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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/watchdog/orion_wdt.c
4 *
5 * Watchdog driver for Orion/Kirkwood processors
6 *
7 * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
8 *
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/platform_device.h>
18#include <linux/watchdog.h>
19#include <linux/interrupt.h>
20#include <linux/io.h>
21#include <linux/clk.h>
22#include <linux/err.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25
26/* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
27#define ORION_RSTOUT_MASK_OFFSET 0x20108
28
29/* Internal registers can be configured at any 1 MiB aligned address */
30#define INTERNAL_REGS_MASK ~(SZ_1M - 1)
31
32/*
33 * Watchdog timer block registers.
34 */
35#define TIMER_CTRL 0x0000
36#define TIMER1_FIXED_ENABLE_BIT BIT(12)
37#define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
38#define TIMER1_ENABLE_BIT BIT(2)
39
40#define TIMER_A370_STATUS 0x0004
41#define WDT_A370_EXPIRED BIT(31)
42#define TIMER1_STATUS_BIT BIT(8)
43
44#define TIMER1_VAL_OFF 0x001c
45
46#define WDT_MAX_CYCLE_COUNT 0xffffffff
47
48#define WDT_A370_RATIO_MASK(v) ((v) << 16)
49#define WDT_A370_RATIO_SHIFT 5
50#define WDT_A370_RATIO (1 << WDT_A370_RATIO_SHIFT)
51
52static bool nowayout = WATCHDOG_NOWAYOUT;
53static int heartbeat; /* module parameter (seconds) */
54
55struct orion_watchdog;
56
57struct orion_watchdog_data {
58 int wdt_counter_offset;
59 int wdt_enable_bit;
60 int rstout_enable_bit;
61 int rstout_mask_bit;
62 int (*clock_init)(struct platform_device *,
63 struct orion_watchdog *);
64 int (*enabled)(struct orion_watchdog *);
65 int (*start)(struct watchdog_device *);
66 int (*stop)(struct watchdog_device *);
67};
68
69struct orion_watchdog {
70 struct watchdog_device wdt;
71 void __iomem *reg;
72 void __iomem *rstout;
73 void __iomem *rstout_mask;
74 unsigned long clk_rate;
75 struct clk *clk;
76 const struct orion_watchdog_data *data;
77};
78
79static int orion_wdt_clock_init(struct platform_device *pdev,
80 struct orion_watchdog *dev)
81{
82 int ret;
83
84 dev->clk = clk_get(&pdev->dev, NULL);
85 if (IS_ERR(dev->clk))
86 return PTR_ERR(dev->clk);
87 ret = clk_prepare_enable(dev->clk);
88 if (ret) {
89 clk_put(dev->clk);
90 return ret;
91 }
92
93 dev->clk_rate = clk_get_rate(dev->clk);
94 return 0;
95}
96
97static int armada370_wdt_clock_init(struct platform_device *pdev,
98 struct orion_watchdog *dev)
99{
100 int ret;
101
102 dev->clk = clk_get(&pdev->dev, NULL);
103 if (IS_ERR(dev->clk))
104 return PTR_ERR(dev->clk);
105 ret = clk_prepare_enable(dev->clk);
106 if (ret) {
107 clk_put(dev->clk);
108 return ret;
109 }
110
111 /* Setup watchdog input clock */
112 atomic_io_modify(dev->reg + TIMER_CTRL,
113 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
114 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
115
116 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
117 return 0;
118}
119
120static int armada375_wdt_clock_init(struct platform_device *pdev,
121 struct orion_watchdog *dev)
122{
123 int ret;
124
125 dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
126 if (!IS_ERR(dev->clk)) {
127 ret = clk_prepare_enable(dev->clk);
128 if (ret) {
129 clk_put(dev->clk);
130 return ret;
131 }
132
133 atomic_io_modify(dev->reg + TIMER_CTRL,
134 WDT_AXP_FIXED_ENABLE_BIT,
135 WDT_AXP_FIXED_ENABLE_BIT);
136 dev->clk_rate = clk_get_rate(dev->clk);
137
138 return 0;
139 }
140
141 /* Mandatory fallback for proper devicetree backward compatibility */
142 dev->clk = clk_get(&pdev->dev, NULL);
143 if (IS_ERR(dev->clk))
144 return PTR_ERR(dev->clk);
145
146 ret = clk_prepare_enable(dev->clk);
147 if (ret) {
148 clk_put(dev->clk);
149 return ret;
150 }
151
152 atomic_io_modify(dev->reg + TIMER_CTRL,
153 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
154 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
155 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
156
157 return 0;
158}
159
160static int armadaxp_wdt_clock_init(struct platform_device *pdev,
161 struct orion_watchdog *dev)
162{
163 int ret;
164 u32 val;
165
166 dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
167 if (IS_ERR(dev->clk))
168 return PTR_ERR(dev->clk);
169 ret = clk_prepare_enable(dev->clk);
170 if (ret) {
171 clk_put(dev->clk);
172 return ret;
173 }
174
175 /* Fix the wdt and timer1 clock frequency to 25MHz */
176 val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT;
177 atomic_io_modify(dev->reg + TIMER_CTRL, val, val);
178
179 dev->clk_rate = clk_get_rate(dev->clk);
180 return 0;
181}
182
183static int orion_wdt_ping(struct watchdog_device *wdt_dev)
184{
185 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
186 /* Reload watchdog duration */
187 writel(dev->clk_rate * wdt_dev->timeout,
188 dev->reg + dev->data->wdt_counter_offset);
189 if (dev->wdt.info->options & WDIOF_PRETIMEOUT)
190 writel(dev->clk_rate * (wdt_dev->timeout - wdt_dev->pretimeout),
191 dev->reg + TIMER1_VAL_OFF);
192
193 return 0;
194}
195
196static int armada375_start(struct watchdog_device *wdt_dev)
197{
198 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
199 u32 reg;
200
201 /* Set watchdog duration */
202 writel(dev->clk_rate * wdt_dev->timeout,
203 dev->reg + dev->data->wdt_counter_offset);
204 if (dev->wdt.info->options & WDIOF_PRETIMEOUT)
205 writel(dev->clk_rate * (wdt_dev->timeout - wdt_dev->pretimeout),
206 dev->reg + TIMER1_VAL_OFF);
207
208 /* Clear the watchdog expiration bit */
209 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
210
211 /* Enable watchdog timer */
212 reg = dev->data->wdt_enable_bit;
213 if (dev->wdt.info->options & WDIOF_PRETIMEOUT)
214 reg |= TIMER1_ENABLE_BIT;
215 atomic_io_modify(dev->reg + TIMER_CTRL, reg, reg);
216
217 /* Enable reset on watchdog */
218 reg = readl(dev->rstout);
219 reg |= dev->data->rstout_enable_bit;
220 writel(reg, dev->rstout);
221
222 atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
223 return 0;
224}
225
226static int armada370_start(struct watchdog_device *wdt_dev)
227{
228 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
229 u32 reg;
230
231 /* Set watchdog duration */
232 writel(dev->clk_rate * wdt_dev->timeout,
233 dev->reg + dev->data->wdt_counter_offset);
234
235 /* Clear the watchdog expiration bit */
236 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
237
238 /* Enable watchdog timer */
239 reg = dev->data->wdt_enable_bit;
240 if (dev->wdt.info->options & WDIOF_PRETIMEOUT)
241 reg |= TIMER1_ENABLE_BIT;
242 atomic_io_modify(dev->reg + TIMER_CTRL, reg, reg);
243
244 /* Enable reset on watchdog */
245 reg = readl(dev->rstout);
246 reg |= dev->data->rstout_enable_bit;
247 writel(reg, dev->rstout);
248 return 0;
249}
250
251static int orion_start(struct watchdog_device *wdt_dev)
252{
253 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
254
255 /* Set watchdog duration */
256 writel(dev->clk_rate * wdt_dev->timeout,
257 dev->reg + dev->data->wdt_counter_offset);
258
259 /* Enable watchdog timer */
260 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
261 dev->data->wdt_enable_bit);
262
263 /* Enable reset on watchdog */
264 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
265 dev->data->rstout_enable_bit);
266
267 return 0;
268}
269
270static int orion_wdt_start(struct watchdog_device *wdt_dev)
271{
272 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
273
274 /* There are some per-SoC quirks to handle */
275 return dev->data->start(wdt_dev);
276}
277
278static int orion_stop(struct watchdog_device *wdt_dev)
279{
280 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
281
282 /* Disable reset on watchdog */
283 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
284
285 /* Disable watchdog timer */
286 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
287
288 return 0;
289}
290
291static int armada375_stop(struct watchdog_device *wdt_dev)
292{
293 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
294 u32 reg, mask;
295
296 /* Disable reset on watchdog */
297 atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit,
298 dev->data->rstout_mask_bit);
299 reg = readl(dev->rstout);
300 reg &= ~dev->data->rstout_enable_bit;
301 writel(reg, dev->rstout);
302
303 /* Disable watchdog timer */
304 mask = dev->data->wdt_enable_bit;
305 if (wdt_dev->info->options & WDIOF_PRETIMEOUT)
306 mask |= TIMER1_ENABLE_BIT;
307 atomic_io_modify(dev->reg + TIMER_CTRL, mask, 0);
308
309 return 0;
310}
311
312static int armada370_stop(struct watchdog_device *wdt_dev)
313{
314 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
315 u32 reg, mask;
316
317 /* Disable reset on watchdog */
318 reg = readl(dev->rstout);
319 reg &= ~dev->data->rstout_enable_bit;
320 writel(reg, dev->rstout);
321
322 /* Disable watchdog timer */
323 mask = dev->data->wdt_enable_bit;
324 if (wdt_dev->info->options & WDIOF_PRETIMEOUT)
325 mask |= TIMER1_ENABLE_BIT;
326 atomic_io_modify(dev->reg + TIMER_CTRL, mask, 0);
327
328 return 0;
329}
330
331static int orion_wdt_stop(struct watchdog_device *wdt_dev)
332{
333 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
334
335 return dev->data->stop(wdt_dev);
336}
337
338static int orion_enabled(struct orion_watchdog *dev)
339{
340 bool enabled, running;
341
342 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
343 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
344
345 return enabled && running;
346}
347
348static int armada375_enabled(struct orion_watchdog *dev)
349{
350 bool masked, enabled, running;
351
352 masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit;
353 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
354 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
355
356 return !masked && enabled && running;
357}
358
359static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
360{
361 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
362
363 return dev->data->enabled(dev);
364}
365
366static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
367{
368 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
369 return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
370}
371
372static struct watchdog_info orion_wdt_info = {
373 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
374 .identity = "Orion Watchdog",
375};
376
377static const struct watchdog_ops orion_wdt_ops = {
378 .owner = THIS_MODULE,
379 .start = orion_wdt_start,
380 .stop = orion_wdt_stop,
381 .ping = orion_wdt_ping,
382 .get_timeleft = orion_wdt_get_timeleft,
383};
384
385static irqreturn_t orion_wdt_irq(int irq, void *devid)
386{
387 panic("Watchdog Timeout");
388 return IRQ_HANDLED;
389}
390
391static irqreturn_t orion_wdt_pre_irq(int irq, void *devid)
392{
393 struct orion_watchdog *dev = devid;
394
395 atomic_io_modify(dev->reg + TIMER_A370_STATUS,
396 TIMER1_STATUS_BIT, 0);
397 watchdog_notify_pretimeout(&dev->wdt);
398 return IRQ_HANDLED;
399}
400
401/*
402 * The original devicetree binding for this driver specified only
403 * one memory resource, so in order to keep DT backwards compatibility
404 * we try to fallback to a hardcoded register address, if the resource
405 * is missing from the devicetree.
406 */
407static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
408 phys_addr_t internal_regs)
409{
410 struct resource *res;
411 phys_addr_t rstout;
412
413 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
414 if (res)
415 return devm_ioremap(&pdev->dev, res->start,
416 resource_size(res));
417
418 rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
419
420 WARN(1, FW_BUG "falling back to hardcoded RSTOUT reg %pa\n", &rstout);
421 return devm_ioremap(&pdev->dev, rstout, 0x4);
422}
423
424static const struct orion_watchdog_data orion_data = {
425 .rstout_enable_bit = BIT(1),
426 .wdt_enable_bit = BIT(4),
427 .wdt_counter_offset = 0x24,
428 .clock_init = orion_wdt_clock_init,
429 .enabled = orion_enabled,
430 .start = orion_start,
431 .stop = orion_stop,
432};
433
434static const struct orion_watchdog_data armada370_data = {
435 .rstout_enable_bit = BIT(8),
436 .wdt_enable_bit = BIT(8),
437 .wdt_counter_offset = 0x34,
438 .clock_init = armada370_wdt_clock_init,
439 .enabled = orion_enabled,
440 .start = armada370_start,
441 .stop = armada370_stop,
442};
443
444static const struct orion_watchdog_data armadaxp_data = {
445 .rstout_enable_bit = BIT(8),
446 .wdt_enable_bit = BIT(8),
447 .wdt_counter_offset = 0x34,
448 .clock_init = armadaxp_wdt_clock_init,
449 .enabled = orion_enabled,
450 .start = armada370_start,
451 .stop = armada370_stop,
452};
453
454static const struct orion_watchdog_data armada375_data = {
455 .rstout_enable_bit = BIT(8),
456 .rstout_mask_bit = BIT(10),
457 .wdt_enable_bit = BIT(8),
458 .wdt_counter_offset = 0x34,
459 .clock_init = armada375_wdt_clock_init,
460 .enabled = armada375_enabled,
461 .start = armada375_start,
462 .stop = armada375_stop,
463};
464
465static const struct orion_watchdog_data armada380_data = {
466 .rstout_enable_bit = BIT(8),
467 .rstout_mask_bit = BIT(10),
468 .wdt_enable_bit = BIT(8),
469 .wdt_counter_offset = 0x34,
470 .clock_init = armadaxp_wdt_clock_init,
471 .enabled = armada375_enabled,
472 .start = armada375_start,
473 .stop = armada375_stop,
474};
475
476static const struct of_device_id orion_wdt_of_match_table[] = {
477 {
478 .compatible = "marvell,orion-wdt",
479 .data = &orion_data,
480 },
481 {
482 .compatible = "marvell,armada-370-wdt",
483 .data = &armada370_data,
484 },
485 {
486 .compatible = "marvell,armada-xp-wdt",
487 .data = &armadaxp_data,
488 },
489 {
490 .compatible = "marvell,armada-375-wdt",
491 .data = &armada375_data,
492 },
493 {
494 .compatible = "marvell,armada-380-wdt",
495 .data = &armada380_data,
496 },
497 {},
498};
499MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
500
501static int orion_wdt_get_regs(struct platform_device *pdev,
502 struct orion_watchdog *dev)
503{
504 struct device_node *node = pdev->dev.of_node;
505 struct resource *res;
506
507 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
508 if (!res)
509 return -ENODEV;
510 dev->reg = devm_ioremap(&pdev->dev, res->start,
511 resource_size(res));
512 if (!dev->reg)
513 return -ENOMEM;
514
515 /* Each supported compatible has some RSTOUT register quirk */
516 if (of_device_is_compatible(node, "marvell,orion-wdt")) {
517
518 dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
519 INTERNAL_REGS_MASK);
520 if (!dev->rstout)
521 return -ENODEV;
522
523 } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
524 of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
525
526 /* Dedicated RSTOUT register, can be requested. */
527 dev->rstout = devm_platform_ioremap_resource(pdev, 1);
528 if (IS_ERR(dev->rstout))
529 return PTR_ERR(dev->rstout);
530
531 } else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
532 of_device_is_compatible(node, "marvell,armada-380-wdt")) {
533
534 /* Dedicated RSTOUT register, can be requested. */
535 dev->rstout = devm_platform_ioremap_resource(pdev, 1);
536 if (IS_ERR(dev->rstout))
537 return PTR_ERR(dev->rstout);
538
539 res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
540 if (!res)
541 return -ENODEV;
542 dev->rstout_mask = devm_ioremap(&pdev->dev, res->start,
543 resource_size(res));
544 if (!dev->rstout_mask)
545 return -ENOMEM;
546
547 } else {
548 return -ENODEV;
549 }
550
551 return 0;
552}
553
554static int orion_wdt_probe(struct platform_device *pdev)
555{
556 struct orion_watchdog *dev;
557 const struct of_device_id *match;
558 unsigned int wdt_max_duration; /* (seconds) */
559 int ret, irq;
560
561 dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
562 GFP_KERNEL);
563 if (!dev)
564 return -ENOMEM;
565
566 match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
567 if (!match)
568 /* Default legacy match */
569 match = &orion_wdt_of_match_table[0];
570
571 dev->wdt.info = &orion_wdt_info;
572 dev->wdt.ops = &orion_wdt_ops;
573 dev->wdt.min_timeout = 1;
574 dev->data = match->data;
575
576 ret = orion_wdt_get_regs(pdev, dev);
577 if (ret)
578 return ret;
579
580 ret = dev->data->clock_init(pdev, dev);
581 if (ret) {
582 dev_err(&pdev->dev, "cannot initialize clock\n");
583 return ret;
584 }
585
586 wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
587
588 dev->wdt.timeout = wdt_max_duration;
589 dev->wdt.max_timeout = wdt_max_duration;
590 dev->wdt.parent = &pdev->dev;
591 watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
592
593 platform_set_drvdata(pdev, &dev->wdt);
594 watchdog_set_drvdata(&dev->wdt, dev);
595
596 /*
597 * Let's make sure the watchdog is fully stopped, unless it's
598 * explicitly enabled. This may be the case if the module was
599 * removed and re-inserted, or if the bootloader explicitly
600 * set a running watchdog before booting the kernel.
601 */
602 if (!orion_wdt_enabled(&dev->wdt))
603 orion_wdt_stop(&dev->wdt);
604 else
605 set_bit(WDOG_HW_RUNNING, &dev->wdt.status);
606
607 /* Request the IRQ only after the watchdog is disabled */
608 irq = platform_get_irq_optional(pdev, 0);
609 if (irq > 0) {
610 /*
611 * Not all supported platforms specify an interrupt for the
612 * watchdog, so let's make it optional.
613 */
614 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
615 pdev->name, dev);
616 if (ret < 0) {
617 dev_err(&pdev->dev, "failed to request IRQ\n");
618 goto disable_clk;
619 }
620 }
621
622 /* Optional 2nd interrupt for pretimeout */
623 irq = platform_get_irq_optional(pdev, 1);
624 if (irq > 0) {
625 orion_wdt_info.options |= WDIOF_PRETIMEOUT;
626 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_pre_irq,
627 0, pdev->name, dev);
628 if (ret < 0) {
629 dev_err(&pdev->dev, "failed to request IRQ\n");
630 goto disable_clk;
631 }
632 }
633
634
635 watchdog_set_nowayout(&dev->wdt, nowayout);
636 ret = watchdog_register_device(&dev->wdt);
637 if (ret)
638 goto disable_clk;
639
640 pr_info("Initial timeout %d sec%s\n",
641 dev->wdt.timeout, nowayout ? ", nowayout" : "");
642 return 0;
643
644disable_clk:
645 clk_disable_unprepare(dev->clk);
646 clk_put(dev->clk);
647 return ret;
648}
649
650static void orion_wdt_remove(struct platform_device *pdev)
651{
652 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
653 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
654
655 watchdog_unregister_device(wdt_dev);
656 clk_disable_unprepare(dev->clk);
657 clk_put(dev->clk);
658}
659
660static void orion_wdt_shutdown(struct platform_device *pdev)
661{
662 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
663 orion_wdt_stop(wdt_dev);
664}
665
666static struct platform_driver orion_wdt_driver = {
667 .probe = orion_wdt_probe,
668 .remove_new = orion_wdt_remove,
669 .shutdown = orion_wdt_shutdown,
670 .driver = {
671 .name = "orion_wdt",
672 .of_match_table = orion_wdt_of_match_table,
673 },
674};
675
676module_platform_driver(orion_wdt_driver);
677
678MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
679MODULE_DESCRIPTION("Orion Processor Watchdog");
680
681module_param(heartbeat, int, 0);
682MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
683
684module_param(nowayout, bool, 0);
685MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
686 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
687
688MODULE_LICENSE("GPL v2");
689MODULE_ALIAS("platform:orion_wdt");
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#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/fs.h>
18#include <linux/miscdevice.h>
19#include <linux/platform_device.h>
20#include <linux/watchdog.h>
21#include <linux/init.h>
22#include <linux/uaccess.h>
23#include <linux/io.h>
24#include <linux/spinlock.h>
25#include <mach/bridge-regs.h>
26#include <plat/orion_wdt.h>
27
28/*
29 * Watchdog timer block registers.
30 */
31#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000)
32#define WDT_EN 0x0010
33#define WDT_VAL (TIMER_VIRT_BASE + 0x0024)
34
35#define WDT_MAX_CYCLE_COUNT 0xffffffff
36#define WDT_IN_USE 0
37#define WDT_OK_TO_CLOSE 1
38
39static int nowayout = WATCHDOG_NOWAYOUT;
40static int heartbeat = -1; /* module parameter (seconds) */
41static unsigned int wdt_max_duration; /* (seconds) */
42static unsigned int wdt_tclk;
43static unsigned long wdt_status;
44static spinlock_t wdt_lock;
45
46static void orion_wdt_ping(void)
47{
48 spin_lock(&wdt_lock);
49
50 /* Reload watchdog duration */
51 writel(wdt_tclk * heartbeat, WDT_VAL);
52
53 spin_unlock(&wdt_lock);
54}
55
56static void orion_wdt_enable(void)
57{
58 u32 reg;
59
60 spin_lock(&wdt_lock);
61
62 /* Set watchdog duration */
63 writel(wdt_tclk * heartbeat, WDT_VAL);
64
65 /* Clear watchdog timer interrupt */
66 reg = readl(BRIDGE_CAUSE);
67 reg &= ~WDT_INT_REQ;
68 writel(reg, BRIDGE_CAUSE);
69
70 /* Enable watchdog timer */
71 reg = readl(TIMER_CTRL);
72 reg |= WDT_EN;
73 writel(reg, TIMER_CTRL);
74
75 /* Enable reset on watchdog */
76 reg = readl(RSTOUTn_MASK);
77 reg |= WDT_RESET_OUT_EN;
78 writel(reg, RSTOUTn_MASK);
79
80 spin_unlock(&wdt_lock);
81}
82
83static void orion_wdt_disable(void)
84{
85 u32 reg;
86
87 spin_lock(&wdt_lock);
88
89 /* Disable reset on watchdog */
90 reg = readl(RSTOUTn_MASK);
91 reg &= ~WDT_RESET_OUT_EN;
92 writel(reg, RSTOUTn_MASK);
93
94 /* Disable watchdog timer */
95 reg = readl(TIMER_CTRL);
96 reg &= ~WDT_EN;
97 writel(reg, TIMER_CTRL);
98
99 spin_unlock(&wdt_lock);
100}
101
102static int orion_wdt_get_timeleft(int *time_left)
103{
104 spin_lock(&wdt_lock);
105 *time_left = readl(WDT_VAL) / wdt_tclk;
106 spin_unlock(&wdt_lock);
107 return 0;
108}
109
110static int orion_wdt_open(struct inode *inode, struct file *file)
111{
112 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
113 return -EBUSY;
114 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
115 orion_wdt_enable();
116 return nonseekable_open(inode, file);
117}
118
119static ssize_t orion_wdt_write(struct file *file, const char *data,
120 size_t len, loff_t *ppos)
121{
122 if (len) {
123 if (!nowayout) {
124 size_t i;
125
126 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
127 for (i = 0; i != len; i++) {
128 char c;
129
130 if (get_user(c, data + i))
131 return -EFAULT;
132 if (c == 'V')
133 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
134 }
135 }
136 orion_wdt_ping();
137 }
138 return len;
139}
140
141static int orion_wdt_settimeout(int new_time)
142{
143 if ((new_time <= 0) || (new_time > wdt_max_duration))
144 return -EINVAL;
145
146 /* Set new watchdog time to be used when
147 * orion_wdt_enable() or orion_wdt_ping() is called. */
148 heartbeat = new_time;
149 return 0;
150}
151
152static const struct watchdog_info ident = {
153 .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
154 WDIOF_KEEPALIVEPING,
155 .identity = "Orion Watchdog",
156};
157
158static long orion_wdt_ioctl(struct file *file, unsigned int cmd,
159 unsigned long arg)
160{
161 int ret = -ENOTTY;
162 int time;
163
164 switch (cmd) {
165 case WDIOC_GETSUPPORT:
166 ret = copy_to_user((struct watchdog_info *)arg, &ident,
167 sizeof(ident)) ? -EFAULT : 0;
168 break;
169
170 case WDIOC_GETSTATUS:
171 case WDIOC_GETBOOTSTATUS:
172 ret = put_user(0, (int *)arg);
173 break;
174
175 case WDIOC_KEEPALIVE:
176 orion_wdt_ping();
177 ret = 0;
178 break;
179
180 case WDIOC_SETTIMEOUT:
181 ret = get_user(time, (int *)arg);
182 if (ret)
183 break;
184
185 if (orion_wdt_settimeout(time)) {
186 ret = -EINVAL;
187 break;
188 }
189 orion_wdt_ping();
190 /* Fall through */
191
192 case WDIOC_GETTIMEOUT:
193 ret = put_user(heartbeat, (int *)arg);
194 break;
195
196 case WDIOC_GETTIMELEFT:
197 if (orion_wdt_get_timeleft(&time)) {
198 ret = -EINVAL;
199 break;
200 }
201 ret = put_user(time, (int *)arg);
202 break;
203 }
204 return ret;
205}
206
207static int orion_wdt_release(struct inode *inode, struct file *file)
208{
209 if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
210 orion_wdt_disable();
211 else
212 printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
213 "timer will not stop\n");
214 clear_bit(WDT_IN_USE, &wdt_status);
215 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
216
217 return 0;
218}
219
220
221static const struct file_operations orion_wdt_fops = {
222 .owner = THIS_MODULE,
223 .llseek = no_llseek,
224 .write = orion_wdt_write,
225 .unlocked_ioctl = orion_wdt_ioctl,
226 .open = orion_wdt_open,
227 .release = orion_wdt_release,
228};
229
230static struct miscdevice orion_wdt_miscdev = {
231 .minor = WATCHDOG_MINOR,
232 .name = "watchdog",
233 .fops = &orion_wdt_fops,
234};
235
236static int __devinit orion_wdt_probe(struct platform_device *pdev)
237{
238 struct orion_wdt_platform_data *pdata = pdev->dev.platform_data;
239 int ret;
240
241 if (pdata) {
242 wdt_tclk = pdata->tclk;
243 } else {
244 printk(KERN_ERR "Orion Watchdog misses platform data\n");
245 return -ENODEV;
246 }
247
248 if (orion_wdt_miscdev.parent)
249 return -EBUSY;
250 orion_wdt_miscdev.parent = &pdev->dev;
251
252 wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
253 if (orion_wdt_settimeout(heartbeat))
254 heartbeat = wdt_max_duration;
255
256 ret = misc_register(&orion_wdt_miscdev);
257 if (ret)
258 return ret;
259
260 printk(KERN_INFO "Orion Watchdog Timer: Initial timeout %d sec%s\n",
261 heartbeat, nowayout ? ", nowayout" : "");
262 return 0;
263}
264
265static int __devexit orion_wdt_remove(struct platform_device *pdev)
266{
267 int ret;
268
269 if (test_bit(WDT_IN_USE, &wdt_status)) {
270 orion_wdt_disable();
271 clear_bit(WDT_IN_USE, &wdt_status);
272 }
273
274 ret = misc_deregister(&orion_wdt_miscdev);
275 if (!ret)
276 orion_wdt_miscdev.parent = NULL;
277
278 return ret;
279}
280
281static void orion_wdt_shutdown(struct platform_device *pdev)
282{
283 if (test_bit(WDT_IN_USE, &wdt_status))
284 orion_wdt_disable();
285}
286
287static struct platform_driver orion_wdt_driver = {
288 .probe = orion_wdt_probe,
289 .remove = __devexit_p(orion_wdt_remove),
290 .shutdown = orion_wdt_shutdown,
291 .driver = {
292 .owner = THIS_MODULE,
293 .name = "orion_wdt",
294 },
295};
296
297static int __init orion_wdt_init(void)
298{
299 spin_lock_init(&wdt_lock);
300 return platform_driver_register(&orion_wdt_driver);
301}
302
303static void __exit orion_wdt_exit(void)
304{
305 platform_driver_unregister(&orion_wdt_driver);
306}
307
308module_init(orion_wdt_init);
309module_exit(orion_wdt_exit);
310
311MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
312MODULE_DESCRIPTION("Orion Processor Watchdog");
313
314module_param(heartbeat, int, 0);
315MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
316
317module_param(nowayout, int, 0);
318MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
319 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
320
321MODULE_LICENSE("GPL");
322MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);