Merge tag 'platform-drivers-x86-v4.16-3' of git://github.com/dvhart/linux-pdx86
[sfrench/cifs-2.6.git] / drivers / watchdog / orion_wdt.c
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 hardcoded 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         dev->wdt.parent = &pdev->dev;
571         watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
572
573         platform_set_drvdata(pdev, &dev->wdt);
574         watchdog_set_drvdata(&dev->wdt, dev);
575
576         /*
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-inserted, or if the bootloader explicitly
580          * set a running watchdog before booting the kernel.
581          */
582         if (!orion_wdt_enabled(&dev->wdt))
583                 orion_wdt_stop(&dev->wdt);
584
585         /* Request the IRQ only after the watchdog is disabled */
586         irq = platform_get_irq(pdev, 0);
587         if (irq > 0) {
588                 /*
589                  * Not all supported platforms specify an interrupt for the
590                  * watchdog, so let's make it optional.
591                  */
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;
597                 }
598         }
599
600         watchdog_set_nowayout(&dev->wdt, nowayout);
601         ret = watchdog_register_device(&dev->wdt);
602         if (ret)
603                 goto disable_clk;
604
605         pr_info("Initial timeout %d sec%s\n",
606                 dev->wdt.timeout, nowayout ? ", nowayout" : "");
607         return 0;
608
609 disable_clk:
610         clk_disable_unprepare(dev->clk);
611         clk_put(dev->clk);
612         return ret;
613 }
614
615 static int orion_wdt_remove(struct platform_device *pdev)
616 {
617         struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
618         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
619
620         watchdog_unregister_device(wdt_dev);
621         clk_disable_unprepare(dev->clk);
622         clk_put(dev->clk);
623         return 0;
624 }
625
626 static void orion_wdt_shutdown(struct platform_device *pdev)
627 {
628         struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
629         orion_wdt_stop(wdt_dev);
630 }
631
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,
639         },
640 };
641
642 module_platform_driver(orion_wdt_driver);
643
644 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
645 MODULE_DESCRIPTION("Orion Processor Watchdog");
646
647 module_param(heartbeat, int, 0);
648 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
649
650 module_param(nowayout, bool, 0);
651 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
652                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
653
654 MODULE_LICENSE("GPL v2");
655 MODULE_ALIAS("platform:orion_wdt");