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2e62c498 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
b63aa731 FF |
2 | /* |
3 | * Broadcom BCM63xx SoC watchdog driver | |
4 | * | |
5 | * Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com> | |
6 | * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org> | |
7 | * | |
b63aa731 FF |
8 | */ |
9 | ||
27c766aa JP |
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
11 | ||
b63aa731 FF |
12 | #include <linux/bitops.h> |
13 | #include <linux/errno.h> | |
14 | #include <linux/fs.h> | |
626d65aa | 15 | #include <linux/io.h> |
b63aa731 FF |
16 | #include <linux/kernel.h> |
17 | #include <linux/miscdevice.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/moduleparam.h> | |
b63aa731 FF |
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 /* Fclk */ | |
38 | #define WDT_DEFAULT_TIME 30 /* seconds */ | |
39 | #define WDT_MAX_TIME 256 /* seconds */ | |
40 | ||
41 | static struct { | |
42 | void __iomem *regs; | |
43 | struct timer_list timer; | |
b63aa731 FF |
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; | |
86a1e189 WVS |
51 | static bool nowayout = WATCHDOG_NOWAYOUT; |
52 | module_param(nowayout, bool, 0); | |
b63aa731 FF |
53 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
54 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
55 | ||
56 | /* HW functions */ | |
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 | ||
e99e88a9 | 77 | static void bcm63xx_timer_tick(struct timer_list *unused) |
b63aa731 FF |
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 | |
27c766aa | 83 | pr_crit("watchdog will restart system\n"); |
b63aa731 FF |
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(); | |
c5bf68fe | 119 | return stream_open(inode, file); |
b63aa731 FF |
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 { | |
27c766aa | 127 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
b63aa731 FF |
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 | /* In case it was set long ago */ | |
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 | ||
b63aa731 FF |
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 | ||
b63aa731 | 234 | |
2d991a16 | 235 | static int bcm63xx_wdt_probe(struct platform_device *pdev) |
b63aa731 FF |
236 | { |
237 | int ret; | |
238 | struct resource *r; | |
239 | ||
e99e88a9 | 240 | timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0); |
b63aa731 FF |
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 | ||
626d65aa JH |
248 | bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start, |
249 | resource_size(r)); | |
b63aa731 FF |
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"); | |
626d65aa | 258 | return ret; |
b63aa731 FF |
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 | ||
b63aa731 FF |
268 | ret = misc_register(&bcm63xx_wdt_miscdev); |
269 | if (ret < 0) { | |
270 | dev_err(&pdev->dev, "failed to register watchdog device\n"); | |
e6c3b699 | 271 | goto unregister_timer; |
b63aa731 FF |
272 | } |
273 | ||
274 | dev_info(&pdev->dev, " started, timer margin: %d sec\n", | |
275 | WDT_DEFAULT_TIME); | |
276 | ||
277 | return 0; | |
278 | ||
b63aa731 FF |
279 | unregister_timer: |
280 | bcm63xx_timer_unregister(TIMER_WDT_ID); | |
b63aa731 FF |
281 | return ret; |
282 | } | |
283 | ||
4b12b896 | 284 | static int bcm63xx_wdt_remove(struct platform_device *pdev) |
b63aa731 FF |
285 | { |
286 | if (!nowayout) | |
287 | bcm63xx_wdt_pause(); | |
288 | ||
289 | misc_deregister(&bcm63xx_wdt_miscdev); | |
b63aa731 | 290 | bcm63xx_timer_unregister(TIMER_WDT_ID); |
b63aa731 FF |
291 | return 0; |
292 | } | |
293 | ||
e6c3b699 WVS |
294 | static void bcm63xx_wdt_shutdown(struct platform_device *pdev) |
295 | { | |
296 | bcm63xx_wdt_pause(); | |
297 | } | |
298 | ||
5a135f3c | 299 | static struct platform_driver bcm63xx_wdt_driver = { |
b63aa731 | 300 | .probe = bcm63xx_wdt_probe, |
82268714 | 301 | .remove = bcm63xx_wdt_remove, |
e6c3b699 | 302 | .shutdown = bcm63xx_wdt_shutdown, |
b63aa731 FF |
303 | .driver = { |
304 | .name = "bcm63xx-wdt", | |
305 | } | |
306 | }; | |
307 | ||
5a135f3c | 308 | module_platform_driver(bcm63xx_wdt_driver); |
b63aa731 FF |
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"); | |
b63aa731 | 314 | MODULE_ALIAS("platform:bcm63xx-wdt"); |