Linux 4.10-rc3
[linux/fpc-iii.git] / drivers / watchdog / orion_wdt.c
blobc6b8f4a43bdeff2df7faa71f6356819f8129c326
1 /*
2 * drivers/watchdog/orion_wdt.c
4 * Watchdog driver for Orion/Kirkwood processors
6 * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
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.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
28 /* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
29 #define ORION_RSTOUT_MASK_OFFSET 0x20108
31 /* Internal registers can be configured at any 1 MiB aligned address */
32 #define INTERNAL_REGS_MASK ~(SZ_1M - 1)
35 * Watchdog timer block registers.
37 #define TIMER_CTRL 0x0000
38 #define TIMER_A370_STATUS 0x04
40 #define WDT_MAX_CYCLE_COUNT 0xffffffff
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)
46 #define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
47 #define WDT_A370_EXPIRED BIT(31)
49 static bool nowayout = WATCHDOG_NOWAYOUT;
50 static int heartbeat = -1; /* module parameter (seconds) */
52 struct orion_watchdog;
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 *);
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;
76 static int orion_wdt_clock_init(struct platform_device *pdev,
77 struct orion_watchdog *dev)
79 int ret;
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;
90 dev->clk_rate = clk_get_rate(dev->clk);
91 return 0;
94 static int armada370_wdt_clock_init(struct platform_device *pdev,
95 struct orion_watchdog *dev)
97 int ret;
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;
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));
113 dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
114 return 0;
117 static int armada375_wdt_clock_init(struct platform_device *pdev,
118 struct orion_watchdog *dev)
120 int ret;
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;
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);
135 return 0;
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);
143 ret = clk_prepare_enable(dev->clk);
144 if (ret) {
145 clk_put(dev->clk);
146 return ret;
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;
154 return 0;
157 static int armadaxp_wdt_clock_init(struct platform_device *pdev,
158 struct orion_watchdog *dev)
160 int ret;
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;
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);
176 dev->clk_rate = clk_get_rate(dev->clk);
177 return 0;
180 static int orion_wdt_ping(struct watchdog_device *wdt_dev)
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;
189 static int armada375_start(struct watchdog_device *wdt_dev)
191 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
192 u32 reg;
194 /* Set watchdog duration */
195 writel(dev->clk_rate * wdt_dev->timeout,
196 dev->reg + dev->data->wdt_counter_offset);
198 /* Clear the watchdog expiration bit */
199 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
201 /* Enable watchdog timer */
202 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
203 dev->data->wdt_enable_bit);
205 /* Enable reset on watchdog */
206 reg = readl(dev->rstout);
207 reg |= dev->data->rstout_enable_bit;
208 writel(reg, dev->rstout);
210 atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
211 return 0;
214 static int armada370_start(struct watchdog_device *wdt_dev)
216 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
217 u32 reg;
219 /* Set watchdog duration */
220 writel(dev->clk_rate * wdt_dev->timeout,
221 dev->reg + dev->data->wdt_counter_offset);
223 /* Clear the watchdog expiration bit */
224 atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
226 /* Enable watchdog timer */
227 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
228 dev->data->wdt_enable_bit);
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;
237 static int orion_start(struct watchdog_device *wdt_dev)
239 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
241 /* Set watchdog duration */
242 writel(dev->clk_rate * wdt_dev->timeout,
243 dev->reg + dev->data->wdt_counter_offset);
245 /* Enable watchdog timer */
246 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
247 dev->data->wdt_enable_bit);
249 /* Enable reset on watchdog */
250 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
251 dev->data->rstout_enable_bit);
253 return 0;
256 static int orion_wdt_start(struct watchdog_device *wdt_dev)
258 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
260 /* There are some per-SoC quirks to handle */
261 return dev->data->start(wdt_dev);
264 static int orion_stop(struct watchdog_device *wdt_dev)
266 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
268 /* Disable reset on watchdog */
269 atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
271 /* Disable watchdog timer */
272 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
274 return 0;
277 static int armada375_stop(struct watchdog_device *wdt_dev)
279 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
280 u32 reg;
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);
289 /* Disable watchdog timer */
290 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
292 return 0;
295 static int armada370_stop(struct watchdog_device *wdt_dev)
297 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
298 u32 reg;
300 /* Disable reset on watchdog */
301 reg = readl(dev->rstout);
302 reg &= ~dev->data->rstout_enable_bit;
303 writel(reg, dev->rstout);
305 /* Disable watchdog timer */
306 atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
308 return 0;
311 static int orion_wdt_stop(struct watchdog_device *wdt_dev)
313 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
315 return dev->data->stop(wdt_dev);
318 static int orion_enabled(struct orion_watchdog *dev)
320 bool enabled, running;
322 enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
323 running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
325 return enabled && running;
328 static int armada375_enabled(struct orion_watchdog *dev)
330 bool masked, enabled, running;
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;
336 return !masked && enabled && running;
339 static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
341 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
343 return dev->data->enabled(dev);
346 static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
348 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
349 return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
352 static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
353 unsigned int timeout)
355 wdt_dev->timeout = timeout;
356 return 0;
359 static const struct watchdog_info orion_wdt_info = {
360 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
361 .identity = "Orion Watchdog",
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,
373 static irqreturn_t orion_wdt_irq(int irq, void *devid)
375 panic("Watchdog Timeout");
376 return IRQ_HANDLED;
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.
