forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
290 lines
6.3 KiB
290 lines
6.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* Watchdog timer for machines with the CS5535/CS5536 companion chip |
|
* |
|
* Copyright (C) 2006-2007, Advanced Micro Devices, Inc. |
|
* Copyright (C) 2009 Andres Salomon <[email protected]> |
|
*/ |
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
|
|
|
#include <linux/module.h> |
|
#include <linux/moduleparam.h> |
|
#include <linux/types.h> |
|
#include <linux/miscdevice.h> |
|
#include <linux/watchdog.h> |
|
#include <linux/fs.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/reboot.h> |
|
#include <linux/uaccess.h> |
|
|
|
#include <linux/cs5535.h> |
|
|
|
#define GEODEWDT_HZ 500 |
|
#define GEODEWDT_SCALE 6 |
|
#define GEODEWDT_MAX_SECONDS 131 |
|
|
|
#define WDT_FLAGS_OPEN 1 |
|
#define WDT_FLAGS_ORPHAN 2 |
|
|
|
#define DRV_NAME "geodewdt" |
|
#define WATCHDOG_NAME "Geode GX/LX WDT" |
|
#define WATCHDOG_TIMEOUT 60 |
|
|
|
static int timeout = WATCHDOG_TIMEOUT; |
|
module_param(timeout, int, 0); |
|
MODULE_PARM_DESC(timeout, |
|
"Watchdog timeout in seconds. 1<= timeout <=131, default=" |
|
__MODULE_STRING(WATCHDOG_TIMEOUT) "."); |
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT; |
|
module_param(nowayout, bool, 0); |
|
MODULE_PARM_DESC(nowayout, |
|
"Watchdog cannot be stopped once started (default=" |
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
|
|
|
static struct platform_device *geodewdt_platform_device; |
|
static unsigned long wdt_flags; |
|
static struct cs5535_mfgpt_timer *wdt_timer; |
|
static int safe_close; |
|
|
|
static void geodewdt_ping(void) |
|
{ |
|
/* Stop the counter */ |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0); |
|
|
|
/* Reset the counter */ |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0); |
|
|
|
/* Enable the counter */ |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN); |
|
} |
|
|
|
static void geodewdt_disable(void) |
|
{ |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0); |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0); |
|
} |
|
|
|
static int geodewdt_set_heartbeat(int val) |
|
{ |
|
if (val < 1 || val > GEODEWDT_MAX_SECONDS) |
|
return -EINVAL; |
|
|
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0); |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, val * GEODEWDT_HZ); |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0); |
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN); |
|
|
|
timeout = val; |
|
return 0; |
|
} |
|
|
|
static int geodewdt_open(struct inode *inode, struct file *file) |
|
{ |
|
if (test_and_set_bit(WDT_FLAGS_OPEN, &wdt_flags)) |
|
return -EBUSY; |
|
|
|
if (!test_and_clear_bit(WDT_FLAGS_ORPHAN, &wdt_flags)) |
|
__module_get(THIS_MODULE); |
|
|
|
geodewdt_ping(); |
|
return stream_open(inode, file); |
|
} |
|
|
|
static int geodewdt_release(struct inode *inode, struct file *file) |
|
{ |
|
if (safe_close) { |
|
geodewdt_disable(); |
|
module_put(THIS_MODULE); |
|
} else { |
|
pr_crit("Unexpected close - watchdog is not stopping\n"); |
|
geodewdt_ping(); |
|
|
|
set_bit(WDT_FLAGS_ORPHAN, &wdt_flags); |
|
} |
|
|
|
clear_bit(WDT_FLAGS_OPEN, &wdt_flags); |
|
safe_close = 0; |
|
return 0; |
|
} |
|
|
|
static ssize_t geodewdt_write(struct file *file, const char __user *data, |
|
size_t len, loff_t *ppos) |
|
{ |
|
if (len) { |
|
if (!nowayout) { |
|
size_t i; |
|
safe_close = 0; |
|
|
|
for (i = 0; i != len; i++) { |
|
char c; |
|
|
|
if (get_user(c, data + i)) |
|
return -EFAULT; |
|
|
|
if (c == 'V') |
|
safe_close = 1; |
|
} |
|
} |
|
|
|
geodewdt_ping(); |
|
} |
|
return len; |
|
} |
|
|
|
static long geodewdt_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
void __user *argp = (void __user *)arg; |
|
int __user *p = argp; |
|
int interval; |
|
|
|
static const struct watchdog_info ident = { |
|
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
|
| WDIOF_MAGICCLOSE, |
|
.firmware_version = 1, |
|
.identity = WATCHDOG_NAME, |
|
}; |
|
|
|
switch (cmd) { |
|
case WDIOC_GETSUPPORT: |
|
return copy_to_user(argp, &ident, |
|
sizeof(ident)) ? -EFAULT : 0; |
|
case WDIOC_GETSTATUS: |
|
case WDIOC_GETBOOTSTATUS: |
|
return put_user(0, p); |
|
|
|
case WDIOC_SETOPTIONS: |
|
{ |
|
int options, ret = -EINVAL; |
|
|
|
if (get_user(options, p)) |
|
return -EFAULT; |
|
|
|
if (options & WDIOS_DISABLECARD) { |
|
geodewdt_disable(); |
|
ret = 0; |
|
} |
|
|
|
if (options & WDIOS_ENABLECARD) { |
|
geodewdt_ping(); |
|
ret = 0; |
|
} |
|
|
|
return ret; |
|
} |
|
case WDIOC_KEEPALIVE: |
|
geodewdt_ping(); |
|
return 0; |
|
|
|
case WDIOC_SETTIMEOUT: |
|
if (get_user(interval, p)) |
|
return -EFAULT; |
|
|
|
if (geodewdt_set_heartbeat(interval)) |
|
return -EINVAL; |
|
fallthrough; |
|
case WDIOC_GETTIMEOUT: |
|
return put_user(timeout, p); |
|
|
|
default: |
|
return -ENOTTY; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static const struct file_operations geodewdt_fops = { |
|
.owner = THIS_MODULE, |
|
.llseek = no_llseek, |
|
.write = geodewdt_write, |
|
.unlocked_ioctl = geodewdt_ioctl, |
|
.compat_ioctl = compat_ptr_ioctl, |
|
.open = geodewdt_open, |
|
.release = geodewdt_release, |
|
}; |
|
|
|
static struct miscdevice geodewdt_miscdev = { |
|
.minor = WATCHDOG_MINOR, |
|
.name = "watchdog", |
|
.fops = &geodewdt_fops, |
|
}; |
|
|
|
static int __init geodewdt_probe(struct platform_device *dev) |
|
{ |
|
int ret; |
|
|
|
wdt_timer = cs5535_mfgpt_alloc_timer(MFGPT_TIMER_ANY, MFGPT_DOMAIN_WORKING); |
|
if (!wdt_timer) { |
|
pr_err("No timers were available\n"); |
|
return -ENODEV; |
|
} |
|
|
|
/* Set up the timer */ |
|
|
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, |
|
GEODEWDT_SCALE | (3 << 8)); |
|
|
|
/* Set up comparator 2 to reset when the event fires */ |
|
cs5535_mfgpt_toggle_event(wdt_timer, MFGPT_CMP2, MFGPT_EVENT_RESET, 1); |
|
|
|
/* Set up the initial timeout */ |
|
|
|
cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, |
|
timeout * GEODEWDT_HZ); |
|
|
|
ret = misc_register(&geodewdt_miscdev); |
|
|
|
return ret; |
|
} |
|
|
|
static int geodewdt_remove(struct platform_device *dev) |
|
{ |
|
misc_deregister(&geodewdt_miscdev); |
|
return 0; |
|
} |
|
|
|
static void geodewdt_shutdown(struct platform_device *dev) |
|
{ |
|
geodewdt_disable(); |
|
} |
|
|
|
static struct platform_driver geodewdt_driver = { |
|
.remove = geodewdt_remove, |
|
.shutdown = geodewdt_shutdown, |
|
.driver = { |
|
.name = DRV_NAME, |
|
}, |
|
}; |
|
|
|
static int __init geodewdt_init(void) |
|
{ |
|
int ret; |
|
|
|
geodewdt_platform_device = platform_device_register_simple(DRV_NAME, |
|
-1, NULL, 0); |
|
if (IS_ERR(geodewdt_platform_device)) |
|
return PTR_ERR(geodewdt_platform_device); |
|
|
|
ret = platform_driver_probe(&geodewdt_driver, geodewdt_probe); |
|
if (ret) |
|
goto err; |
|
|
|
return 0; |
|
err: |
|
platform_device_unregister(geodewdt_platform_device); |
|
return ret; |
|
} |
|
|
|
static void __exit geodewdt_exit(void) |
|
{ |
|
platform_device_unregister(geodewdt_platform_device); |
|
platform_driver_unregister(&geodewdt_driver); |
|
} |
|
|
|
module_init(geodewdt_init); |
|
module_exit(geodewdt_exit); |
|
|
|
MODULE_AUTHOR("Advanced Micro Devices, Inc"); |
|
MODULE_DESCRIPTION("Geode GX/LX Watchdog Driver"); |
|
MODULE_LICENSE("GPL");
|
|
|