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drivers/watchdog/atlas7_wdt.c
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b466ee895 watchdog: atlas7:... |
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/* * Watchdog driver for CSR Atlas7 * * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company. * * Licensed under GPLv2. */ #include <linux/clk.h> #include <linux/io.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/watchdog.h> #define ATLAS7_TIMER_WDT_INDEX 5 #define ATLAS7_WDT_DEFAULT_TIMEOUT 20 #define ATLAS7_WDT_CNT_CTRL (0 + 4 * ATLAS7_TIMER_WDT_INDEX) #define ATLAS7_WDT_CNT_MATCH (0x18 + 4 * ATLAS7_TIMER_WDT_INDEX) #define ATLAS7_WDT_CNT (0x48 + 4 * ATLAS7_TIMER_WDT_INDEX) #define ATLAS7_WDT_CNT_EN (BIT(0) | BIT(1)) #define ATLAS7_WDT_EN 0x64 static unsigned int timeout = ATLAS7_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) ")"); struct atlas7_wdog { struct device *dev; void __iomem *base; unsigned long tick_rate; struct clk *clk; }; static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); u32 counter, match, delta; counter = readl(wdt->base + ATLAS7_WDT_CNT); match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH); delta = match - counter; return delta / wdt->tick_rate; } static int atlas7_wdt_ping(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); u32 counter, match, delta; counter = readl(wdt->base + ATLAS7_WDT_CNT); delta = wdd->timeout * wdt->tick_rate; match = counter + delta; writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH); return 0; } static int atlas7_wdt_enable(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); atlas7_wdt_ping(wdd); writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) | ATLAS7_WDT_CNT_EN, wdt->base + ATLAS7_WDT_CNT_CTRL); writel(1, wdt->base + ATLAS7_WDT_EN); return 0; } static int atlas7_wdt_disable(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); writel(0, wdt->base + ATLAS7_WDT_EN); writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN, wdt->base + ATLAS7_WDT_CNT_CTRL); return 0; } static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) { wdd->timeout = to; return 0; } #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) static const struct watchdog_info atlas7_wdt_ident = { .options = OPTIONS, .firmware_version = 0, .identity = "atlas7 Watchdog", }; static struct watchdog_ops atlas7_wdt_ops = { .owner = THIS_MODULE, .start = atlas7_wdt_enable, .stop = atlas7_wdt_disable, .get_timeleft = atlas7_wdt_gettimeleft, .ping = atlas7_wdt_ping, .set_timeout = atlas7_wdt_settimeout, }; static struct watchdog_device atlas7_wdd = { .info = &atlas7_wdt_ident, .ops = &atlas7_wdt_ops, .timeout = ATLAS7_WDT_DEFAULT_TIMEOUT, }; static const struct of_device_id atlas7_wdt_ids[] = { { .compatible = "sirf,atlas7-tick"}, {} }; static int atlas7_wdt_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct atlas7_wdog *wdt; struct resource *res; struct clk *clk; int ret; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); wdt->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(wdt->base)) return PTR_ERR(wdt->base); clk = of_clk_get(np, 0); if (IS_ERR(clk)) return PTR_ERR(clk); ret = clk_prepare_enable(clk); if (ret) { dev_err(&pdev->dev, "clk enable failed "); goto err; } /* disable watchdog hardware */ writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL); wdt->tick_rate = clk_get_rate(clk); |
ccc8208d0 watchdog: atlas7_... |
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if (!wdt->tick_rate) { ret = -EINVAL; goto err1; } |
b466ee895 watchdog: atlas7:... |
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wdt->clk = clk; atlas7_wdd.min_timeout = 1; atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate; watchdog_init_timeout(&atlas7_wdd, 0, &pdev->dev); watchdog_set_nowayout(&atlas7_wdd, nowayout); watchdog_set_drvdata(&atlas7_wdd, wdt); platform_set_drvdata(pdev, &atlas7_wdd); ret = watchdog_register_device(&atlas7_wdd); if (ret) goto err1; return 0; err1: clk_disable_unprepare(clk); err: clk_put(clk); return ret; } static void atlas7_wdt_shutdown(struct platform_device *pdev) { struct watchdog_device *wdd = platform_get_drvdata(pdev); struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); atlas7_wdt_disable(wdd); clk_disable_unprepare(wdt->clk); } static int atlas7_wdt_remove(struct platform_device *pdev) { struct watchdog_device *wdd = platform_get_drvdata(pdev); struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); atlas7_wdt_shutdown(pdev); clk_put(wdt->clk); return 0; } static int __maybe_unused atlas7_wdt_suspend(struct device *dev) { /* * NOTE:timer controller registers settings are saved * and restored back by the timer-atlas7.c */ return 0; } static int __maybe_unused atlas7_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-atlas7.c, so we need not * update WD settings except refreshing timeout. */ atlas7_wdt_ping(wdd); return 0; } static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops, atlas7_wdt_suspend, atlas7_wdt_resume); MODULE_DEVICE_TABLE(of, atlas7_wdt_ids); static struct platform_driver atlas7_wdt_driver = { .driver = { .name = "atlas7-wdt", .pm = &atlas7_wdt_pm_ops, .of_match_table = atlas7_wdt_ids, }, .probe = atlas7_wdt_probe, .remove = atlas7_wdt_remove, .shutdown = atlas7_wdt_shutdown, }; module_platform_driver(atlas7_wdt_driver); MODULE_DESCRIPTION("CSRatlas7 watchdog driver"); MODULE_AUTHOR("Guo Zeng <Guo.Zeng@csr.com>"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:atlas7-wdt"); |