diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-06-17 08:59:01 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-06-17 08:59:10 +0200 |
commit | cc4949e1fdade5d063e9f8783cf0e2cc92041ce5 (patch) | |
tree | 4023bd641bfe464efbde518fb504d6865c9df014 /drivers/watchdog/orion_wdt.c | |
parent | 28b4868820a56de661f54742ff91b78e12f1e582 (diff) | |
parent | 300df7dc89cc276377fc020704e34875d5c473b6 (diff) |
Merge branch 'linus' into x86/urgent
Merge reason: pull in latest to fix a bug in it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/watchdog/orion_wdt.c')
-rw-r--r-- | drivers/watchdog/orion_wdt.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c new file mode 100644 index 00000000000..2d9fb96a9ee --- /dev/null +++ b/drivers/watchdog/orion_wdt.c @@ -0,0 +1,322 @@ +/* + * drivers/watchdog/orion_wdt.c + * + * Watchdog driver for Orion/Kirkwood processors + * + * Author: Sylver Bruneau <sylver.bruneau@googlemail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> +#include <linux/init.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/spinlock.h> +#include <mach/bridge-regs.h> +#include <plat/orion_wdt.h> + +/* + * Watchdog timer block registers. + */ +#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000) +#define WDT_EN 0x0010 +#define WDT_VAL (TIMER_VIRT_BASE + 0x0024) + +#define WDT_MAX_CYCLE_COUNT 0xffffffff +#define WDT_IN_USE 0 +#define WDT_OK_TO_CLOSE 1 + +static int nowayout = WATCHDOG_NOWAYOUT; +static int heartbeat = -1; /* module parameter (seconds) */ +static unsigned int wdt_max_duration; /* (seconds) */ +static unsigned int wdt_tclk; +static unsigned long wdt_status; +static spinlock_t wdt_lock; + +static void orion_wdt_ping(void) +{ + spin_lock(&wdt_lock); + + /* Reload watchdog duration */ + writel(wdt_tclk * heartbeat, WDT_VAL); + + spin_unlock(&wdt_lock); +} + +static void orion_wdt_enable(void) +{ + u32 reg; + + spin_lock(&wdt_lock); + + /* Set watchdog duration */ + writel(wdt_tclk * heartbeat, WDT_VAL); + + /* Clear watchdog timer interrupt */ + reg = readl(BRIDGE_CAUSE); + reg &= ~WDT_INT_REQ; + writel(reg, BRIDGE_CAUSE); + + /* Enable watchdog timer */ + reg = readl(TIMER_CTRL); + reg |= WDT_EN; + writel(reg, TIMER_CTRL); + + /* Enable reset on watchdog */ + reg = readl(RSTOUTn_MASK); + reg |= WDT_RESET_OUT_EN; + writel(reg, RSTOUTn_MASK); + + spin_unlock(&wdt_lock); +} + +static void orion_wdt_disable(void) +{ + u32 reg; + + spin_lock(&wdt_lock); + + /* Disable reset on watchdog */ + reg = readl(RSTOUTn_MASK); + reg &= ~WDT_RESET_OUT_EN; + writel(reg, RSTOUTn_MASK); + + /* Disable watchdog timer */ + reg = readl(TIMER_CTRL); + reg &= ~WDT_EN; + writel(reg, TIMER_CTRL); + + spin_unlock(&wdt_lock); +} + +static int orion_wdt_get_timeleft(int *time_left) +{ + spin_lock(&wdt_lock); + *time_left = readl(WDT_VAL) / wdt_tclk; + spin_unlock(&wdt_lock); + return 0; +} + +static int orion_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(WDT_IN_USE, &wdt_status)) + return -EBUSY; + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + orion_wdt_enable(); + return nonseekable_open(inode, file); +} + +static ssize_t orion_wdt_write(struct file *file, const char *data, + size_t len, loff_t *ppos) +{ + if (len) { + if (!nowayout) { + size_t i; + + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + set_bit(WDT_OK_TO_CLOSE, &wdt_status); + } + } + orion_wdt_ping(); + } + return len; +} + +static int orion_wdt_settimeout(int new_time) +{ + if ((new_time <= 0) || (new_time > wdt_max_duration)) + return -EINVAL; + + /* Set new watchdog time to be used when + * orion_wdt_enable() or orion_wdt_ping() is called. */ + heartbeat = new_time; + return 0; +} + +static const struct watchdog_info ident = { + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING, + .identity = "Orion Watchdog", +}; + +static long orion_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int ret = -ENOTTY; + int time; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user((struct watchdog_info *)arg, &ident, + sizeof(ident)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, (int *)arg); + break; + + case WDIOC_KEEPALIVE: + orion_wdt_ping(); + ret = 0; + break; + + case WDIOC_SETTIMEOUT: + ret = get_user(time, (int *)arg); + if (ret) + break; + + if (orion_wdt_settimeout(time)) { + ret = -EINVAL; + break; + } + orion_wdt_ping(); + /* Fall through */ + + case WDIOC_GETTIMEOUT: + ret = put_user(heartbeat, (int *)arg); + break; + + case WDIOC_GETTIMELEFT: + if (orion_wdt_get_timeleft(&time)) { + ret = -EINVAL; + break; + } + ret = put_user(time, (int *)arg); + break; + } + return ret; +} + +static int orion_wdt_release(struct inode *inode, struct file *file) +{ + if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) + orion_wdt_disable(); + else + printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " + "timer will not stop\n"); + clear_bit(WDT_IN_USE, &wdt_status); + clear_bit(WDT_OK_TO_CLOSE, &wdt_status); + + return 0; +} + + +static const struct file_operations orion_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = orion_wdt_write, + .unlocked_ioctl = orion_wdt_ioctl, + .open = orion_wdt_open, + .release = orion_wdt_release, +}; + +static struct miscdevice orion_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &orion_wdt_fops, +}; + +static int __devinit orion_wdt_probe(struct platform_device *pdev) +{ + struct orion_wdt_platform_data *pdata = pdev->dev.platform_data; + int ret; + + if (pdata) { + wdt_tclk = pdata->tclk; + } else { + printk(KERN_ERR "Orion Watchdog misses platform data\n"); + return -ENODEV; + } + + if (orion_wdt_miscdev.parent) + return -EBUSY; + orion_wdt_miscdev.parent = &pdev->dev; + + wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk; + if (orion_wdt_settimeout(heartbeat)) + heartbeat = wdt_max_duration; + + ret = misc_register(&orion_wdt_miscdev); + if (ret) + return ret; + + printk(KERN_INFO "Orion Watchdog Timer: Initial timeout %d sec%s\n", + heartbeat, nowayout ? ", nowayout" : ""); + return 0; +} + +static int __devexit orion_wdt_remove(struct platform_device *pdev) +{ + int ret; + + if (test_bit(WDT_IN_USE, &wdt_status)) { + orion_wdt_disable(); + clear_bit(WDT_IN_USE, &wdt_status); + } + + ret = misc_deregister(&orion_wdt_miscdev); + if (!ret) + orion_wdt_miscdev.parent = NULL; + + return ret; +} + +static void orion_wdt_shutdown(struct platform_device *pdev) +{ + if (test_bit(WDT_IN_USE, &wdt_status)) + orion_wdt_disable(); +} + +static struct platform_driver orion_wdt_driver = { + .probe = orion_wdt_probe, + .remove = __devexit_p(orion_wdt_remove), + .shutdown = orion_wdt_shutdown, + .driver = { + .owner = THIS_MODULE, + .name = "orion_wdt", + }, +}; + +static int __init orion_wdt_init(void) +{ + spin_lock_init(&wdt_lock); + return platform_driver_register(&orion_wdt_driver); +} + +static void __exit orion_wdt_exit(void) +{ + platform_driver_unregister(&orion_wdt_driver); +} + +module_init(orion_wdt_init); +module_exit(orion_wdt_exit); + +MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>"); +MODULE_DESCRIPTION("Orion Processor Watchdog"); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds"); + +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |