blob: e37d81178b9e7bd5326cd5dbbbfafe3f91a2d885 [file] [log] [blame]
dmitry pervushinaccde162009-06-03 20:21:21 +04001/*
2 * Watchdog driver for Freescale STMP37XX/STMP378X
3 *
4 * Author: Vitaly Wool <vital@embeddedalley.com>
5 *
6 * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
7 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
8 */
9#include <linux/init.h>
10#include <linux/kernel.h>
11#include <linux/fs.h>
12#include <linux/miscdevice.h>
13#include <linux/watchdog.h>
14#include <linux/platform_device.h>
15#include <linux/spinlock.h>
16#include <linux/uaccess.h>
Paul Gortmakere7455b7a2011-08-29 10:58:55 -040017#include <linux/module.h>
dmitry pervushinaccde162009-06-03 20:21:21 +040018
19#include <mach/platform.h>
20#include <mach/regs-rtc.h>
21
22#define DEFAULT_HEARTBEAT 19
23#define MAX_HEARTBEAT (0x10000000 >> 6)
24
25/* missing bitmask in headers */
26#define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER 0x80000000
27
28#define WDT_IN_USE 0
29#define WDT_OK_TO_CLOSE 1
30
31#define WDOG_COUNTER_RATE 1000 /* 1 kHz clock */
32
33static DEFINE_SPINLOCK(stmp3xxx_wdt_io_lock);
34static unsigned long wdt_status;
35static const int nowayout = WATCHDOG_NOWAYOUT;
36static int heartbeat = DEFAULT_HEARTBEAT;
37static unsigned long boot_status;
38
39static void wdt_enable(u32 value)
40{
41 spin_lock(&stmp3xxx_wdt_io_lock);
42 __raw_writel(value, REGS_RTC_BASE + HW_RTC_WATCHDOG);
43 stmp3xxx_setl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
44 stmp3xxx_setl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
45 REGS_RTC_BASE + HW_RTC_PERSISTENT1);
46 spin_unlock(&stmp3xxx_wdt_io_lock);
47}
48
49static void wdt_disable(void)
50{
51 spin_lock(&stmp3xxx_wdt_io_lock);
52 stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
53 REGS_RTC_BASE + HW_RTC_PERSISTENT1);
54 stmp3xxx_clearl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
55 spin_unlock(&stmp3xxx_wdt_io_lock);
56}
57
58static void wdt_ping(void)
59{
60 wdt_enable(heartbeat * WDOG_COUNTER_RATE);
61}
62
63static int stmp3xxx_wdt_open(struct inode *inode, struct file *file)
64{
65 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
66 return -EBUSY;
67
68 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
69 wdt_ping();
70
71 return nonseekable_open(inode, file);
72}
73
74static ssize_t stmp3xxx_wdt_write(struct file *file, const char __user *data,
75 size_t len, loff_t *ppos)
76{
77 if (len) {
78 if (!nowayout) {
79 size_t i;
80
81 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
82
83 for (i = 0; i != len; i++) {
84 char c;
85
86 if (get_user(c, data + i))
87 return -EFAULT;
88 if (c == 'V')
89 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
90 }
91 }
92 wdt_ping();
93 }
94
95 return len;
96}
97
Wim Van Sebroeck42747d72009-12-26 18:55:22 +000098static const struct watchdog_info ident = {
dmitry pervushinaccde162009-06-03 20:21:21 +040099 .options = WDIOF_CARDRESET |
100 WDIOF_MAGICCLOSE |
101 WDIOF_SETTIMEOUT |
102 WDIOF_KEEPALIVEPING,
103 .identity = "STMP3XXX Watchdog",
104};
105
106static long stmp3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
107 unsigned long arg)
108{
109 void __user *argp = (void __user *)arg;
110 int __user *p = argp;
111 int new_heartbeat, opts;
112 int ret = -ENOTTY;
113
114 switch (cmd) {
115 case WDIOC_GETSUPPORT:
116 ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
117 break;
118
119 case WDIOC_GETSTATUS:
120 ret = put_user(0, p);
121 break;
122
123 case WDIOC_GETBOOTSTATUS:
124 ret = put_user(boot_status, p);
125 break;
126
127 case WDIOC_SETOPTIONS:
128 if (get_user(opts, p)) {
129 ret = -EFAULT;
130 break;
131 }
132 if (opts & WDIOS_DISABLECARD)
133 wdt_disable();
134 else if (opts & WDIOS_ENABLECARD)
135 wdt_ping();
136 else {
137 pr_debug("%s: unknown option 0x%x\n", __func__, opts);
138 ret = -EINVAL;
139 break;
140 }
141 ret = 0;
142 break;
143
144 case WDIOC_KEEPALIVE:
145 wdt_ping();
146 ret = 0;
147 break;
148
149 case WDIOC_SETTIMEOUT:
150 if (get_user(new_heartbeat, p)) {
151 ret = -EFAULT;
152 break;
153 }
154 if (new_heartbeat <= 0 || new_heartbeat > MAX_HEARTBEAT) {
155 ret = -EINVAL;
156 break;
157 }
158
159 heartbeat = new_heartbeat;
160 wdt_ping();
161 /* Fall through */
162
163 case WDIOC_GETTIMEOUT:
164 ret = put_user(heartbeat, p);
165 break;
166 }
167 return ret;
168}
169
170static int stmp3xxx_wdt_release(struct inode *inode, struct file *file)
171{
172 int ret = 0;
173
174 if (!nowayout) {
175 if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
176 wdt_ping();
Masanari Iidab1785df2012-01-20 23:56:19 +0900177 pr_debug("%s: Device closed unexpectedly\n", __func__);
dmitry pervushinaccde162009-06-03 20:21:21 +0400178 ret = -EINVAL;
179 } else {
180 wdt_disable();
181 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
182 }
183 }
184 clear_bit(WDT_IN_USE, &wdt_status);
185
186 return ret;
187}
188
189static const struct file_operations stmp3xxx_wdt_fops = {
190 .owner = THIS_MODULE,
191 .llseek = no_llseek,
192 .write = stmp3xxx_wdt_write,
193 .unlocked_ioctl = stmp3xxx_wdt_ioctl,
194 .open = stmp3xxx_wdt_open,
195 .release = stmp3xxx_wdt_release,
196};
197
198static struct miscdevice stmp3xxx_wdt_miscdev = {
199 .minor = WATCHDOG_MINOR,
200 .name = "watchdog",
201 .fops = &stmp3xxx_wdt_fops,
202};
203
204static int __devinit stmp3xxx_wdt_probe(struct platform_device *pdev)
205{
206 int ret = 0;
207
208 if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
209 heartbeat = DEFAULT_HEARTBEAT;
210
211 boot_status = __raw_readl(REGS_RTC_BASE + HW_RTC_PERSISTENT1) &
212 BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER;
213 boot_status = !!boot_status;
214 stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
215 REGS_RTC_BASE + HW_RTC_PERSISTENT1);
216 wdt_disable(); /* disable for now */
217
218 ret = misc_register(&stmp3xxx_wdt_miscdev);
219 if (ret < 0) {
220 dev_err(&pdev->dev, "cannot register misc device\n");
221 return ret;
222 }
223
224 printk(KERN_INFO "stmp3xxx watchdog: initialized, heartbeat %d sec\n",
225 heartbeat);
226
227 return ret;
228}
229
230static int __devexit stmp3xxx_wdt_remove(struct platform_device *pdev)
231{
232 misc_deregister(&stmp3xxx_wdt_miscdev);
233 return 0;
234}
235
236#ifdef CONFIG_PM
237static int wdt_suspended;
238static u32 wdt_saved_time;
239
240static int stmp3xxx_wdt_suspend(struct platform_device *pdev,
241 pm_message_t state)
242{
243 if (__raw_readl(REGS_RTC_BASE + HW_RTC_CTRL) &
244 BM_RTC_CTRL_WATCHDOGEN) {
245 wdt_suspended = 1;
246 wdt_saved_time = __raw_readl(REGS_RTC_BASE + HW_RTC_WATCHDOG);
247 wdt_disable();
248 }
249 return 0;
250}
251
252static int stmp3xxx_wdt_resume(struct platform_device *pdev)
253{
254 if (wdt_suspended) {
255 wdt_enable(wdt_saved_time);
256 wdt_suspended = 0;
257 }
258 return 0;
259}
260#else
261#define stmp3xxx_wdt_suspend NULL
262#define stmp3xxx_wdt_resume NULL
263#endif
264
265static struct platform_driver platform_wdt_driver = {
266 .driver = {
267 .name = "stmp3xxx_wdt",
268 },
269 .probe = stmp3xxx_wdt_probe,
270 .remove = __devexit_p(stmp3xxx_wdt_remove),
271 .suspend = stmp3xxx_wdt_suspend,
272 .resume = stmp3xxx_wdt_resume,
273};
274
Axel Linb8ec6112011-11-29 13:56:27 +0800275module_platform_driver(platform_wdt_driver);
dmitry pervushinaccde162009-06-03 20:21:21 +0400276
277MODULE_DESCRIPTION("STMP3XXX Watchdog Driver");
278MODULE_LICENSE("GPL");
279
280module_param(heartbeat, int, 0);
281MODULE_PARM_DESC(heartbeat,
282 "Watchdog heartbeat period in seconds from 1 to "
283 __MODULE_STRING(MAX_HEARTBEAT) ", default "
284 __MODULE_STRING(DEFAULT_HEARTBEAT));
285
286MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);