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![Wolfram Sang](/assets/img/avatar_default.png)
A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
202 lines
5.3 KiB
C
202 lines
5.3 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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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(pdev->dev.parent);
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drv_data = devm_kzalloc(&pdev->dev,
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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->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(&pdev->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, &pdev->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(&pdev->dev, "failed to set Watchdog bootstatus\n");
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return ret;
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}
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ret = watchdog_register_device(&drv_data->wdt);
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if (ret) {
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dev_err(&pdev->dev, "failed to register Watchdog device\n");
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return ret;
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}
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dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
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return 0;
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}
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static int menf21bmc_wdt_remove(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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dev_warn(&pdev->dev,
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"Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
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watchdog_unregister_device(&drv_data->wdt);
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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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.remove = menf21bmc_wdt_remove,
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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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