Merge tag 'mfd-hwmon-leds-watchdog-v3.18' into hwmon-next

Immutable branch between MFD, HWMON, LEDs and Watchdog for v3.18

Documentation/hwmon/menf21bmc

+Kernel driver menf21bmc_hwmon
+=============================
+
+Supported chips:
+	* MEN 14F021P00
+	  Prefix: 'menf21bmc_hwmon'
+	  Adresses scanned: -
+
+Author: Andreas Werner <andreas.werner@men.de>
+
+Description
+-----------
+
+The menf21bmc is a Board Management Controller (BMC) which provides an I2C
+interface to the host to access the features implemented in the BMC.
+
+This driver gives access to the voltage monitoring feature of the main
+voltages of the board.
+The voltage sensors are connected to the ADC inputs of the BMC which is
+a PIC16F917 Mikrocontroller.
+
+Usage Notes
+-----------
+
+This driver is part of the MFD driver named "menf21bmc" and does
+not auto-detect devices.
+You will have to instantiate the MFD driver explicitly.
+Please see Documentation/i2c/instantiating-devices for
+details.
+
+Sysfs entries
+-------------
+
+The following attributes are supported. All attributes are read only
+The Limits are read once by the driver.
+
+in0_input	+3.3V input voltage
+in1_input	+5.0V input voltage
+in2_input	+12.0V input voltage
+in3_input	+5V Standby input voltage
+in4_input	VBAT (on board battery)
+
+in[0-4]_min	Minimum voltage limit
+in[0-4]_max	Maximum voltage limit
+
+in0_label	"MON_3_3V"
+in1_label	"MON_5V"
+in2_label	"MON_12V"
+in3_label	"5V_STANDBY"
+in4_label	"VBAT"

drivers/hwmon/Kconfig

@@ -839,6 +839,16 @@ config SENSORS_MCP3021
 	  This driver can also be built as a module.  If so, the module
 	  will be called mcp3021.
 
+config SENSORS_MENF21BMC_HWMON
+	tristate "MEN 14F021P00 BMC Hardware Monitoring"
+	depends on MFD_MENF21BMC
+	help
+	  Say Y here to include support for the MEN 14F021P00 BMC
+	  hardware monitoring.
+
+	  This driver can also be built as a module. If so the module
+	  will be called menf21bmc_hwmon.
+
 config SENSORS_ADCXX
 	tristate "National Semiconductor ADCxxxSxxx"
 	depends on SPI_MASTER

drivers/hwmon/Makefile

@@ -115,6 +115,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
 obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
 obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
+obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
 obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
 obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
 obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o

drivers/hwmon/menf21bmc_hwmon.c

+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
+ *
+ *  This is the core hwmon driver of the MEN 14F021P00 BMC.
+ *  The BMC monitors the board voltages which can be access with this
+ *  driver through sysfs.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  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 the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+
+#define DRV_NAME  "menf21bmc_hwmon"
+
+#define BMC_VOLT_COUNT	5
+#define MENF21BMC_V33	0
+#define MENF21BMC_V5	1
+#define MENF21BMC_V12	2
+#define MENF21BMC_V5_SB	3
+#define MENF21BMC_VBAT	4
+
+#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
+#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
+#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
+
+struct menf21bmc_hwmon {
+	bool valid;
+	struct i2c_client *i2c_client;
+	unsigned long last_update;
+	int in_val[BMC_VOLT_COUNT];
+	int in_min[BMC_VOLT_COUNT];
+	int in_max[BMC_VOLT_COUNT];
+};
+
+static const char *const input_names[] = {
+	[MENF21BMC_V33]		= "MON_3_3V",
+	[MENF21BMC_V5]		= "MON_5V",
+	[MENF21BMC_V12]		= "MON_12V",
+	[MENF21BMC_V5_SB]	= "5V_STANDBY",
+	[MENF21BMC_VBAT]	= "VBAT"
+};
+
+static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
+{
+	int i;
+	int val;
+	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
+	struct menf21bmc_hwmon *data_ret = drv_data;
+
+	if (time_after(jiffies, drv_data->last_update + HZ)
+	    || !drv_data->valid) {
+		for (i = 0; i < BMC_VOLT_COUNT; i++) {
+			val = i2c_smbus_read_word_data(drv_data->i2c_client,
+						       IDX_TO_VOLT_INP_CMD(i));
+			if (val < 0) {
+				data_ret = ERR_PTR(val);
+				goto abort;
+			}
+			drv_data->in_val[i] = val;
+		}
+		drv_data->last_update = jiffies;
+		drv_data->valid = true;
+	}
+abort:
+	return data_ret;
+}
+
+static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
+{
+	int i, val;
+
+	for (i = 0; i < BMC_VOLT_COUNT; i++) {
+		val = i2c_smbus_read_word_data(drv_data->i2c_client,
+					       IDX_TO_VOLT_MIN_CMD(i));
+		if (val < 0)
+			return val;
+
+		drv_data->in_min[i] = val;
+
+		val = i2c_smbus_read_word_data(drv_data->i2c_client,
+					       IDX_TO_VOLT_MAX_CMD(i));
+		if (val < 0)
+			return val;
+
+		drv_data->in_max[i] = val;
+	}
+	return 0;
+}
+
+static ssize_t
+show_label(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return sprintf(buf, "%s\n", input_names[attr->index]);
+}
+
+static ssize_t
+show_in(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
+
+	if (IS_ERR(drv_data))
+		return PTR_ERR(drv_data);
+
+	return sprintf(buf, "%d\n", drv_data->in_val[attr->index]);
+}
+
+static ssize_t
+show_min(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
+}
+
+static ssize_t
+show_max(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
+}
+
+#define create_voltage_sysfs(idx)			\
+static SENSOR_DEVICE_ATTR(in##idx##_input, S_IRUGO,	\
+			show_in, NULL, idx);		\
+static SENSOR_DEVICE_ATTR(in##idx##_min, S_IRUGO,	\
+			show_min, NULL, idx);		\
+static SENSOR_DEVICE_ATTR(in##idx##_max, S_IRUGO,	\
+			show_max, NULL, idx);		\
+static SENSOR_DEVICE_ATTR(in##idx##_label, S_IRUGO,	\
+			show_label, NULL, idx);
+
+create_voltage_sysfs(0);
+create_voltage_sysfs(1);
+create_voltage_sysfs(2);
+create_voltage_sysfs(3);
+create_voltage_sysfs(4);
+
+static struct attribute *menf21bmc_hwmon_attrs[] = {
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in0_min.dev_attr.attr,
+	&sensor_dev_attr_in0_max.dev_attr.attr,
+	&sensor_dev_attr_in0_label.dev_attr.attr,
+
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in1_min.dev_attr.attr,
+	&sensor_dev_attr_in1_max.dev_attr.attr,
+	&sensor_dev_attr_in1_label.dev_attr.attr,
+
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in2_min.dev_attr.attr,
+	&sensor_dev_attr_in2_max.dev_attr.attr,
+	&sensor_dev_attr_in2_label.dev_attr.attr,
+
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_in3_min.dev_attr.attr,
+	&sensor_dev_attr_in3_max.dev_attr.attr,
+	&sensor_dev_attr_in3_label.dev_attr.attr,
+
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+	&sensor_dev_attr_in4_min.dev_attr.attr,
+	&sensor_dev_attr_in4_max.dev_attr.attr,
+	&sensor_dev_attr_in4_label.dev_attr.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(menf21bmc_hwmon);
+
+static int menf21bmc_hwmon_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct menf21bmc_hwmon *drv_data;
+	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+	struct device *hwmon_dev;
+
+	drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
+				GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	drv_data->i2c_client = i2c_client;
+
+	ret = menf21bmc_hwmon_get_volt_limits(drv_data);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to read sensor limits");
+		return ret;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
+						   "menf21bmc", drv_data,
+						   menf21bmc_hwmon_groups);
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
+
+	return 0;
+}
+
+static struct platform_driver menf21bmc_hwmon = {
+	.probe		= menf21bmc_hwmon_probe,
+	.driver		= {
+		.name		= DRV_NAME,
+		.owner		= THIS_MODULE,
+	},
+};
+
+module_platform_driver(menf21bmc_hwmon);
+
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_hwmon");

drivers/leds/Kconfig

@@ -468,6 +468,15 @@ config LEDS_OT200
 	  This option enables support for the LEDs on the Bachmann OT200.
 	  Say Y to enable LEDs on the Bachmann OT200.
 
+config LEDS_MENF21BMC
+	tristate "LED support for the MEN 14F021P00 BMC"
+	depends on LEDS_CLASS && MFD_MENF21BMC
+	help
+	  Say Y here to include support for the MEN 14F021P00 BMC LEDs.
+
+	  This driver can also be built as a module. If so the module
+	  will be called leds-menf21bmc.
+
 comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
 
 config LEDS_BLINKM

drivers/leds/Makefile

@@ -54,6 +54,7 @@ obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
 obj-$(CONFIG_LEDS_LM355x)		+= leds-lm355x.o
 obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
 obj-$(CONFIG_LEDS_VERSATILE)		+= leds-versatile.o
+obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

drivers/leds/leds-menf21bmc.c

+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
+ *
+ *  This is the core LED driver of the MEN 14F021P00 BMC.
+ *  There are four LEDs available which can be switched on and off.
+ *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  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 the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/leds.h>
+#include <linux/i2c.h>
+
+#define BMC_CMD_LED_GET_SET	0xA0
+#define BMC_BIT_LED_STATUS	BIT(0)
+#define BMC_BIT_LED_HOTSWAP	BIT(1)
+#define BMC_BIT_LED_USER1	BIT(2)
+#define BMC_BIT_LED_USER2	BIT(3)
+
+struct menf21bmc_led {
+	struct led_classdev cdev;
+	u8 led_bit;
+	const char *name;
+	struct i2c_client *i2c_client;
+};
+
+static struct menf21bmc_led leds[] = {
+	{
+		.name = "menf21bmc:led_status",
+		.led_bit = BMC_BIT_LED_STATUS,
+	},
+	{
+		.name = "menf21bmc:led_hotswap",
+		.led_bit = BMC_BIT_LED_HOTSWAP,
+	},
+	{
+		.name = "menf21bmc:led_user1",
+		.led_bit = BMC_BIT_LED_USER1,
+	},
+	{
+		.name = "menf21bmc:led_user2",
+		.led_bit = BMC_BIT_LED_USER2,
+	}
+};
+
+static DEFINE_MUTEX(led_lock);
+
+static void
+menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
+{
+	int led_val;
+	struct menf21bmc_led *led = container_of(led_cdev,
+					struct menf21bmc_led, cdev);
+
+	mutex_lock(&led_lock);
+	led_val = i2c_smbus_read_byte_data(led->i2c_client,
+					   BMC_CMD_LED_GET_SET);
+	if (led_val < 0)
+		goto err_out;
+
+	if (value == LED_OFF)
+		led_val &= ~led->led_bit;
+	else
+		led_val |= led->led_bit;
+
+	i2c_smbus_write_byte_data(led->i2c_client,
+				  BMC_CMD_LED_GET_SET, led_val);
+err_out:
+	mutex_unlock(&led_lock);
+}
+
+static int menf21bmc_led_probe(struct platform_device *pdev)
+{
+	int i;
+	int ret;
+	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+
+	for (i = 0; i < ARRAY_SIZE(leds); i++) {
+		leds[i].cdev.name = leds[i].name;
+		leds[i].cdev.brightness_set = menf21bmc_led_set;
+		leds[i].i2c_client = i2c_client;
+		ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
+		if (ret < 0)
+			goto err_free_leds;
+	}
+	dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
+
+	return 0;
+
+err_free_leds:
+	dev_err(&pdev->dev, "failed to register LED device\n");
+
+	for (i = i - 1; i >= 0; i--)
+		led_classdev_unregister(&leds[i].cdev);
+
+	return ret;
+}
+
+static int menf21bmc_led_remove(struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(leds); i++)
+		led_classdev_unregister(&leds[i].cdev);
+
+	return 0;
+}
+
+static struct platform_driver menf21bmc_led = {
+	.probe		= menf21bmc_led_probe,
+	.remove		= menf21bmc_led_remove,
+	.driver		= {
+		.name		= "menf21bmc_led",
+		.owner		= THIS_MODULE,
+	},
+};
+
+module_platform_driver(menf21bmc_led);
+
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_led");

drivers/mfd/Kconfig

@@ -454,6 +454,21 @@ config MFD_MAX8998
 	  additional drivers must be enabled in order to use the functionality
 	  of the device.
 
+config MFD_MENF21BMC
+	tristate "MEN 14F021P00 Board Management Controller Support"
+	depends on I2C
+	select MFD_CORE
+	help
+	  Say yes here to add support for the MEN 14F021P00 BMC
+	  which is a Board Management Controller connected to the I2C bus.
+	  The device supports multiple sub-devices like LED, HWMON and WDT.
+	  This driver provides common support for accessing the devices;
+	  additional drivers must be enabled in order to use the
+	  functionality of the BMC device.
+
+	  This driver can also be built as a module. If so the module
+	  will be called menf21bmc.
+
 config EZX_PCAP
 	bool "Motorola EZXPCAP Support"
 	depends on SPI_MASTER

drivers/mfd/Makefile

@@ -169,6 +169,7 @@ obj-$(CONFIG_MFD_AS3711)	+= as3711.o
 obj-$(CONFIG_MFD_AS3722)	+= as3722.o
 obj-$(CONFIG_MFD_STW481X)	+= stw481x.o
 obj-$(CONFIG_MFD_IPAQ_MICRO)	+= ipaq-micro.o
+obj-$(CONFIG_MFD_MENF21BMC)	+= menf21bmc.o
 
 intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o

drivers/mfd/menf21bmc.c

+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) MFD Core Driver.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  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 the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+
+#define BMC_CMD_WDT_EXIT_PROD	0x18
+#define BMC_CMD_WDT_PROD_STAT	0x19
+#define BMC_CMD_REV_MAJOR	0x80
+#define BMC_CMD_REV_MINOR	0x81
+#define BMC_CMD_REV_MAIN	0x82
+
+static struct mfd_cell menf21bmc_cell[] = {
+	{ .name = "menf21bmc_wdt", },
+	{ .name = "menf21bmc_led", },
+	{ .name = "menf21bmc_hwmon", }
+};
+
+static int menf21bmc_wdt_exit_prod_mode(struct i2c_client *client)
+{
+	int val, ret;
+
+	val = i2c_smbus_read_byte_data(client, BMC_CMD_WDT_PROD_STAT);
+	if (val < 0)
+		return val;
+
+	/*
+	 * Production mode should be not active after delivery of the Board.
+	 * To be sure we check it, inform the user and exit the mode
+	 * if active.
+	 */
+	if (val == 0x00) {
+		dev_info(&client->dev,
+			"BMC in production mode. Exit production mode\n");
+
+		ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int
+menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
+{
+	int rev_major, rev_minor, rev_main;
+	int ret;
+
+	ret = i2c_check_functionality(client->adapter,
+				      I2C_FUNC_SMBUS_BYTE_DATA |
+				      I2C_FUNC_SMBUS_WORD_DATA |
+				      I2C_FUNC_SMBUS_BYTE);
+	if (!ret)
+		return -ENODEV;
+
+	rev_major = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAJOR);
+	if (rev_major < 0) {
+		dev_err(&client->dev, "failed to get BMC major revision\n");
+		return rev_major;
+	}
+
+	rev_minor = i2c_smbus_read_word_data(client, BMC_CMD_REV_MINOR);
+	if (rev_minor < 0) {
+		dev_err(&client->dev, "failed to get BMC minor revision\n");
+		return rev_minor;
+	}
+
+	rev_main = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAIN);
+	if (rev_main < 0) {
+		dev_err(&client->dev, "failed to get BMC main revision\n");
+		return rev_main;
+	}
+
+	dev_info(&client->dev, "FW Revision: %02d.%02d.%02d\n",
+		 rev_major, rev_minor, rev_main);
+
+	/*
+	 * We have to exit the Production Mode of the BMC to activate the
+	 * Watchdog functionality and the BIOS life sign monitoring.
+	 */
+	ret = menf21bmc_wdt_exit_prod_mode(client);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to leave production mode\n");
+		return ret;
+	}
+
+	ret = mfd_add_devices(&client->dev, 0, menf21bmc_cell,
+			      ARRAY_SIZE(menf21bmc_cell), NULL, 0, NULL);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to add BMC sub-devices\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int menf21bmc_remove(struct i2c_client *client)
+{
+	mfd_remove_devices(&client->dev);
+	return 0;
+}
+
+static const struct i2c_device_id menf21bmc_id_table[] = {
+	{ "menf21bmc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
+
+static struct i2c_driver menf21bmc_driver = {
+	.driver.name	= "menf21bmc",
+	.id_table	= menf21bmc_id_table,
+	.probe		= menf21bmc_probe,
+	.remove		= menf21bmc_remove,
+};
+
+module_i2c_driver(menf21bmc_driver);
+
+MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL v2");

drivers/watchdog/Kconfig

@@ -95,6 +95,16 @@ config GPIO_WATCHDOG
 	  If you say yes here you get support for watchdog device
 	  controlled through GPIO-line.
 
+config MENF21BMC_WATCHDOG
+	tristate "MEN 14F021P00 BMC Watchdog"
+	depends on MFD_MENF21BMC
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the MEN 14F021P00 BMC Watchdog.
+
+	  This driver can also be built as a module. If so the module
+	  will be called menf21bmc_wdt.
+
 config WM831X_WATCHDOG
 	tristate "WM831x watchdog"
 	depends on MFD_WM831X

drivers/watchdog/Makefile

@@ -178,3 +178,4 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
+obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o

drivers/watchdog/menf21bmc_wdt.c

+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  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 the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+
+#define DEVNAME "menf21bmc_wdt"
+
+#define BMC_CMD_WD_ON		0x11
+#define BMC_CMD_WD_OFF		0x12
+#define BMC_CMD_WD_TRIG		0x13
+#define BMC_CMD_WD_TIME		0x14
+#define BMC_CMD_WD_STATE	0x17
+#define BMC_WD_OFF_VAL		0x69
+#define BMC_CMD_RST_RSN		0x92
+
+#define BMC_WD_TIMEOUT_MIN	1	/* in sec */
+#define BMC_WD_TIMEOUT_MAX	6553	/* in sec */
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct menf21bmc_wdt {
+	struct watchdog_device wdt;
+	struct i2c_client *i2c_client;
+};
+
+static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data)
+{
+	int rst_rsn;
+
+	rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN);
+	if (rst_rsn < 0)
+		return rst_rsn;
+
+	if (rst_rsn == 0x02)
+		data->wdt.bootstatus |= WDIOF_CARDRESET;
+	else if (rst_rsn == 0x05)
+		data->wdt.bootstatus |= WDIOF_EXTERN1;
+	else if (rst_rsn == 0x06)
+		data->wdt.bootstatus |= WDIOF_EXTERN2;
+	else if (rst_rsn == 0x0A)
+		data->wdt.bootstatus |= WDIOF_POWERUNDER;
+
+	return 0;
+}
+
+static int menf21bmc_wdt_start(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON);
+}
+
+static int menf21bmc_wdt_stop(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte_data(drv_data->i2c_client,
+					 BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static int
+menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
+{
+	int ret;
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	/*
+	 *  BMC Watchdog does have a resolution of 100ms.
+	 *  Watchdog API defines the timeout in seconds, so we have to
+	 *  multiply the value.
+	 */
+	ret = i2c_smbus_write_word_data(drv_data->i2c_client,
+					BMC_CMD_WD_TIME, timeout * 10);
+	if (ret < 0)
+		return ret;
+
+	wdt->timeout = timeout;
+
+	return 0;
+}
+
+static int menf21bmc_wdt_ping(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG);
+}
+
+static const struct watchdog_info menf21bmc_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity = DEVNAME,
+};
+
+static const struct watchdog_ops menf21bmc_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= menf21bmc_wdt_start,
+	.stop		= menf21bmc_wdt_stop,
+	.ping		= menf21bmc_wdt_ping,
+	.set_timeout	= menf21bmc_wdt_settimeout,
+};
+
+static int menf21bmc_wdt_probe(struct platform_device *pdev)
+{
+	int ret, bmc_timeout;
+	struct menf21bmc_wdt *drv_data;
+	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+
+	drv_data = devm_kzalloc(&pdev->dev,
+				sizeof(struct menf21bmc_wdt), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	drv_data->wdt.ops = &menf21bmc_wdt_ops;
+	drv_data->wdt.info = &menf21bmc_wdt_info;
+	drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN;
+	drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX;
+	drv_data->i2c_client = i2c_client;
+
+	/*
+	 * Get the current wdt timeout value from the BMC because
+	 * the BMC will save the value set before if the system restarts.
+	 */
+	bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
+					       BMC_CMD_WD_TIME);
+	if (bmc_timeout < 0) {
+		dev_err(&pdev->dev, "failed to get current WDT timeout\n");
+		return bmc_timeout;
+	}
+
+	watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev);
+	watchdog_set_nowayout(&drv_data->wdt, nowayout);
+	watchdog_set_drvdata(&drv_data->wdt, drv_data);
+	platform_set_drvdata(pdev, drv_data);
+
+	ret = menf21bmc_wdt_set_bootstatus(drv_data);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
+		return ret;
+	}
+
+	ret = watchdog_register_device(&drv_data->wdt);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register Watchdog device\n");
+		return ret;
+	}
+
+	dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
+
+	return 0;
+}
+
+static int menf21bmc_wdt_remove(struct platform_device *pdev)
+{
+	struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+	dev_warn(&pdev->dev,
+		 "Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
+
+	watchdog_unregister_device(&drv_data->wdt);
+
+	return 0;
+}
+
+static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
+{
+	struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+	i2c_smbus_write_word_data(drv_data->i2c_client,
+				  BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static struct  platform_driver menf21bmc_wdt = {
+	.driver		= {
+		.owner = THIS_MODULE,
+		.name	= DEVNAME,
+	},
+	.probe		= menf21bmc_wdt_probe,
+	.remove		= menf21bmc_wdt_remove,
+	.shutdown	= menf21bmc_wdt_shutdown,
+};
+
+module_platform_driver(menf21bmc_wdt);
+
+MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_wdt");