Commit | Line | Data |
---|---|---|
22ac9232 | 1 | /* |
3b937a7d | 2 | * drivers/watchdog/orion_wdt.c |
22ac9232 | 3 | * |
3b937a7d | 4 | * Watchdog driver for Orion/Kirkwood processors |
22ac9232 SB |
5 | * |
6 | * Author: Sylver Bruneau <sylver.bruneau@googlemail.com> | |
7 | * | |
8 | * This file is licensed under the terms of the GNU General Public | |
9 | * License version 2. This program is licensed "as is" without any | |
10 | * warranty of any kind, whether express or implied. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/moduleparam.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/miscdevice.h> | |
9e058d4f | 19 | #include <linux/platform_device.h> |
22ac9232 SB |
20 | #include <linux/watchdog.h> |
21 | #include <linux/init.h> | |
22 | #include <linux/uaccess.h> | |
23 | #include <linux/io.h> | |
6d0f0dfd | 24 | #include <linux/spinlock.h> |
fdd8b079 | 25 | #include <mach/bridge-regs.h> |
3b937a7d | 26 | #include <plat/orion_wdt.h> |
22ac9232 SB |
27 | |
28 | /* | |
29 | * Watchdog timer block registers. | |
30 | */ | |
31 | #define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000) | |
32 | #define WDT_EN 0x0010 | |
33 | #define WDT_VAL (TIMER_VIRT_BASE + 0x0024) | |
34 | ||
9e058d4f | 35 | #define WDT_MAX_CYCLE_COUNT 0xffffffff |
22ac9232 SB |
36 | #define WDT_IN_USE 0 |
37 | #define WDT_OK_TO_CLOSE 1 | |
38 | ||
39 | static int nowayout = WATCHDOG_NOWAYOUT; | |
9e058d4f TR |
40 | static int heartbeat = -1; /* module parameter (seconds) */ |
41 | static unsigned int wdt_max_duration; /* (seconds) */ | |
42 | static unsigned int wdt_tclk; | |
22ac9232 | 43 | static unsigned long wdt_status; |
1334f329 | 44 | static DEFINE_SPINLOCK(wdt_lock); |
22ac9232 | 45 | |
3b937a7d | 46 | static void orion_wdt_ping(void) |
df6707b2 TR |
47 | { |
48 | spin_lock(&wdt_lock); | |
49 | ||
50 | /* Reload watchdog duration */ | |
51 | writel(wdt_tclk * heartbeat, WDT_VAL); | |
52 | ||
53 | spin_unlock(&wdt_lock); | |
54 | } | |
55 | ||
3b937a7d | 56 | static void orion_wdt_enable(void) |
22ac9232 SB |
57 | { |
58 | u32 reg; | |
59 | ||
6d0f0dfd WVS |
60 | spin_lock(&wdt_lock); |
61 | ||
22ac9232 | 62 | /* Set watchdog duration */ |
9e058d4f | 63 | writel(wdt_tclk * heartbeat, WDT_VAL); |
22ac9232 SB |
64 | |
65 | /* Clear watchdog timer interrupt */ | |
66 | reg = readl(BRIDGE_CAUSE); | |
67 | reg &= ~WDT_INT_REQ; | |
68 | writel(reg, BRIDGE_CAUSE); | |
69 | ||
70 | /* Enable watchdog timer */ | |
71 | reg = readl(TIMER_CTRL); | |
72 | reg |= WDT_EN; | |
73 | writel(reg, TIMER_CTRL); | |
74 | ||
75 | /* Enable reset on watchdog */ | |
6462c616 TR |
76 | reg = readl(RSTOUTn_MASK); |
77 | reg |= WDT_RESET_OUT_EN; | |
78 | writel(reg, RSTOUTn_MASK); | |
6d0f0dfd WVS |
79 | |
80 | spin_unlock(&wdt_lock); | |
22ac9232 SB |
81 | } |
82 | ||
3b937a7d | 83 | static void orion_wdt_disable(void) |
22ac9232 SB |
84 | { |
85 | u32 reg; | |
86 | ||
6d0f0dfd WVS |
87 | spin_lock(&wdt_lock); |
88 | ||
22ac9232 | 89 | /* Disable reset on watchdog */ |
6462c616 TR |
90 | reg = readl(RSTOUTn_MASK); |
91 | reg &= ~WDT_RESET_OUT_EN; | |
92 | writel(reg, RSTOUTn_MASK); | |
22ac9232 SB |
93 | |
94 | /* Disable watchdog timer */ | |
95 | reg = readl(TIMER_CTRL); | |
96 | reg &= ~WDT_EN; | |
97 | writel(reg, TIMER_CTRL); | |
6d0f0dfd WVS |
98 | |
99 | spin_unlock(&wdt_lock); | |
100 | } | |
101 | ||
3b937a7d | 102 | static int orion_wdt_get_timeleft(int *time_left) |
6d0f0dfd WVS |
103 | { |
104 | spin_lock(&wdt_lock); | |
9e058d4f | 105 | *time_left = readl(WDT_VAL) / wdt_tclk; |
6d0f0dfd WVS |
106 | spin_unlock(&wdt_lock); |
107 | return 0; | |
22ac9232 SB |
108 | } |
109 | ||
3b937a7d | 110 | static int orion_wdt_open(struct inode *inode, struct file *file) |
22ac9232 SB |
111 | { |
112 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
113 | return -EBUSY; | |
114 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
3b937a7d | 115 | orion_wdt_enable(); |
22ac9232 SB |
116 | return nonseekable_open(inode, file); |
117 | } | |
118 | ||
3b937a7d | 119 | static ssize_t orion_wdt_write(struct file *file, const char *data, |
22ac9232 SB |
120 | size_t len, loff_t *ppos) |
121 | { | |
122 | if (len) { | |
123 | if (!nowayout) { | |
124 | size_t i; | |
125 | ||
126 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
127 | for (i = 0; i != len; i++) { | |
128 | char c; | |
129 | ||
130 | if (get_user(c, data + i)) | |
131 | return -EFAULT; | |
132 | if (c == 'V') | |
133 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
134 | } | |
135 | } | |
3b937a7d | 136 | orion_wdt_ping(); |
22ac9232 SB |
137 | } |
138 | return len; | |
139 | } | |
140 | ||
3b937a7d | 141 | static int orion_wdt_settimeout(int new_time) |
df6707b2 TR |
142 | { |
143 | if ((new_time <= 0) || (new_time > wdt_max_duration)) | |
144 | return -EINVAL; | |
145 | ||
146 | /* Set new watchdog time to be used when | |
3b937a7d | 147 | * orion_wdt_enable() or orion_wdt_ping() is called. */ |
df6707b2 TR |
148 | heartbeat = new_time; |
149 | return 0; | |
150 | } | |
151 | ||
152 | static const struct watchdog_info ident = { | |
22ac9232 SB |
153 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | |
154 | WDIOF_KEEPALIVEPING, | |
3b937a7d | 155 | .identity = "Orion Watchdog", |
22ac9232 SB |
156 | }; |
157 | ||
3b937a7d | 158 | static long orion_wdt_ioctl(struct file *file, unsigned int cmd, |
22ac9232 SB |
159 | unsigned long arg) |
160 | { | |
161 | int ret = -ENOTTY; | |
162 | int time; | |
163 | ||
164 | switch (cmd) { | |
165 | case WDIOC_GETSUPPORT: | |
166 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
167 | sizeof(ident)) ? -EFAULT : 0; | |
168 | break; | |
169 | ||
170 | case WDIOC_GETSTATUS: | |
171 | case WDIOC_GETBOOTSTATUS: | |
172 | ret = put_user(0, (int *)arg); | |
173 | break; | |
174 | ||
175 | case WDIOC_KEEPALIVE: | |
3b937a7d | 176 | orion_wdt_ping(); |
22ac9232 SB |
177 | ret = 0; |
178 | break; | |
179 | ||
180 | case WDIOC_SETTIMEOUT: | |
181 | ret = get_user(time, (int *)arg); | |
182 | if (ret) | |
183 | break; | |
184 | ||
3b937a7d | 185 | if (orion_wdt_settimeout(time)) { |
22ac9232 SB |
186 | ret = -EINVAL; |
187 | break; | |
188 | } | |
3b937a7d | 189 | orion_wdt_ping(); |
22ac9232 SB |
190 | /* Fall through */ |
191 | ||
192 | case WDIOC_GETTIMEOUT: | |
193 | ret = put_user(heartbeat, (int *)arg); | |
194 | break; | |
195 | ||
196 | case WDIOC_GETTIMELEFT: | |
3b937a7d | 197 | if (orion_wdt_get_timeleft(&time)) { |
22ac9232 SB |
198 | ret = -EINVAL; |
199 | break; | |
200 | } | |
201 | ret = put_user(time, (int *)arg); | |
202 | break; | |
203 | } | |
204 | return ret; | |
205 | } | |
206 | ||
3b937a7d | 207 | static int orion_wdt_release(struct inode *inode, struct file *file) |
22ac9232 SB |
208 | { |
209 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) | |
3b937a7d | 210 | orion_wdt_disable(); |
22ac9232 SB |
211 | else |
212 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " | |
213 | "timer will not stop\n"); | |
214 | clear_bit(WDT_IN_USE, &wdt_status); | |
215 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
220 | ||
3b937a7d | 221 | static const struct file_operations orion_wdt_fops = { |
22ac9232 SB |
222 | .owner = THIS_MODULE, |
223 | .llseek = no_llseek, | |
3b937a7d NP |
224 | .write = orion_wdt_write, |
225 | .unlocked_ioctl = orion_wdt_ioctl, | |
226 | .open = orion_wdt_open, | |
227 | .release = orion_wdt_release, | |
22ac9232 SB |
228 | }; |
229 | ||
3b937a7d | 230 | static struct miscdevice orion_wdt_miscdev = { |
22ac9232 SB |
231 | .minor = WATCHDOG_MINOR, |
232 | .name = "watchdog", | |
3b937a7d | 233 | .fops = &orion_wdt_fops, |
22ac9232 SB |
234 | }; |
235 | ||
3b937a7d | 236 | static int __devinit orion_wdt_probe(struct platform_device *pdev) |
22ac9232 | 237 | { |
3b937a7d | 238 | struct orion_wdt_platform_data *pdata = pdev->dev.platform_data; |
22ac9232 SB |
239 | int ret; |
240 | ||
9e058d4f TR |
241 | if (pdata) { |
242 | wdt_tclk = pdata->tclk; | |
243 | } else { | |
3b937a7d | 244 | printk(KERN_ERR "Orion Watchdog misses platform data\n"); |
9e058d4f TR |
245 | return -ENODEV; |
246 | } | |
247 | ||
3b937a7d | 248 | if (orion_wdt_miscdev.parent) |
9e058d4f | 249 | return -EBUSY; |
3b937a7d | 250 | orion_wdt_miscdev.parent = &pdev->dev; |
9e058d4f TR |
251 | |
252 | wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk; | |
3b937a7d | 253 | if (orion_wdt_settimeout(heartbeat)) |
9e058d4f | 254 | heartbeat = wdt_max_duration; |
6d0f0dfd | 255 | |
3b937a7d | 256 | ret = misc_register(&orion_wdt_miscdev); |
9e058d4f TR |
257 | if (ret) |
258 | return ret; | |
259 | ||
3b937a7d | 260 | printk(KERN_INFO "Orion Watchdog Timer: Initial timeout %d sec%s\n", |
9e058d4f TR |
261 | heartbeat, nowayout ? ", nowayout" : ""); |
262 | return 0; | |
263 | } | |
264 | ||
3b937a7d | 265 | static int __devexit orion_wdt_remove(struct platform_device *pdev) |
9e058d4f TR |
266 | { |
267 | int ret; | |
268 | ||
269 | if (test_bit(WDT_IN_USE, &wdt_status)) { | |
3b937a7d | 270 | orion_wdt_disable(); |
9e058d4f TR |
271 | clear_bit(WDT_IN_USE, &wdt_status); |
272 | } | |
273 | ||
3b937a7d | 274 | ret = misc_deregister(&orion_wdt_miscdev); |
9e058d4f | 275 | if (!ret) |
3b937a7d | 276 | orion_wdt_miscdev.parent = NULL; |
22ac9232 SB |
277 | |
278 | return ret; | |
279 | } | |
280 | ||
3b937a7d | 281 | static void orion_wdt_shutdown(struct platform_device *pdev) |
df6707b2 TR |
282 | { |
283 | if (test_bit(WDT_IN_USE, &wdt_status)) | |
3b937a7d | 284 | orion_wdt_disable(); |
df6707b2 TR |
285 | } |
286 | ||
3b937a7d NP |
287 | static struct platform_driver orion_wdt_driver = { |
288 | .probe = orion_wdt_probe, | |
289 | .remove = __devexit_p(orion_wdt_remove), | |
290 | .shutdown = orion_wdt_shutdown, | |
9e058d4f TR |
291 | .driver = { |
292 | .owner = THIS_MODULE, | |
3b937a7d | 293 | .name = "orion_wdt", |
9e058d4f TR |
294 | }, |
295 | }; | |
296 | ||
b8ec6118 | 297 | module_platform_driver(orion_wdt_driver); |
22ac9232 SB |
298 | |
299 | MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>"); | |
3b937a7d | 300 | MODULE_DESCRIPTION("Orion Processor Watchdog"); |
22ac9232 SB |
301 | |
302 | module_param(heartbeat, int, 0); | |
df6707b2 | 303 | MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds"); |
22ac9232 SB |
304 | |
305 | module_param(nowayout, int, 0); | |
df6707b2 TR |
306 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
307 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
22ac9232 SB |
308 | |
309 | MODULE_LICENSE("GPL"); | |
310 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |