blob: 8379dc32fd908f9bf0e76532ca27d847ca145fd3 [file] [log] [blame]
Florian Fainellib63aa732010-08-28 22:03:45 +02001/*
2 * Broadcom BCM63xx SoC watchdog driver
3 *
4 * Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
5 * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
6 *
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.
11 */
12
Joe Perches27c766a2012-02-15 15:06:19 -080013#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
Florian Fainellib63aa732010-08-28 22:03:45 +020015#include <linux/bitops.h>
16#include <linux/errno.h>
17#include <linux/fs.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/miscdevice.h>
21#include <linux/module.h>
22#include <linux/moduleparam.h>
Florian Fainellib63aa732010-08-28 22:03:45 +020023#include <linux/types.h>
24#include <linux/uaccess.h>
25#include <linux/watchdog.h>
26#include <linux/timer.h>
27#include <linux/jiffies.h>
28#include <linux/interrupt.h>
29#include <linux/ptrace.h>
30#include <linux/resource.h>
31#include <linux/platform_device.h>
32
33#include <bcm63xx_cpu.h>
34#include <bcm63xx_io.h>
35#include <bcm63xx_regs.h>
36#include <bcm63xx_timer.h>
37
38#define PFX KBUILD_MODNAME
39
40#define WDT_HZ 50000000 /* Fclk */
41#define WDT_DEFAULT_TIME 30 /* seconds */
42#define WDT_MAX_TIME 256 /* seconds */
43
44static struct {
45 void __iomem *regs;
46 struct timer_list timer;
47 int default_ticks;
48 unsigned long inuse;
49 atomic_t ticks;
50} bcm63xx_wdt_device;
51
52static int expect_close;
53
54static int wdt_time = WDT_DEFAULT_TIME;
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010055static bool nowayout = WATCHDOG_NOWAYOUT;
56module_param(nowayout, bool, 0);
Florian Fainellib63aa732010-08-28 22:03:45 +020057MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
58 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
59
60/* HW functions */
61static void bcm63xx_wdt_hw_start(void)
62{
63 bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
64 bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
65 bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
66}
67
68static void bcm63xx_wdt_hw_stop(void)
69{
70 bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
71 bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
72}
73
74static void bcm63xx_wdt_isr(void *data)
75{
76 struct pt_regs *regs = get_irq_regs();
77
78 die(PFX " fire", regs);
79}
80
81static void bcm63xx_timer_tick(unsigned long unused)
82{
83 if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
84 bcm63xx_wdt_hw_start();
85 mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
86 } else
Joe Perches27c766a2012-02-15 15:06:19 -080087 pr_crit("watchdog will restart system\n");
Florian Fainellib63aa732010-08-28 22:03:45 +020088}
89
90static void bcm63xx_wdt_pet(void)
91{
92 atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
93}
94
95static void bcm63xx_wdt_start(void)
96{
97 bcm63xx_wdt_pet();
98 bcm63xx_timer_tick(0);
99}
100
101static void bcm63xx_wdt_pause(void)
102{
103 del_timer_sync(&bcm63xx_wdt_device.timer);
104 bcm63xx_wdt_hw_stop();
105}
106
107static int bcm63xx_wdt_settimeout(int new_time)
108{
109 if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
110 return -EINVAL;
111
112 wdt_time = new_time;
113
114 return 0;
115}
116
117static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
118{
119 if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
120 return -EBUSY;
121
122 bcm63xx_wdt_start();
123 return nonseekable_open(inode, file);
124}
125
126static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
127{
128 if (expect_close == 42)
129 bcm63xx_wdt_pause();
130 else {
Joe Perches27c766a2012-02-15 15:06:19 -0800131 pr_crit("Unexpected close, not stopping watchdog!\n");
Florian Fainellib63aa732010-08-28 22:03:45 +0200132 bcm63xx_wdt_start();
133 }
134 clear_bit(0, &bcm63xx_wdt_device.inuse);
135 expect_close = 0;
136 return 0;
137}
138
139static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
140 size_t len, loff_t *ppos)
141{
142 if (len) {
143 if (!nowayout) {
144 size_t i;
145
146 /* In case it was set long ago */
147 expect_close = 0;
148
149 for (i = 0; i != len; i++) {
150 char c;
151 if (get_user(c, data + i))
152 return -EFAULT;
153 if (c == 'V')
154 expect_close = 42;
155 }
156 }
157 bcm63xx_wdt_pet();
158 }
159 return len;
160}
161
162static struct watchdog_info bcm63xx_wdt_info = {
163 .identity = PFX,
164 .options = WDIOF_SETTIMEOUT |
165 WDIOF_KEEPALIVEPING |
166 WDIOF_MAGICCLOSE,
167};
168
169
170static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
171 unsigned long arg)
172{
173 void __user *argp = (void __user *)arg;
174 int __user *p = argp;
175 int new_value, retval = -EINVAL;
176
177 switch (cmd) {
