Commit | Line | Data |
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bb2fd8a8 WS |
1 | /* |
2 | * Watchdog driver for IMX2 and later processors | |
3 | * | |
4 | * Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de> | |
1a9c5efa | 5 | * Copyright (C) 2014 Freescale Semiconductor, Inc. |
bb2fd8a8 WS |
6 | * |
7 | * some parts adapted by similar drivers from Darius Augulis and Vladimir | |
8 | * Zapolskiy, additional improvements by Wim Van Sebroeck. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify it | |
11 | * under the terms of the GNU General Public License version 2 as published by | |
12 | * the Free Software Foundation. | |
13 | * | |
14 | * NOTE: MX1 has a slightly different Watchdog than MX2 and later: | |
15 | * | |
16 | * MX1: MX2+: | |
17 | * ---- ----- | |
18 | * Registers: 32-bit 16-bit | |
19 | * Stopable timer: Yes No | |
20 | * Need to enable clk: No Yes | |
21 | * Halt on suspend: Manual Can be automatic | |
22 | */ | |
23 | ||
30cb042a | 24 | #include <linux/clk.h> |
334a9d81 | 25 | #include <linux/delay.h> |
bb2fd8a8 | 26 | #include <linux/init.h> |
30cb042a XL |
27 | #include <linux/io.h> |
28 | #include <linux/jiffies.h> | |
bb2fd8a8 | 29 | #include <linux/kernel.h> |
bb2fd8a8 WS |
30 | #include <linux/module.h> |
31 | #include <linux/moduleparam.h> | |
334a9d81 | 32 | #include <linux/notifier.h> |
f728f4bf | 33 | #include <linux/of_address.h> |
bb2fd8a8 | 34 | #include <linux/platform_device.h> |
334a9d81 | 35 | #include <linux/reboot.h> |
a7977003 | 36 | #include <linux/regmap.h> |
bb2fd8a8 | 37 | #include <linux/timer.h> |
30cb042a | 38 | #include <linux/watchdog.h> |
bb2fd8a8 WS |
39 | |
40 | #define DRIVER_NAME "imx2-wdt" | |
41 | ||
42 | #define IMX2_WDT_WCR 0x00 /* Control Register */ | |
43 | #define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */ | |
44 | #define IMX2_WDT_WCR_WRE (1 << 3) /* -> WDOG Reset Enable */ | |
45 | #define IMX2_WDT_WCR_WDE (1 << 2) /* -> Watchdog Enable */ | |
1a9c5efa | 46 | #define IMX2_WDT_WCR_WDZST (1 << 0) /* -> Watchdog timer Suspend */ |
bb2fd8a8 WS |
47 | |
48 | #define IMX2_WDT_WSR 0x02 /* Service Register */ | |
49 | #define IMX2_WDT_SEQ1 0x5555 /* -> service sequence 1 */ | |
50 | #define IMX2_WDT_SEQ2 0xAAAA /* -> service sequence 2 */ | |
51 | ||
474ef121 OS |
52 | #define IMX2_WDT_WRSR 0x04 /* Reset Status Register */ |
53 | #define IMX2_WDT_WRSR_TOUT (1 << 1) /* -> Reset due to Timeout */ | |
54 | ||
5fe65ce7 MP |
55 | #define IMX2_WDT_WMCR 0x08 /* Misc Register */ |
56 | ||
bb2fd8a8 WS |
57 | #define IMX2_WDT_MAX_TIME 128 |
58 | #define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */ | |
59 | ||
60 | #define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8) | |
61 | ||
faad5de0 | 62 | struct imx2_wdt_device { |
bb2fd8a8 | 63 | struct clk *clk; |
a7977003 | 64 | struct regmap *regmap; |
bb2fd8a8 | 65 | struct timer_list timer; /* Pings the watchdog when closed */ |
faad5de0 | 66 | struct watchdog_device wdog; |
334a9d81 | 67 | struct notifier_block restart_handler; |
faad5de0 | 68 | }; |
bb2fd8a8 | 69 | |
86a1e189 WVS |
70 | static bool nowayout = WATCHDOG_NOWAYOUT; |
71 | module_param(nowayout, bool, 0); | |
bb2fd8a8 WS |
72 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
73 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
74 | ||
75 | ||
76 | static unsigned timeout = IMX2_WDT_DEFAULT_TIME; | |
77 | module_param(timeout, uint, 0); | |
78 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=" | |
79 | __MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")"); | |
80 | ||
81 | static const struct watchdog_info imx2_wdt_info = { | |
82 | .identity = "imx2+ watchdog", | |
83 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
84 | }; | |
85 | ||
334a9d81 JL |
86 | static int imx2_restart_handler(struct notifier_block *this, unsigned long mode, |
87 | void *cmd) | |
88 | { | |
89 | unsigned int wcr_enable = IMX2_WDT_WCR_WDE; | |
90 | struct imx2_wdt_device *wdev = container_of(this, | |
91 | struct imx2_wdt_device, | |
92 | restart_handler); | |
93 | /* Assert SRS signal */ | |
94 | regmap_write(wdev->regmap, 0, wcr_enable); | |
95 | /* | |
96 | * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be | |
97 | * written twice), we add another two writes to ensure there must be at | |
98 | * least two writes happen in the same one 32kHz clock period. We save | |
99 | * the target check here, since the writes shouldn't be a huge burden | |
100 | * for other platforms. | |
101 | */ | |
102 | regmap_write(wdev->regmap, 0, wcr_enable); | |
103 | regmap_write(wdev->regmap, 0, wcr_enable); | |
104 | ||
105 | /* wait for reset to assert... */ | |
106 | mdelay(500); | |
107 | ||
108 | return NOTIFY_DONE; | |
109 | } | |
110 | ||
faad5de0 | 111 | static inline void imx2_wdt_setup(struct watchdog_device *wdog) |
bb2fd8a8 | 112 | { |
faad5de0 | 113 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); |
a7977003 XL |
114 | u32 val; |
115 | ||
faad5de0 | 116 | regmap_read(wdev->regmap, IMX2_WDT_WCR, &val); |
bb2fd8a8 | 117 | |
1a9c5efa AH |
118 | /* Suspend timer in low power mode, write once-only */ |
119 | val |= IMX2_WDT_WCR_WDZST; | |
bb2fd8a8 WS |
120 | /* Strip the old watchdog Time-Out value */ |
121 | val &= ~IMX2_WDT_WCR_WT; | |
122 | /* Generate reset if WDOG times out */ | |
123 | val &= ~IMX2_WDT_WCR_WRE; | |
124 | /* Keep Watchdog Disabled */ | |
125 | val &= ~IMX2_WDT_WCR_WDE; | |
126 | /* Set the watchdog's Time-Out value */ | |
faad5de0 | 127 | val |= WDOG_SEC_TO_COUNT(wdog->timeout); |
bb2fd8a8 | 128 | |
faad5de0 | 129 | regmap_write(wdev->regmap, IMX2_WDT_WCR, val); |
bb2fd8a8 WS |
130 | |
131 | /* enable the watchdog */ | |
132 | val |= IMX2_WDT_WCR_WDE; | |
faad5de0 | 133 | regmap_write(wdev->regmap, IMX2_WDT_WCR, val); |
bb2fd8a8 WS |
134 | } |
135 | ||
faad5de0 | 136 | static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev) |
bb2fd8a8 | 137 | { |
faad5de0 | 138 | u32 val; |
bb2fd8a8 | 139 | |
faad5de0 AG |
140 | regmap_read(wdev->regmap, IMX2_WDT_WCR, &val); |
141 | ||
142 | return val & IMX2_WDT_WCR_WDE; | |
bb2fd8a8 WS |
143 | } |
144 | ||
faad5de0 | 145 | static int imx2_wdt_ping(struct watchdog_device *wdog) |
bb2fd8a8 | 146 | { |
faad5de0 | 147 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); |
bb2fd8a8 | 148 | |
faad5de0 AG |
149 | regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1); |
150 | regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2); | |
151 | return 0; | |
bb2fd8a8 WS |
152 | } |
153 | ||
faad5de0 | 154 | static void imx2_wdt_timer_ping(unsigned long arg) |
bb2fd8a8 | 155 | { |
faad5de0 AG |
156 | struct watchdog_device *wdog = (struct watchdog_device *)arg; |
157 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); | |
158 | ||
159 | /* ping it every wdog->timeout / 2 seconds to prevent reboot */ | |
160 | imx2_wdt_ping(wdog); | |
161 | mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2); | |
bb2fd8a8 WS |
162 | } |
163 | ||
faad5de0 AG |
164 | static int imx2_wdt_set_timeout(struct watchdog_device *wdog, |
165 | unsigned int new_timeout) | |
bb2fd8a8 | 166 | { |
faad5de0 AG |
167 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); |
168 | ||
30dd4a8f MG |
169 | wdog->timeout = new_timeout; |
170 | ||
faad5de0 | 171 | regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT, |
a7977003 | 172 | WDOG_SEC_TO_COUNT(new_timeout)); |
faad5de0 | 173 | return 0; |
bb2fd8a8 WS |
174 | } |
175 | ||
faad5de0 | 176 | static int imx2_wdt_start(struct watchdog_device *wdog) |
bb2fd8a8 | 177 | { |
faad5de0 | 178 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); |
bb2fd8a8 | 179 | |
faad5de0 AG |
180 | if (imx2_wdt_is_running(wdev)) { |
181 | /* delete the timer that pings the watchdog after close */ | |
182 | del_timer_sync(&wdev->timer); | |
183 | imx2_wdt_set_timeout(wdog, wdog->timeout); | |
184 | } else | |
185 | imx2_wdt_setup(wdog); | |
186 | ||
187 | return imx2_wdt_ping(wdog); | |
bb2fd8a8 WS |
188 | } |
189 | ||
faad5de0 | 190 | static int imx2_wdt_stop(struct watchdog_device *wdog) |
bb2fd8a8 | 191 | { |
faad5de0 AG |
192 | /* |
193 | * We don't need a clk_disable, it cannot be disabled once started. | |
194 | * We use a timer to ping the watchdog while /dev/watchdog is closed | |
195 | */ | |
196 | imx2_wdt_timer_ping((unsigned long)wdog); | |
bb2fd8a8 WS |
197 | return 0; |
198 | } | |
199 | ||
faad5de0 | 200 | static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog) |
bb2fd8a8 | 201 | { |
faad5de0 | 202 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); |
bb2fd8a8 | 203 | |
faad5de0 AG |
204 | if (imx2_wdt_is_running(wdev)) { |
205 | imx2_wdt_set_timeout(wdog, wdog->timeout); | |
206 | imx2_wdt_timer_ping((unsigned long)wdog); | |
bb2fd8a8 WS |
207 | } |
208 | } | |
209 | ||
4bd8ce33 | 210 | static const struct watchdog_ops imx2_wdt_ops = { |
bb2fd8a8 | 211 | .owner = THIS_MODULE, |
faad5de0 AG |
212 | .start = imx2_wdt_start, |
213 | .stop = imx2_wdt_stop, | |
214 | .ping = imx2_wdt_ping, | |
215 | .set_timeout = imx2_wdt_set_timeout, | |
bb2fd8a8 WS |
216 | }; |
217 | ||
4bd8ce33 | 218 | static const struct regmap_config imx2_wdt_regmap_config = { |
a7977003 XL |
219 | .reg_bits = 16, |
220 | .reg_stride = 2, | |
221 | .val_bits = 16, | |
222 | .max_register = 0x8, | |
223 | }; | |
224 | ||
bb2fd8a8 WS |
225 | static int __init imx2_wdt_probe(struct platform_device *pdev) |
226 | { | |
faad5de0 AG |
227 | struct imx2_wdt_device *wdev; |
228 | struct watchdog_device *wdog; | |
bb2fd8a8 | 229 | struct resource *res; |
a7977003 XL |
230 | void __iomem *base; |
231 | int ret; | |
faad5de0 AG |
232 | u32 val; |
233 | ||
234 | wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL); | |
235 | if (!wdev) | |
236 | return -ENOMEM; | |
bb2fd8a8 WS |
237 | |
238 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
a7977003 XL |
239 | base = devm_ioremap_resource(&pdev->dev, res); |
240 | if (IS_ERR(base)) | |
241 | return PTR_ERR(base); | |
242 | ||
faad5de0 AG |
243 | wdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base, |
244 | &imx2_wdt_regmap_config); | |
245 | if (IS_ERR(wdev->regmap)) { | |
a7977003 | 246 | dev_err(&pdev->dev, "regmap init failed\n"); |
faad5de0 | 247 | return PTR_ERR(wdev->regmap); |
a7977003 | 248 | } |
bb2fd8a8 | 249 | |
faad5de0 AG |
250 | wdev->clk = devm_clk_get(&pdev->dev, NULL); |
251 | if (IS_ERR(wdev->clk)) { | |
bb2fd8a8 | 252 | dev_err(&pdev->dev, "can't get Watchdog clock\n"); |
faad5de0 | 253 | return PTR_ERR(wdev->clk); |
bb2fd8a8 WS |
254 | } |
255 | ||
faad5de0 AG |
256 | wdog = &wdev->wdog; |
257 | wdog->info = &imx2_wdt_info; | |
258 | wdog->ops = &imx2_wdt_ops; | |
259 | wdog->min_timeout = 1; | |
260 | wdog->max_timeout = IMX2_WDT_MAX_TIME; | |
8135193c | 261 | wdog->parent = &pdev->dev; |
bb2fd8a8 | 262 | |
aefb163c FE |
263 | ret = clk_prepare_enable(wdev->clk); |
264 | if (ret) | |
265 | return ret; | |
bb2fd8a8 | 266 | |
faad5de0 AG |
267 | regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val); |
268 | wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0; | |
bb2fd8a8 | 269 | |
faad5de0 AG |
270 | wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME); |
271 | if (wdog->timeout != timeout) | |
272 | dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n", | |
273 | timeout, wdog->timeout); | |
274 | ||
275 | platform_set_drvdata(pdev, wdog); | |
276 | watchdog_set_drvdata(wdog, wdev); | |
277 | watchdog_set_nowayout(wdog, nowayout); | |
278 | watchdog_init_timeout(wdog, timeout, &pdev->dev); | |
279 | ||
280 | setup_timer(&wdev->timer, imx2_wdt_timer_ping, (unsigned long)wdog); | |
bb2fd8a8 | 281 | |
faad5de0 AG |
282 | imx2_wdt_ping_if_active(wdog); |
283 | ||
5fe65ce7 MP |
284 | /* |
285 | * Disable the watchdog power down counter at boot. Otherwise the power | |
286 | * down counter will pull down the #WDOG interrupt line for one clock | |
287 | * cycle. | |
288 | */ | |
289 | regmap_write(wdev->regmap, IMX2_WDT_WMCR, 0); | |
290 | ||
faad5de0 AG |
291 | ret = watchdog_register_device(wdog); |
292 | if (ret) { | |
293 | dev_err(&pdev->dev, "cannot register watchdog device\n"); | |
db11cba2 | 294 | goto disable_clk; |
faad5de0 AG |
295 | } |
296 | ||
334a9d81 JL |
297 | wdev->restart_handler.notifier_call = imx2_restart_handler; |
298 | wdev->restart_handler.priority = 128; | |
299 | ret = register_restart_handler(&wdev->restart_handler); | |
300 | if (ret) | |
301 | dev_err(&pdev->dev, "cannot register restart handler\n"); | |
302 | ||
faad5de0 AG |
303 | dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n", |
304 | wdog->timeout, nowayout); | |
305 | ||
306 | return 0; | |
db11cba2 FE |
307 | |
308 | disable_clk: | |
309 | clk_disable_unprepare(wdev->clk); | |
310 | return ret; | |
bb2fd8a8 WS |
311 | } |
312 | ||
313 | static int __exit imx2_wdt_remove(struct platform_device *pdev) | |
314 | { | |
faad5de0 AG |
315 | struct watchdog_device *wdog = platform_get_drvdata(pdev); |
316 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); | |
bb2fd8a8 | 317 | |
334a9d81 JL |
318 | unregister_restart_handler(&wdev->restart_handler); |
319 | ||
faad5de0 | 320 | watchdog_unregister_device(wdog); |
bb2fd8a8 | 321 | |
faad5de0 AG |
322 | if (imx2_wdt_is_running(wdev)) { |
323 | del_timer_sync(&wdev->timer); | |
324 | imx2_wdt_ping(wdog); | |
325 | dev_crit(&pdev->dev, "Device removed: Expect reboot!\n"); | |
bdf49574 | 326 | } |
bb2fd8a8 WS |
327 | return 0; |
328 | } | |
329 | ||
330 | static void imx2_wdt_shutdown(struct platform_device *pdev) | |
331 | { | |
faad5de0 AG |
332 | struct watchdog_device *wdog = platform_get_drvdata(pdev); |
333 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); | |
334 | ||
335 | if (imx2_wdt_is_running(wdev)) { | |
336 | /* | |
337 | * We are running, we need to delete the timer but will | |
338 | * give max timeout before reboot will take place | |
339 | */ | |
340 | del_timer_sync(&wdev->timer); | |
341 | imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); | |
342 | imx2_wdt_ping(wdog); | |
343 | dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n"); | |
bb2fd8a8 WS |
344 | } |
345 | } | |
346 | ||
aefbaf3a | 347 | #ifdef CONFIG_PM_SLEEP |
bbd59009 | 348 | /* Disable watchdog if it is active or non-active but still running */ |
aefbaf3a XL |
349 | static int imx2_wdt_suspend(struct device *dev) |
350 | { | |
351 | struct watchdog_device *wdog = dev_get_drvdata(dev); | |
352 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); | |
353 | ||
bbd59009 XL |
354 | /* The watchdog IP block is running */ |
355 | if (imx2_wdt_is_running(wdev)) { | |
356 | imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); | |
357 | imx2_wdt_ping(wdog); | |
aefbaf3a | 358 | |
bbd59009 XL |
359 | /* The watchdog is not active */ |
360 | if (!watchdog_active(wdog)) | |
361 | del_timer_sync(&wdev->timer); | |
362 | } | |
aefbaf3a XL |
363 | |
364 | clk_disable_unprepare(wdev->clk); | |
365 | ||
366 | return 0; | |
367 | } | |
368 | ||
369 | /* Enable watchdog and configure it if necessary */ | |
370 | static int imx2_wdt_resume(struct device *dev) | |
371 | { | |
372 | struct watchdog_device *wdog = dev_get_drvdata(dev); | |
373 | struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); | |
aefb163c | 374 | int ret; |
aefbaf3a | 375 | |
aefb163c FE |
376 | ret = clk_prepare_enable(wdev->clk); |
377 | if (ret) | |
378 | return ret; | |
aefbaf3a XL |
379 | |
380 | if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) { | |
bbd59009 XL |
381 | /* |
382 | * If the watchdog is still active and resumes | |
383 | * from deep sleep state, need to restart the | |
384 | * watchdog again. | |
aefbaf3a XL |
385 | */ |
386 | imx2_wdt_setup(wdog); | |
387 | imx2_wdt_set_timeout(wdog, wdog->timeout); | |
388 | imx2_wdt_ping(wdog); | |
389 | } else if (imx2_wdt_is_running(wdev)) { | |
bbd59009 XL |
390 | /* Resuming from non-deep sleep state. */ |
391 | imx2_wdt_set_timeout(wdog, wdog->timeout); | |
aefbaf3a | 392 | imx2_wdt_ping(wdog); |
bbd59009 XL |
393 | /* |
394 | * But the watchdog is not active, then start | |
395 | * the timer again. | |
396 | */ | |
397 | if (!watchdog_active(wdog)) | |
398 | mod_timer(&wdev->timer, | |
399 | jiffies + wdog->timeout * HZ / 2); | |
aefbaf3a XL |
400 | } |
401 | ||
402 | return 0; | |
403 | } | |
404 | #endif | |
405 | ||
406 | static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend, | |
407 | imx2_wdt_resume); | |
408 | ||
f5a427ee SG |
409 | static const struct of_device_id imx2_wdt_dt_ids[] = { |
410 | { .compatible = "fsl,imx21-wdt", }, | |
411 | { /* sentinel */ } | |
412 | }; | |
813296a1 | 413 | MODULE_DEVICE_TABLE(of, imx2_wdt_dt_ids); |
f5a427ee | 414 | |
bb2fd8a8 | 415 | static struct platform_driver imx2_wdt_driver = { |
bb2fd8a8 WS |
416 | .remove = __exit_p(imx2_wdt_remove), |
417 | .shutdown = imx2_wdt_shutdown, | |
418 | .driver = { | |
419 | .name = DRIVER_NAME, | |
aefbaf3a | 420 | .pm = &imx2_wdt_pm_ops, |
f5a427ee | 421 | .of_match_table = imx2_wdt_dt_ids, |
bb2fd8a8 WS |
422 | }, |
423 | }; | |
424 | ||
1cb9204c | 425 | module_platform_driver_probe(imx2_wdt_driver, imx2_wdt_probe); |
bb2fd8a8 WS |
426 | |
427 | MODULE_AUTHOR("Wolfram Sang"); | |
428 | MODULE_DESCRIPTION("Watchdog driver for IMX2 and later"); | |
429 | MODULE_LICENSE("GPL v2"); | |
bb2fd8a8 | 430 | MODULE_ALIAS("platform:" DRIVER_NAME); |