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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
41static struct {
42 void __iomem *regs;
43 struct timer_list timer;
44 unsigned long inuse;
45 atomic_t ticks;
46} bcm63xx_wdt_device;
47
48static int expect_close;
49
50static int wdt_time = WDT_DEFAULT_TIME;
51static bool nowayout = WATCHDOG_NOWAYOUT;
52module_param(nowayout, bool, 0);
53MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
54 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
55
56
57static 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
64static 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
70static void bcm63xx_wdt_isr(void *data)
71{
72 struct pt_regs *regs = get_irq_regs();
73
74 die(PFX " fire", regs);
75}
76
77static 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
86static void bcm63xx_wdt_pet(void)
87{
88 atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
89}
90
91static void bcm63xx_wdt_start(void)
92{
93 bcm63xx_wdt_pet();
94 bcm63xx_timer_tick(0);
95}
96
97static void bcm63xx_wdt_pause(void)
98{
99 del_timer_sync(&bcm63xx_wdt_device.timer);
100 bcm63xx_wdt_hw_stop();
101}
102
103static 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
113static 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
122static 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
135static 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
158static struct watchdog_info bcm63xx_wdt_info = {
159 .identity = PFX,
160 .options = WDIOF_SETTIMEOUT |
161 WDIOF_KEEPALIVEPING |
162 WDIOF_MAGICCLOSE,
163};
164
165
166static 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
219static 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 .compat_ioctl = compat_ptr_ioctl,
225 .open = bcm63xx_wdt_open,
226 .release = bcm63xx_wdt_release,
227};
228
229static struct miscdevice bcm63xx_wdt_miscdev = {
230 .minor = WATCHDOG_MINOR,
231 .name = "watchdog",
232 .fops = &bcm63xx_wdt_fops,
233};
234
235
236static int bcm63xx_wdt_probe(struct platform_device *pdev)
237{
238 int ret;
239 struct resource *r;
240
241 timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0);
242
243 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
244 if (!r) {
245 dev_err(&pdev->dev, "failed to get resources\n");
246 return -ENODEV;
247 }
248
249 bcm63xx_wdt_device.regs = devm_ioremap(&pdev->dev, r->start,
250 resource_size(r));
251 if (!bcm63xx_wdt_device.regs) {
252 dev_err(&pdev->dev, "failed to remap I/O resources\n");
253 return -ENXIO;
254 }
255
256 ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
257 if (ret < 0) {
258 dev_err(&pdev->dev, "failed to register wdt timer isr\n");
259 return ret;
260 }
261
262 if (bcm63xx_wdt_settimeout(wdt_time)) {
263 bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
264 dev_info(&pdev->dev,
265 ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
266 wdt_time);
267 }
268
269 ret = misc_register(&bcm63xx_wdt_miscdev);
270 if (ret < 0) {
271 dev_err(&pdev->dev, "failed to register watchdog device\n");
272 goto unregister_timer;
273 }
274
275 dev_info(&pdev->dev, " started, timer margin: %d sec\n",
276 WDT_DEFAULT_TIME);
277
278 return 0;
279
280unregister_timer:
281 bcm63xx_timer_unregister(TIMER_WDT_ID);
282 return ret;
283}
284
285static int bcm63xx_wdt_remove(struct platform_device *pdev)
286{
287 if (!nowayout)
288 bcm63xx_wdt_pause();
289
290 misc_deregister(&bcm63xx_wdt_miscdev);
291 bcm63xx_timer_unregister(TIMER_WDT_ID);
292 return 0;
293}
294
295static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
296{
297 bcm63xx_wdt_pause();
298}
299
300static struct platform_driver bcm63xx_wdt_driver = {
301 .probe = bcm63xx_wdt_probe,
302 .remove = bcm63xx_wdt_remove,
303 .shutdown = bcm63xx_wdt_shutdown,
304 .driver = {
305 .name = "bcm63xx-wdt",
306 }
307};
308
309module_platform_driver(bcm63xx_wdt_driver);
310
311MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
312MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
313MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
314MODULE_LICENSE("GPL");
315MODULE_ALIAS("platform:bcm63xx-wdt");
316
