1de6303abSWolfram Sang /* 2de6303abSWolfram Sang * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28 3de6303abSWolfram Sang * 4de6303abSWolfram Sang * Author: Wolfram Sang <w.sang@pengutronix.de> 5de6303abSWolfram Sang * 6de6303abSWolfram Sang * Copyright (C) 2011-12 Wolfram Sang, Pengutronix 7de6303abSWolfram Sang * 8de6303abSWolfram Sang * This program is free software; you can redistribute it and/or modify it 9de6303abSWolfram Sang * under the terms of the GNU General Public License version 2 as published by 10de6303abSWolfram Sang * the Free Software Foundation. 11de6303abSWolfram Sang */ 12de6303abSWolfram Sang #include <linux/init.h> 13de6303abSWolfram Sang #include <linux/kernel.h> 14de6303abSWolfram Sang #include <linux/module.h> 15de6303abSWolfram Sang #include <linux/miscdevice.h> 16de6303abSWolfram Sang #include <linux/watchdog.h> 17de6303abSWolfram Sang #include <linux/platform_device.h> 18de6303abSWolfram Sang #include <linux/stmp3xxx_rtc_wdt.h> 19de6303abSWolfram Sang 20de6303abSWolfram Sang #define WDOG_TICK_RATE 1000 /* 1 kHz clock */ 21de6303abSWolfram Sang #define STMP3XXX_DEFAULT_TIMEOUT 19 22de6303abSWolfram Sang #define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE) 23de6303abSWolfram Sang 24de6303abSWolfram Sang static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT; 25de6303abSWolfram Sang module_param(heartbeat, uint, 0); 26de6303abSWolfram Sang MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to " 27de6303abSWolfram Sang __MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default " 28de6303abSWolfram Sang __MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT)); 29de6303abSWolfram Sang 30de6303abSWolfram Sang static int wdt_start(struct watchdog_device *wdd) 31de6303abSWolfram Sang { 32de6303abSWolfram Sang struct device *dev = watchdog_get_drvdata(wdd); 33*bc8fdfbeSJingoo Han struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev); 34de6303abSWolfram Sang 35de6303abSWolfram Sang pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE); 36de6303abSWolfram Sang return 0; 37de6303abSWolfram Sang } 38de6303abSWolfram Sang 39de6303abSWolfram Sang static int wdt_stop(struct watchdog_device *wdd) 40de6303abSWolfram Sang { 41de6303abSWolfram Sang struct device *dev = watchdog_get_drvdata(wdd); 42*bc8fdfbeSJingoo Han struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev); 43de6303abSWolfram Sang 44de6303abSWolfram Sang pdata->wdt_set_timeout(dev->parent, 0); 45de6303abSWolfram Sang return 0; 46de6303abSWolfram Sang } 47de6303abSWolfram Sang 48de6303abSWolfram Sang static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout) 49de6303abSWolfram Sang { 50de6303abSWolfram Sang wdd->timeout = new_timeout; 51de6303abSWolfram Sang return wdt_start(wdd); 52de6303abSWolfram Sang } 53de6303abSWolfram Sang 54de6303abSWolfram Sang static const struct watchdog_info stmp3xxx_wdt_ident = { 55de6303abSWolfram Sang .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, 56de6303abSWolfram Sang .identity = "STMP3XXX RTC Watchdog", 57de6303abSWolfram Sang }; 58de6303abSWolfram Sang 59de6303abSWolfram Sang static const struct watchdog_ops stmp3xxx_wdt_ops = { 60de6303abSWolfram Sang .owner = THIS_MODULE, 61de6303abSWolfram Sang .start = wdt_start, 62de6303abSWolfram Sang .stop = wdt_stop, 63de6303abSWolfram Sang .set_timeout = wdt_set_timeout, 64de6303abSWolfram Sang }; 65de6303abSWolfram Sang 66de6303abSWolfram Sang static struct watchdog_device stmp3xxx_wdd = { 67de6303abSWolfram Sang .info = &stmp3xxx_wdt_ident, 68de6303abSWolfram Sang .ops = &stmp3xxx_wdt_ops, 69de6303abSWolfram Sang .min_timeout = 1, 70de6303abSWolfram Sang .max_timeout = STMP3XXX_MAX_TIMEOUT, 71de6303abSWolfram Sang .status = WATCHDOG_NOWAYOUT_INIT_STATUS, 72de6303abSWolfram Sang }; 73de6303abSWolfram Sang 74de6303abSWolfram Sang static int stmp3xxx_wdt_probe(struct platform_device *pdev) 75de6303abSWolfram Sang { 76de6303abSWolfram Sang int ret; 77de6303abSWolfram Sang 78de6303abSWolfram Sang watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev); 79de6303abSWolfram Sang 80de6303abSWolfram Sang stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT); 81de6303abSWolfram Sang 82de6303abSWolfram Sang ret = watchdog_register_device(&stmp3xxx_wdd); 83de6303abSWolfram Sang if (ret < 0) { 84de6303abSWolfram Sang dev_err(&pdev->dev, "cannot register watchdog device\n"); 85de6303abSWolfram Sang return ret; 86de6303abSWolfram Sang } 87de6303abSWolfram Sang 88de6303abSWolfram Sang dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n", 89de6303abSWolfram Sang stmp3xxx_wdd.timeout); 90de6303abSWolfram Sang return 0; 91de6303abSWolfram Sang } 92de6303abSWolfram Sang 93de6303abSWolfram Sang static int stmp3xxx_wdt_remove(struct platform_device *pdev) 94de6303abSWolfram Sang { 95de6303abSWolfram Sang watchdog_unregister_device(&stmp3xxx_wdd); 96de6303abSWolfram Sang return 0; 97de6303abSWolfram Sang } 98de6303abSWolfram Sang 99de6303abSWolfram Sang static struct platform_driver stmp3xxx_wdt_driver = { 100de6303abSWolfram Sang .driver = { 101de6303abSWolfram Sang .name = "stmp3xxx_rtc_wdt", 102de6303abSWolfram Sang }, 103de6303abSWolfram Sang .probe = stmp3xxx_wdt_probe, 104de6303abSWolfram Sang .remove = stmp3xxx_wdt_remove, 105de6303abSWolfram Sang }; 106de6303abSWolfram Sang module_platform_driver(stmp3xxx_wdt_driver); 107de6303abSWolfram Sang 108de6303abSWolfram Sang MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver"); 109de6303abSWolfram Sang MODULE_LICENSE("GPL v2"); 110de6303abSWolfram Sang MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>"); 111de6303abSWolfram Sang MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 112