watchdog: menf21bmc_wdt: Introduce MEN 14F021P00 BMC Watchdog driver (50332639) · Commits · 戴 / test

drivers/watchdog/Kconfig

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		@@ -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

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

0 → 100644

+203 −0

Original line number	Diff line number	Diff line
		/*
		* 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");

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