1 // SPDX-License-Identifier: GPL-2.0+
3  * Watchdog driver for Broadcom BCM2835
6  * branch "rpi-3.6.y" of git://github.com/raspberrypi/linux.git was used
7  * as a hardware reference for the Broadcom BCM2835 watchdog timer.
15 #include <linux/mfd/bcm2835-pm.h>
56 static bool bcm2835_wdt_is_running(struct bcm2835_wdt *wdt)  in bcm2835_wdt_is_running()  argument
60 	cur = readl(wdt->base + PM_RSTC);  in bcm2835_wdt_is_running()
67 	struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);  in bcm2835_wdt_start()  local
71 	spin_lock_irqsave(&wdt->lock, flags);  in bcm2835_wdt_start()
73 	writel_relaxed(PM_PASSWORD | (SECS_TO_WDOG_TICKS(wdog->timeout) &  in bcm2835_wdt_start()
74 				PM_WDOG_TIME_SET), wdt->base + PM_WDOG);  in bcm2835_wdt_start()
75 	cur = readl_relaxed(wdt->base + PM_RSTC);  in bcm2835_wdt_start()
77 		  PM_RSTC_WRCFG_FULL_RESET, wdt->base + PM_RSTC);  in bcm2835_wdt_start()
79 	spin_unlock_irqrestore(&wdt->lock, flags);  in bcm2835_wdt_start()
86 	struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);  in bcm2835_wdt_stop()  local
88 	writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC);  in bcm2835_wdt_stop()
94 	struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);  in bcm2835_wdt_get_timeleft()  local
96 	uint32_t ret = readl_relaxed(wdt->base + PM_WDOG);  in bcm2835_wdt_get_timeleft()
100 static void __bcm2835_restart(struct bcm2835_wdt *wdt)  in __bcm2835_restart()  argument
105 	writel_relaxed(10 | PM_PASSWORD, wdt->base + PM_WDOG);  in __bcm2835_restart()
106 	val = readl_relaxed(wdt->base + PM_RSTC);  in __bcm2835_restart()
109 	writel_relaxed(val, wdt->base + PM_RSTC);  in __bcm2835_restart()
118 	struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);  in bcm2835_restart()  local
120 	__bcm2835_restart(wdt);  in bcm2835_restart()
136 	.identity =	"Broadcom BCM2835 Watchdog timer",
154 	struct bcm2835_wdt *wdt = bcm2835_power_off_wdt;  in bcm2835_power_off()  local
162 	val = readl_relaxed(wdt->base + PM_RSTS);  in bcm2835_power_off()
164 	writel_relaxed(val, wdt->base + PM_RSTS);  in bcm2835_power_off()
167 	__bcm2835_restart(wdt);  in bcm2835_power_off()
172 	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);  in bcm2835_wdt_probe()  local
173 	struct device *dev = &pdev->dev;  in bcm2835_wdt_probe()
174 	struct bcm2835_wdt *wdt;  in bcm2835_wdt_probe()  local
177 	wdt = devm_kzalloc(dev, sizeof(struct bcm2835_wdt), GFP_KERNEL);  in bcm2835_wdt_probe()
178 	if (!wdt)  in bcm2835_wdt_probe()
179 		return -ENOMEM;  in bcm2835_wdt_probe()
181 	spin_lock_init(&wdt->lock);  in bcm2835_wdt_probe()
183 	wdt->base = pm->base;  in bcm2835_wdt_probe()
185 	watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt);  in bcm2835_wdt_probe()
189 	if (bcm2835_wdt_is_running(wdt)) {  in bcm2835_wdt_probe()
208 	if (of_device_is_system_power_controller(pdev->dev.parent->of_node)) {  in bcm2835_wdt_probe()
211 			bcm2835_power_off_wdt = wdt;  in bcm2835_wdt_probe()
217 	dev_info(dev, "Broadcom BCM2835 watchdog timer");  in bcm2835_wdt_probe()
231 		.name =		"bcm2835-wdt",
243 MODULE_ALIAS("platform:bcm2835-wdt");
245 MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer");