2 * Broadcom BCM63xx SoC watchdog driver
4 * Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
5 * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/bitops.h>
16 #include <linux/errno.h>
18 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/miscdevice.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/types.h>
25 #include <linux/uaccess.h>
26 #include <linux/watchdog.h>
27 #include <linux/timer.h>
28 #include <linux/jiffies.h>
29 #include <linux/interrupt.h>
30 #include <linux/ptrace.h>
31 #include <linux/resource.h>
32 #include <linux/platform_device.h>
34 #include <bcm63xx_cpu.h>
35 #include <bcm63xx_io.h>
36 #include <bcm63xx_regs.h>
37 #include <bcm63xx_timer.h>
39 #define PFX KBUILD_MODNAME
41 #define WDT_HZ 50000000 /* Fclk */
42 #define WDT_DEFAULT_TIME 30 /* seconds */
43 #define WDT_MAX_TIME 256 /* seconds */
47 struct timer_list timer;
53 static int expect_close;
55 static int wdt_time = WDT_DEFAULT_TIME;
56 static bool nowayout = WATCHDOG_NOWAYOUT;
57 module_param(nowayout, bool, 0);
58 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
59 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
62 static void bcm63xx_wdt_hw_start(void)
64 bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
65 bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
66 bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
69 static void bcm63xx_wdt_hw_stop(void)
71 bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
72 bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
75 static void bcm63xx_wdt_isr(void *data)
77 struct pt_regs *regs = get_irq_regs();
79 die(PFX " fire", regs);
82 static void bcm63xx_timer_tick(unsigned long unused)
84 if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
85 bcm63xx_wdt_hw_start();
86 mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
88 pr_crit("watchdog will restart system\n");
91 static void bcm63xx_wdt_pet(void)
93 atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
96 static void bcm63xx_wdt_start(void)
99 bcm63xx_timer_tick(0);
102 static void bcm63xx_wdt_pause(void)
104 del_timer_sync(&bcm63xx_wdt_device.timer);
105 bcm63xx_wdt_hw_stop();
108 static int bcm63xx_wdt_settimeout(int new_time)
110 if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
118 static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
120 if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
124 return nonseekable_open(inode, file);
127 static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
129 if (expect_close == 42)
132 pr_crit("Unexpected close, not stopping watchdog!\n");
135 clear_bit(0, &bcm63xx_wdt_device.inuse);
140 static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
141 size_t len, loff_t *ppos)
147 /* In case it was set long ago */
150 for (i = 0; i != len; i++) {
152 if (get_user(c, data + i))
163 static struct watchdog_info bcm63xx_wdt_info = {
165 .options = WDIOF_SETTIMEOUT |
166 WDIOF_KEEPALIVEPING |
171 static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
174 void __user *argp = (void __user *)arg;
175 int __user *p = argp;
176 int new_value, retval = -EINVAL;
179 case WDIOC_GETSUPPORT:
180 return copy_to_user(argp, &bcm63xx_wdt_info,
181 sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
183 case WDIOC_GETSTATUS:
184 case WDIOC_GETBOOTSTATUS:
185 return put_user(0, p);
187 case WDIOC_SETOPTIONS:
188 if (get_user(new_value, p))
191 if (new_value & WDIOS_DISABLECARD) {
195 if (new_value & WDIOS_ENABLECARD) {
202 case WDIOC_KEEPALIVE:
206 case WDIOC_SETTIMEOUT:
207 if (get_user(new_value, p))
210 if (bcm63xx_wdt_settimeout(new_value))
215 case WDIOC_GETTIMEOUT:
216 return put_user(wdt_time, p);
224 static const struct file_operations bcm63xx_wdt_fops = {
225 .owner = THIS_MODULE,
227 .write = bcm63xx_wdt_write,
228 .unlocked_ioctl = bcm63xx_wdt_ioctl,
229 .open = bcm63xx_wdt_open,
230 .release = bcm63xx_wdt_release,
233 static struct miscdevice bcm63xx_wdt_miscdev = {
234 .minor = WATCHDOG_MINOR,
236 .fops = &bcm63xx_wdt_fops,
240 static int bcm63xx_wdt_probe(struct platform_device *pdev)
245 setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
247 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
249 dev_err(&pdev->dev, "failed to get resources\n");
253 bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
255 if (!bcm63xx_wdt_device.regs) {
256 dev_err(&pdev->dev, "failed to remap I/O resources\n");
260 ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
262 dev_err(&pdev->dev, "failed to register wdt timer isr\n");
266 if (bcm63xx_wdt_settimeout(wdt_time)) {
267 bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
269 ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
273 ret = misc_register(&bcm63xx_wdt_miscdev);
275 dev_err(&pdev->dev, "failed to register watchdog device\n");
276 goto unregister_timer;
279 dev_info(&pdev->dev, " started, timer margin: %d sec\n",
285 bcm63xx_timer_unregister(TIMER_WDT_ID);
289 static int bcm63xx_wdt_remove(struct platform_device *pdev)
294 misc_deregister(&bcm63xx_wdt_miscdev);
295 bcm63xx_timer_unregister(TIMER_WDT_ID);
299 static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
304 static struct platform_driver bcm63xx_wdt_driver = {
305 .probe = bcm63xx_wdt_probe,
306 .remove = bcm63xx_wdt_remove,
307 .shutdown = bcm63xx_wdt_shutdown,
309 .owner = THIS_MODULE,
310 .name = "bcm63xx-wdt",
314 module_platform_driver(bcm63xx_wdt_driver);
316 MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
317 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
318 MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
319 MODULE_LICENSE("GPL");
320 MODULE_ALIAS("platform:bcm63xx-wdt");