![Guenter Roeck](/assets/img/avatar_default.png)
Use device managed functions to simplify error handling, reduce source code size, improve readability, and reduce the likelyhood of bugs. Other improvements as listed below. The conversion was done automatically with coccinelle using the following semantic patches. The semantic patches and the scripts used to generate this commit log are available at https://github.com/groeck/coccinelle-patches - Drop assignments to otherwise unused variables - Drop empty remove function - Introduce local variable 'struct device *dev' and use it instead of dereferencing it repeatedly - Use devm_watchdog_register_driver() to register watchdog device Cc: Andreas Werner <andreas.werner@men.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
191 lines
5 KiB
C
191 lines
5 KiB
C
/*
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* MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
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*
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* Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/watchdog.h>
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#include <linux/platform_device.h>
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#include <linux/i2c.h>
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#define DEVNAME "menf21bmc_wdt"
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#define BMC_CMD_WD_ON 0x11
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#define BMC_CMD_WD_OFF 0x12
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#define BMC_CMD_WD_TRIG 0x13
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#define BMC_CMD_WD_TIME 0x14
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#define BMC_CMD_WD_STATE 0x17
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#define BMC_WD_OFF_VAL 0x69
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#define BMC_CMD_RST_RSN 0x92
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#define BMC_WD_TIMEOUT_MIN 1 /* in sec */
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#define BMC_WD_TIMEOUT_MAX 6553 /* in sec */
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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struct menf21bmc_wdt {
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struct watchdog_device wdt;
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struct i2c_client *i2c_client;
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};
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static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data)
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{
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int rst_rsn;
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rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN);
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if (rst_rsn < 0)
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return rst_rsn;
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if (rst_rsn == 0x02)
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data->wdt.bootstatus |= WDIOF_CARDRESET;
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else if (rst_rsn == 0x05)
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data->wdt.bootstatus |= WDIOF_EXTERN1;
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else if (rst_rsn == 0x06)
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data->wdt.bootstatus |= WDIOF_EXTERN2;
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else if (rst_rsn == 0x0A)
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data->wdt.bootstatus |= WDIOF_POWERUNDER;
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return 0;
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}
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static int menf21bmc_wdt_start(struct watchdog_device *wdt)
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{
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struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
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return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON);
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}
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static int menf21bmc_wdt_stop(struct watchdog_device *wdt)
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{
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struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
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return i2c_smbus_write_byte_data(drv_data->i2c_client,
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BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
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}
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static int
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menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
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{
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int ret;
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struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
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/*
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* BMC Watchdog does have a resolution of 100ms.
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* Watchdog API defines the timeout in seconds, so we have to
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* multiply the value.
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*/
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ret = i2c_smbus_write_word_data(drv_data->i2c_client,
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BMC_CMD_WD_TIME, timeout * 10);
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if (ret < 0)
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return ret;
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wdt->timeout = timeout;
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return 0;
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}
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static int menf21bmc_wdt_ping(struct watchdog_device *wdt)
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{
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struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
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return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG);
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}
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static const struct watchdog_info menf21bmc_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
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.identity = DEVNAME,
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};
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static const struct watchdog_ops menf21bmc_wdt_ops = {
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.owner = THIS_MODULE,
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.start = menf21bmc_wdt_start,
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.stop = menf21bmc_wdt_stop,
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.ping = menf21bmc_wdt_ping,
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.set_timeout = menf21bmc_wdt_settimeout,
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};
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static int menf21bmc_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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int ret, bmc_timeout;
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struct menf21bmc_wdt *drv_data;
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struct i2c_client *i2c_client = to_i2c_client(dev->parent);
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drv_data = devm_kzalloc(dev, sizeof(struct menf21bmc_wdt), GFP_KERNEL);
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if (!drv_data)
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return -ENOMEM;
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drv_data->wdt.ops = &menf21bmc_wdt_ops;
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drv_data->wdt.info = &menf21bmc_wdt_info;
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drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN;
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drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX;
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drv_data->wdt.parent = dev;
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drv_data->i2c_client = i2c_client;
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/*
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* Get the current wdt timeout value from the BMC because
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* the BMC will save the value set before if the system restarts.
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*/
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bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
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BMC_CMD_WD_TIME);
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if (bmc_timeout < 0) {
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dev_err(dev, "failed to get current WDT timeout\n");
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return bmc_timeout;
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}
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watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, dev);
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watchdog_set_nowayout(&drv_data->wdt, nowayout);
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watchdog_set_drvdata(&drv_data->wdt, drv_data);
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platform_set_drvdata(pdev, drv_data);
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ret = menf21bmc_wdt_set_bootstatus(drv_data);
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if (ret < 0) {
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dev_err(dev, "failed to set Watchdog bootstatus\n");
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return ret;
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}
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ret = devm_watchdog_register_device(dev, &drv_data->wdt);
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if (ret) {
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dev_err(dev, "failed to register Watchdog device\n");
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return ret;
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}
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dev_info(dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
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return 0;
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}
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static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
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{
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struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
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i2c_smbus_write_word_data(drv_data->i2c_client,
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BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
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}
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static struct platform_driver menf21bmc_wdt = {
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.driver = {
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.name = DEVNAME,
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},
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.probe = menf21bmc_wdt_probe,
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.shutdown = menf21bmc_wdt_shutdown,
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};
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module_platform_driver(menf21bmc_wdt);
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MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
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MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:menf21bmc_wdt");
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