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[media] DocBook media: xmllint fixes
[linux-2.6/btrfs-unstable.git] / drivers / watchdog / orion_wdt.c
blobef0c628d503797d87b223eb2cbc81061290a10bc
1 /*
2 * drivers/watchdog/orion_wdt.c
3 *
4 * Watchdog driver for Orion/Kirkwood processors
5 *
6 * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/module.h>
16 #include <linux/moduleparam.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/platform_device.h>
20 #include <linux/watchdog.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/clk.h>
24 #include <linux/err.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27
28 /* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
29 #define ORION_RSTOUT_MASK_OFFSET 0x20108
30
31 /* Internal registers can be configured at any 1 MiB aligned address */
32 #define INTERNAL_REGS_MASK ~(SZ_1M - 1)
33
34 /*
35 * Watchdog timer block registers.
36 */
37 #define TIMER_CTRL 0x0000
38 #define TIMER_A370_STATUS 0x04
39
40 #define WDT_MAX_CYCLE_COUNT 0xffffffff
41
42 #define WDT_A370_RATIO_MASK(v) ((v) << 16)
43 #define WDT_A370_RATIO_SHIFT 5
44 #define WDT_A370_RATIO (1 << WDT_A370_RATIO_SHIFT)
45
46 #define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
47 #define WDT_A370_EXPIRED BIT(31)
48
49 static bool nowayout = WATCHDOG_NOWAYOUT;
50 static int heartbeat = -1; /* module parameter (seconds) */
51
52 struct orion_watchdog;
53
54 struct orion_watchdog_data {
55 int wdt_counter_offset;
56 int wdt_enable_bit;
57 int rstout_enable_bit;
58 int rstout_mask_bit;
59 int (*clock_init)(struct platform_device *,
60 struct orion_watchdog *);
61 int (*enabled)(struct orion_watchdog *);
62 int (*start)(struct watchdog_device *);
63 int (*stop)(struct watchdog_device *);
64 };
65
66 struct orion_watchdog {
67 struct watchdog_device wdt;
68 void __iomem *reg;
69 void __iomem *rstout;
70 void __iomem *rstout_mask;
71 unsigned long clk_rate;
72 struct clk *clk;
73 const struct orion_watchdog_data *data;
74 };
75
76 static int orion_wdt_clock_init(struct platform_device *pdev,
77 struct orion_watchdog *dev)
78 {
79 int ret;
80
81 dev->clk = clk_get(&pdev->dev, NULL);
82 if (IS_ERR(dev->clk))
83 return PTR_ERR(dev->clk);
84 ret = clk_prepare_enable(dev->clk);
85 if (ret) {
86 clk_put(dev->clk);
87 return ret;
88 }
89
90 dev->clk_rate = clk_get_rate(dev->clk);
91 return 0;
92 }
93
94 static int armada370_wdt_clock_init(struct platform_device *pdev,
95 struct orion_watchdog *dev)
96 {
97 int ret;
98
99 dev->clk = clk_get(&pdev->dev, NULL);
100 if (IS_ERR(dev->clk))
101 return PTR_ERR(dev->clk);
102 ret = clk_prepare_enable(dev->clk);
103 if (ret) {
104 clk_put(dev->clk);
105 return ret;
106 }
107
108 /* Setup watchdog input clock */
109 atomic_io_modify(dev->reg + TIMER_CTRL,
110 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
111 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
112
113 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
114 return 0;
115 }
116
117 static int armada375_wdt_clock_init(struct platform_device *pdev,
118 struct orion_watchdog *dev)
119 {
120 int ret;
121
122 dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
123 if (!IS_ERR(dev->clk)) {
124 ret = clk_prepare_enable(dev->clk);
125 if (ret) {
126 clk_put(dev->clk);
127 return ret;
128 }
129
130 atomic_io_modify(dev->reg + TIMER_CTRL,
131 WDT_AXP_FIXED_ENABLE_BIT,
132 WDT_AXP_FIXED_ENABLE_BIT);
133 dev->clk_rate = clk_get_rate(dev->clk);
134
135 return 0;
136 }
137
138 /* Mandatory fallback for proper devicetree backward compatibility */
139 dev->clk = clk_get(&pdev->dev, NULL);
140 if (IS_ERR(dev->clk))
141 return PTR_ERR(dev->clk);
142
143 ret = clk_prepare_enable(dev->clk);
144 if (ret) {
145 clk_put(dev->clk);
146 return ret;
147 }
148
149 atomic_io_modify(dev->reg + TIMER_CTRL,
150 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
151 WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
152 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
153
154 return 0;
155 }
156
157 static int armadaxp_wdt_clock_init(struct platform_device *pdev,
158 struct orion_watchdog *dev)
159 {
160 int ret;
161
162 dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
163 if (IS_ERR(dev->clk))
164 return PTR_ERR(dev->clk);
165 ret = clk_prepare_enable(dev->clk);
166 if (ret) {
167 clk_put(dev->clk);
168 return ret;
169 }
170
171 /* Enable the fixed watchdog clock input */
172 atomic_io_modify(dev->reg + TIMER_CTRL,
173 WDT_AXP_FIXED_ENABLE_BIT,
174 WDT_AXP_FIXED_ENABLE_BIT);
175
176 dev->clk_rate = clk_get_rate(dev->clk);
177 return 0;
178 }
179
180 static int orion_wdt_ping(struct watchdog_device *wdt_dev)
181 {
182 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
183 /* Reload watchdog duration */
184 writel(dev->clk_rate * wdt_dev->timeout,
185 dev->reg + dev->data->wdt_counter_offset);
186 return 0;
187 }
188
189 static int armada375_start(struct watchdog_device *wdt_dev)
190 {
191 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
192 u32 reg;
193
194 /* Set watchdog duration */
195 writel(dev->clk_rate * wdt_dev->timeout,
196 dev->reg + dev->data->wdt_counter_offset);
197
198 /* Clear the watchdog expiration bit */
199 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
200
201 /* Enable watchdog timer */
202 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
203 dev->data->wdt_enable_bit);
204
205 /* Enable reset on watchdog */
206 reg = readl(dev->rstout);
207 reg |= dev->data->rstout_enable_bit;
208 writel(reg, dev->rstout);
209
210 atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
211 return 0;
212 }
213
214 static int armada370_start(struct watchdog_device *wdt_dev)
215 {
216 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
217 u32 reg;
218
219 /* Set watchdog duration */
220 writel(dev->clk_rate * wdt_dev->timeout,
221 dev->reg + dev->data->wdt_counter_offset);
222
223 /* Clear the watchdog expiration bit */
224 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
225
226 /* Enable watchdog timer */
227 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
228 dev->data->wdt_enable_bit);
229
230 /* Enable reset on watchdog */
231 reg = readl(dev->rstout);
232 reg |= dev->data->rstout_enable_bit;
233 writel(reg, dev->rstout);
234 return 0;
235 }
236
237 static int orion_start(struct watchdog_device *wdt_dev)
238 {
239 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
240
241 /* Set watchdog duration */
242 writel(dev->clk_rate * wdt_dev->timeout,
243 dev->reg + dev->data->wdt_counter_offset);
244
245 /* Enable watchdog timer */
246 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
247 dev->data->wdt_enable_bit);
248
249 /* Enable reset on watchdog */
250 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
251 dev->data->rstout_enable_bit);
252
253 return 0;
254 }
255
256 static int orion_wdt_start(struct watchdog_device *wdt_dev)
257 {
258 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
259
260 /* There are some per-SoC quirks to handle */
261 return dev->data->start(wdt_dev);
262 }
263
264 static int orion_stop(struct watchdog_device *wdt_dev)
265 {
266 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
267
268 /* Disable reset on watchdog */
269 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
270
271 /* Disable watchdog timer */
272 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
273
274 return 0;
275 }
276
277 static int armada375_stop(struct watchdog_device *wdt_dev)
278 {
279 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
280 u32 reg;
281
282 /* Disable reset on watchdog */
283 atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit,
284 dev->data->rstout_mask_bit);
285 reg = readl(dev->rstout);
286 reg &= ~dev->data->rstout_enable_bit;
287 writel(reg, dev->rstout);
288
289 /* Disable watchdog timer */
290 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
291
292 return 0;
293 }
294
295 static int armada370_stop(struct watchdog_device *wdt_dev)
296 {
297 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
298 u32 reg;
299
300 /* Disable reset on watchdog */
301 reg = readl(dev->rstout);
302 reg &= ~dev->data->rstout_enable_bit;
303 writel(reg, dev->rstout);
304
305 /* Disable watchdog timer */
306 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
307
308 return 0;
309 }
310
311 static int orion_wdt_stop(struct watchdog_device *wdt_dev)
312 {
313 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
314
315 return dev->data->stop(wdt_dev);
316 }
317
318 static int orion_enabled(struct orion_watchdog *dev)
319 {
320 bool enabled, running;
321
322 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
323 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
324
325 return enabled && running;
326 }
327
328 static int armada375_enabled(struct orion_watchdog *dev)
329 {
330 bool masked, enabled, running;
331
332 masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit;
333 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
334 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
335
336 return !masked && enabled && running;
337 }
338
339 static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
340 {
341 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
342
343 return dev->data->enabled(dev);
344 }
345
346 static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
347 {
348 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
349 return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
350 }
351
352 static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
353 unsigned int timeout)
354 {
355 wdt_dev->timeout = timeout;
356 return 0;
357 }
358
359 static const struct watchdog_info orion_wdt_info = {
360 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
361 .identity = "Orion Watchdog",
362 };
363
364 static const struct watchdog_ops orion_wdt_ops = {
365 .owner = THIS_MODULE,
366 .start = orion_wdt_start,
367 .stop = orion_wdt_stop,
368 .ping = orion_wdt_ping,
369 .set_timeout = orion_wdt_set_timeout,
370 .get_timeleft = orion_wdt_get_timeleft,
371 };
372
373 static irqreturn_t orion_wdt_irq(int irq, void *devid)
374 {
375 panic("Watchdog Timeout");
376 return IRQ_HANDLED;
377 }
378
379 /*
380 * The original devicetree binding for this driver specified only
381 * one memory resource, so in order to keep DT backwards compatibility
382 * we try to fallback to a hardcoded register address, if the resource
383 * is missing from the devicetree.
384 */
385 static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
386 phys_addr_t internal_regs)
387 {
388 struct resource *res;
389 phys_addr_t rstout;
390
391 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
392 if (res)
393 return devm_ioremap(&pdev->dev, res->start,
394 resource_size(res));
395
396 rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
397
398 WARN(1, FW_BUG "falling back to harcoded RSTOUT reg %pa\n", &rstout);
399 return devm_ioremap(&pdev->dev, rstout, 0x4);
400 }
401
402 static const struct orion_watchdog_data orion_data = {
403 .rstout_enable_bit = BIT(1),
404 .wdt_enable_bit = BIT(4),
405 .wdt_counter_offset = 0x24,
406 .clock_init = orion_wdt_clock_init,
407 .enabled = orion_enabled,
408 .start = orion_start,
409 .stop = orion_stop,
410 };
411
412 static const struct orion_watchdog_data armada370_data = {
413 .rstout_enable_bit = BIT(8),
414 .wdt_enable_bit = BIT(8),
415 .wdt_counter_offset = 0x34,
416 .clock_init = armada370_wdt_clock_init,
417 .enabled = orion_enabled,
418 .start = armada370_start,
419 .stop = armada370_stop,
420 };
421
422 static const struct orion_watchdog_data armadaxp_data = {
423 .rstout_enable_bit = BIT(8),
424 .wdt_enable_bit = BIT(8),
425 .wdt_counter_offset = 0x34,
426 .clock_init = armadaxp_wdt_clock_init,
427 .enabled = orion_enabled,
428 .start = armada370_start,
429 .stop = armada370_stop,
430 };
431
432 static const struct orion_watchdog_data armada375_data = {
433 .rstout_enable_bit = BIT(8),
434 .rstout_mask_bit = BIT(10),
435 .wdt_enable_bit = BIT(8),
436 .wdt_counter_offset = 0x34,
437 .clock_init = armada375_wdt_clock_init,
438 .enabled = armada375_enabled,
439 .start = armada375_start,
440 .stop = armada375_stop,
441 };
442
443 static const struct orion_watchdog_data armada380_data = {
444 .rstout_enable_bit = BIT(8),
445 .rstout_mask_bit = BIT(10),
446 .wdt_enable_bit = BIT(8),
447 .wdt_counter_offset = 0x34,
448 .clock_init = armadaxp_wdt_clock_init,
449 .enabled = armada375_enabled,
450 .start = armada375_start,
451 .stop = armada375_stop,
452 };
453
454 static const struct of_device_id orion_wdt_of_match_table[] = {
455 {
456 .compatible = "marvell,orion-wdt",
457 .data = &orion_data,
458 },
459 {
460 .compatible = "marvell,armada-370-wdt",
461 .data = &armada370_data,
462 },
463 {
464 .compatible = "marvell,armada-xp-wdt",
465 .data = &armadaxp_data,
466 },
467 {
468 .compatible = "marvell,armada-375-wdt",
469 .data = &armada375_data,
470 },
471 {
472 .compatible = "marvell,armada-380-wdt",
473 .data = &armada380_data,
474 },
475 {},
476 };
477 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
478
479 static int orion_wdt_get_regs(struct platform_device *pdev,
480 struct orion_watchdog *dev)
481 {
482 struct device_node *node = pdev->dev.of_node;
483 struct resource *res;
484
485 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
486 if (!res)
487 return -ENODEV;
488 dev->reg = devm_ioremap(&pdev->dev, res->start,
489 resource_size(res));
490 if (!dev->reg)
491 return -ENOMEM;
492
493 /* Each supported compatible has some RSTOUT register quirk */
494 if (of_device_is_compatible(node, "marvell,orion-wdt")) {
495
496 dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
497 INTERNAL_REGS_MASK);
498 if (!dev->rstout)
499 return -ENODEV;
500
501 } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
502 of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
503
504 /* Dedicated RSTOUT register, can be requested. */
505 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
506 dev->rstout = devm_ioremap_resource(&pdev->dev, res);
507 if (IS_ERR(dev->rstout))
508 return PTR_ERR(dev->rstout);
509
510 } else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
511 of_device_is_compatible(node, "marvell,armada-380-wdt")) {
512
513 /* Dedicated RSTOUT register, can be requested. */
514 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
515 dev->rstout = devm_ioremap_resource(&pdev->dev, res);
516 if (IS_ERR(dev->rstout))
517 return PTR_ERR(dev->rstout);
518
519 res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
520 if (!res)
521 return -ENODEV;
522 dev->rstout_mask = devm_ioremap(&pdev->dev, res->start,
523 resource_size(res));
524 if (!dev->rstout_mask)
525 return -ENOMEM;
526
527 } else {
528 return -ENODEV;
529 }
530
531 return 0;
532 }
533
534 static int orion_wdt_probe(struct platform_device *pdev)
535 {
536 struct orion_watchdog *dev;
537 const struct of_device_id *match;
538 unsigned int wdt_max_duration; /* (seconds) */
539 int ret, irq;
540
541 dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
542 GFP_KERNEL);
543 if (!dev)
544 return -ENOMEM;
545
546 match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
547 if (!match)
548 /* Default legacy match */
549 match = &orion_wdt_of_match_table[0];
550
551 dev->wdt.info = &orion_wdt_info;
552 dev->wdt.ops = &orion_wdt_ops;
553 dev->wdt.min_timeout = 1;
554 dev->data = match->data;
555
556 ret = orion_wdt_get_regs(pdev, dev);
557 if (ret)
558 return ret;
559
560 ret = dev->data->clock_init(pdev, dev);
561 if (ret) {
562 dev_err(&pdev->dev, "cannot initialize clock\n");
563 return ret;
564 }
565
566 wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
567
568 dev->wdt.timeout = wdt_max_duration;
569 dev->wdt.max_timeout = wdt_max_duration;
570 watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
571
572 platform_set_drvdata(pdev, &dev->wdt);
573 watchdog_set_drvdata(&dev->wdt, dev);
574
575 /*
576 * Let's make sure the watchdog is fully stopped, unless it's
577 * explicitly enabled. This may be the case if the module was
578 * removed and re-insterted, or if the bootloader explicitly
579 * set a running watchdog before booting the kernel.
580 */
581 if (!orion_wdt_enabled(&dev->wdt))
582 orion_wdt_stop(&dev->wdt);
583
584 /* Request the IRQ only after the watchdog is disabled */
585 irq = platform_get_irq(pdev, 0);
586 if (irq > 0) {
587 /*
588 * Not all supported platforms specify an interrupt for the
589 * watchdog, so let's make it optional.
590 */
591 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
592 pdev->name, dev);
593 if (ret < 0) {
594 dev_err(&pdev->dev, "failed to request IRQ\n");
595 goto disable_clk;
596 }
597 }
598
599 watchdog_set_nowayout(&dev->wdt, nowayout);
600 ret = watchdog_register_device(&dev->wdt);
601 if (ret)
602 goto disable_clk;
603
604 pr_info("Initial timeout %d sec%s\n",
605 dev->wdt.timeout, nowayout ? ", nowayout" : "");
606 return 0;
607
608 disable_clk:
609 clk_disable_unprepare(dev->clk);
610 clk_put(dev->clk);
611 return ret;
612 }
613
614 static int orion_wdt_remove(struct platform_device *pdev)
615 {
616 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
617 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
618
619 watchdog_unregister_device(wdt_dev);
620 clk_disable_unprepare(dev->clk);
621 clk_put(dev->clk);
622 return 0;
623 }
624
625 static void orion_wdt_shutdown(struct platform_device *pdev)
626 {
627 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
628 orion_wdt_stop(wdt_dev);
629 }
630
631 static struct platform_driver orion_wdt_driver = {
632 .probe = orion_wdt_probe,
633 .remove = orion_wdt_remove,
634 .shutdown = orion_wdt_shutdown,
635 .driver = {
636 .name = "orion_wdt",
637 .of_match_table = orion_wdt_of_match_table,
638 },
639 };
640
641 module_platform_driver(orion_wdt_driver);
642
643 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
644 MODULE_DESCRIPTION("Orion Processor Watchdog");
645
646 module_param(heartbeat, int, 0);
647 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
648
649 module_param(nowayout, bool, 0);
650 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
651 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
652
653 MODULE_LICENSE("GPL");
654 MODULE_ALIAS("platform:orion_wdt");
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