diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/watchdog/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/bcm2835_wdt.c | 189 |
3 files changed, 201 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 6042e9ed542..f17ffdb75bb 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1100,6 +1100,17 @@ config BCM63XX_WDT To compile this driver as a loadable module, choose M here. The module will be called bcm63xx_wdt. +config BCM2835_WDT + tristate "Broadcom BCM2835 hardware watchdog" + depends on ARCH_BCM2835 + select WATCHDOG_CORE + help + Watchdog driver for the built in watchdog hardware in Broadcom + BCM2835 SoC. + + To compile this driver as a loadable module, choose M here. + The module will be called bcm2835_wdt. + config LANTIQ_WDT tristate "Lantiq SoC watchdog" depends on LANTIQ diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 291828b356c..c443f6247fa 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -53,6 +53,7 @@ obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o +obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c new file mode 100644 index 00000000000..61566fc47f8 --- /dev/null +++ b/drivers/watchdog/bcm2835_wdt.c @@ -0,0 +1,189 @@ +/* + * Watchdog driver for Broadcom BCM2835 + * + * "bcm2708_wdog" driver written by Luke Diamand that was obtained from + * branch "rpi-3.6.y" of git://github.com/raspberrypi/linux.git was used + * as a hardware reference for the Broadcom BCM2835 watchdog timer. + * + * Copyright (C) 2013 Lubomir Rintel <lkundrak@v3.sk> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/watchdog.h> +#include <linux/platform_device.h> +#include <linux/of_address.h> +#include <linux/miscdevice.h> + +#define PM_RSTC 0x1c +#define PM_WDOG 0x24 + +#define PM_PASSWORD 0x5a000000 + +#define PM_WDOG_TIME_SET 0x000fffff +#define PM_RSTC_WRCFG_CLR 0xffffffcf +#define PM_RSTC_WRCFG_SET 0x00000030 +#define PM_RSTC_WRCFG_FULL_RESET 0x00000020 +#define PM_RSTC_RESET 0x00000102 + +#define SECS_TO_WDOG_TICKS(x) ((x) << 16) +#define WDOG_TICKS_TO_SECS(x) ((x) >> 16) + +struct bcm2835_wdt { + void __iomem *base; + spinlock_t lock; +}; + +static unsigned int heartbeat; +static bool nowayout = WATCHDOG_NOWAYOUT; + +static int bcm2835_wdt_start(struct watchdog_device *wdog) +{ + struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); + uint32_t cur; + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + + writel_relaxed(PM_PASSWORD | (SECS_TO_WDOG_TICKS(wdog->timeout) & + PM_WDOG_TIME_SET), wdt->base + PM_WDOG); + cur = readl_relaxed(wdt->base + PM_RSTC); + writel_relaxed(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) | + PM_RSTC_WRCFG_FULL_RESET, wdt->base + PM_RSTC); + + spin_unlock_irqrestore(&wdt->lock, flags); + + return 0; +} + +static int bcm2835_wdt_stop(struct watchdog_device *wdog) +{ + struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); + + writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC); + dev_info(wdog->dev, "Watchdog timer stopped"); + return 0; +} + +static int bcm2835_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t) +{ + wdog->timeout = t; + return 0; +} + +static unsigned int bcm2835_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); + + uint32_t ret = readl_relaxed(wdt->base + PM_WDOG); + return WDOG_TICKS_TO_SECS(ret & PM_WDOG_TIME_SET); +} + +static struct watchdog_ops bcm2835_wdt_ops = { + .owner = THIS_MODULE, + .start = bcm2835_wdt_start, + .stop = bcm2835_wdt_stop, + .set_timeout = bcm2835_wdt_set_timeout, + .get_timeleft = bcm2835_wdt_get_timeleft, +}; + +static struct watchdog_info bcm2835_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING, + .identity = "Broadcom BCM2835 Watchdog timer", +}; + +static struct watchdog_device bcm2835_wdt_wdd = { + .info = &bcm2835_wdt_info, + .ops = &bcm2835_wdt_ops, + .min_timeout = 1, + .max_timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET), + .timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET), +}; + +static int bcm2835_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct bcm2835_wdt *wdt; + int err; + + wdt = devm_kzalloc(dev, sizeof(struct bcm2835_wdt), GFP_KERNEL); + if (!wdt) { + dev_err(dev, "Failed to allocate memory for watchdog device"); + return -ENOMEM; + } + platform_set_drvdata(pdev, wdt); + + spin_lock_init(&wdt->lock); + + wdt->base = of_iomap(np, 0); + if (!wdt->base) { + dev_err(dev, "Failed to remap watchdog regs"); + return -ENODEV; + } + + watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt); + watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev); + watchdog_set_nowayout(&bcm2835_wdt_wdd, nowayout); + err = watchdog_register_device(&bcm2835_wdt_wdd); + if (err) { + dev_err(dev, "Failed to register watchdog device"); + iounmap(wdt->base); + return err; + } + + dev_info(dev, "Broadcom BCM2835 watchdog timer"); + return 0; +} + +static int bcm2835_wdt_remove(struct platform_device *pdev) +{ + struct bcm2835_wdt *wdt = platform_get_drvdata(pdev); + + watchdog_unregister_device(&bcm2835_wdt_wdd); + iounmap(wdt->base); + + return 0; +} + +static void bcm2835_wdt_shutdown(struct platform_device *pdev) +{ + bcm2835_wdt_stop(&bcm2835_wdt_wdd); +} + +static const struct of_device_id bcm2835_wdt_of_match[] = { + { .compatible = "brcm,bcm2835-pm-wdt", }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match); + +static struct platform_driver bcm2835_wdt_driver = { + .probe = bcm2835_wdt_probe, + .remove = bcm2835_wdt_remove, + .shutdown = bcm2835_wdt_shutdown, + .driver = { + .name = "bcm2835-wdt", + .owner = THIS_MODULE, + .of_match_table = bcm2835_wdt_of_match, + }, +}; +module_platform_driver(bcm2835_wdt_driver); + +module_param(heartbeat, uint, 0); +MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>"); +MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |