Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for Atmel SAMA5D4 Watchdog Timer
4 *
5 * Copyright (C) 2015-2019 Microchip Technology Inc. and its subsidiaries
6 */
7
8#include <linux/delay.h>
9#include <linux/interrupt.h>
10#include <linux/io.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/of_device.h>
15#include <linux/of_irq.h>
16#include <linux/platform_device.h>
17#include <linux/reboot.h>
18#include <linux/watchdog.h>
19
20#include "at91sam9_wdt.h"
21
22/* minimum and maximum watchdog timeout, in seconds */
23#define MIN_WDT_TIMEOUT 1
24#define MAX_WDT_TIMEOUT 16
25#define WDT_DEFAULT_TIMEOUT MAX_WDT_TIMEOUT
26
27#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0)
28
29struct sama5d4_wdt {
30 struct watchdog_device wdd;
31 void __iomem *reg_base;
32 u32 mr;
33 u32 ir;
34 unsigned long last_ping;
35 bool need_irq;
36 bool sam9x60_support;
37};
38
39static int wdt_timeout;
40static bool nowayout = WATCHDOG_NOWAYOUT;
41
42module_param(wdt_timeout, int, 0);
43MODULE_PARM_DESC(wdt_timeout,
44 "Watchdog timeout in seconds. (default = "
45 __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
46
47module_param(nowayout, bool, 0);
48MODULE_PARM_DESC(nowayout,
49 "Watchdog cannot be stopped once started (default="
50 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
51
52#define wdt_enabled (!(wdt->mr & AT91_WDT_WDDIS))
53
54#define wdt_read(wdt, field) \
55 readl_relaxed((wdt)->reg_base + (field))
56
57/* 4 slow clock periods is 4/32768 = 122.07µs*/
58#define WDT_DELAY usecs_to_jiffies(123)
59
60static void wdt_write(struct sama5d4_wdt *wdt, u32 field, u32 val)
61{
62 /*
63 * WDT_CR and WDT_MR must not be modified within three slow clock
64 * periods following a restart of the watchdog performed by a write
65 * access in WDT_CR.
66 */
67 while (time_before(jiffies, wdt->last_ping + WDT_DELAY))
68 usleep_range(30, 125);
69 writel_relaxed(val, wdt->reg_base + field);
70 wdt->last_ping = jiffies;
71}
72
73static void wdt_write_nosleep(struct sama5d4_wdt *wdt, u32 field, u32 val)
74{
75 if (time_before(jiffies, wdt->last_ping + WDT_DELAY))
76 udelay(123);
77 writel_relaxed(val, wdt->reg_base + field);
78 wdt->last_ping = jiffies;
79}
80
81static int sama5d4_wdt_start(struct watchdog_device *wdd)
82{
83 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
84
85 if (wdt->sam9x60_support) {
86 writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IER);
87 wdt->mr &= ~AT91_SAM9X60_WDDIS;
88 } else {
89 wdt->mr &= ~AT91_WDT_WDDIS;
90 }
91 wdt_write(wdt, AT91_WDT_MR, wdt->mr);
92
93 return 0;
94}
95
96static int sama5d4_wdt_stop(struct watchdog_device *wdd)
97{
98 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
99
100 if (wdt->sam9x60_support) {
101 writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IDR);
102 wdt->mr |= AT91_SAM9X60_WDDIS;
103 } else {
104 wdt->mr |= AT91_WDT_WDDIS;
105 }
106 wdt_write(wdt, AT91_WDT_MR, wdt->mr);
107
108 return 0;
109}
110
111static int sama5d4_wdt_ping(struct watchdog_device *wdd)
112{
113 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
114
115 wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
116
117 return 0;
118}
119
120static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
121 unsigned int timeout)
122{
123 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
124 u32 value = WDT_SEC2TICKS(timeout);
125
126 if (wdt->sam9x60_support) {
127 wdt_write(wdt, AT91_SAM9X60_WLR,
128 AT91_SAM9X60_SET_COUNTER(value));
129
130 wdd->timeout = timeout;
131 return 0;
132 }
133
134 wdt->mr &= ~AT91_WDT_WDV;
135 wdt->mr |= AT91_WDT_SET_WDV(value);
136
137 /*
138 * WDDIS has to be 0 when updating WDD/WDV. The datasheet states: When
139 * setting the WDDIS bit, and while it is set, the fields WDV and WDD
140 * must not be modified.
141 * If the watchdog is enabled, then the timeout can be updated. Else,
142 * wait that the user enables it.
143 */
144 if (wdt_enabled)
145 wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS);
146
147 wdd->timeout = timeout;
148
149 return 0;
150}
151
152static const struct watchdog_info sama5d4_wdt_info = {
153 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
154 .identity = "Atmel SAMA5D4 Watchdog",
155};
156
157static const struct watchdog_ops sama5d4_wdt_ops = {
158 .owner = THIS_MODULE,
159 .start = sama5d4_wdt_start,
160 .stop = sama5d4_wdt_stop,
161 .ping = sama5d4_wdt_ping,
162 .set_timeout = sama5d4_wdt_set_timeout,
163};
164
165static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
166{
167 struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
168 u32 reg;
169
170 if (wdt->sam9x60_support)
171 reg = wdt_read(wdt, AT91_SAM9X60_ISR);
172 else
173 reg = wdt_read(wdt, AT91_WDT_SR);
174
175 if (reg) {
176 pr_crit("Atmel Watchdog Software Reset\n");
177 emergency_restart();
178 pr_crit("Reboot didn't succeed\n");
179 }
180
181 return IRQ_HANDLED;
182}
183
184static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
185{
186 const char *tmp;
187
188 if (wdt->sam9x60_support)
189 wdt->mr = AT91_SAM9X60_WDDIS;
190 else
191 wdt->mr = AT91_WDT_WDDIS;
192
193 if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
194 !strcmp(tmp, "software"))
195 wdt->need_irq = true;
196
197 if (of_property_read_bool(np, "atmel,idle-halt"))
198 wdt->mr |= AT91_WDT_WDIDLEHLT;
199
200 if (of_property_read_bool(np, "atmel,dbg-halt"))
201 wdt->mr |= AT91_WDT_WDDBGHLT;
202
203 return 0;
204}
205
206static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
207{
208 u32 reg, val;
209
210 val = WDT_SEC2TICKS(WDT_DEFAULT_TIMEOUT);
211 /*
212 * When booting and resuming, the bootloader may have changed the
213 * watchdog configuration.
214 * If the watchdog is already running, we can safely update it.
215 * Else, we have to disable it properly.
216 */
217 if (!wdt_enabled) {
218 reg = wdt_read(wdt, AT91_WDT_MR);
219 if (wdt->sam9x60_support && (!(reg & AT91_SAM9X60_WDDIS)))
220 wdt_write_nosleep(wdt, AT91_WDT_MR,
221 reg | AT91_SAM9X60_WDDIS);
222 else if (!wdt->sam9x60_support &&
223 (!(reg & AT91_WDT_WDDIS)))
224 wdt_write_nosleep(wdt, AT91_WDT_MR,
225 reg | AT91_WDT_WDDIS);
226 }
227
228 if (wdt->sam9x60_support) {
229 if (wdt->need_irq)
230 wdt->ir = AT91_SAM9X60_PERINT;
231 else
232 wdt->mr |= AT91_SAM9X60_PERIODRST;
233
234 wdt_write(wdt, AT91_SAM9X60_IER, wdt->ir);
235 wdt_write(wdt, AT91_SAM9X60_WLR, AT91_SAM9X60_SET_COUNTER(val));
236 } else {
237 wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
238 wdt->mr |= AT91_WDT_SET_WDV(val);
239
240 if (wdt->need_irq)
241 wdt->mr |= AT91_WDT_WDFIEN;
242 else
243 wdt->mr |= AT91_WDT_WDRSTEN;
244 }
245
246 wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
247
248 return 0;
249}
250
251static int sama5d4_wdt_probe(struct platform_device *pdev)
252{
253 struct device *dev = &pdev->dev;
254 struct watchdog_device *wdd;
255 struct sama5d4_wdt *wdt;
256 void __iomem *regs;
257 u32 irq = 0;
258 int ret;
259
260 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
261 if (!wdt)
262 return -ENOMEM;
263
264 wdd = &wdt->wdd;
265 wdd->timeout = WDT_DEFAULT_TIMEOUT;
266 wdd->info = &sama5d4_wdt_info;
267 wdd->ops = &sama5d4_wdt_ops;
268 wdd->min_timeout = MIN_WDT_TIMEOUT;
269 wdd->max_timeout = MAX_WDT_TIMEOUT;
270 wdt->last_ping = jiffies;
271 wdt->sam9x60_support = of_device_is_compatible(dev->of_node,
272 "microchip,sam9x60-wdt");
273
274 watchdog_set_drvdata(wdd, wdt);
275
276 regs = devm_platform_ioremap_resource(pdev, 0);
277 if (IS_ERR(regs))
278 return PTR_ERR(regs);
279
280 wdt->reg_base = regs;
281
282 ret = of_sama5d4_wdt_init(dev->of_node, wdt);
283 if (ret)
284 return ret;
285
286 if (wdt->need_irq) {
287 irq = irq_of_parse_and_map(dev->of_node, 0);
288 if (!irq) {
289 dev_warn(dev, "failed to get IRQ from DT\n");
290 wdt->need_irq = false;
291 }
292 }
293
