diff options
Diffstat (limited to 'target/linux/ar71xx/files/drivers')
| -rw-r--r-- | target/linux/ar71xx/files/drivers/watchdog/ar71xx_wdt.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/target/linux/ar71xx/files/drivers/watchdog/ar71xx_wdt.c b/target/linux/ar71xx/files/drivers/watchdog/ar71xx_wdt.c new file mode 100644 index 000000000..9f14ff756 --- /dev/null +++ b/target/linux/ar71xx/files/drivers/watchdog/ar71xx_wdt.c @@ -0,0 +1,270 @@ +/* + * Driver for the Atheros AR71xx SoC's built-in hardware watchdog timer. + * + * Copyright (C) 2008 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 <asm/mach-ar71xx/ar71xx.h> + +#define DRV_NAME "ar71xx-wdt" +#define DRV_DESC "Atheros AR71xx hardware watchdog driver" +#define DRV_VERSION "0.1.0" + +#define WDT_TIMEOUT 15 /* seconds */ + +static int nowayout = WATCHDOG_NOWAYOUT; + +#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 wdt_flags; + +#define WDT_FLAGS_BUSY 0 +#define WDT_FLAGS_EXPECT_CLOSE 1 + +static int wdt_timeout = WDT_TIMEOUT; +static int boot_status; +static int max_timeout; + +static void inline ar71xx_wdt_keepalive(void) +{ + ar71xx_reset_wr(RESET_REG_WDOG, ar71xx_ahb_freq * wdt_timeout); +} + +static void inline ar71xx_wdt_enable(void) +{ + printk(KERN_DEBUG DRV_NAME ": enabling watchdog timer\n"); + ar71xx_wdt_keepalive(); + ar71xx_reset_wr(RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_FCR); +} + +static void inline ar71xx_wdt_disable(void) +{ + printk(KERN_DEBUG DRV_NAME ": disabling watchdog timer\n"); + ar71xx_reset_wr(RESET_REG_WDOG_CTRL, WDOG_CTRL_ACTION_NONE); +} + +static int ar71xx_wdt_set_timeout(int val) +{ + if (val < 1 || val > max_timeout) + return -EINVAL; + + wdt_timeout = val; + ar71xx_wdt_keepalive(); + + printk(KERN_DEBUG DRV_NAME ": timeout=%d secs\n", wdt_timeout); + + return 0; +} + +static int ar71xx_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); + + ar71xx_wdt_enable(); + + return nonseekable_open(inode, file); +} + +static int ar71xx_wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags)) { + ar71xx_wdt_disable(); + } else { + printk(KERN_CRIT DRV_NAME ": device closed unexpectedly, " + "watchdog timer will not stop!\n"); + } + + clear_bit(WDT_FLAGS_BUSY, &wdt_flags); + clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags); + + return 0; +} + +static ssize_t ar71xx_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); + } + } + + ar71xx_wdt_keepalive(); + } + + return len; +} + +static struct watchdog_info ar71xx_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE | WDIOF_CARDRESET, + .firmware_version = 0, + .identity = "AR71XX watchdog", +}; + +static int ar71xx_wdt_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int t; + int ret; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user((struct watchdog_info *)arg, + &ar71xx_wdt_info, + sizeof(&ar71xx_wdt_info)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + ret = put_user(0, (int *)arg) ? -EFAULT : 0; + break; + + case WDIOC_GETBOOTSTATUS: + ret = put_user(boot_status, (int *)arg) ? -EFAULT : 0; + break; + + case WDIOC_KEEPALIVE: + ar71xx_wdt_keepalive(); + ret = 0; + break; + + case WDIOC_SETTIMEOUT: + ret = get_user(t, (int *)arg) ? -EFAULT : 0; + if (ret) + break; + + ret = ar71xx_wdt_set_timeout(t); + if (ret) + break; + + /* fallthrough */ + case WDIOC_GETTIMEOUT: + ret = put_user(wdt_timeout, (int *)arg) ? -EFAULT : 0; + break; + + default: + ret = -ENOTTY; + break; + } + + return ret; +} + +static const struct file_operations ar71xx_wdt_fops = { + .owner = THIS_MODULE, + .write = ar71xx_wdt_write, + .ioctl = ar71xx_wdt_ioctl, + .open = ar71xx_wdt_open, + .release = ar71xx_wdt_release, +}; + +static struct miscdevice ar71xx_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &ar71xx_wdt_fops, +}; + +static int __devinit ar71xx_wdt_probe(struct platform_device *pdev) +{ + int ret; + + max_timeout = (0xfffffffful / ar71xx_ahb_freq); + wdt_timeout = (max_timeout < WDT_TIMEOUT) ? max_timeout : WDT_TIMEOUT; + + boot_status = + (ar71xx_reset_rr(RESET_REG_WDOG_CTRL) & WDOG_CTRL_LAST_RESET) ? + WDIOF_CARDRESET : 0; + + ret = misc_register(&ar71xx_wdt_miscdev); + if (ret) + goto err_out; + + printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n"); + + printk(KERN_DEBUG DRV_NAME ": timeout=%d secs (max=%d)\n", + wdt_timeout, max_timeout); + + return 0; + +err_out: + return ret; +} + +static int __devexit ar71xx_wdt_remove(struct platform_device *pdev) +{ + misc_deregister(&ar71xx_wdt_miscdev); + return 0; +} + +static struct platform_driver ar71xx_wdt_driver = { + .probe = ar71xx_wdt_probe, + .remove = __devexit_p(ar71xx_wdt_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init ar71xx_wdt_init(void) +{ + return platform_driver_register(&ar71xx_wdt_driver); +} +module_init(ar71xx_wdt_init); + +static void __exit ar71xx_wdt_exit(void) +{ + platform_driver_unregister(&ar71xx_wdt_driver); +} +module_exit(ar71xx_wdt_exit); + +MODULE_DESCRIPTION(DRV_DESC); +MODULE_VERSION(DRV_VERSION); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org"); +MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRV_NAME); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |