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[mirror_ubuntu-hirsute-kernel.git] / drivers / watchdog / orion_wdt.c
1 /*
2 * drivers/watchdog/orion_wdt.c
3 *
4 * Watchdog driver for Orion/Kirkwood processors
5 *
6 * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/module.h>
16 #include <linux/moduleparam.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/platform_device.h>
20 #include <linux/watchdog.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/clk.h>
24 #include <linux/err.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27
28 /* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
29 #define ORION_RSTOUT_MASK_OFFSET 0x20108
30
31 /* Internal registers can be configured at any 1 MiB aligned address */
32 #define INTERNAL_REGS_MASK ~(SZ_1M - 1)
33
34 /*
35 * Watchdog timer block registers.
36 */
37 #define TIMER_CTRL 0x0000
38 #define TIMER_A370_STATUS 0x04
39
40 #define WDT_MAX_CYCLE_COUNT 0xffffffff
41
42 #define WDT_A370_RATIO_MASK(v) ((v) << 16)
43 #define WDT_A370_RATIO_SHIFT 5
44 #define WDT_A370_RATIO (1 << WDT_A370_RATIO_SHIFT)
45
46 #define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
47 #define WDT_A370_EXPIRED BIT(31)
48
49 static bool nowayout = WATCHDOG_NOWAYOUT;
50 static int heartbeat = -1; /* module parameter (seconds) */
51
52 struct orion_watchdog;
53
54 struct orion_watchdog_data {
55 int wdt_counter_offset;
56 int wdt_enable_bit;
57 int rstout_enable_bit;
58 int rstout_mask_bit;
59 int (*clock_init)(struct platform_device *,
60 struct orion_watchdog *);
61 int (*enabled)(struct orion_watchdog *);
62 int (*start)(struct watchdog_device *);
63 int (*stop)(struct watchdog_device *);
64 };
65
66 struct orion_watchdog {
67 struct watchdog_device wdt;
68 void __iomem *reg;
69 void __iomem *rstout;
70 void __iomem *rstout_mask;
71 unsigned long clk_rate;
72 struct clk *clk;
73 const struct orion_watchdog_data *data;
74 };
75
76 static int orion_wdt_clock_init(struct platform_device *pdev,
77 struct orion_watchdog *dev)
78 {
79 int ret;
80
81 dev->clk = clk_get(&pdev->dev, NULL);
82 if (IS_ERR(dev->clk))
83 return PTR_ERR(dev->clk);
84 ret = clk_prepare_enable(dev->clk);
85 if (ret) {
86 clk_put(dev->clk);
87 return ret;
88 }
89
90 dev->clk_rate = clk_get_rate(dev->clk);
91 return 0;
92 }
93
94 static int armada370_wdt_clock_init(struct platform_device *pdev,
95 struct orion_watchdog *dev)
96 {
97 int ret;
98
99 dev->clk = clk_get(&pdev->dev, NULL);
100 if (IS_ERR(dev->clk))
101 return PTR_ERR(dev->clk);
102 ret = clk_prepare_enable(dev->clk);
103 if (ret) {
104 clk_put(dev->clk);
105 return ret;
106 }
107
108 /* Setup watchdog input clock */
109 atomic_io_modify(dev->reg + TIMER_CTRL,
110 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
111 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
112
113 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
114 return 0;
115 }
116
117 static int armada375_wdt_clock_init(struct platform_device *pdev,
118 struct orion_watchdog *dev)
119 {
120 int ret;
121
122 dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
123 if (!IS_ERR(dev->clk)) {
124 ret = clk_prepare_enable(dev->clk);
125 if (ret) {
126 clk_put(dev->clk);
127 return ret;
128 }
129
130 atomic_io_modify(dev->reg + TIMER_CTRL,
131 WDT_AXP_FIXED_ENABLE_BIT,
132 WDT_AXP_FIXED_ENABLE_BIT);
133 dev->clk_rate = clk_get_rate(dev->clk);
134
135 return 0;
136 }
137
138 /* Mandatory fallback for proper devicetree backward compatibility */
139 dev->clk = clk_get(&pdev->dev, NULL);
140 if (IS_ERR(dev->clk))
141 return PTR_ERR(dev->clk);
142
143 ret = clk_prepare_enable(dev->clk);
144 if (ret) {
145 clk_put(dev->clk);
146 return ret;
147 }
148
149 atomic_io_modify(dev->reg + TIMER_CTRL,
150 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
151 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
152 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
153
154 return 0;
155 }
156
157 static int armadaxp_wdt_clock_init(struct platform_device *pdev,
158 struct orion_watchdog *dev)
159 {
160 int ret;
161
162 dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
163 if (IS_ERR(dev->clk))
164 return PTR_ERR(dev->clk);
165 ret = clk_prepare_enable(dev->clk);
166 if (ret) {
167 clk_put(dev->clk);
168 return ret;
169 }
170
171 /* Enable the fixed watchdog clock input */
172 atomic_io_modify(dev->reg + TIMER_CTRL,
173 WDT_AXP_FIXED_ENABLE_BIT,
174 WDT_AXP_FIXED_ENABLE_BIT);
175
176 dev->clk_rate = clk_get_rate(dev->clk);
177 return 0;
178 }
179
180 static int orion_wdt_ping(struct watchdog_device *wdt_dev)
181 {
182 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
183 /* Reload watchdog duration */
184 writel(dev->clk_rate * wdt_dev->timeout,
185 dev->reg + dev->data->wdt_counter_offset);
186 return 0;
187 }
188
189 static int armada375_start(struct watchdog_device *wdt_dev)
190 {
191 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
192 u32 reg;
193
194 /* Set watchdog duration */
195 writel(dev->clk_rate * wdt_dev->timeout,
196 dev->reg + dev->data->wdt_counter_offset);
197
198 /* Clear the watchdog expiration bit */
199 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
200
201 /* Enable watchdog timer */
202 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
203 dev->data->wdt_enable_bit);
204
205 /* Enable reset on watchdog */
206 reg = readl(dev->rstout);
207 reg |= dev->data->rstout_enable_bit;
208 writel(reg, dev->rstout);
209
210 atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
211 return 0;
212 }
213
214 static int armada370_start(struct watchdog_device *wdt_dev)
215 {
216 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
217 u32 reg;
218
219 /* Set watchdog duration */
220 writel(dev->clk_rate * wdt_dev->timeout,
221 dev->reg + dev->data->wdt_counter_offset);
222
223 /* Clear the watchdog expiration bit */
224 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
225
226 /* Enable watchdog timer */
227 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
228 dev->data->wdt_enable_bit);
229
230 /* Enable reset on watchdog */
231 reg = readl(dev->rstout);
232 reg |= dev->data->rstout_enable_bit;
233 writel(reg, dev->rstout);
234 return 0;
235 }
236
237 static int orion_start(struct watchdog_device *wdt_dev)
238 {
239 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
240
241 /* Set watchdog duration */
242 writel(dev->clk_rate * wdt_dev->timeout,
243 dev->reg + dev->data->wdt_counter_offset);
244
245 /* Enable watchdog timer */
246 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
247 dev->data->wdt_enable_bit);
248
249 /* Enable reset on watchdog */
250 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
251 dev->data->rstout_enable_bit);
252
253 return 0;
254 }
255
256 static int orion_wdt_start(struct watchdog_device *wdt_dev)
257 {
258 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
259
260 /* There are some per-SoC quirks to handle */
261 return dev->data->start(wdt_dev);
262 }
263
264 static int orion_stop(struct watchdog_device *wdt_dev)
265 {
266 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
267
268 /* Disable reset on watchdog */
269 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
270
271 /* Disable watchdog timer */
272 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
273
274 return 0;
275 }
276
277 static int armada375_stop(struct watchdog_device *wdt_dev)
278 {
279 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
280 u32 reg;
281
282 /* Disable reset on watchdog */
283 atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit,
284 dev->data->rstout_mask_bit);
285 reg = readl(dev->rstout);
286 reg &= ~dev->data->rstout_enable_bit;
287 writel(reg, dev->rstout);
288
289 /* Disable watchdog timer */
290 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
291
292 return 0;
293 }
294
295 static int armada370_stop(struct watchdog_device *wdt_dev)
296 {
297 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
298 u32 reg;
299
300 /* Disable reset on watchdog */
301 reg = readl(dev->rstout);
302 reg &= ~dev->data->rstout_enable_bit;
303 writel(reg, dev->rstout);
304
305 /* Disable watchdog timer */
306 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
307
308 return 0;
309 }
310
311 static int orion_wdt_stop(struct watchdog_device *wdt_dev)
312 {
313 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
314
315 return dev->data->stop(wdt_dev);
316 }
317
318 static int orion_enabled(struct orion_watchdog *dev)
319 {
320 bool enabled, running;
321
322 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
323 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
324
325 return enabled && running;
326 }
327
328 static int armada375_enabled(struct orion_watchdog *dev)
329 {
330 bool masked, enabled, running;
331
332 masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit;
333 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
334 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
335
336 return !masked && enabled && running;
337 }
338
339 static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
340 {
341 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
342
343 return dev->data->enabled(dev);
344 }
345
346 static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
347 {
348 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
349 return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
350 }
351
352 static const struct watchdog_info orion_wdt_info = {
353 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
354 .identity = "Orion Watchdog",
355 };
356
357 static const struct watchdog_ops orion_wdt_ops = {
358 .owner = THIS_MODULE,
359 .start = orion_wdt_start,
360 .stop = orion_wdt_stop,
361 .ping = orion_wdt_ping,
362 .get_timeleft = orion_wdt_get_timeleft,
363 };
364
365 static irqreturn_t orion_wdt_irq(int irq, void *devid)
366 {
367 panic("Watchdog Timeout");
368 return IRQ_HANDLED;
369 }
370
371 /*
372 * The original devicetree binding for this driver specified only
373 * one memory resource, so in order to keep DT backwards compatibility
374 * we try to fallback to a hardcoded register address, if the resource
375 * is missing from the devicetree.
376 */
377 static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
378 phys_addr_t internal_regs)
379 {
380 struct resource *res;
381 phys_addr_t rstout;
382
383 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
384 if (res)
385 return devm_ioremap(&pdev->dev, res->start,
386 resource_size(res));
387
388 rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
389
390 WARN(1, FW_BUG "falling back to hardcoded RSTOUT reg %pa\n", &rstout);
391 return devm_ioremap(&pdev->dev, rstout, 0x4);
392 }
393
394 static const struct orion_watchdog_data orion_data = {
395 .rstout_enable_bit = BIT(1),
396 .wdt_enable_bit = BIT(4),
397 .wdt_counter_offset = 0x24,
398 .clock_init = orion_wdt_clock_init,
399 .enabled = orion_enabled,
400 .start = orion_start,
401 .stop = orion_stop,
402 };
403
404 static const struct orion_watchdog_data armada370_data = {
405 .rstout_enable_bit = BIT(8),
406 .wdt_enable_bit = BIT(8),
407 .wdt_counter_offset = 0x34,
408 .clock_init = armada370_wdt_clock_init,
409 .enabled = orion_enabled,
410 .start = armada370_start,
411 .stop = armada370_stop,
412 };
413
414 static const struct orion_watchdog_data armadaxp_data = {
415 .rstout_enable_bit = BIT(8),
416 .wdt_enable_bit = BIT(8),
417 .wdt_counter_offset = 0x34,
418 .clock_init = armadaxp_wdt_clock_init,
419 .enabled = orion_enabled,
420 .start = armada370_start,
421 .stop = armada370_stop,
422 };
423
424 static const struct orion_watchdog_data armada375_data = {
425 .rstout_enable_bit = BIT(8),
426 .rstout_mask_bit = BIT(10),
427 .wdt_enable_bit = BIT(8),
428 .wdt_counter_offset = 0x34,
429 .clock_init = armada375_wdt_clock_init,
430 .enabled = armada375_enabled,
431 .start = armada375_start,
432 .stop = armada375_stop,
433 };
434
435 static const struct orion_watchdog_data armada380_data = {
436 .rstout_enable_bit = BIT(8),
437 .rstout_mask_bit = BIT(10),
438 .wdt_enable_bit = BIT(8),
439 .wdt_counter_offset = 0x34,
440 .clock_init = armadaxp_wdt_clock_init,
441 .enabled = armada375_enabled,
442 .start = armada375_start,
443 .stop = armada375_stop,
444 };
445
446 static const struct of_device_id orion_wdt_of_match_table[] = {
447 {
448 .compatible = "marvell,orion-wdt",
449 .data = &orion_data,
450 },
451 {
452 .compatible = "marvell,armada-370-wdt",
453 .data = &armada370_data,
454 },
455 {
456 .compatible = "marvell,armada-xp-wdt",
457 .data = &armadaxp_data,
458 },
459 {
460 .compatible = "marvell,armada-375-wdt",
461 .data = &armada375_data,
462 },
463 {
464 .compatible = "marvell,armada-380-wdt",
465 .data = &armada380_data,
466 },
467 {},
468 };
469 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
470
471 static int orion_wdt_get_regs(struct platform_device *pdev,
472 struct orion_watchdog *dev)
473 {
474 struct device_node *node = pdev->dev.of_node;
475 struct resource *res;
476
477 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
478 if (!res)
479 return -ENODEV;
480 dev->reg = devm_ioremap(&pdev->dev, res->start,
481 resource_size(res));
482 if (!dev->reg)
483 return -ENOMEM;
484
485 /* Each supported compatible has some RSTOUT register quirk */
486 if (of_device_is_compatible(node, "marvell,orion-wdt")) {
487
488 dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
489 INTERNAL_REGS_MASK);
490 if (!dev->rstout)
491 return -ENODEV;
492
493 } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
494 of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
495
496 /* Dedicated RSTOUT register, can be requested. */
497 dev->rstout = devm_platform_ioremap_resource(pdev, 1);
498 if (IS_ERR(dev->rstout))
499 return PTR_ERR(dev->rstout);
500
501 } else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
502 of_device_is_compatible(node, "marvell,armada-380-wdt")) {
503
504 /* Dedicated RSTOUT register, can be requested. */
505 dev->rstout = devm_platform_ioremap_resource(pdev, 1);
506 if (IS_ERR(dev->rstout))
507 return PTR_ERR(dev->rstout);
508
509 res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
510 if (!res)
511 return -ENODEV;
512 dev->rstout_mask = devm_ioremap(&pdev->dev, res->start,
513 resource_size(res));
514 if (!dev->rstout_mask)
515 return -ENOMEM;
516
517 } else {
518 return -ENODEV;
519 }
520
521 return 0;
522 }
523
524 static int orion_wdt_probe(struct platform_device *pdev)
525 {
526 struct orion_watchdog *dev;
527 const struct of_device_id *match;
528 unsigned int wdt_max_duration; /* (seconds) */
529 int ret, irq;
530
531 dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
532 GFP_KERNEL);
533 if (!dev)
534 return -ENOMEM;
535
536 match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
537 if (!match)
538 /* Default legacy match */
539 match = &orion_wdt_of_match_table[0];
540
541 dev->wdt.info = &orion_wdt_info;
542 dev->wdt.ops = &orion_wdt_ops;
543 dev->wdt.min_timeout = 1;
544 dev->data = match->data;
545
546 ret = orion_wdt_get_regs(pdev, dev);
547 if (ret)
548 return ret;
549
550 ret = dev->data->clock_init(pdev, dev);
551 if (ret) {
552 dev_err(&pdev->dev, "cannot initialize clock\n");
553 return ret;
554 }
555
556 wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
557
558 dev->wdt.timeout = wdt_max_duration;
559 dev->wdt.max_timeout = wdt_max_duration;
560 dev->wdt.parent = &pdev->dev;
561 watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
562
563 platform_set_drvdata(pdev, &dev->wdt);
564 watchdog_set_drvdata(&dev->wdt, dev);
565
566 /*
567 * Let's make sure the watchdog is fully stopped, unless it's
568 * explicitly enabled. This may be the case if the module was
569 * removed and re-inserted, or if the bootloader explicitly
570 * set a running watchdog before booting the kernel.
571 */
572 if (!orion_wdt_enabled(&dev->wdt))
573 orion_wdt_stop(&dev->wdt);
574 else
575 set_bit(WDOG_HW_RUNNING, &dev->wdt.status);
576
577 /* Request the IRQ only after the watchdog is disabled */
578 irq = platform_get_irq(pdev, 0);
579 if (irq > 0) {
580 /*
581 * Not all supported platforms specify an interrupt for the
582 * watchdog, so let's make it optional.
583 */
584 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
585 pdev->name, dev);
586 if (ret < 0) {
587 dev_err(&pdev->dev, "failed to request IRQ\n");
588 goto disable_clk;
589 }
590 }
591
592 watchdog_set_nowayout(&dev->wdt, nowayout);
593 ret = watchdog_register_device(&dev->wdt);
594 if (ret)
595 goto disable_clk;
596
597 pr_info("Initial timeout %d sec%s\n",
598 dev->wdt.timeout, nowayout ? ", nowayout" : "");
599 return 0;
600
601 disable_clk:
602 clk_disable_unprepare(dev->clk);
603 clk_put(dev->clk);
604 return ret;
605 }
606
607 static int orion_wdt_remove(struct platform_device *pdev)
608 {
609 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
610 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
611
612 watchdog_unregister_device(wdt_dev);
613 clk_disable_unprepare(dev->clk);
614 clk_put(dev->clk);
615 return 0;
616 }
617
618 static void orion_wdt_shutdown(struct platform_device *pdev)
619 {
620 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
621 orion_wdt_stop(wdt_dev);
622 }
623
624 static struct platform_driver orion_wdt_driver = {
625 .probe = orion_wdt_probe,
626 .remove = orion_wdt_remove,
627 .shutdown = orion_wdt_shutdown,
628 .driver = {
629 .name = "orion_wdt",
630 .of_match_table = orion_wdt_of_match_table,
631 },
632 };
633
634 module_platform_driver(orion_wdt_driver);
635
636 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
637 MODULE_DESCRIPTION("Orion Processor Watchdog");
638
639 module_param(heartbeat, int, 0);
640 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
641
642 module_param(nowayout, bool, 0);
643 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
644 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
645
646 MODULE_LICENSE("GPL v2");
647 MODULE_ALIAS("platform:orion_wdt");