294 if (wdt->need_irq) {
295 ret = devm_request_irq(dev, irq, sama5d4_wdt_irq_handler,
296 IRQF_SHARED | IRQF_IRQPOLL |
297 IRQF_NO_SUSPEND, pdev->name, pdev);
298 if (ret) {
299 dev_err(dev, "cannot register interrupt handler\n");
300 return ret;
301 }
302 }
303
304 watchdog_init_timeout(wdd, wdt_timeout, dev);
305
306 ret = sama5d4_wdt_init(wdt);
307 if (ret)
308 return ret;
309
310 watchdog_set_nowayout(wdd, nowayout);
311
312 watchdog_stop_on_unregister(wdd);
313 ret = devm_watchdog_register_device(dev, wdd);
314 if (ret)
315 return ret;
316
317 platform_set_drvdata(pdev, wdt);
318
319 dev_info(dev, "initialized (timeout = %d sec, nowayout = %d)\n",
320 wdd->timeout, nowayout);
321
322 return 0;
323}
324
325static const struct of_device_id sama5d4_wdt_of_match[] = {
326 {
327 .compatible = "atmel,sama5d4-wdt",
328 },
329 {
330 .compatible = "microchip,sam9x60-wdt",
331 },
332 { }
333};
334MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
335
336#ifdef CONFIG_PM_SLEEP
337static int sama5d4_wdt_suspend_late(struct device *dev)
338{
339 struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
340
341 if (watchdog_active(&wdt->wdd))
342 sama5d4_wdt_stop(&wdt->wdd);
343
344 return 0;
345}
346
347static int sama5d4_wdt_resume_early(struct device *dev)
348{
349 struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
350
351 /*
352 * FIXME: writing MR also pings the watchdog which may not be desired.
353 * This should only be done when the registers are lost on suspend but
354 * there is no way to get this information right now.
355 */
356 sama5d4_wdt_init(wdt);
357
358 if (watchdog_active(&wdt->wdd))
359 sama5d4_wdt_start(&wdt->wdd);
360
361 return 0;
362}
363#endif
364
365static const struct dev_pm_ops sama5d4_wdt_pm_ops = {
366 SET_LATE_SYSTEM_SLEEP_PM_OPS(sama5d4_wdt_suspend_late,
367 sama5d4_wdt_resume_early)
368};
369
370static struct platform_driver sama5d4_wdt_driver = {
371 .probe = sama5d4_wdt_probe,
372 .driver = {
373 .name = "sama5d4_wdt",
374 .pm = &sama5d4_wdt_pm_ops,
375 .of_match_table = sama5d4_wdt_of_match,
376 }
377};
378module_platform_driver(sama5d4_wdt_driver);
379
380MODULE_AUTHOR("Atmel Corporation");
381MODULE_DESCRIPTION("Atmel SAMA5D4 Watchdog Timer driver");
382MODULE_LICENSE("GPL v2");
1/*
2 * Driver for Atmel SAMA5D4 Watchdog Timer
3 *
4 * Copyright (C) 2015 Atmel Corporation
5 *
6 * Licensed under GPLv2.
7 */
8
9#include <linux/delay.h>
10#include <linux/interrupt.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/of_irq.h>
16#include <linux/platform_device.h>
17#include <linux/reboot.h>
18#include <linux/watchdog.h>
19
20#include "at91sam9_wdt.h"
21
22/* minimum and maximum watchdog timeout, in seconds */
23#define MIN_WDT_TIMEOUT 1
24#define MAX_WDT_TIMEOUT 16
25#define WDT_DEFAULT_TIMEOUT MAX_WDT_TIMEOUT
26
27#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0)
28
29struct sama5d4_wdt {
30 struct watchdog_device wdd;
31 void __iomem *reg_base;
32 u32 mr;
33 unsigned long last_ping;
34};
35
36static int wdt_timeout;
37static bool nowayout = WATCHDOG_NOWAYOUT;
38
39module_param(wdt_timeout, int, 0);
40MODULE_PARM_DESC(wdt_timeout,
41 "Watchdog timeout in seconds. (default = "
42 __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
43
44module_param(nowayout, bool, 0);
45MODULE_PARM_DESC(nowayout,
46 "Watchdog cannot be stopped once started (default="
47 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
48
49#define wdt_enabled (!(wdt->mr & AT91_WDT_WDDIS))
50
51#define wdt_read(wdt, field) \
52 readl_relaxed((wdt)->reg_base + (field))
53
54/* 4 slow clock periods is 4/32768 = 122.07µs*/
55#define WDT_DELAY usecs_to_jiffies(123)
56
57static void wdt_write(struct sama5d4_wdt *wdt, u32 field, u32 val)
58{
59 /*
60 * WDT_CR and WDT_MR must not be modified within three slow clock
61 * periods following a restart of the watchdog performed by a write
62 * access in WDT_CR.
63 */
64 while (time_before(jiffies, wdt->last_ping + WDT_DELAY))
65 usleep_range(30, 125);
66 writel_relaxed(val, wdt->reg_base + field);
67 wdt->last_ping = jiffies;
68}
69
70static void wdt_write_nosleep(struct sama5d4_wdt *wdt, u32 field, u32 val)
71{
72 if (time_before(jiffies, wdt->last_ping + WDT_DELAY))
73 udelay(123);
74 writel_relaxed(val, wdt->reg_base + field);
75 wdt->last_ping = jiffies;
76}
77
78static int sama5d4_wdt_start(struct watchdog_device *wdd)
79{
80 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
81
82 wdt->mr &= ~AT91_WDT_WDDIS;
83 wdt_write(wdt, AT91_WDT_MR, wdt->mr);
84
85 return 0;
86}
87
88static int sama5d4_wdt_stop(struct watchdog_device *wdd)
89{
90 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
91
92 wdt->mr |= AT91_WDT_WDDIS;
93 wdt_write(wdt, AT91_WDT_MR, wdt->mr);
94
95 return 0;
96}
97
98static int sama5d4_wdt_ping(struct watchdog_device *wdd)
99{
100 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
101
102 wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
103
104 return 0;
105}
106
107static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
108 unsigned int timeout)
109{
110 struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
111 u32 value = WDT_SEC2TICKS(timeout);
112
113 wdt->mr &= ~AT91_WDT_WDV;
114 wdt->mr &= ~AT91_WDT_WDD;
115 wdt->mr |= AT91_WDT_SET_WDV(value);
116 wdt->mr |= AT91_WDT_SET_WDD(value);
117
118 /*
119 * WDDIS has to be 0 when updating WDD/WDV. The datasheet states: When
120 * setting the WDDIS bit, and while it is set, the fields WDV and WDD
121 * must not be modified.
122 * If the watchdog is enabled, then the timeout can be updated. Else,
123 * wait that the user enables it.
124 */
125 if (wdt_enabled)
126 wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS);
127
128 wdd->timeout = timeout;
129
130 return 0;
131}
132
133static const struct watchdog_info sama5d4_wdt_info = {
134 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
135 .identity = "Atmel SAMA5D4 Watchdog",
136};
137
138static const struct watchdog_ops sama5d4_wdt_ops = {
139 .owner = THIS_MODULE,
140 .start = sama5d4_wdt_start,
141 .stop = sama5d4_wdt_stop,
142 .ping = sama5d4_wdt_ping,
143 .set_timeout = sama5d4_wdt_set_timeout,
144};
145
146static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
147{
148 struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
149
150 if (wdt_read(wdt, AT91_WDT_SR)) {
151 pr_crit("Atmel Watchdog Software Reset\n");
152 emergency_restart();
153 pr_crit("Reboot didn't succeed\n");
154 }
155
156 return IRQ_HANDLED;
157}
158
159static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
160{
161 const char *tmp;
162
163 wdt->mr = AT91_WDT_WDDIS;
164
165 if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
166 !strcmp(tmp, "software"))
167 wdt->mr |= AT91_WDT_WDFIEN;
168 else
169 wdt->mr |= AT91_WDT_WDRSTEN;
170
171 if (of_property_read_bool(np, "atmel,idle-halt"))
172 wdt->mr |= AT91_WDT_WDIDLEHLT;
173
174 if (of_property_read_bool(np, "atmel,dbg-halt"))
175 wdt->mr |= AT91_WDT_WDDBGHLT;
176
177 return 0;
178}
179
180static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
181{
182 u32 reg;
183 /*
184 * When booting and resuming, the bootloader may have changed the
185 * watchdog configuration.
186 * If the watchdog is already running, we can safely update it.
187 * Else, we have to disable it properly.
188 */
189 if (wdt_enabled) {
190 wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
191 } else {
192 reg = wdt_read(wdt, AT91_WDT_MR);
193 if (!(reg & AT91_WDT_WDDIS))
194 wdt_write_nosleep(wdt, AT91_WDT_MR,
195 reg | AT91_WDT_WDDIS);
196 }
197 return 0;
198}
199
200static int sama5d4_wdt_probe(struct platform_device *pdev)
201{
202 struct watchdog_device *wdd;
203 struct sama5d4_wdt *wdt;
204 struct resource *res;
205 void __iomem *regs;
206 u32 irq = 0;
207 u32 timeout;
208 int ret;
209
210 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
211 if (!wdt)
212 return -ENOMEM;
213
214 wdd = &wdt->wdd;
215 wdd->timeout = WDT_DEFAULT_TIMEOUT;
216 wdd->info = &sama5d4_wdt_info;
217 wdd->ops = &sama5d4_wdt_ops;
218 wdd->min_timeout = MIN_WDT_TIMEOUT;
219 wdd->max_timeout = MAX_WDT_TIMEOUT;
220 wdt->last_ping = jiffies;
221
222 watchdog_set_drvdata(wdd, wdt);
223
224 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225 regs = devm_ioremap_resource(&pdev->dev, res);
226 if (IS_ERR(regs))
227 return PTR_ERR(regs);
228
229 wdt->reg_base = regs;
230
231 irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
232 if (!irq)
233 dev_warn(&pdev->dev, "failed to get IRQ from DT\n");
234
235 ret = of_sama5d4_wdt_init(pdev->dev.of_node, wdt);
236 if (ret)
237 return ret;
238
239 if ((wdt->mr & AT91_WDT_WDFIEN) && irq) {
240 ret = devm_request_irq(&pdev->dev, irq, sama5d4_wdt_irq_handler,
241 IRQF_SHARED | IRQF_IRQPOLL |
242 IRQF_NO_SUSPEND, pdev->name, pdev);
243 if (ret) {
244 dev_err(&pdev->dev,
245 "cannot register interrupt handler\n");
246 return ret;
247 }
248 }
249
250 ret = watchdog_init_timeout(wdd, wdt_timeout, &pdev->dev);
251 if (ret) {
252 dev_err(&pdev->dev, "unable to set timeout value\n");
253 return ret;
254 }
255
256 timeout = WDT_SEC2TICKS(wdd->timeout);
257
258 wdt->mr |= AT91_WDT_SET_WDD(timeout);
259 wdt->mr |= AT91_WDT_SET_WDV(timeout);
260
261 ret = sama5d4_wdt_init(wdt);
262 if (ret)
263 return ret;
264
265 watchdog_set_nowayout(wdd, nowayout);
266
267 ret = watchdog_register_device(wdd);
268 if (ret) {
269 dev_err(&pdev->dev, "failed to register watchdog device\n");
270 return ret;
271 }
272
273 platform_set_drvdata(pdev, wdt);
274
275 dev_info(&pdev->dev, "initialized (timeout = %d sec, nowayout = %d)\n",
276 wdd->timeout, nowayout);
277
278 return 0;
279}
280
281static int sama5d4_wdt_remove(struct platform_device *pdev)
282{
283 struct sama5d4_wdt *wdt = platform_get_drvdata(pdev);
284
285 sama5d4_wdt_stop(&wdt->wdd);
286
287 watchdog_unregister_device(&wdt->wdd);
288
289 return 0;
290}
291
292static const struct of_device_id sama5d4_wdt_of_match[] = {
293 { .compatible = "atmel,sama5d4-wdt", },
294 { }
295};
296MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
297
298#ifdef CONFIG_PM_SLEEP
299static int sama5d4_wdt_resume(struct device *dev)
300{
301 struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
302
303 /*
304 * FIXME: writing MR also pings the watchdog which may not be desired.
305 * This should only be done when the registers are lost on suspend but
306 * there is no way to get this information right now.
307 */
308 sama5d4_wdt_init(wdt);
309
310 return 0;
311}
312#endif
313
314static SIMPLE_DEV_PM_OPS(sama5d4_wdt_pm_ops, NULL,
315 sama5d4_wdt_resume);
316
317static struct platform_driver sama5d4_wdt_driver = {
318 .probe = sama5d4_wdt_probe,
319 .remove = sama5d4_wdt_remove,
320 .driver = {
321 .name = "sama5d4_wdt",
322 .pm = &sama5d4_wdt_pm_ops,
323 .of_match_table = sama5d4_wdt_of_match,
324 }
325};
326module_platform_driver(sama5d4_wdt_driver);
327
328MODULE_AUTHOR("Atmel Corporation");
329MODULE_DESCRIPTION("Atmel SAMA5D4 Watchdog Timer driver");
330MODULE_LICENSE("GPL v2");