1
2
3
4
5
6
7
8
9
10
11
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/bitops.h>
16#include <linux/errno.h>
17#include <linux/fs.h>
18#include <linux/init.h>
19#include <linux/io.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>
33
34#include <bcm63xx_cpu.h>
35#include <bcm63xx_io.h>
36#include <bcm63xx_regs.h>
37#include <bcm63xx_timer.h>
38
39#define PFX KBUILD_MODNAME
40
41#define WDT_HZ 50000000
42#define WDT_DEFAULT_TIME 30
43#define WDT_MAX_TIME 256
44
45static struct {
46 void __iomem *regs;
47 struct timer_list timer;
48 int default_ticks;
49 unsigned long inuse;
50 atomic_t ticks;
51} bcm63xx_wdt_device;
52
53static int expect_close;
54
55static int wdt_time = WDT_DEFAULT_TIME;
56static bool nowayout = WATCHDOG_NOWAYOUT;
57module_param(nowayout, bool, 0);
58MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
59 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
60
61
62static void bcm63xx_wdt_hw_start(void)
63{
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);
67}
68
69static void bcm63xx_wdt_hw_stop(void)
70{
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);
73}
74
75static void bcm63xx_wdt_isr(void *data)
76{
77 struct pt_regs *regs = get_irq_regs();
78
79 die(PFX " fire", regs);
80}
81
82static void bcm63xx_timer_tick(unsigned long unused)
83{
84 if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
85 bcm63xx_wdt_hw_start();
86 mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
87 } else
88 pr_crit("watchdog will restart system\n");
89}
90
91static void bcm63xx_wdt_pet(void)
92{
93 atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
94}
95
96static void bcm63xx_wdt_start(void)
97{
98 bcm63xx_wdt_pet();
99 bcm63xx_timer_tick(0);
100}
101
102static void bcm63xx_wdt_pause(void)
103{
104 del_timer_sync(&bcm63xx_wdt_device.timer);
105 bcm63xx_wdt_hw_stop();
106}
107
108static int bcm63xx_wdt_settimeout(int new_time)
109{
110 if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
111 return -EINVAL;
112
113 wdt_time = new_time;
114
115 return 0;
116}
117
118static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
119{
120 if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
121 return -EBUSY;
122
123 bcm63xx_wdt_start();
124 return nonseekable_open(inode, file);
125}
126
127static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
128{
129 if (expect_close == 42)
130 bcm63xx_wdt_pause();
131 else {
132 pr_crit("Unexpected close, not stopping watchdog!\n");
133 bcm63xx_wdt_start();
134 }
135 clear_bit(0, &bcm63xx_wdt_device.inuse);
136 expect_close = 0;
137 return 0;
138}
139
140static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
141 size_t len, loff_t *ppos)
142{
143 if (len) {
144 if (!nowayout) {
145 size_t i;
146
147
148 expect_close = 0;
149
150 for (i = 0; i != len; i++) {
151 char c;
152 if (get_user(c, data + i))
153 return -EFAULT;
154 if (c == 'V')
155 expect_close = 42;
156 }
157 }
158 bcm63xx_wdt_pet();
159 }
160 return len;
161}
162
163static struct watchdog_info bcm63xx_wdt_info = {
164 .identity = PFX,
165 .options = WDIOF_SETTIMEOUT |
166 WDIOF_KEEPALIVEPING |
167 WDIOF_MAGICCLOSE,
168};
169
170
171static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
172 unsigned long arg)
173{
174 void __user *argp = (void __user *)arg;
175 int __user *p = argp;
176 int new_value, retval = -EINVAL;
177
178 switch (cmd) {
179 case WDIOC_GETSUPPORT:
180 return copy_to_user(argp, &bcm63xx_wdt_info,
181 sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
182
183 case WDIOC_GETSTATUS:
184 case WDIOC_GETBOOTSTATUS:
185 return put_user(0, p);
186
187 case WDIOC_SETOPTIONS:
188 if (get_user(new_value, p))
189 return -EFAULT;
190
191 if (new_value & WDIOS_DISABLECARD) {
192 bcm63xx_wdt_pause();
193 retval = 0;
194 }
195 if (new_value & WDIOS_ENABLECARD) {
196 bcm63xx_wdt_start();
197 retval = 0;
198 }
199
200 return retval;
201
202 case WDIOC_KEEPALIVE:
203 bcm63xx_wdt_pet();
204 return 0;
205
206 case WDIOC_SETTIMEOUT:
207 if (get_user(new_value, p))
208 return -EFAULT;
209
210 if (bcm63xx_wdt_settimeout(new_value))
211 return -EINVAL;
212
213 bcm63xx_wdt_pet();
214
215 case WDIOC_GETTIMEOUT:
216 return put_user(wdt_time, p);
217
218 default:
219 return -ENOTTY;
220
221 }
222}
223
224static const struct file_operations bcm63xx_wdt_fops = {
225 .owner = THIS_MODULE,
226 .llseek = no_llseek,
227 .write = bcm63xx_wdt_write,
228 .unlocked_ioctl = bcm63xx_wdt_ioctl,
229 .open = bcm63xx_wdt_open,
230 .release = bcm63xx_wdt_release,
231};
232
233static struct miscdevice bcm63xx_wdt_miscdev = {
234 .minor = WATCHDOG_MINOR,
235 .name = "watchdog",
236 .fops = &bcm63xx_wdt_fops,
237};
238
239
240static int bcm63xx_wdt_probe(struct platform_device *pdev)
241{
242 int ret;
243 struct resource *r;
244
245 setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
246
247 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
248 if (!r) {
249 dev_err(&pdev->dev, "failed to get resources\n");
250 return -ENODEV;
251 }
252
253 bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start,
254 resource_size(r));
255 if (!bcm63xx_wdt_device.regs) {
256 dev_err(&pdev->dev, "failed to remap I/O resources\n");
257 return -ENXIO;
258 }
259
260 ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
261 if (ret < 0) {
262 dev_err(&pdev->dev, "failed to register wdt timer isr\n");
263 return ret;
264 }
265
266 if (bcm63xx_wdt_settimeout(wdt_time)) {
267 bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
268 dev_info(&pdev->dev,
269 ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
270 wdt_time);
271 }
272
273 ret = misc_register(&bcm63xx_wdt_miscdev);
274 if (ret < 0) {
275 dev_err(&pdev->dev, "failed to register watchdog device\n");
276 goto unregister_timer;
277 }
278
279 dev_info(&pdev->dev, " started, timer margin: %d sec\n",
280 WDT_DEFAULT_TIME);
281
282 return 0;
283
284unregister_timer:
285 bcm63xx_timer_unregister(TIMER_WDT_ID);
286 return ret;
287}
288
289static int bcm63xx_wdt_remove(struct platform_device *pdev)
290{
291 if (!nowayout)
292 bcm63xx_wdt_pause();
293
294 misc_deregister(&bcm63xx_wdt_miscdev);
295 bcm63xx_timer_unregister(TIMER_WDT_ID);
296 return 0;
297}
298
299static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
300{
301 bcm63xx_wdt_pause();
302}
303
304static struct platform_driver bcm63xx_wdt_driver = {
305 .probe = bcm63xx_wdt_probe,
306 .remove = bcm63xx_wdt_remove,
307 .shutdown = bcm63xx_wdt_shutdown,
308 .driver = {
309 .owner = THIS_MODULE,
310 .name = "bcm63xx-wdt",
311 }
312};
313
314module_platform_driver(bcm63xx_wdt_driver);
315
316MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
317MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
318MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
319MODULE_LICENSE("GPL");
320MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
321MODULE_ALIAS("platform:bcm63xx-wdt");
322
