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/wm8350_wdt.c | 329 |
3 files changed, 337 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 81f7021b381..ec68c741b56 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -55,6 +55,13 @@ config SOFT_WATCHDOG To compile this driver as a module, choose M here: the module will be called softdog. +config WM8350_WATCHDOG + tristate "WM8350 watchdog" + depends on MFD_WM8350 + help + Support for the watchdog in the WM8350 AudioPlus PMIC. When + the watchdog triggers the system will be reset. + # ALPHA Architecture # ARM Architecture diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 0cd47867b19..c19b866f5ed 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -134,4 +134,5 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o # XTENSA Architecture # Architecture Independant +obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o diff --git a/drivers/watchdog/wm8350_wdt.c b/drivers/watchdog/wm8350_wdt.c new file mode 100644 index 00000000000..2bc0d4d4b41 --- /dev/null +++ b/drivers/watchdog/wm8350_wdt.c @@ -0,0 +1,329 @@ +/* + * Watchdog driver for the wm8350 + * + * Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com> + * + * 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 + */ + +#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/uaccess.h> +#include <linux/mfd/wm8350/core.h> + +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 unsigned long wm8350_wdt_users; +static struct miscdevice wm8350_wdt_miscdev; +static int wm8350_wdt_expect_close; +static DEFINE_MUTEX(wdt_mutex); + +static struct { + int time; /* Seconds */ + u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */ +} wm8350_wdt_cfgs[] = { + { 1, 0x02 }, + { 2, 0x04 }, + { 4, 0x05 }, +}; + +static struct wm8350 *get_wm8350(void) +{ + return dev_get_drvdata(wm8350_wdt_miscdev.parent); +} + +static int wm8350_wdt_set_timeout(struct wm8350 *wm8350, u16 value) +{ + int ret; + u16 reg; + + mutex_lock(&wdt_mutex); + wm8350_reg_unlock(wm8350); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + reg &= ~WM8350_WDOG_TO_MASK; + reg |= value; + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + wm8350_reg_lock(wm8350); + mutex_unlock(&wdt_mutex); + + return ret; +} + +static int wm8350_wdt_start(struct wm8350 *wm8350) +{ + int ret; + u16 reg; + + mutex_lock(&wdt_mutex); + wm8350_reg_unlock(wm8350); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + reg &= ~WM8350_WDOG_MODE_MASK; + reg |= 0x20; + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + wm8350_reg_lock(wm8350); + mutex_unlock(&wdt_mutex); + + return ret; +} + +static int wm8350_wdt_stop(struct wm8350 *wm8350) +{ + int ret; + u16 reg; + + mutex_lock(&wdt_mutex); + wm8350_reg_unlock(wm8350); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + reg &= ~WM8350_WDOG_MODE_MASK; + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + wm8350_reg_lock(wm8350); + mutex_unlock(&wdt_mutex); + + return ret; +} + +static int wm8350_wdt_kick(struct wm8350 *wm8350) +{ + int ret; + u16 reg; + + mutex_lock(&wdt_mutex); + + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg); + + mutex_unlock(&wdt_mutex); + + return ret; +} + +static int wm8350_wdt_open(struct inode *inode, struct file *file) +{ + struct wm8350 *wm8350 = get_wm8350(); + int ret; + + if (!wm8350) + return -ENODEV; + + if (test_and_set_bit(0, &wm8350_wdt_users)) + return -EBUSY; + + ret = wm8350_wdt_start(wm8350); + if (ret != 0) + return ret; + + return nonseekable_open(inode, file); +} + +static int wm8350_wdt_release(struct inode *inode, struct file *file) +{ + struct wm8350 *wm8350 = get_wm8350(); + + if (wm8350_wdt_expect_close) + wm8350_wdt_stop(wm8350); + else { + dev_warn(wm8350->dev, "Watchdog device closed uncleanly\n"); + wm8350_wdt_kick(wm8350); + } + + clear_bit(0, &wm8350_wdt_users); + + return 0; +} + +static ssize_t wm8350_wdt_write(struct file *file, + const char __user *data, size_t count, + loff_t *ppos) +{ + struct wm8350 *wm8350 = get_wm8350(); + size_t i; + + if (count) { + wm8350_wdt_kick(wm8350); + + if (!nowayout) { + /* In case it was set long ago */ + wm8350_wdt_expect_close = 0; + + /* scan to see whether or not we got the magic + character */ + for (i = 0; i != count; i++) { + char c; + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + wm8350_wdt_expect_close = 42; + } + } + } + return count; +} + +static struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "WM8350 Watchdog", +}; + +static long wm8350_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct wm8350 *wm8350 = get_wm8350(); + int ret = -ENOTTY, time, i; + void __user *argp = (void __user *)arg; + int __user *p = argp; + u16 reg; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, p); + break; + + case WDIOC_SETOPTIONS: + { + int options; + + if (get_user(options, p)) + return -EFAULT; + + ret = -EINVAL; + + /* Setting both simultaneously means at least one must fail */ + if (options == WDIOS_DISABLECARD) + ret = wm8350_wdt_start(wm8350); + + if (options == WDIOS_ENABLECARD) + ret = wm8350_wdt_stop(wm8350); + break; + } + + case WDIOC_KEEPALIVE: + ret = wm8350_wdt_kick(wm8350); + break; + + case WDIOC_SETTIMEOUT: + ret = get_user(time, p); + if (ret) + break; + + if (time == 0) { + if (nowayout) + ret = -EINVAL; + else + wm8350_wdt_stop(wm8350); + break; + } + + for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++) + if (wm8350_wdt_cfgs[i].time == time) + break; + if (i == ARRAY_SIZE(wm8350_wdt_cfgs)) + ret = -EINVAL; + else + ret = wm8350_wdt_set_timeout(wm8350, + wm8350_wdt_cfgs[i].val); + break; + + case WDIOC_GETTIMEOUT: + reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2); + reg &= WM8350_WDOG_TO_MASK; + for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++) + if (wm8350_wdt_cfgs[i].val == reg) + break; + if (i == ARRAY_SIZE(wm8350_wdt_cfgs)) { + dev_warn(wm8350->dev, + "Unknown watchdog configuration: %x\n", reg); + ret = -EINVAL; + } else + ret = put_user(wm8350_wdt_cfgs[i].time, p); + + } + + return ret; +} + +static const struct file_operations wm8350_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = wm8350_wdt_write, + .unlocked_ioctl = wm8350_wdt_ioctl, + .open = wm8350_wdt_open, + .release = wm8350_wdt_release, +}; + +static struct miscdevice wm8350_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &wm8350_wdt_fops, +}; + +static int wm8350_wdt_probe(struct platform_device *pdev) +{ + struct wm8350 *wm8350 = platform_get_drvdata(pdev); + + if (!wm8350) { + dev_err(wm8350->dev, "No driver data supplied\n"); + return -ENODEV; + } + + /* Default to 4s timeout */ + wm8350_wdt_set_timeout(wm8350, 0x05); + + wm8350_wdt_miscdev.parent = &pdev->dev; + + return misc_register(&wm8350_wdt_miscdev); +} + +static int __exit wm8350_wdt_remove(struct platform_device *pdev) +{ + misc_deregister(&wm8350_wdt_miscdev); + + return 0; +} + +static struct platform_driver wm8350_wdt_driver = { + .probe = wm8350_wdt_probe, + .remove = wm8350_wdt_remove, + .driver = { + .name = "wm8350-wdt", + }, +}; + +static int __init wm8350_wdt_init(void) +{ + return platform_driver_register(&wm8350_wdt_driver); +} +module_init(wm8350_wdt_init); + +static void __exit wm8350_wdt_exit(void) +{ + platform_driver_unregister(&wm8350_wdt_driver); +} +module_exit(wm8350_wdt_exit); + +MODULE_AUTHOR("Mark Brown"); +MODULE_DESCRIPTION("WM8350 Watchdog"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:wm8350-wdt"); |