385 static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
386 phys_addr_t internal_regs)
388 struct resource *res;
389 phys_addr_t rstout;
391 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
392 if (res)
393 return devm_ioremap(&pdev->dev, res->start,
394 resource_size(res));
396 rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
398 WARN(1, FW_BUG "falling back to harcoded RSTOUT reg %pa\n", &rstout);
399 return devm_ioremap(&pdev->dev, rstout, 0x4);
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,
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,
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,
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,
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,
454 static const struct of_device_id orion_wdt_of_match_table[] = {
456 .compatible = "marvell,orion-wdt",
457 .data = &orion_data,
460 .compatible = "marvell,armada-370-wdt",
461 .data = &armada370_data,
464 .compatible = "marvell,armada-xp-wdt",
465 .data = &armadaxp_data,
468 .compatible = "marvell,armada-375-wdt",
469 .data = &armada375_data,
472 .compatible = "marvell,armada-380-wdt",
473 .data = &armada380_data,
477 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
479 static int orion_wdt_get_regs(struct platform_device *pdev,
480 struct orion_watchdog *dev)
482 struct device_node *node = pdev->dev.of_node;
483 struct resource *res;
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;
493 /* Each supported compatible has some RSTOUT register quirk */
494 if (of_device_is_compatible(node, "marvell,orion-wdt")) {
496 dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
497 INTERNAL_REGS_MASK);
498 if (!dev->rstout)
499 return -ENODEV;
501 } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
502 of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
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);
510 } else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
511 of_device_is_compatible(node, "marvell,armada-380-wdt")) {
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);
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;
527 } else {
528 return -ENODEV;
531 return 0;
534 static int orion_wdt_probe(struct platform_device *pdev)
536 struct orion_watchdog *dev;
537 const struct of_device_id *match;
538 unsigned int wdt_max_duration; /* (seconds) */
539 int ret, irq;
541 dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
542 GFP_KERNEL);
543 if (!dev)
544 return -ENOMEM;
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];
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;
556 ret = orion_wdt_get_regs(pdev, dev);
557 if (ret)
558 return ret;
560 ret = dev->data->clock_init(pdev, dev);
561 if (ret) {
562 dev_err(&pdev->dev, "cannot initialize clock\n");
563 return ret;
566 wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
568 dev->wdt.timeout = wdt_max_duration;
569 dev->wdt.max_timeout = wdt_max_duration;
570 dev->wdt.parent = &pdev->dev;
571 watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
573 platform_set_drvdata(pdev, &dev->wdt);
574 watchdog_set_drvdata(&dev->wdt, dev);
577 * Let's make sure the watchdog is fully stopped, unless it's
578 * explicitly enabled. This may be the case if the module was
579 * removed and re-insterted, or if the bootloader explicitly
580 * set a running watchdog before booting the kernel.
582 if (!orion_wdt_enabled(&dev->wdt))
583 orion_wdt_stop(&dev->wdt);
585 /* Request the IRQ only after the watchdog is disabled */
586 irq = platform_get_irq(pdev, 0);
587 if (irq > 0) {
589 * Not all supported platforms specify an interrupt for the
590 * watchdog, so let's make it optional.
592 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
593 pdev->name, dev);
594 if (ret < 0) {
595 dev_err(&pdev->dev, "failed to request IRQ\n");
596 goto disable_clk;
600 watchdog_set_nowayout(&dev->wdt, nowayout);
601 ret = watchdog_register_device(&dev->wdt);
602 if (ret)
603 goto disable_clk;
605 pr_info("Initial timeout %d sec%s\n",
606 dev->wdt.timeout, nowayout ? ", nowayout" : "");
607 return 0;
609 disable_clk:
610 clk_disable_unprepare(dev->clk);
611 clk_put(dev->clk);
612 return ret;
615 static int orion_wdt_remove(struct platform_device *pdev)
617 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
618 struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
620 watchdog_unregister_device(wdt_dev);
621 clk_disable_unprepare(dev->clk);
622 clk_put(dev->clk);
623 return 0;
626 static void orion_wdt_shutdown(struct platform_device *pdev)
628 struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
629 orion_wdt_stop(wdt_dev);
632 static struct platform_driver orion_wdt_driver = {
633 .probe = orion_wdt_probe,
634 .remove = orion_wdt_remove,
635 .shutdown = orion_wdt_shutdown,
636 .driver = {
637 .name = "orion_wdt",
638 .of_match_table = orion_wdt_of_match_table,
642 module_platform_driver(orion_wdt_driver);
644 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
645 MODULE_DESCRIPTION("Orion Processor Watchdog");
647 module_param(heartbeat, int, 0);
648 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
650 module_param(nowayout, bool, 0);
651 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
652 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
654 MODULE_LICENSE("GPL");
655 MODULE_ALIAS("platform:orion_wdt");