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v6.8
  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");
v5.9
 
  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 TIMER1_FIXED_ENABLE_BIT	BIT(12)
 39#define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
 40#define TIMER1_ENABLE_BIT	BIT(2)
 41
 42#define TIMER_A370_STATUS	0x0004
 43#define WDT_A370_EXPIRED	BIT(31)
 44#define TIMER1_STATUS_BIT	BIT(8)
 45
 46#define TIMER1_VAL_OFF		0x001c
 47
 48#define WDT_MAX_CYCLE_COUNT	0xffffffff
 49
 50#define WDT_A370_RATIO_MASK(v)	((v) << 16)
 51#define WDT_A370_RATIO_SHIFT	5
 52#define WDT_A370_RATIO		(1 << WDT_A370_RATIO_SHIFT)
 53
 54static bool nowayout = WATCHDOG_NOWAYOUT;
 55static int heartbeat;		/* module parameter (seconds) */
 56
 57struct orion_watchdog;
 58
 59struct orion_watchdog_data {
 60	int wdt_counter_offset;
 61	int wdt_enable_bit;
 62	int rstout_enable_bit;
 63	int rstout_mask_bit;
 64	int (*clock_init)(struct platform_device *,
 65			  struct orion_watchdog *);
 66	int (*enabled)(struct orion_watchdog *);
 67	int (*start)(struct watchdog_device *);
 68	int (*stop)(struct watchdog_device *);
 69};
 70
 71struct orion_watchdog {
 72	struct watchdog_device wdt;
 73	void __iomem *reg;
 74	void __iomem *rstout;
 75	void __iomem *rstout_mask;
 76	unsigned long clk_rate;
 77	struct clk *clk;
 78	const struct orion_watchdog_data *data;
 79};
 80
 81static int orion_wdt_clock_init(struct platform_device *pdev,
 82				struct orion_watchdog *dev)
 83{
 84	int ret;
 85
 86	dev->clk = clk_get(&pdev->dev, NULL);
 87	if (IS_ERR(dev->clk))
 88		return PTR_ERR(dev->clk);
 89	ret = clk_prepare_enable(dev->clk);
 90	if (ret) {
 91		clk_put(dev->clk);
 92		return ret;
 93	}
 94
 95	dev->clk_rate = clk_get_rate(dev->clk);
 96	return 0;
 97}
 98
 99static int armada370_wdt_clock_init(struct platform_device *pdev,
100				    struct orion_watchdog *dev)
101{
102	int ret;
103
104	dev->clk = clk_get(&pdev->dev, NULL);
105	if (IS_ERR(dev->clk))
106		return PTR_ERR(dev->clk);
107	ret = clk_prepare_enable(dev->clk);
108	if (ret) {
109		clk_put(dev->clk);
110		return ret;
111	}
112
113	/* Setup watchdog input clock */
114	atomic_io_modify(dev->reg + TIMER_CTRL,
115			WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
116			WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
117
118	dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
119	return 0;
120}
121
122static int armada375_wdt_clock_init(struct platform_device *pdev,
123				    struct orion_watchdog *dev)
124{
125	int ret;
126
127	dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
128	if (!IS_ERR(dev->clk)) {
129		ret = clk_prepare_enable(dev->clk);
130		if (ret) {
131			clk_put(dev->clk);
132			return ret;
133		}
134
135		atomic_io_modify(dev->reg + TIMER_CTRL,
136				WDT_AXP_FIXED_ENABLE_BIT,
137				WDT_AXP_FIXED_ENABLE_BIT);
138		dev->clk_rate = clk_get_rate(dev->clk);
139
140		return 0;
141	}
142
143	/* Mandatory fallback for proper devicetree backward compatibility */
144	dev->clk = clk_get(&pdev->dev, NULL);
145	if (IS_ERR(dev->clk))
146		return PTR_ERR(dev->clk);
147
148	ret = clk_prepare_enable(dev->clk);
149	if (ret) {
150		clk_put(dev->clk);
151		return ret;
152	}
153
154	atomic_io_modify(dev->reg + TIMER_CTRL,
155			WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
156			WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
157	dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
158
159	return 0;
160}
161
162static int armadaxp_wdt_clock_init(struct platform_device *pdev,
163				   struct orion_watchdog *dev)
164{
165	int ret;
166	u32 val;
167
168	dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
169	if (IS_ERR(dev->clk))
170		return PTR_ERR(dev->clk);
171	ret = clk_prepare_enable(dev->clk);
172	if (ret) {
173		clk_put(dev->clk);
174		return ret;
175	}
176
177	/* Fix the wdt and timer1 clock freqency to 25MHz */
178	val = WDT_AXP_FIXED_ENABLE_BIT | TIMER1_FIXED_ENABLE_BIT;
179	atomic_io_modify(dev->reg + TIMER_CTRL, val, val);
180
181	dev->clk_rate = clk_get_rate(dev->clk);
182	return 0;
183}
184
185static int orion_wdt_ping(struct watchdog_device *wdt_dev)
186{
187	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
188	/* Reload watchdog duration */
189	writel(dev->clk_rate * wdt_dev->timeout,
190	       dev->reg + dev->data->wdt_counter_offset);
191	if (dev->wdt.info->options & WDIOF_PRETIMEOUT)
192		writel(dev->clk_rate * (wdt_dev->timeout - wdt_dev->pretimeout),
193		       dev->reg + TIMER1_VAL_OFF);
194
195	return 0;
196}
197
198static int armada375_start(struct watchdog_device *wdt_dev)
199{
200	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
201	u32 reg;
202
203	/* Set watchdog duration */
204	writel(dev->clk_rate * wdt_dev->timeout,
205	       dev->reg + dev->data->wdt_counter_offset);
206	if (dev->wdt.info->options & WDIOF_PRETIMEOUT)
207		writel(dev->clk_rate * (wdt_dev->timeout - wdt_dev->pretimeout),
208		       dev->reg + TIMER1_VAL_OFF);
209
210	/* Clear the watchdog expiration bit */
211	atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
212
213	/* Enable watchdog timer */
214	reg = dev->data->wdt_enable_bit;
215	if (dev->wdt.info->options & WDIOF_PRETIMEOUT)
216		reg |= TIMER1_ENABLE_BIT;
217	atomic_io_modify(dev->reg + TIMER_CTRL, reg, reg);
218
219	/* Enable reset on watchdog */
220	reg = readl(dev->rstout);
221	reg |= dev->data->rstout_enable_bit;
222	writel(reg, dev->rstout);
223
224	atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
225	return 0;
226}
227
228static int armada370_start(struct watchdog_device *wdt_dev)
229{
230	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
231	u32 reg;
232
233	/* Set watchdog duration */
234	writel(dev->clk_rate * wdt_dev->timeout,
235	       dev->reg + dev->data->wdt_counter_offset);
236
237	/* Clear the watchdog expiration bit */
238	atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
239
240	/* Enable watchdog timer */
241	atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
242						dev->data->wdt_enable_bit);
 
 
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;
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	atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 
 
 
324
325	return 0;
326}
327
328static int orion_wdt_stop(struct watchdog_device *wdt_dev)
329{
330	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
331
332	return dev->data->stop(wdt_dev);
333}
334
335static int orion_enabled(struct orion_watchdog *dev)
336{
337	bool enabled, running;
338
339	enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
340	running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
341
342	return enabled && running;
343}
344
345static int armada375_enabled(struct orion_watchdog *dev)
346{
347	bool masked, enabled, running;
348
349	masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit;
350	enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
351	running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
352
353	return !masked && enabled && running;
354}
355
356static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
357{
358	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
359
360	return dev->data->enabled(dev);
361}
362
363static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
364{
365	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
366	return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
367}
368
369static struct watchdog_info orion_wdt_info = {
370	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
371	.identity = "Orion Watchdog",
372};
373
374static const struct watchdog_ops orion_wdt_ops = {
375	.owner = THIS_MODULE,
376	.start = orion_wdt_start,
377	.stop = orion_wdt_stop,
378	.ping = orion_wdt_ping,
379	.get_timeleft = orion_wdt_get_timeleft,
380};
381
382static irqreturn_t orion_wdt_irq(int irq, void *devid)
383{
384	panic("Watchdog Timeout");
385	return IRQ_HANDLED;
386}
387
388static irqreturn_t orion_wdt_pre_irq(int irq, void *devid)
389{
390	struct orion_watchdog *dev = devid;
391
392	atomic_io_modify(dev->reg + TIMER_A370_STATUS,
393			 TIMER1_STATUS_BIT, 0);
394	watchdog_notify_pretimeout(&dev->wdt);
395	return IRQ_HANDLED;
396}
397
398/*
399 * The original devicetree binding for this driver specified only
400 * one memory resource, so in order to keep DT backwards compatibility
401 * we try to fallback to a hardcoded register address, if the resource
402 * is missing from the devicetree.
