This source file includes following definitions.
- bcm63xx_wdt_hw_start
- bcm63xx_wdt_hw_stop
- bcm63xx_wdt_isr
- bcm63xx_timer_tick
- bcm63xx_wdt_pet
- bcm63xx_wdt_start
- bcm63xx_wdt_pause
- bcm63xx_wdt_settimeout
- bcm63xx_wdt_open
- bcm63xx_wdt_release
- bcm63xx_wdt_write
- bcm63xx_wdt_ioctl
- bcm63xx_wdt_probe
- bcm63xx_wdt_remove
- bcm63xx_wdt_shutdown
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9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12 #include <linux/bitops.h>
13 #include <linux/errno.h>
14 #include <linux/fs.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/miscdevice.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/types.h>
21 #include <linux/uaccess.h>
22 #include <linux/watchdog.h>
23 #include <linux/timer.h>
24 #include <linux/jiffies.h>
25 #include <linux/interrupt.h>
26 #include <linux/ptrace.h>
27 #include <linux/resource.h>
28 #include <linux/platform_device.h>
29
30 #include <bcm63xx_cpu.h>
31 #include <bcm63xx_io.h>
32 #include <bcm63xx_regs.h>
33 #include <bcm63xx_timer.h>
34
35 #define PFX KBUILD_MODNAME
36
37 #define WDT_HZ 50000000
38 #define WDT_DEFAULT_TIME 30
39 #define WDT_MAX_TIME 256
40
41 static struct {
42 void __iomem *regs;
43 struct timer_list timer;
44 unsigned long inuse;
45 atomic_t ticks;
46 } bcm63xx_wdt_device;
47
48 static int expect_close;
49
50 static int wdt_time = WDT_DEFAULT_TIME;
51 static bool nowayout = WATCHDOG_NOWAYOUT;
52 module_param(nowayout, bool, 0);
53 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
54 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
55
56
57 static void bcm63xx_wdt_hw_start(void)
58 {
59 bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
60 bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
61 bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
62 }
63
64 static void bcm63xx_wdt_hw_stop(void)
65 {
66 bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
67 bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
68 }
69
70 static void bcm63xx_wdt_isr(void *data)
71 {
72 struct pt_regs *regs = get_irq_regs();
73
74 die(PFX " fire", regs);
75 }
76
77 static void bcm63xx_timer_tick(struct timer_list *unused)
78 {
79 if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
80 bcm63xx_wdt_hw_start();
81 mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
82 } else
83 pr_crit("watchdog will restart system\n");
84 }
85
86 static void bcm63xx_wdt_pet(void)
87 {
88 atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
89 }
90
91 static void bcm63xx_wdt_start(void)
92 {
93 bcm63xx_wdt_pet();
94 bcm63xx_timer_tick(0);
95 }
96
97 static void bcm63xx_wdt_pause(void)
98 {
99 del_timer_sync(&bcm63xx_wdt_device.timer);
100 bcm63xx_wdt_hw_stop();
101 }
102
103 static int bcm63xx_wdt_settimeout(int new_time)
104 {
105 if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
106 return -EINVAL;
107
108 wdt_time = new_time;
109
110 return 0;
111 }
112
113 static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
114 {
115 if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
116 return -EBUSY;
117
118 bcm63xx_wdt_start();
119 return stream_open(inode, file);
120 }
121
122 static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
123 {
124 if (expect_close == 42)
125 bcm63xx_wdt_pause();
126 else {
127 pr_crit("Unexpected close, not stopping watchdog!\n");
128 bcm63xx_wdt_start();
129 }
130 clear_bit(0, &bcm63xx_wdt_device.inuse);
131 expect_close = 0;
132 return 0;
133 }
134
135 static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
136 size_t len, loff_t *ppos)
137 {
138 if (len) {
139 if (!nowayout) {
140 size_t i;
141
142
143 expect_close = 0;
144
145 for (i = 0; i != len; i++) {
146 char c;
147 if (get_user(c, data + i))
148 return -EFAULT;
149 if (c == 'V')
150 expect_close = 42;
151 }
152 }
153 bcm63xx_wdt_pet();
154 }
155 return len;
156 }
157
158 static struct watchdog_info bcm63xx_wdt_info = {
159 .identity = PFX,
160 .options = WDIOF_SETTIMEOUT |
161 WDIOF_KEEPALIVEPING |
162 WDIOF_MAGICCLOSE,
163 };
164
165
166 static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
167 unsigned long arg)
168 {
169 void __user *argp = (void __user *)arg;
170 int __user *p = argp;
171 int new_value, retval = -EINVAL;
172
173 switch (cmd) {
174 case WDIOC_GETSUPPORT:
175 return copy_to_user(argp, &bcm63xx_wdt_info,
176 sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
177
178 case WDIOC_GETSTATUS:
179 case WDIOC_GETBOOTSTATUS:
180 return put_user(0, p);
181
182 case WDIOC_SETOPTIONS:
183 if (get_user(new_value, p))
184 return -EFAULT;
185
186 if (new_value & WDIOS_DISABLECARD) {
187 bcm63xx_wdt_pause();
188 retval = 0;
189 }
190 if (new_value & WDIOS_ENABLECARD) {
191 bcm63xx_wdt_start();
192 retval = 0;
193 }
194
195 return retval;
196
197 case WDIOC_KEEPALIVE:
198 bcm63xx_wdt_pet();
199 return 0;
200
201 case WDIOC_SETTIMEOUT:
202 if (get_user(new_value, p))
203 return -EFAULT;
204
205 if (bcm63xx_wdt_settimeout(new_value))
206 return -EINVAL;
207
208 bcm63xx_wdt_pet();
209
210 case WDIOC_GETTIMEOUT:
211 return put_user(wdt_time, p);
212
213 default:
214 return -ENOTTY;
215
216 }
217 }
218
219 static const struct file_operations bcm63xx_wdt_fops = {
220 .owner = THIS_MODULE,
221 .llseek = no_llseek,
222 .write = bcm63xx_wdt_write,
223 .unlocked_ioctl = bcm63xx_wdt_ioctl,
224 .open = bcm63xx_wdt_open,
225 .release = bcm63xx_wdt_release,
226 };
227
228 static struct miscdevice bcm63xx_wdt_miscdev = {
229 .minor = WATCHDOG_MINOR,
230 .name = "watchdog",
231 .fops = &bcm63xx_wdt_fops,
232 };
233
234
235 static int bcm63xx_wdt_probe(struct platform_device *pdev)
236 {
237 int ret;
238 struct resource *r;
239
240 timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0);
241
242 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
243 if (!r) {
244 dev_err(&pdev->dev, "failed to get resources\n");
245 return -ENODEV;
246 }
247
248 bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
249 resource_size(r));
250 if (!bcm63xx_wdt_device.regs) {
251 dev_err(&pdev->dev, "failed to remap I/O resources\n");
252 return -ENXIO;
253 }
254
255 ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
256 if (ret < 0) {
257 dev_err(&pdev->dev, "failed to register wdt timer isr\n");
258 return ret;
259 }
260
261 if (bcm63xx_wdt_settimeout(wdt_time)) {
262 bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
263 dev_info(&pdev->dev,
264 ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
265 wdt_time);
266 }
267
268 ret = misc_register(&bcm63xx_wdt_miscdev);
269 if (ret < 0) {
270 dev_err(&pdev->dev, "failed to register watchdog device\n");
271 goto unregister_timer;
272 }
273
274 dev_info(&pdev->dev, " started, timer margin: %d sec\n",
275 WDT_DEFAULT_TIME);
276
277 return 0;
278
279 unregister_timer:
280 bcm63xx_timer_unregister(TIMER_WDT_ID);
281 return ret;
282 }
283
284 static int bcm63xx_wdt_remove(struct platform_device *pdev)
285 {
286 if (!nowayout)
287 bcm63xx_wdt_pause();
288
289 misc_deregister(&bcm63xx_wdt_miscdev);
290 bcm63xx_timer_unregister(TIMER_WDT_ID);
291 return 0;
292 }
293
294 static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
295 {
296 bcm63xx_wdt_pause();
297 }
298
299 static struct platform_driver bcm63xx_wdt_driver = {
300 .probe = bcm63xx_wdt_probe,
301 .remove = bcm63xx_wdt_remove,
302 .shutdown = bcm63xx_wdt_shutdown,
303 .driver = {
304 .name = "bcm63xx-wdt",
305 }
306 };
307
308 module_platform_driver(bcm63xx_wdt_driver);
309
310 MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
311 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
312 MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
313 MODULE_LICENSE("GPL");
314 MODULE_ALIAS("platform:bcm63xx-wdt");