112 lines
3.0 KiB
C
112 lines
3.0 KiB
C
/*
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* Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
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*
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* Author: Wolfram Sang <w.sang@pengutronix.de>
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*
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* Copyright (C) 2011-12 Wolfram Sang, Pengutronix
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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 version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/platform_device.h>
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#include <linux/stmp3xxx_rtc_wdt.h>
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#define WDOG_TICK_RATE 1000 /* 1 kHz clock */
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#define STMP3XXX_DEFAULT_TIMEOUT 19
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#define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)
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static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT;
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module_param(heartbeat, uint, 0);
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MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to "
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__MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
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__MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));
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static int wdt_start(struct watchdog_device *wdd)
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{
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struct device *dev = watchdog_get_drvdata(wdd);
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struct stmp3xxx_wdt_pdata *pdata = dev->platform_data;
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pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
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return 0;
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}
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static int wdt_stop(struct watchdog_device *wdd)
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{
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struct device *dev = watchdog_get_drvdata(wdd);
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struct stmp3xxx_wdt_pdata *pdata = dev->platform_data;
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pdata->wdt_set_timeout(dev->parent, 0);
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return 0;
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}
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static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
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{
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wdd->timeout = new_timeout;
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return wdt_start(wdd);
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}
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static const struct watchdog_info stmp3xxx_wdt_ident = {
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.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
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.identity = "STMP3XXX RTC Watchdog",
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};
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static const struct watchdog_ops stmp3xxx_wdt_ops = {
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.owner = THIS_MODULE,
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.start = wdt_start,
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.stop = wdt_stop,
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.set_timeout = wdt_set_timeout,
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};
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static struct watchdog_device stmp3xxx_wdd = {
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.info = &stmp3xxx_wdt_ident,
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.ops = &stmp3xxx_wdt_ops,
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.min_timeout = 1,
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.max_timeout = STMP3XXX_MAX_TIMEOUT,
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.status = WATCHDOG_NOWAYOUT_INIT_STATUS,
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};
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static int stmp3xxx_wdt_probe(struct platform_device *pdev)
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{
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int ret;
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watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);
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stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
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ret = watchdog_register_device(&stmp3xxx_wdd);
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if (ret < 0) {
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dev_err(&pdev->dev, "cannot register watchdog device\n");
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return ret;
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}
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dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
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stmp3xxx_wdd.timeout);
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return 0;
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}
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static int stmp3xxx_wdt_remove(struct platform_device *pdev)
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{
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watchdog_unregister_device(&stmp3xxx_wdd);
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return 0;
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}
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static struct platform_driver stmp3xxx_wdt_driver = {
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.driver = {
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.name = "stmp3xxx_rtc_wdt",
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},
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.probe = stmp3xxx_wdt_probe,
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.remove = stmp3xxx_wdt_remove,
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};
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module_platform_driver(stmp3xxx_wdt_driver);
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MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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