monitor up to 5 voltages, 4 fans and 8 temperatures.
 
+The SMSC SCH5627 hardware monitoring part also contains an integrated
+watchdog. In order for this watchdog to function some motherboard specific
+initialization most be done by the BIOS, so if the watchdog is not enabled
+by the BIOS the sch5627 driver will not register a watchdog device.
+
 The hardware monitoring part of the SMSC SCH5627 is accessed by talking
 through an embedded microcontroller. An application note describing the
 protocol for communicating with the microcontroller is available upon

Documentation/hwmon/sch5636

@@ -26,6 +26,9 @@ temperatures. Note that the driver detects how many fan headers /
 temperature sensors are actually implemented on the motherboard, so you will
 likely see fewer temperature and fan inputs.
 
+The Fujitsu Theseus hwmon solution also contains an integrated watchdog.
+This watchdog is fully supported by the sch5636 driver.
+
 An application note describing the Theseus' registers, as well as an
 application note describing the protocol for communicating with the
 microcontroller is available upon request. Please mail me if you want a copy.

drivers/hwmon/Kconfig

@@ -1028,7 +1028,8 @@ config SENSORS_SCH5627
 	select SENSORS_SCH56XX_COMMON
 	help
 	  If you say yes here you get support for the hardware monitoring
-	  features of the SMSC SCH5627 Super-I/O chip.
+	  features of the SMSC SCH5627 Super-I/O chip including support for
+	  the integrated watchdog.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called sch5627.
@@ -1044,7 +1045,8 @@ config SENSORS_SCH5636
 
 	  Currently this driver only supports the Fujitsu Theseus SCH5636 based
 	  hwmon solution. Say yes here if you want support for the Fujitsu
-	  Theseus' hardware monitoring features.
+	  Theseus' hardware monitoring features including support for the
+	  integrated watchdog.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called sch5636.

drivers/hwmon/sch5627.c

 /***************************************************************************
- *   Copyright (C) 2010-2011 Hans de Goede <hdegoede@redhat.com>           *
+ *   Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com>           *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -79,6 +79,7 @@ static const char * const SCH5627_IN_LABELS[SCH5627_NO_IN] = {
 struct sch5627_data {
 	unsigned short addr;
 	struct device *hwmon_dev;
+	struct sch56xx_watchdog_data *watchdog;
 	u8 control;
 	u8 temp_max[SCH5627_NO_TEMPS];
 	u8 temp_crit[SCH5627_NO_TEMPS];
@@ -453,6 +454,9 @@ static int sch5627_remove(struct platform_device *pdev)
 {
 	struct sch5627_data *data = platform_get_drvdata(pdev);
 
+	if (data->watchdog)
+		sch56xx_watchdog_unregister(data->watchdog);
+
 	if (data->hwmon_dev)
 		hwmon_device_unregister(data->hwmon_dev);
 
@@ -574,6 +578,11 @@ static int __devinit sch5627_probe(struct platform_device *pdev)
 		goto error;
 	}
 
+	/* Note failing to register the watchdog is not a fatal error */
+	data->watchdog = sch56xx_watchdog_register(data->addr,
+			(build_code << 24) | (build_id << 8) | hwmon_rev,
+			&data->update_lock, 1);
+
 	return 0;
 
 error:

drivers/hwmon/sch5636.c

 /***************************************************************************
- *   Copyright (C) 2011 Hans de Goede <hdegoede@redhat.com>                *
+ *   Copyright (C) 2011-2012 Hans de Goede <hdegoede@redhat.com>           *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -67,6 +67,7 @@ static const u16 SCH5636_REG_FAN_VAL[SCH5636_NO_FANS] = {
 struct sch5636_data {
 	unsigned short addr;
 	struct device *hwmon_dev;
+	struct sch56xx_watchdog_data *watchdog;
 
 	struct mutex update_lock;
 	char valid;			/* !=0 if following fields are valid */
@@ -384,6 +385,9 @@ static int sch5636_remove(struct platform_device *pdev)
 	struct sch5636_data *data = platform_get_drvdata(pdev);
 	int i;
 
+	if (data->watchdog)
+		sch56xx_watchdog_unregister(data->watchdog);
+
 	if (data->hwmon_dev)
 		hwmon_device_unregister(data->hwmon_dev);
 
@@ -505,6 +509,11 @@ static int __devinit sch5636_probe(struct platform_device *pdev)
 		goto error;
 	}
 
+	/* Note failing to register the watchdog is not a fatal error */
+	data->watchdog = sch56xx_watchdog_register(data->addr,
+					(revision[0] << 8) | revision[1],
+					&data->update_lock, 0);
+
 	return 0;
 
 error:

drivers/hwmon/sch56xx-common.h

 /***************************************************************************
- *   Copyright (C) 2010-2011 Hans de Goede <hdegoede@redhat.com>           *
+ *   Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com>           *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -17,8 +17,16 @@
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
 
+#include <linux/mutex.h>
+
+struct sch56xx_watchdog_data;
+
 int sch56xx_read_virtual_reg(u16 addr, u16 reg);
 int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val);
 int sch56xx_read_virtual_reg16(u16 addr, u16 reg);
 int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg,
 			       int high_nibble);
+
+struct sch56xx_watchdog_data *sch56xx_watchdog_register(
+	u16 addr, u32 revision, struct mutex *io_lock, int check_enabled);
+void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data);