diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/watchdog/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/ath79_wdt.c | 305 |
3 files changed, 313 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index db00fa9f697..68a9527f92d 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -866,6 +866,13 @@ config SBC_EPX_C3_WATCHDOG # MIPS Architecture +config ATH79_WDT + tristate "Atheros AR71XX/AR724X/AR913X hardware watchdog" + depends on ATH79 + help + Hardware driver for the built-in watchdog timer on the Atheros + AR71XX/AR724X/AR913X SoCs. + config BCM47XX_WDT tristate "Broadcom BCM47xx Watchdog Timer" depends on BCM47XX diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index cd77f5492f9..9b6b33a0207 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -110,6 +110,7 @@ obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o # M68KNOMMU Architecture # MIPS Architecture +obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o obj-$(CONFIG_BCM47XX_WDT) += bcm47xx_wdt.o obj-$(CONFIG_BCM63XX_WDT) += bcm63xx_wdt.o obj-$(CONFIG_RC32434_WDT) += rc32434_wdt.o diff --git a/drivers/watchdog/ath79_wdt.c b/drivers/watchdog/ath79_wdt.c new file mode 100644 index 00000000000..725c84bfdd7 --- /dev/null +++ b/drivers/watchdog/ath79_wdt.c @@ -0,0 +1,305 @@ +/* + * Atheros AR71XX/AR724X/AR913X built-in hardware watchdog timer. + * + * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org> + * + * This driver was based on: drivers/watchdog/ixp4xx_wdt.c + * Author: Deepak Saxena <dsaxena@plexity.net> + * Copyright 2004 (c) MontaVista, Software, Inc. + * + * which again was based on sa1100 driver, + * Copyright (C) 2000 Oleg Drokin <green@crimea.edu> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + */ + +#include <linux/bitops.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/platform_device.h> +#include <linux/types.h> +#include <linux/watchdog.h> +#include <linux/clk.h> +#include <linux/err.h> + +#include <asm/mach-ath79/ath79.h> +#include <asm/mach-ath79/ar71xx_regs.h> + +#define DRIVER_NAME "ath79-wdt" + +#define WDT_TIMEOUT 15 /* seconds */ + +#define WDOG_CTRL_LAST_RESET BIT(31) +#define WDOG_CTRL_ACTION_MASK 3 +#define WDOG_CTRL_ACTION_NONE 0 /* no action */ +#define WDOG_CTRL_ACTION_GPI 1 /* general purpose interrupt */ +#define WDOG_CTRL_ACTION_NMI 2 /* NMI */ +#define WDOG_CTRL_ACTION_FCR 3 /* full chip reset */ + +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +static int timeout = WDT_TIMEOUT; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds " + "(default=" __MODULE_STRING(WDT_TIMEOUT) "s)"); + +static unsigned long wdt_flags; + +#define WDT_FLAGS_BUSY 0 +#define WDT_FLAGS_EXPECT_CLOSE 1 + +static struct clk *wdt_clk; +static unsigned long wdt_freq; +static int boot_status; +static int max_timeout; + +static inline void ath79_wdt_keepalive(void) +{ + ath79_reset_wr(AR71XX_RESET_REG_WDOG, wdt_freq * timeout); +} + +static inline void ath79_wdt_enable(void) +{ + ath79_wdt_keepalive(); + ath79_reset_wr(AR71XX_RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_FCR); +} + +static inline void ath79_wdt_disable(void) +{ + ath79_reset_wr(AR71XX_RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_NONE); +} + +static int ath79_wdt_set_timeout(int val) +{ + if (val < 1 || val > max_timeout) + return -EINVAL; + + timeout = val; + ath79_wdt_keepalive(); + + return 0; +} + +static int ath79_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(WDT_FLAGS_BUSY, &wdt_flags)) + return -EBUSY; + + clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags); + ath79_wdt_enable(); + + return nonseekable_open(inode, file); +} + +static int ath79_wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags)) + ath79_wdt_disable(); + else { + pr_crit(DRIVER_NAME ": device closed unexpectedly, " + "watchdog timer will not stop!