178 case WDIOC_GETSUPPORT:
179 return copy_to_user(argp, &bcm63xx_wdt_info,
180 sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
181
182 case WDIOC_GETSTATUS:
183 case WDIOC_GETBOOTSTATUS:
184 return put_user(0, p);
185
186 case WDIOC_SETOPTIONS:
187 if (get_user(new_value, p))
188 return -EFAULT;
189
190 if (new_value & WDIOS_DISABLECARD) {
191 bcm63xx_wdt_pause();
192 retval = 0;
193 }
194 if (new_value & WDIOS_ENABLECARD) {
195 bcm63xx_wdt_start();
196 retval = 0;
197 }
198
199 return retval;
200
201 case WDIOC_KEEPALIVE:
202 bcm63xx_wdt_pet();
203 return 0;
204
205 case WDIOC_SETTIMEOUT:
206 if (get_user(new_value, p))
207 return -EFAULT;
208
209 if (bcm63xx_wdt_settimeout(new_value))
210 return -EINVAL;
211
212 bcm63xx_wdt_pet();
213
214 case WDIOC_GETTIMEOUT:
215 return put_user(wdt_time, p);
216
217 default:
218 return -ENOTTY;
219
220 }
221}
222
Florian Fainellib63aa732010-08-28 22:03:45 +0200223static const struct file_operations bcm63xx_wdt_fops = {
224 .owner = THIS_MODULE,
225 .llseek = no_llseek,
226 .write = bcm63xx_wdt_write,
227 .unlocked_ioctl = bcm63xx_wdt_ioctl,
228 .open = bcm63xx_wdt_open,
229 .release = bcm63xx_wdt_release,
230};
231
232static struct miscdevice bcm63xx_wdt_miscdev = {
233 .minor = WATCHDOG_MINOR,
234 .name = "watchdog",
235 .fops = &bcm63xx_wdt_fops,
236};
237
Florian Fainellib63aa732010-08-28 22:03:45 +0200238
Wim Van Sebroecke6c3b692010-10-23 20:59:42 +0000239static int __devinit bcm63xx_wdt_probe(struct platform_device *pdev)
Florian Fainellib63aa732010-08-28 22:03:45 +0200240{
241 int ret;
242 struct resource *r;
243
244 setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
245
246 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
247 if (!r) {
248 dev_err(&pdev->dev, "failed to get resources\n");
249 return -ENODEV;
250 }
251
Joe Perches06794ea2011-03-23 12:55:36 -0700252 bcm63xx_wdt_device.regs = ioremap_nocache(r->start, resource_size(r));
Florian Fainellib63aa732010-08-28 22:03:45 +0200253 if (!bcm63xx_wdt_device.regs) {
254 dev_err(&pdev->dev, "failed to remap I/O resources\n");
255 return -ENXIO;
256 }
257
258 ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
259 if (ret < 0) {
260 dev_err(&pdev->dev, "failed to register wdt timer isr\n");
261 goto unmap;
262 }
263
264 if (bcm63xx_wdt_settimeout(wdt_time)) {
265 bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
266 dev_info(&pdev->dev,
267 ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
268 wdt_time);
269 }
270
Florian Fainellib63aa732010-08-28 22:03:45 +0200271 ret = misc_register(&bcm63xx_wdt_miscdev);
272 if (ret < 0) {
273 dev_err(&pdev->dev, "failed to register watchdog device\n");
Wim Van Sebroecke6c3b692010-10-23 20:59:42 +0000274 goto unregister_timer;
Florian Fainellib63aa732010-08-28 22:03:45 +0200275 }
276
277 dev_info(&pdev->dev, " started, timer margin: %d sec\n",
278 WDT_DEFAULT_TIME);
279
280 return 0;
281
Florian Fainellib63aa732010-08-28 22:03:45 +0200282unregister_timer:
283 bcm63xx_timer_unregister(TIMER_WDT_ID);
284unmap:
285 iounmap(bcm63xx_wdt_device.regs);
286 return ret;
287}
288
Wim Van Sebroecke6c3b692010-10-23 20:59:42 +0000289static int __devexit bcm63xx_wdt_remove(struct platform_device *pdev)
Florian Fainellib63aa732010-08-28 22:03:45 +0200290{
291 if (!nowayout)
292 bcm63xx_wdt_pause();
293
294 misc_deregister(&bcm63xx_wdt_miscdev);
Florian Fainellib63aa732010-08-28 22:03:45 +0200295 bcm63xx_timer_unregister(TIMER_WDT_ID);
Wim Van Sebroecke6c3b692010-10-23 20:59:42 +0000296 iounmap(bcm63xx_wdt_device.regs);
Florian Fainellib63aa732010-08-28 22:03:45 +0200297 return 0;
298}
299
Wim Van Sebroecke6c3b692010-10-23 20:59:42 +0000300static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
301{
302 bcm63xx_wdt_pause();
303}
304
Florian Fainellib63aa732010-08-28 22:03:45 +0200305static struct platform_driver bcm63xx_wdt = {
306 .probe = bcm63xx_wdt_probe,
Wim Van Sebroecke6c3b692010-10-23 20:59:42 +0000307 .remove = __devexit_p(bcm63xx_wdt_remove),
308 .shutdown = bcm63xx_wdt_shutdown,
Florian Fainellib63aa732010-08-28 22:03:45 +0200309 .driver = {
Wim Van Sebroecke6c3b692010-10-23 20:59:42 +0000310 .owner = THIS_MODULE,
Florian Fainellib63aa732010-08-28 22:03:45 +0200311 .name = "bcm63xx-wdt",
312 }
313};
314
Axel Linb8ec6112011-11-29 13:56:27 +0800315module_platform_driver(bcm63xx_wdt);
Florian Fainellib63aa732010-08-28 22:03:45 +0200316
317MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
318MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
319MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
320MODULE_LICENSE("GPL");
321MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
322MODULE_ALIAS("platform:bcm63xx-wdt");