403 */
404static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
405					      phys_addr_t internal_regs)
406{
407	struct resource *res;
408	phys_addr_t rstout;
409
410	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
411	if (res)
412		return devm_ioremap(&pdev->dev, res->start,
413				    resource_size(res));
414
415	rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
416
417	WARN(1, FW_BUG "falling back to hardcoded RSTOUT reg %pa\n", &rstout);
418	return devm_ioremap(&pdev->dev, rstout, 0x4);
419}
420
421static const struct orion_watchdog_data orion_data = {
422	.rstout_enable_bit = BIT(1),
423	.wdt_enable_bit = BIT(4),
424	.wdt_counter_offset = 0x24,
425	.clock_init = orion_wdt_clock_init,
426	.enabled = orion_enabled,
427	.start = orion_start,
428	.stop = orion_stop,
429};
430
431static const struct orion_watchdog_data armada370_data = {
432	.rstout_enable_bit = BIT(8),
433	.wdt_enable_bit = BIT(8),
434	.wdt_counter_offset = 0x34,
435	.clock_init = armada370_wdt_clock_init,
436	.enabled = orion_enabled,
437	.start = armada370_start,
438	.stop = armada370_stop,
439};
440
441static const struct orion_watchdog_data armadaxp_data = {
442	.rstout_enable_bit = BIT(8),
443	.wdt_enable_bit = BIT(8),
444	.wdt_counter_offset = 0x34,
445	.clock_init = armadaxp_wdt_clock_init,
446	.enabled = orion_enabled,
447	.start = armada370_start,
448	.stop = armada370_stop,
449};
450
451static const struct orion_watchdog_data armada375_data = {
452	.rstout_enable_bit = BIT(8),
453	.rstout_mask_bit = BIT(10),
454	.wdt_enable_bit = BIT(8),
455	.wdt_counter_offset = 0x34,
456	.clock_init = armada375_wdt_clock_init,
457	.enabled = armada375_enabled,
458	.start = armada375_start,
459	.stop = armada375_stop,
460};
461
462static const struct orion_watchdog_data armada380_data = {
463	.rstout_enable_bit = BIT(8),
464	.rstout_mask_bit = BIT(10),
465	.wdt_enable_bit = BIT(8),
466	.wdt_counter_offset = 0x34,
467	.clock_init = armadaxp_wdt_clock_init,
468	.enabled = armada375_enabled,
469	.start = armada375_start,
470	.stop = armada375_stop,
471};
472
473static const struct of_device_id orion_wdt_of_match_table[] = {
474	{
475		.compatible = "marvell,orion-wdt",
476		.data = &orion_data,
477	},
478	{
479		.compatible = "marvell,armada-370-wdt",
480		.data = &armada370_data,
481	},
482	{
483		.compatible = "marvell,armada-xp-wdt",
484		.data = &armadaxp_data,
485	},
486	{
487		.compatible = "marvell,armada-375-wdt",
488		.data = &armada375_data,
489	},
490	{
491		.compatible = "marvell,armada-380-wdt",
492		.data = &armada380_data,
493	},
494	{},
495};
496MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
497
498static int orion_wdt_get_regs(struct platform_device *pdev,
499			      struct orion_watchdog *dev)
500{
501	struct device_node *node = pdev->dev.of_node;
502	struct resource *res;
503
504	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
505	if (!res)
506		return -ENODEV;
507	dev->reg = devm_ioremap(&pdev->dev, res->start,
508				resource_size(res));
509	if (!dev->reg)
510		return -ENOMEM;
511
512	/* Each supported compatible has some RSTOUT register quirk */
513	if (of_device_is_compatible(node, "marvell,orion-wdt")) {
514
515		dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
516						       INTERNAL_REGS_MASK);
517		if (!dev->rstout)
518			return -ENODEV;
519
520	} else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
521		   of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
522
523		/* Dedicated RSTOUT register, can be requested. */
524		dev->rstout = devm_platform_ioremap_resource(pdev, 1);
525		if (IS_ERR(dev->rstout))
526			return PTR_ERR(dev->rstout);
527
528	} else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
529		   of_device_is_compatible(node, "marvell,armada-380-wdt")) {
530
531		/* Dedicated RSTOUT register, can be requested. */
532		dev->rstout = devm_platform_ioremap_resource(pdev, 1);
533		if (IS_ERR(dev->rstout))
534			return PTR_ERR(dev->rstout);
535
536		res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
537		if (!res)
538			return -ENODEV;
539		dev->rstout_mask = devm_ioremap(&pdev->dev, res->start,
540						resource_size(res));
541		if (!dev->rstout_mask)
542			return -ENOMEM;
543
544	} else {
545		return -ENODEV;
546	}
547
548	return 0;
549}
550
551static int orion_wdt_probe(struct platform_device *pdev)
552{
553	struct orion_watchdog *dev;
554	const struct of_device_id *match;
555	unsigned int wdt_max_duration;	/* (seconds) */
556	int ret, irq;
557
558	dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
559			   GFP_KERNEL);
560	if (!dev)
561		return -ENOMEM;
562
563	match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
564	if (!match)
565		/* Default legacy match */
566		match = &orion_wdt_of_match_table[0];
567
568	dev->wdt.info = &orion_wdt_info;
569	dev->wdt.ops = &orion_wdt_ops;
570	dev->wdt.min_timeout = 1;
571	dev->data = match->data;
572
573	ret = orion_wdt_get_regs(pdev, dev);
574	if (ret)
575		return ret;
576
577	ret = dev->data->clock_init(pdev, dev);
578	if (ret) {
579		dev_err(&pdev->dev, "cannot initialize clock\n");
580		return ret;
581	}
582
583	wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
584
585	dev->wdt.timeout = wdt_max_duration;
586	dev->wdt.max_timeout = wdt_max_duration;
587	dev->wdt.parent = &pdev->dev;
588	watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
589
590	platform_set_drvdata(pdev, &dev->wdt);
591	watchdog_set_drvdata(&dev->wdt, dev);
592
593	/*
594	 * Let's make sure the watchdog is fully stopped, unless it's
595	 * explicitly enabled. This may be the case if the module was
596	 * removed and re-inserted, or if the bootloader explicitly
597	 * set a running watchdog before booting the kernel.
598	 */
599	if (!orion_wdt_enabled(&dev->wdt))
600		orion_wdt_stop(&dev->wdt);
601	else
602		set_bit(WDOG_HW_RUNNING, &dev->wdt.status);
603
604	/* Request the IRQ only after the watchdog is disabled */
605	irq = platform_get_irq_optional(pdev, 0);
606	if (irq > 0) {
607		/*
608		 * Not all supported platforms specify an interrupt for the
609		 * watchdog, so let's make it optional.
610		 */
611		ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
612				       pdev->name, dev);
613		if (ret < 0) {
614			dev_err(&pdev->dev, "failed to request IRQ\n");
615			goto disable_clk;
616		}
617	}
618
619	/* Optional 2nd interrupt for pretimeout */
620	irq = platform_get_irq_optional(pdev, 1);
621	if (irq > 0) {
622		orion_wdt_info.options |= WDIOF_PRETIMEOUT;
623		ret = devm_request_irq(&pdev->dev, irq, orion_wdt_pre_irq,
624				       0, pdev->name, dev);
625		if (ret < 0) {
626			dev_err(&pdev->dev, "failed to request IRQ\n");
627			goto disable_clk;
628		}
629	}
630
631
632	watchdog_set_nowayout(&dev->wdt, nowayout);
633	ret = watchdog_register_device(&dev->wdt);
634	if (ret)
635		goto disable_clk;
636
637	pr_info("Initial timeout %d sec%s\n",
638		dev->wdt.timeout, nowayout ? ", nowayout" : "");
639	return 0;
640
641disable_clk:
642	clk_disable_unprepare(dev->clk);
643	clk_put(dev->clk);
644	return ret;
645}
646
647static int orion_wdt_remove(struct platform_device *pdev)
648{
649	struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
650	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
651
652	watchdog_unregister_device(wdt_dev);
653	clk_disable_unprepare(dev->clk);
654	clk_put(dev->clk);
655	return 0;
656}
657
658static void orion_wdt_shutdown(struct platform_device *pdev)
659{
660	struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
661	orion_wdt_stop(wdt_dev);
662}
663
664static struct platform_driver orion_wdt_driver = {
665	.probe		= orion_wdt_probe,
666	.remove		= orion_wdt_remove,
667	.shutdown	= orion_wdt_shutdown,
668	.driver		= {
669		.name	= "orion_wdt",
670		.of_match_table = orion_wdt_of_match_table,
671	},
672};
673
674module_platform_driver(orion_wdt_driver);
675
676MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
677MODULE_DESCRIPTION("Orion Processor Watchdog");
678
679module_param(heartbeat, int, 0);
680MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
681
682module_param(nowayout, bool, 0);
683MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
684				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
685
686MODULE_LICENSE("GPL v2");
687MODULE_ALIAS("platform:orion_wdt");