diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/watchdog/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/char/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/char/watchdog/ks8695_wdt.c | 308 |
3 files changed, 316 insertions, 0 deletions
diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig index 1cad32c62ed..53f5538c0c0 100644 --- a/drivers/char/watchdog/Kconfig +++ b/drivers/char/watchdog/Kconfig @@ -115,6 +115,13 @@ config IXP4XX_WATCHDOG Say N if you are unsure. +config KS8695_WATCHDOG + tristate "KS8695 watchdog" + depends on ARCH_KS8695 + help + Watchdog timer embedded into KS8695 processor. This will reboot your + system when the timeout is reached. + config S3C2410_WATCHDOG tristate "S3C2410 Watchdog" depends on ARCH_S3C2410 diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile index 8bfc00cc7c2..d90f649038c 100644 --- a/drivers/char/watchdog/Makefile +++ b/drivers/char/watchdog/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_21285_WATCHDOG) += wdt285.o obj-$(CONFIG_977_WATCHDOG) += wdt977.o obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o +obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o diff --git a/drivers/char/watchdog/ks8695_wdt.c b/drivers/char/watchdog/ks8695_wdt.c new file mode 100644 index 00000000000..7150fb945ea --- /dev/null +++ b/drivers/char/watchdog/ks8695_wdt.c @@ -0,0 +1,308 @@ +/* + * Watchdog driver for Kendin/Micrel KS8695. + * + * (C) 2007 Andrew Victor + * + * 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/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 <asm/bitops.h> +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/arch/regs-timer.h> + + +#define WDT_DEFAULT_TIME 5 /* seconds */ +#define WDT_MAX_TIME 171 /* seconds */ + +static int wdt_time = WDT_DEFAULT_TIME; +static int nowayout = WATCHDOG_NOWAYOUT; + +module_param(wdt_time, int, 0); +MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")"); + +#ifdef CONFIG_WATCHDOG_NOWAYOUT +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +#endif + + +static unsigned long ks8695wdt_busy; + +/* ......................................................................... */ + +/* + * Disable the watchdog. + */ +static void inline ks8695_wdt_stop(void) +{ + unsigned long tmcon; + + /* disable timer0 */ + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); + __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); +} + +/* + * Enable and reset the watchdog. + */ +static void inline ks8695_wdt_start(void) +{ + unsigned long tmcon; + unsigned long tval = wdt_time * CLOCK_TICK_RATE; + + /* disable timer0 */ + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); + __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); + + /* program timer0 */ + __raw_writel(tval | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC); + + /* re-enable timer0 */ + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); + __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); +} + +/* + * Reload the watchdog timer. (ie, pat the watchdog) + */ +static void inline ks8695_wdt_reload(void) +{ + unsigned long tmcon; + + /* disable, then re-enable timer0 */ + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); + __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); + __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); +} + +/* + * Change the watchdog time interval. + */ +static int ks8695_wdt_settimeout(int new_time) +{ + /* + * All counting occurs at SLOW_CLOCK / 128 = 0.256 Hz + * + * Since WDV is a 16-bit counter, the maximum period is + * 65536 / 0.256 = 256 seconds. + */ + if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) + return -EINVAL; + + /* Set new watchdog time. It will be used when ks8695_wdt_start() is called. */ + wdt_time = new_time; + return 0; +} + +/* ......................................................................... */ + +/* + * Watchdog device is opened, and watchdog starts running. + */ +static int ks8695_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &ks8695wdt_busy)) + return -EBUSY; + + ks8695_wdt_start(); + return nonseekable_open(inode, file); +} + +/* + * Close the watchdog device. + * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also + * disabled. + */ +static int ks8695_wdt_close(struct inode *inode, struct file *file) +{ + if (!nowayout) + ks8695_wdt_stop(); /* Disable the watchdog when file is closed */ + + clear_bit(0, &ks8695wdt_busy); + return 0; +} + +static struct watchdog_info ks8695_wdt_info = { + .identity = "ks8695 watchdog", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, +}; + +/* + * Handle commands from user-space. + */ +static int ks8695_wdt_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + int new_value; + + switch(cmd) { + case WDIOC_KEEPALIVE: + ks8695_wdt_reload(); /* pat the watchdog */ + return 0; + + case WDIOC_GETSUPPORT: + return copy_to_user(argp, &ks8695_wdt_info, sizeof(ks8695_wdt_info)) ? -EFAULT : 0; + + case WDIOC_SETTIMEOUT: + if (get_user(new_value, p)) + return -EFAULT; + + if (ks8695_wdt_settimeout(new_value)) + return -EINVAL; + + /* Enable new time value */ + ks8695_wdt_start(); + + /* Return current value */ + return put_user(wdt_time, p); + + case WDIOC_GETTIMEOUT: + return put_user(wdt_time, p); + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, p); + + case WDIOC_SETOPTIONS: + if (get_user(new_value, p)) + return -EFAULT; + + if (new_value & WDIOS_DISABLECARD) + ks8695_wdt_stop(); + if (new_value & WDIOS_ENABLECARD) + ks8695_wdt_start(); + return 0; + + default: + return -ENOTTY; + } +} + +/* + * Pat the watchdog whenever device is written to. + */ +static ssize_t ks8695_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) +{ + ks8695_wdt_reload(); /* pat the watchdog */ + return len; +} + +/* ......................................................................... */ + +static const struct file_operations ks8695wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .ioctl = ks8695_wdt_ioctl, + .open = ks8695_wdt_open, + .release = ks8695_wdt_close, + .write = ks8695_wdt_write, +}; + +static struct miscdevice ks8695wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ks8695wdt_fops, +}; + +static int __init ks8695wdt_probe(struct platform_device *pdev) +{ + int res; + + if (ks8695wdt_miscdev.parent) + return -EBUSY; + ks8695wdt_miscdev.parent = &pdev->dev; + + res = misc_register(&ks8695wdt_miscdev); + if (res) + return res; + + printk("KS8695 Watchdog Timer enabled (%d seconds%s)\n", wdt_time, nowayout ? ", nowayout" : ""); + return 0; +} + +static int __exit ks8695wdt_remove(struct platform_device *pdev) +{ + int res; + + res = misc_deregister(&ks8695wdt_miscdev); + if (!res) + ks8695wdt_miscdev.parent = NULL; + + return res; +} + +static void ks8695wdt_shutdown(struct platform_device *pdev) +{ + ks8695_wdt_stop(); +} + +#ifdef CONFIG_PM + +static int ks8695wdt_suspend(struct platform_device *pdev, pm_message_t message) +{ + ks8695_wdt_stop(); + return 0; +} + +static int ks8695wdt_resume(struct platform_device *pdev) +{ + if (ks8695wdt_busy) + ks8695_wdt_start(); + return 0; +} + +#else +#define ks8695wdt_suspend NULL +#define ks8695wdt_resume NULL +#endif + +static struct platform_driver ks8695wdt_driver = { + .probe = ks8695wdt_probe, + .remove = __exit_p(ks8695wdt_remove), + .shutdown = ks8695wdt_shutdown, + .suspend = ks8695wdt_suspend, + .resume = ks8695wdt_resume, + .driver = { + .name = "ks8695_wdt", + .owner = THIS_MODULE, + }, +}; + +static int __init ks8695_wdt_init(void) +{ + /* Check that the heartbeat value is within range; if not reset to the default */ + if (ks8695_wdt_settimeout(wdt_time)) { + ks8695_wdt_settimeout(WDT_DEFAULT_TIME); + pr_info("ks8695_wdt: wdt_time value must be 1 <= wdt_time <= %i, using %d\n", wdt_time, WDT_MAX_TIME); + } + + return platform_driver_register(&ks8695wdt_driver); +} + +static void __exit ks8695_wdt_exit(void) +{ + platform_driver_unregister(&ks8695wdt_driver); +} + +module_init(ks8695_wdt_init); +module_exit(ks8695_wdt_exit); + +MODULE_AUTHOR("Andrew Victor"); +MODULE_DESCRIPTION("Watchdog driver for KS8695"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |