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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Mediatek Watchdog Driver
4 *
5 * Copyright (C) 2014 Matthias Brugger
6 *
7 * Matthias Brugger <matthias.bgg@gmail.com>
8 *
9 * Based on sunxi_wdt.c
10 */
11
12#include <dt-bindings/reset/mt2712-resets.h>
13#include <dt-bindings/reset/mediatek,mt6795-resets.h>
14#include <dt-bindings/reset/mt7986-resets.h>
15#include <dt-bindings/reset/mt8183-resets.h>
16#include <dt-bindings/reset/mt8186-resets.h>
17#include <dt-bindings/reset/mt8188-resets.h>
18#include <dt-bindings/reset/mt8192-resets.h>
19#include <dt-bindings/reset/mt8195-resets.h>
20#include <linux/delay.h>
21#include <linux/err.h>
22#include <linux/init.h>
23#include <linux/io.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/of.h>
28#include <linux/of_device.h>
29#include <linux/platform_device.h>
30#include <linux/reset-controller.h>
31#include <linux/types.h>
32#include <linux/watchdog.h>
33#include <linux/interrupt.h>
34
35#define WDT_MAX_TIMEOUT 31
36#define WDT_MIN_TIMEOUT 2
37#define WDT_LENGTH_TIMEOUT(n) ((n) << 5)
38
39#define WDT_LENGTH 0x04
40#define WDT_LENGTH_KEY 0x8
41
42#define WDT_RST 0x08
43#define WDT_RST_RELOAD 0x1971
44
45#define WDT_MODE 0x00
46#define WDT_MODE_EN (1 << 0)
47#define WDT_MODE_EXT_POL_LOW (0 << 1)
48#define WDT_MODE_EXT_POL_HIGH (1 << 1)
49#define WDT_MODE_EXRST_EN (1 << 2)
50#define WDT_MODE_IRQ_EN (1 << 3)
51#define WDT_MODE_AUTO_START (1 << 4)
52#define WDT_MODE_DUAL_EN (1 << 6)
53#define WDT_MODE_KEY 0x22000000
54
55#define WDT_SWRST 0x14
56#define WDT_SWRST_KEY 0x1209
57
58#define WDT_SWSYSRST 0x18U
59#define WDT_SWSYS_RST_KEY 0x88000000
60
61#define DRV_NAME "mtk-wdt"
62#define DRV_VERSION "1.0"
63
64static bool nowayout = WATCHDOG_NOWAYOUT;
65static unsigned int timeout;
66
67struct mtk_wdt_dev {
68 struct watchdog_device wdt_dev;
69 void __iomem *wdt_base;
70 spinlock_t lock; /* protects WDT_SWSYSRST reg */
71 struct reset_controller_dev rcdev;
72 bool disable_wdt_extrst;
73};
74
75struct mtk_wdt_data {
76 int toprgu_sw_rst_num;
77};
78
79static const struct mtk_wdt_data mt2712_data = {
80 .toprgu_sw_rst_num = MT2712_TOPRGU_SW_RST_NUM,
81};
82
83static const struct mtk_wdt_data mt6795_data = {
84 .toprgu_sw_rst_num = MT6795_TOPRGU_SW_RST_NUM,
85};
86
87static const struct mtk_wdt_data mt7986_data = {
88 .toprgu_sw_rst_num = MT7986_TOPRGU_SW_RST_NUM,
89};
90
91static const struct mtk_wdt_data mt8183_data = {
92 .toprgu_sw_rst_num = MT8183_TOPRGU_SW_RST_NUM,
93};
94
95static const struct mtk_wdt_data mt8186_data = {
96 .toprgu_sw_rst_num = MT8186_TOPRGU_SW_RST_NUM,
97};
98
99static const struct mtk_wdt_data mt8188_data = {
100 .toprgu_sw_rst_num = MT8188_TOPRGU_SW_RST_NUM,
101};
102
103static const struct mtk_wdt_data mt8192_data = {
104 .toprgu_sw_rst_num = MT8192_TOPRGU_SW_RST_NUM,
105};
106
107static const struct mtk_wdt_data mt8195_data = {
108 .toprgu_sw_rst_num = MT8195_TOPRGU_SW_RST_NUM,
109};
110
111static int toprgu_reset_update(struct reset_controller_dev *rcdev,
112 unsigned long id, bool assert)
113{
114 unsigned int tmp;
115 unsigned long flags;
116 struct mtk_wdt_dev *data =
117 container_of(rcdev, struct mtk_wdt_dev, rcdev);
118
119 spin_lock_irqsave(&data->lock, flags);
120
121 tmp = readl(data->wdt_base + WDT_SWSYSRST);
122 if (assert)
123 tmp |= BIT(id);
124 else
125 tmp &= ~BIT(id);
126 tmp |= WDT_SWSYS_RST_KEY;
127 writel(tmp, data->wdt_base + WDT_SWSYSRST);
128
129 spin_unlock_irqrestore(&data->lock, flags);
130
131 return 0;
132}
133
134static int toprgu_reset_assert(struct reset_controller_dev *rcdev,
135 unsigned long id)
136{
137 return toprgu_reset_update(rcdev, id, true);
138}
139
140static int toprgu_reset_deassert(struct reset_controller_dev *rcdev,
141 unsigned long id)
142{
143 return toprgu_reset_update(rcdev, id, false);
144}
145
146static int toprgu_reset(struct reset_controller_dev *rcdev,
147 unsigned long id)
148{
149 int ret;
150
151 ret = toprgu_reset_assert(rcdev, id);
152 if (ret)
153 return ret;
154
155 return toprgu_reset_deassert(rcdev, id);
156}
157
158static const struct reset_control_ops toprgu_reset_ops = {
159 .assert = toprgu_reset_assert,
160 .deassert = toprgu_reset_deassert,
161 .reset = toprgu_reset,
162};
163
164static int toprgu_register_reset_controller(struct platform_device *pdev,
165 int rst_num)
166{
167 int ret;
168 struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
169
170 spin_lock_init(&mtk_wdt->lock);
171
172 mtk_wdt->rcdev.owner = THIS_MODULE;
173 mtk_wdt->rcdev.nr_resets = rst_num;
174 mtk_wdt->rcdev.ops = &toprgu_reset_ops;
175 mtk_wdt->rcdev.of_node = pdev->dev.of_node;
176 ret = devm_reset_controller_register(&pdev->dev, &mtk_wdt->rcdev);
177 if (ret != 0)
178 dev_err(&pdev->dev,
179 "couldn't register wdt reset controller: %d\n", ret);
180 return ret;
181}
182
183static int mtk_wdt_restart(struct watchdog_device *wdt_dev,
184 unsigned long action, void *data)
185{
186 struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
187 void __iomem *wdt_base;
188
189 wdt_base = mtk_wdt->wdt_base;
190
191 while (1) {
192 writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST);
193 mdelay(5);
194 }
195
196 return 0;
197}
198
199static int mtk_wdt_ping(struct watchdog_device *wdt_dev)
200{
201 struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
202 void __iomem *wdt_base = mtk_wdt->wdt_base;
203
204 iowrite32(WDT_RST_RELOAD, wdt_base + WDT_RST);
205
206 return 0;
207}
208
209static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
210 unsigned int timeout)
211{
212 struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
213 void __iomem *wdt_base = mtk_wdt->wdt_base;
214 u32 reg;
215
216 wdt_dev->timeout = timeout;
217 /*
218 * In dual mode, irq will be triggered at timeout / 2
219 * the real timeout occurs at timeout
220 */
221 if (wdt_dev->pretimeout)
222 wdt_dev->pretimeout = timeout / 2;
223
224 /*
225 * One bit is the value of 512 ticks
226 * The clock has 32 KHz
227 */
228 reg = WDT_LENGTH_TIMEOUT((timeout - wdt_dev->pretimeout) << 6)
229 | WDT_LENGTH_KEY;
230 iowrite32(reg, wdt_base + WDT_LENGTH);
231
232 mtk_wdt_ping(wdt_dev);
233
234 return 0;
235}
236
237static void mtk_wdt_init(struct watchdog_device *wdt_dev)
238{
239 struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
240 void __iomem *wdt_base;
241
242 wdt_base = mtk_wdt->wdt_base;
243
244 if (readl(wdt_base + WDT_MODE) & WDT_MODE_EN) {
245 set_bit(WDOG_HW_RUNNING, &wdt_dev->status);
246 mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
247 }
248}
249
250static int mtk_wdt_stop(struct watchdog_device *wdt_dev)
251{
252 struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
253 void __iomem *wdt_base = mtk_wdt->wdt_base;
254 u32 reg;
255
256 reg = readl(wdt_base + WDT_MODE);
257 reg &= ~WDT_MODE_EN;
258 reg |= WDT_MODE_KEY;
259 iowrite32(reg, wdt_base + WDT_MODE);
260
261 return 0;
262}
263
264static int mtk_wdt_start(struct watchdog_device *wdt_dev)
265{
266 u32 reg;
267 struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
268 void __iomem *wdt_base = mtk_wdt->wdt_base;
269 int ret;
270
271 ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
272 if (ret < 0)
273 return ret;
274
275 reg = ioread32(wdt_base + WDT_MODE);
276 if (wdt_dev->pretimeout)
277 reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
278 else
279 reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
280 if (mtk_wdt->disable_wdt_extrst)
281 reg &= ~WDT_MODE_EXRST_EN;
282 reg |= (WDT_MODE_EN | WDT_MODE_KEY);
283 iowrite32(reg, wdt_base + WDT_MODE);
284
285 return 0;
286}
287
288static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
289 unsigned int timeout)
290{
291 struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);
292 void __iomem *wdt_base = mtk_wdt->wdt_base;
293 u32 reg = ioread32(wdt_base + WDT_MODE);
294
295 if (timeout && !wdd->pretimeout) {
296 wdd->pretimeout = wdd->timeout / 2;
297 reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
298 } else if (!timeout && wdd->pretimeout) {
299 wdd->pretimeout = 0;
300 reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
301 } else {
302 return 0;
303 }
304
305 reg |= WDT_MODE_KEY;
306 iowrite32(reg, wdt_base + WDT_MODE);
307
308 return mtk_wdt_set_timeout(wdd, wdd->timeout);
309}
310
311static irqreturn_t mtk_wdt_isr(int irq, void *arg)
312{
313 struct watchdog_device *wdd = arg;
314
315 watchdog_notify_pretimeout(wdd);
316
317 return IRQ_HANDLED;
318}
319
320static const struct watchdog_info mtk_wdt_info = {
321 .identity = DRV_NAME,
322 .options = WDIOF_SETTIMEOUT |
323 WDIOF_KEEPALIVEPING |
324 WDIOF_MAGICCLOSE,
325};
326
327static const struct watchdog_info mtk_wdt_pt_info = {
328 .identity = DRV_NAME,
329 .options = WDIOF_SETTIMEOUT |
330 WDIOF_PRETIMEOUT |
331 WDIOF_KEEPALIVEPING |
332 WDIOF_MAGICCLOSE,
333};
334
335static const struct watchdog_ops mtk_wdt_ops = {
336 .owner = THIS_MODULE,
337 .start = mtk_wdt_start,
338 .stop = mtk_wdt_stop,
339 .ping = mtk_wdt_ping,
340 .set_timeout = mtk_wdt_set_timeout,
341 .set_pretimeout = mtk_wdt_set_pretimeout,
342 .restart = mtk_wdt_restart,
343};
344
345static int mtk_wdt_probe(struct platform_device *pdev)
346{
347 struct device *dev = &pdev->dev;
348 struct mtk_wdt_dev *mtk_wdt;
349 const struct mtk_wdt_data *wdt_data;
350 int err, irq;
351
352 mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
353 if (!mtk_wdt)
354 return -ENOMEM;
355
356 platform_set_drvdata(pdev, mtk_wdt);
357
358 mtk_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
359 if (IS_ERR(mtk_wdt->wdt_base))
360 return PTR_ERR(mtk_wdt->wdt_base);
361
362 irq = platform_get_irq_optional(pdev, 0);
363 if (irq > 0) {
364 err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
365 &mtk_wdt->wdt_dev);
366 if (err)
367 return err;
368
369 mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
370 mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;
371 } else {
372 if (irq == -EPROBE_DEFER)
373 return -EPROBE_DEFER;
374
375 mtk_wdt->wdt_dev.info = &mtk_wdt_info;
376 }
377
378 mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
379 mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
380 mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
381 mtk_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
382 mtk_wdt->wdt_dev.parent = dev;
383
384 watchdog_init_timeout(&mtk_wdt->wdt_dev, timeout, dev);
385 watchdog_set_nowayout(&mtk_wdt->wdt_dev, nowayout);
386 watchdog_set_restart_priority(&mtk_wdt->wdt_dev, 128);
387
388 watchdog_set_drvdata(&mtk_wdt->wdt_dev, mtk_wdt);
389
390 mtk_wdt_init(&mtk_wdt->wdt_dev);
391
392 watchdog_stop_on_reboot(&mtk_wdt->wdt_dev);
393 err = devm_watchdog_register_device(dev, &mtk_wdt->wdt_dev);
394 if (unlikely(err))
395 return err;
396
397 dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)\n",
398 mtk_wdt->wdt_dev.timeout, nowayout);
399
400 wdt_data = of_device_get_match_data(dev);
401 if (wdt_data) {
402 err = toprgu_register_reset_controller(pdev,
403 wdt_data->toprgu_sw_rst_num);
404 if (err)
405 return err;
406 }
407
408 mtk_wdt->disable_wdt_extrst =
409 of_property_read_bool(dev->of_node, "mediatek,disable-extrst");
410
411 return 0;
412}
413
414static int mtk_wdt_suspend(struct device *dev)
415{
416 struct mtk_wdt_dev *mtk_wdt = dev_get_drvdata(dev);
417
418 if (watchdog_active(&mtk_wdt->wdt_dev))
419 mtk_wdt_stop(&mtk_wdt->wdt_dev);
420
421 return 0;
422}
423
424static int mtk_wdt_resume(struct device *dev)
425{
426 struct mtk_wdt_dev *mtk_wdt = dev_get_drvdata(dev);
427
428 if (watchdog_active(&mtk_wdt->wdt_dev)) {
429 mtk_wdt_start(&mtk_wdt->wdt_dev);
430 mtk_wdt_ping(&mtk_wdt->wdt_dev);
431 }
432
433 return 0;
434}
435
436static const struct of_device_id mtk_wdt_dt_ids[] = {
437 { .compatible = "mediatek,mt2712-wdt", .data = &mt2712_data },
438 { .compatible = "mediatek,mt6589-wdt" },
439 { .compatible = "mediatek,mt6795-wdt", .data = &mt6795_data },
440 { .compatible = "mediatek,mt7986-wdt", .data = &mt7986_data },
441 { .compatible = "mediatek,mt8183-wdt", .data = &mt8183_data },
442 { .compatible = "mediatek,mt8186-wdt", .data = &mt8186_data },
443 { .compatible = "mediatek,mt8188-wdt", .data = &mt8188_data },
444 { .compatible = "mediatek,mt8192-wdt", .data = &mt8192_data },
445 { .compatible = "mediatek,mt8195-wdt", .data = &mt8195_data },
446 { /* sentinel */ }
447};
448MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
449
450static DEFINE_SIMPLE_DEV_PM_OPS(mtk_wdt_pm_ops,
451 mtk_wdt_suspend, mtk_wdt_resume);
452
453static struct platform_driver mtk_wdt_driver = {
454 .probe = mtk_wdt_probe,
455 .driver = {
456 .name = DRV_NAME,
457 .pm = pm_sleep_ptr(&mtk_wdt_pm_ops),
458 .of_match_table = mtk_wdt_dt_ids,
459 },
460};
461
462module_platform_driver(mtk_wdt_driver);
463
464module_param(timeout, uint, 0);
465MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
466
467module_param(nowayout, bool, 0);
468MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
469 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
470
471MODULE_LICENSE("GPL");
472MODULE_AUTHOR("Matthias Brugger <matthias.bgg@gmail.com>");
473MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver");
474MODULE_VERSION(DRV_VERSION);