diff options
Diffstat (limited to 'kernel/drivers/watchdog/menf21bmc_wdt.c')
| -rw-r--r-- | kernel/drivers/watchdog/menf21bmc_wdt.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/kernel/drivers/watchdog/menf21bmc_wdt.c b/kernel/drivers/watchdog/menf21bmc_wdt.c new file mode 100644 index 000000000..59f0913c7 --- /dev/null +++ b/kernel/drivers/watchdog/menf21bmc_wdt.c @@ -0,0 +1,202 @@ +/* + * 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 = { + .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"); |