Linux 6.9-rc1
[linux-2.6-microblaze.git] / drivers / watchdog / orion_wdt.c
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
52 static bool nowayout = WATCHDOG_NOWAYOUT;
53 static int heartbeat;           /* module parameter (seconds) */
54
55 struct orion_watchdog;
56
57 struct 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
69 struct 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
79 static 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
97 static 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
120 static 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
160 static 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
183 static 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
196 static 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
226 static 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
251 static 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
270 static 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
278 static 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
291 static 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
312 static 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
331 static 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
338 static 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
348 static 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
359 static 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
366 static 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
372 static struct watchdog_info orion_wdt_info = {
373         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
374         .identity = "Orion Watchdog",
375 };
376
377 static 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
385 static irqreturn_t orion_wdt_irq(int irq, void *devid)
386 {
387         panic("Watchdog Timeout");
388         return IRQ_HANDLED;
389 }
390
391 static 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  */
407 static 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
424 static 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
434 static 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
444 static 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
454 static 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
465 static 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
476 static 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 };
499 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
500
501 static 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
554 static 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
644 disable_clk:
645         clk_disable_unprepare(dev->clk);
646         clk_put(dev->clk);
647         return ret;
648 }
649
650 static 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
660 static 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
666 static 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
676 module_platform_driver(orion_wdt_driver);
677
678 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
679 MODULE_DESCRIPTION("Orion Processor Watchdog");
680
681 module_param(heartbeat, int, 0);
682 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
683
684 module_param(nowayout, bool, 0);
685 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
686                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
687
688 MODULE_LICENSE("GPL v2");
689 MODULE_ALIAS("platform:orion_wdt");