drivers/watchdog/bcm2835_wdt.c

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>
37  * The Raspberry Pi firmware uses the RSTS register to know which partition
39  * Partition 63 is a special partition used by the firmware to indicate halt.
60 	cur = readl(wdt->base + PM_RSTC);  in bcm2835_wdt_is_running()
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()
88 	writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC);  in bcm2835_wdt_stop()
96 	uint32_t ret = readl_relaxed(wdt->base + PM_WDOG);  in bcm2835_wdt_get_timeleft()
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()
136 	.identity =	"Broadcom BCM2835 Watchdog timer",
162 	val = readl_relaxed(wdt->base + PM_RSTS);  in bcm2835_power_off()
164 	writel_relaxed(val, wdt->base + PM_RSTS);  in bcm2835_power_off()
172 	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);  in bcm2835_wdt_probe()
173 	struct device *dev = &pdev->dev;  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()
213 	dev_info(dev, "Broadcom BCM2835 watchdog timer");  in bcm2835_wdt_probe()
229 		.name =		"bcm2835-wdt",
241 MODULE_ALIAS("platform:bcm2835-wdt");
243 MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer");