/* * Watchdog driver for Technologic Systems TS-72xx based SBCs * (TS-7200, TS-7250 and TS-7260). These boards have external * glue logic CPLD chip, which includes programmable watchdog * timer. * * Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi> * * This driver is based on ep93xx_wdt and wm831x_wdt drivers. * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/platform_device.h> #include <linux/module.h> #include <linux/watchdog.h> #include <linux/io.h> #define TS72XX_WDT_DEFAULT_TIMEOUT 30 static int timeout; module_param(timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds."); static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); /* priv->control_reg */ #define TS72XX_WDT_CTRL_DISABLE 0x00 #define TS72XX_WDT_CTRL_250MS 0x01 #define TS72XX_WDT_CTRL_500MS 0x02 #define TS72XX_WDT_CTRL_1SEC 0x03 #define TS72XX_WDT_CTRL_RESERVED 0x04 #define TS72XX_WDT_CTRL_2SEC 0x05 #define TS72XX_WDT_CTRL_4SEC 0x06 #define TS72XX_WDT_CTRL_8SEC 0x07 /* priv->feed_reg */ #define TS72XX_WDT_FEED_VAL 0x05 struct ts72xx_wdt_priv { void __iomem *control_reg; void __iomem *feed_reg; struct watchdog_device wdd; unsigned char regval; }; static int ts72xx_wdt_start(struct watchdog_device *wdd) { struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); writeb(priv->regval, priv->control_reg); return 0; } static int ts72xx_wdt_stop(struct watchdog_device *wdd) { struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg); return 0; } static int ts72xx_wdt_ping(struct watchdog_device *wdd) { struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); return 0; } static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) { struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); if (to == 1) { priv->regval = TS72XX_WDT_CTRL_1SEC; } else if (to == 2) { priv->regval = TS72XX_WDT_CTRL_2SEC; } else if (to <= 4) { priv->regval = TS72XX_WDT_CTRL_4SEC; to = 4; } else { priv->regval = TS72XX_WDT_CTRL_8SEC; if (to <= 8) to = 8; } wdd->timeout = to; if (watchdog_active(wdd)) { ts72xx_wdt_stop(wdd); ts72xx_wdt_start(wdd); } return 0; } static const struct watchdog_info ts72xx_wdt_ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "TS-72XX WDT", }; static const struct watchdog_ops ts72xx_wdt_ops = { .owner = THIS_MODULE, .start = ts72xx_wdt_start, .stop = ts72xx_wdt_stop, .ping = ts72xx_wdt_ping, .set_timeout = ts72xx_wdt_settimeout, }; static int ts72xx_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct ts72xx_wdt_priv *priv; struct watchdog_device *wdd; int ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->control_reg = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(priv->control_reg)) return PTR_ERR(priv->control_reg); priv->feed_reg = devm_platform_ioremap_resource(pdev, 1); if (IS_ERR(priv->feed_reg)) return PTR_ERR(priv->feed_reg); wdd = &priv->wdd; wdd->info = &ts72xx_wdt_ident; wdd->ops = &ts72xx_wdt_ops; wdd->min_timeout = 1; wdd->max_hw_heartbeat_ms = 8000; wdd->parent = dev; watchdog_set_nowayout(wdd, nowayout); wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT; watchdog_init_timeout(wdd, timeout, dev); watchdog_set_drvdata(wdd, priv); ret = devm_watchdog_register_device(dev, wdd); if (ret) return ret; dev_info(dev, "TS-72xx Watchdog driver\n"); return 0; } static struct platform_driver ts72xx_wdt_driver = { .probe = ts72xx_wdt_probe, .driver = { .name = "ts72xx-wdt", }, }; module_platform_driver(ts72xx_wdt_driver); MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>"); MODULE_DESCRIPTION("TS-72xx SBC Watchdog"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:ts72xx-wdt");