\n"); + ath79_wdt_keepalive(); + } + + clear_bit(WDT_FLAGS_BUSY, &wdt_flags); + clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags); + + return 0; +} + +static ssize_t ath79_wdt_write(struct file *file, const char *data, + size_t len, loff_t *ppos) +{ + if (len) { + if (!nowayout) { + size_t i; + + clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags); + + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, data + i)) + return -EFAULT; + + if (c == 'V') + set_bit(WDT_FLAGS_EXPECT_CLOSE, + &wdt_flags); + } + } + + ath79_wdt_keepalive(); + } + + return len; +} + +static const struct watchdog_info ath79_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE | WDIOF_CARDRESET, + .firmware_version = 0, + .identity = "ATH79 watchdog", +}; + +static long ath79_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + int err; + int t; + + switch (cmd) { + case WDIOC_GETSUPPORT: + err = copy_to_user(argp, &ath79_wdt_info, + sizeof(ath79_wdt_info)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + err = put_user(0, p); + break; + + case WDIOC_GETBOOTSTATUS: + err = put_user(boot_status, p); + break; + + case WDIOC_KEEPALIVE: + ath79_wdt_keepalive(); + err = 0; + break; + + case WDIOC_SETTIMEOUT: + err = get_user(t, p); + if (err) + break; + + err = ath79_wdt_set_timeout(t); + if (err) + break; + + /* fallthrough */ + case WDIOC_GETTIMEOUT: + err = put_user(timeout, p); + break; + + default: + err = -ENOTTY; + break; + } + + return err; +} + +static const struct file_operations ath79_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = ath79_wdt_write, + .unlocked_ioctl = ath79_wdt_ioctl, + .open = ath79_wdt_open, + .release = ath79_wdt_release, +}; + +static struct miscdevice ath79_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ath79_wdt_fops, +}; + +static int __devinit ath79_wdt_probe(struct platform_device *pdev) +{ + u32 ctrl; + int err; + + wdt_clk = clk_get(&pdev->dev, "wdt"); + if (IS_ERR(wdt_clk)) + return PTR_ERR(wdt_clk); + + err = clk_enable(wdt_clk); + if (err) + goto err_clk_put; + + wdt_freq = clk_get_rate(wdt_clk); + if (!wdt_freq) { + err = -EINVAL; + goto err_clk_disable; + } + + max_timeout = (0xfffffffful / wdt_freq); + if (timeout < 1 || timeout > max_timeout) { + timeout = max_timeout; + dev_info(&pdev->dev, + "timeout value must be 0 < timeout < %d, using %d\n", + max_timeout, timeout); + } + + ctrl = ath79_reset_rr(AR71XX_RESET_REG_WDOG_CTRL); + boot_status = (ctrl & WDOG_CTRL_LAST_RESET) ? WDIOF_CARDRESET : 0; + + err = misc_register(&ath79_wdt_miscdev); + if (err) { + dev_err(&pdev->dev, + "unable to register misc device, err=%d\n", err); + goto err_clk_disable; + } + + return 0; + +err_clk_disable: + clk_disable(wdt_clk); +err_clk_put: + clk_put(wdt_clk); + return err; +} + +static int __devexit ath79_wdt_remove(struct platform_device *pdev) +{ + misc_deregister(&ath79_wdt_miscdev); + clk_disable(wdt_clk); + clk_put(wdt_clk); + return 0; +} + +static void ath97_wdt_shutdown(struct platform_device *pdev) +{ + ath79_wdt_disable(); +} + +static struct platform_driver ath79_wdt_driver = { + .remove = __devexit_p(ath79_wdt_remove), + .shutdown = ath97_wdt_shutdown, + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init ath79_wdt_init(void) +{ + return platform_driver_probe(&ath79_wdt_driver, ath79_wdt_probe); +} +module_init(ath79_wdt_init); + +static void __exit ath79_wdt_exit(void) +{ + platform_driver_unregister(&ath79_wdt_driver); +} +module_exit(ath79_wdt_exit); + +MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X hardware watchdog driver"); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org"); +MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRIVER_NAME); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |