diff options
Diffstat (limited to 'target/linux/adm5120/files/drivers/watchdog')
| -rw-r--r-- | target/linux/adm5120/files/drivers/watchdog/adm5120_wdt.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/target/linux/adm5120/files/drivers/watchdog/adm5120_wdt.c b/target/linux/adm5120/files/drivers/watchdog/adm5120_wdt.c new file mode 100644 index 000000000..d5d63b27a --- /dev/null +++ b/target/linux/adm5120/files/drivers/watchdog/adm5120_wdt.c @@ -0,0 +1,202 @@ +/* + * ADM5120_WDT 0.01: Infineon ADM5120 SoC watchdog driver + * Copyright (c) Ondrej Zajicek <santiago@crfreenet.org>, 2007 + * + * based on + * + * RC32434_WDT 0.01: IDT Interprise 79RC32434 watchdog driver + * + * 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; either version + * 2 of the License, or (at your option) any later version. + * + */ +#include <linux/module.h> +#include <linux/types.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/irq.h> + +#include <asm/bootinfo.h> + +#include <asm/mach-adm5120/adm5120_info.h> +#include <asm/mach-adm5120/adm5120_defs.h> +#include <asm/mach-adm5120/adm5120_switch.h> + +#define DEFAULT_TIMEOUT 15 /* (secs) Default is 15 seconds */ +#define MAX_TIMEOUT 327 +/* Max is 327 seconds, counter is 15-bit integer, step is 10 ms */ + +#define NAME "adm5120_wdt" +#define VERSION "0.1" + +static int expect_close; +static int access; +static unsigned int timeout = DEFAULT_TIMEOUT; + +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) ")"); +MODULE_LICENSE("GPL"); + + +static inline void wdt_set_timeout(void) +{ + u32 val = (1 << 31) | (((timeout * 100) & 0x7FFF) << 16); + SW_WRITE_REG(SWITCH_REG_WDOG0, val); +} + +/* + It looks like WDOG0-register-write don't modify counter, + but WDOG0-register-read resets counter. +*/ + +static inline void wdt_reset_counter(void) +{ + SW_READ_REG(SWITCH_REG_WDOG0); +} + +static inline void wdt_disable(void) +{ + SW_WRITE_REG(SWITCH_REG_WDOG0, 0x7FFF0000); +} + + + +static int wdt_open(struct inode *inode, struct file *file) +{ + /* Allow only one person to hold it open */ + if (access) + return -EBUSY; + + if (nowayout) + __module_get(THIS_MODULE); + + /* Activate timer */ + wdt_reset_counter(); + wdt_set_timeout(); + printk(KERN_INFO NAME ": enabling watchdog timer\n"); + access = 1; + return 0; +} + +static int wdt_release(struct inode *inode, struct file *file) +{ + /* + * Shut off the timer. + * Lock it in if it's a module and we set nowayout + */ + if (expect_close && (nowayout == 0)) { + wdt_disable(); + printk(KERN_INFO NAME ": disabling watchdog timer\n"); + module_put(THIS_MODULE); + } else + printk(KERN_CRIT NAME ": device closed unexpectedly. WDT will not stop!\n"); + + access = 0; + return 0; +} + +static ssize_t wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) +{ + /* Refresh the timer. */ + if (len) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + for (i = 0; i != len; i++) { + char c; + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + expect_close = 1; + } + } + wdt_reset_counter(); + return len; + } + return 0; +} + +static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int new_timeout; + static struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .firmware_version = 0, + .identity = "ADM5120_WDT Watchdog", + }; + switch (cmd) { + default: + return -ENOTTY; + case WDIOC_GETSUPPORT: + if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) + return -EFAULT; + return 0; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, (int *)arg); + case WDIOC_KEEPALIVE: + wdt_reset_counter(); + return 0; + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, (int *)arg)) + return -EFAULT; + if (new_timeout < 1) + return -EINVAL; + if (new_timeout > MAX_TIMEOUT) + return -EINVAL; + timeout = new_timeout; + wdt_set_timeout(); + /* Fall */ + case WDIOC_GETTIMEOUT: + return put_user(timeout, (int *)arg); + } +} + +static const struct file_operations wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = wdt_write, + .unlocked_ioctl = wdt_ioctl, + .open = wdt_open, + .release = wdt_release, +}; + +static struct miscdevice wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &wdt_fops, +}; + +static char banner[] __initdata = KERN_INFO NAME ": Watchdog Timer version " VERSION "\n"; + +static int __init watchdog_init(void) +{ + int ret; + + ret = misc_register(&wdt_miscdev); + + if (ret) + return ret; + + wdt_disable(); + printk(banner); + + return 0; +} + +static void __exit watchdog_exit(void) +{ + misc_deregister(&wdt_miscdev); +} + +module_init(watchdog_init); +module_exit(watchdog_exit); |