/* * Watchdog driver for CSR SiRFprimaII and SiRFatlasVI * * Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company. * * Licensed under GPLv2 or later. */ #include <linux/module.h> #include <linux/watchdog.h> #include <linux/platform_device.h> #include <linux/moduleparam.h> #include <linux/of.h> #include <linux/io.h> #include <linux/uaccess.h> #define CLOCK_FREQ 1000000 #define SIRFSOC_TIMER_COUNTER_LO 0x0000 #define SIRFSOC_TIMER_MATCH_0 0x0008 #define SIRFSOC_TIMER_INT_EN 0x0024 #define SIRFSOC_TIMER_WATCHDOG_EN 0x0028 #define SIRFSOC_TIMER_LATCH 0x0030 #define SIRFSOC_TIMER_LATCHED_LO 0x0034 #define SIRFSOC_TIMER_WDT_INDEX 5 #define SIRFSOC_WDT_MIN_TIMEOUT 30 /* 30 secs */ #define SIRFSOC_WDT_MAX_TIMEOUT (10 * 60) /* 10 mins */ #define SIRFSOC_WDT_DEFAULT_TIMEOUT 30 /* 30 secs */ static unsigned int timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT; static bool nowayout = WATCHDOG_NOWAYOUT; module_param(timeout, uint, 0); module_param(nowayout, bool, 0); MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)"); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static unsigned int sirfsoc_wdt_gettimeleft(struct watchdog_device *wdd) { u32 counter, match; void __iomem *wdt_base; int time_left; wdt_base = watchdog_get_drvdata(wdd); counter = readl(wdt_base + SIRFSOC_TIMER_COUNTER_LO); match = readl(wdt_base + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2)); time_left = match - counter; return time_left / CLOCK_FREQ; } static int sirfsoc_wdt_updatetimeout(struct watchdog_device *wdd) { u32 counter, timeout_ticks; void __iomem *wdt_base; timeout_ticks = wdd->timeout * CLOCK_FREQ; wdt_base = watchdog_get_drvdata(wdd); /* Enable the latch before reading the LATCH_LO register */ writel(1, wdt_base + SIRFSOC_TIMER_LATCH); /* Set the TO value */ counter = readl(wdt_base + SIRFSOC_TIMER_LATCHED_LO); counter += timeout_ticks; writel(counter, wdt_base + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2)); return 0; } static int sirfsoc_wdt_enable(struct watchdog_device *wdd) { void __iomem *wdt_base = watchdog_get_drvdata(wdd); sirfsoc_wdt_updatetimeout(wdd); /* * NOTE: If interrupt is not enabled * then WD-Reset doesn't get generated at all. */ writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN) | (1 << SIRFSOC_TIMER_WDT_INDEX), wdt_base + SIRFSOC_TIMER_INT_EN); writel(1, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN); return 0; } static int sirfsoc_wdt_disable(struct watchdog_device *wdd) { void __iomem *wdt_base = watchdog_get_drvdata(wdd); writel(0, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN); writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN) & (~(1 << SIRFSOC_TIMER_WDT_INDEX)), wdt_base + SIRFSOC_TIMER_INT_EN); return 0; } static int sirfsoc_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) { wdd->timeout = to; sirfsoc_wdt_updatetimeout(wdd); return 0; } #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) static const struct watchdog_info sirfsoc_wdt_ident = { .options = OPTIONS, .firmware_version = 0, .identity = "SiRFSOC Watchdog", }; static struct watchdog_ops sirfsoc_wdt_ops = { .owner = THIS_MODULE, .start = sirfsoc_wdt_enable, .stop = sirfsoc_wdt_disable, .get_timeleft = sirfsoc_wdt_gettimeleft, .ping = sirfsoc_wdt_updatetimeout, .set_timeout = sirfsoc_wdt_settimeout, }; static struct watchdog_device sirfsoc_wdd = { .info = &sirfsoc_wdt_ident, .ops = &sirfsoc_wdt_ops, .timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT, .min_timeout = SIRFSOC_WDT_MIN_TIMEOUT, .max_timeout = SIRFSOC_WDT_MAX_TIMEOUT, }; static int sirfsoc_wdt_probe(struct platform_device *pdev) { struct resource *res; int ret; void __iomem *base; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(base)) return PTR_ERR(base); watchdog_set_drvdata(&sirfsoc_wdd, base); watchdog_init_timeout(&sirfsoc_wdd, timeout, &pdev->dev); watchdog_set_nowayout(&sirfsoc_wdd, nowayout); ret = watchdog_register_device(&sirfsoc_wdd); if (ret) return ret; platform_set_drvdata(pdev, &sirfsoc_wdd); return 0; } static void sirfsoc_wdt_shutdown(struct platform_device *pdev) { struct watchdog_device *wdd = platform_get_drvdata(pdev); sirfsoc_wdt_disable(wdd); } static int sirfsoc_wdt_remove(struct platform_device *pdev) { sirfsoc_wdt_shutdown(pdev); return 0; } #ifdef CONFIG_PM_SLEEP static int sirfsoc_wdt_suspend(struct device *dev) { return 0; } static int sirfsoc_wdt_resume(struct device *dev) { struct watchdog_device *wdd = dev_get_drvdata(dev); /* * NOTE: Since timer controller registers settings are saved * and restored back by the timer-prima2.c, so we need not * update WD settings except refreshing timeout. */ sirfsoc_wdt_updatetimeout(wdd); return 0; } #endif static SIMPLE_DEV_PM_OPS(sirfsoc_wdt_pm_ops, sirfsoc_wdt_suspend, sirfsoc_wdt_resume); static const struct of_device_id sirfsoc_wdt_of_match[] = { { .compatible = "sirf,prima2-tick"}, {}, }; MODULE_DEVICE_TABLE(of, sirfsoc_wdt_of_match); static struct platform_driver sirfsoc_wdt_driver = { .driver = { .name = "sirfsoc-wdt", .owner = THIS_MODULE, .pm = &sirfsoc_wdt_pm_ops, .of_match_table = sirfsoc_wdt_of_match, }, .probe = sirfsoc_wdt_probe, .remove = sirfsoc_wdt_remove, .shutdown = sirfsoc_wdt_shutdown, }; module_platform_driver(sirfsoc_wdt_driver); MODULE_DESCRIPTION("SiRF SoC watchdog driver"); MODULE_AUTHOR("Xianglong Du <Xianglong.Du@csr.com>"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:sirfsoc-wdt");