1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2004 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C2410 Watchdog Timer Support
7 *
8 * Based on, softdog.c by Alan Cox,
9 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
10 */
11
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/types.h>
15 #include <linux/timer.h>
16 #include <linux/watchdog.h>
17 #include <linux/platform_device.h>
18 #include <linux/interrupt.h>
19 #include <linux/clk.h>
20 #include <linux/uaccess.h>
21 #include <linux/io.h>
22 #include <linux/cpufreq.h>
23 #include <linux/slab.h>
24 #include <linux/err.h>
25 #include <linux/of.h>
26 #include <linux/mfd/syscon.h>
27 #include <linux/regmap.h>
28 #include <linux/delay.h>
29
30 #define S3C2410_WTCON 0x00
31 #define S3C2410_WTDAT 0x04
32 #define S3C2410_WTCNT 0x08
33 #define S3C2410_WTCLRINT 0x0c
34
35 #define S3C2410_WTCNT_MAXCNT 0xffff
36
37 #define S3C2410_WTCON_RSTEN (1 << 0)
38 #define S3C2410_WTCON_INTEN (1 << 2)
39 #define S3C2410_WTCON_ENABLE (1 << 5)
40
41 #define S3C2410_WTCON_DIV16 (0 << 3)
42 #define S3C2410_WTCON_DIV32 (1 << 3)
43 #define S3C2410_WTCON_DIV64 (2 << 3)
44 #define S3C2410_WTCON_DIV128 (3 << 3)
45
46 #define S3C2410_WTCON_MAXDIV 0x80
47
48 #define S3C2410_WTCON_PRESCALE(x) ((x) << 8)
49 #define S3C2410_WTCON_PRESCALE_MASK (0xff << 8)
50 #define S3C2410_WTCON_PRESCALE_MAX 0xff
51
52 #define S3C2410_WATCHDOG_ATBOOT (0)
53 #define S3C2410_WATCHDOG_DEFAULT_TIME (15)
54
55 #define EXYNOS5_RST_STAT_REG_OFFSET 0x0404
56 #define EXYNOS5_WDT_DISABLE_REG_OFFSET 0x0408
57 #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET 0x040c
58 #define EXYNOS850_CLUSTER0_NONCPU_OUT 0x1220
59 #define EXYNOS850_CLUSTER0_NONCPU_INT_EN 0x1244
60 #define EXYNOS850_CLUSTER1_NONCPU_OUT 0x1620
61 #define EXYNOS850_CLUSTER1_NONCPU_INT_EN 0x1644
62 #define EXYNOSAUTOV9_CLUSTER1_NONCPU_OUT 0x1520
63 #define EXYNOSAUTOV9_CLUSTER1_NONCPU_INT_EN 0x1544
64
65 #define EXYNOS850_CLUSTER0_WDTRESET_BIT 24
66 #define EXYNOS850_CLUSTER1_WDTRESET_BIT 23
67 #define EXYNOSAUTOV9_CLUSTER0_WDTRESET_BIT 25
68 #define EXYNOSAUTOV9_CLUSTER1_WDTRESET_BIT 24
69
70 /**
71 * DOC: Quirk flags for different Samsung watchdog IP-cores
72 *
73 * This driver supports multiple Samsung SoCs, each of which might have
74 * different set of registers and features supported. As watchdog block
75 * sometimes requires modifying PMU registers for proper functioning, register
76 * differences in both watchdog and PMU IP-cores should be accounted for. Quirk
77 * flags described below serve the purpose of telling the driver about mentioned
78 * SoC traits, and can be specified in driver data for each particular supported
79 * device.
80 *
81 * %QUIRK_HAS_WTCLRINT_REG: Watchdog block has WTCLRINT register. It's used to
82 * clear the interrupt once the interrupt service routine is complete. It's
83 * write-only, writing any values to this register clears the interrupt, but
84 * reading is not permitted.
85 *
86 * %QUIRK_HAS_PMU_MASK_RESET: PMU block has the register for disabling/enabling
87 * WDT reset request. On old SoCs it's usually called MASK_WDT_RESET_REQUEST,
88 * new SoCs have CLUSTERx_NONCPU_INT_EN register, which 'mask_bit' value is
89 * inverted compared to the former one.
90 *
91 * %QUIRK_HAS_PMU_RST_STAT: PMU block has RST_STAT (reset status) register,
92 * which contains bits indicating the reason for most recent CPU reset. If
93 * present, driver will use this register to check if previous reboot was due to
94 * watchdog timer reset.
95 *
96 * %QUIRK_HAS_PMU_AUTO_DISABLE: PMU block has AUTOMATIC_WDT_RESET_DISABLE
97 * register. If 'mask_bit' bit is set, PMU will disable WDT reset when
98 * corresponding processor is in reset state.
99 *
100 * %QUIRK_HAS_PMU_CNT_EN: PMU block has some register (e.g. CLUSTERx_NONCPU_OUT)
101 * with "watchdog counter enable" bit. That bit should be set to make watchdog
102 * counter running.
103 */
104 #define QUIRK_HAS_WTCLRINT_REG (1 << 0)
105 #define QUIRK_HAS_PMU_MASK_RESET (1 << 1)
106 #define QUIRK_HAS_PMU_RST_STAT (1 << 2)
107 #define QUIRK_HAS_PMU_AUTO_DISABLE (1 << 3)
108 #define QUIRK_HAS_PMU_CNT_EN (1 << 4)
109
110 /* These quirks require that we have a PMU register map */
111 #define QUIRKS_HAVE_PMUREG \
112 (QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_RST_STAT | \
113 QUIRK_HAS_PMU_AUTO_DISABLE | QUIRK_HAS_PMU_CNT_EN)
114
115 static bool nowayout = WATCHDOG_NOWAYOUT;
116 static int tmr_margin;
117 static int tmr_atboot = S3C2410_WATCHDOG_ATBOOT;
118 static int soft_noboot;
119
120 module_param(tmr_margin, int, 0);
121 module_param(tmr_atboot, int, 0);
122 module_param(nowayout, bool, 0);
123 module_param(soft_noboot, int, 0);
124
125 MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
126 __MODULE_STRING(S3C2410_WATCHDOG_DEFAULT_TIME) ")");
127 MODULE_PARM_DESC(tmr_atboot,
128 "Watchdog is started at boot time if set to 1, default="
129 __MODULE_STRING(S3C2410_WATCHDOG_ATBOOT));
130 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
131 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
132 MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to reboot (default 0)");
133
134 /**
135 * struct s3c2410_wdt_variant - Per-variant config data
136 *
137 * @disable_reg: Offset in pmureg for the register that disables the watchdog
138 * timer reset functionality.
139 * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
140 * timer reset functionality.
141 * @mask_reset_inv: If set, mask_reset_reg value will have inverted meaning.
142 * @mask_bit: Bit number for the watchdog timer in the disable register and the
143 * mask reset register.
144 * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
145 * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
146 * reset.
147 * @cnt_en_reg: Offset in pmureg for the register that enables WDT counter.
148 * @cnt_en_bit: Bit number for "watchdog counter enable" in cnt_en register.
149 * @quirks: A bitfield of quirks.
150 */
151
152 struct s3c2410_wdt_variant {
153 int disable_reg;
154 int mask_reset_reg;
155 bool mask_reset_inv;
156 int mask_bit;
157 int rst_stat_reg;
158 int rst_stat_bit;
159 int cnt_en_reg;
160 int cnt_en_bit;
161 u32 quirks;
162 };
163
164 struct s3c2410_wdt {
165 struct device *dev;
166 struct clk *bus_clk; /* for register interface (PCLK) */
167 struct clk *src_clk; /* for WDT counter */
168 void __iomem *reg_base;
169 unsigned int count;
170 spinlock_t lock;
171 unsigned long wtcon_save;
172 unsigned long wtdat_save;
173 struct watchdog_device wdt_device;
174 struct notifier_block freq_transition;
175 const struct s3c2410_wdt_variant *drv_data;
176 struct regmap *pmureg;
177 };
178
179 static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
180 .quirks = 0
181 };
182
183 #ifdef CONFIG_OF
184 static const struct s3c2410_wdt_variant drv_data_s3c6410 = {
185 .quirks = QUIRK_HAS_WTCLRINT_REG,
186 };
187
188 static const struct s3c2410_wdt_variant drv_data_exynos5250 = {
189 .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
190 .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
191 .mask_bit = 20,
192 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
193 .rst_stat_bit = 20,
194 .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
195 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
196 };
197
198 static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
199 .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
200 .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
201 .mask_bit = 0,
202 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
203 .rst_stat_bit = 9,
204 .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
205 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
206 };
207
208 static const struct s3c2410_wdt_variant drv_data_exynos7 = {
209 .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
210 .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
211 .mask_bit = 23,
212 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
213 .rst_stat_bit = 23, /* A57 WDTRESET */
214 .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
215 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
216 };
217
218 static const struct s3c2410_wdt_variant drv_data_exynos850_cl0 = {
219 .mask_reset_reg = EXYNOS850_CLUSTER0_NONCPU_INT_EN,
220 .mask_bit = 2,
221 .mask_reset_inv = true,
222 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
223 .rst_stat_bit = EXYNOS850_CLUSTER0_WDTRESET_BIT,
224 .cnt_en_reg = EXYNOS850_CLUSTER0_NONCPU_OUT,
225 .cnt_en_bit = 7,
226 .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
227 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
228 };
229
230 static const struct s3c2410_wdt_variant drv_data_exynos850_cl1 = {
231 .mask_reset_reg = EXYNOS850_CLUSTER1_NONCPU_INT_EN,
232 .mask_bit = 2,
233 .mask_reset_inv = true,
234 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
235 .rst_stat_bit = EXYNOS850_CLUSTER1_WDTRESET_BIT,
236 .cnt_en_reg = EXYNOS850_CLUSTER1_NONCPU_OUT,
237 .cnt_en_bit = 7,
238 .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
239 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
240 };
241
242 static const struct s3c2410_wdt_variant drv_data_exynosautov9_cl0 = {
243 .mask_reset_reg = EXYNOS850_CLUSTER0_NONCPU_INT_EN,
244 .mask_bit = 2,
245 .mask_reset_inv = true,
246 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
247 .rst_stat_bit = EXYNOSAUTOV9_CLUSTER0_WDTRESET_BIT,
248 .cnt_en_reg = EXYNOS850_CLUSTER0_NONCPU_OUT,
249 .cnt_en_bit = 7,
250 .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET |
251 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
252 };
253
254 static const struct s3c2410_wdt_variant drv_data_exynosautov9_cl1 = {
255 .mask_reset_reg = EXYNOSAUTOV9_CLUSTER1_NONCPU_INT_EN,
256 .mask_bit = 2,
257 .mask_reset_inv = true,
258 .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
259 .rst_stat_bit = EXYNOSAUTOV9_CLUSTER1_WDTRESET_BIT,
260 .cnt_en_reg = EXYNOSAUTOV9_CLUSTER1_NONCPU_OUT,
261 .cnt_en_bit = 7,
262 .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET |
263 QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
264 };
265
266 static const struct of_device_id s3c2410_wdt_match[] = {
267 { .compatible = "samsung,s3c2410-wdt",
268 .data = &drv_data_s3c2410 },
269 { .compatible = "samsung,s3c6410-wdt",
270 .data = &drv_data_s3c6410 },
271 { .compatible = "samsung,exynos5250-wdt",
272 .data = &drv_data_exynos5250 },
273 { .compatible = "samsung,exynos5420-wdt",
274 .data = &drv_data_exynos5420 },
275 { .compatible = "samsung,exynos7-wdt",
276 .data = &drv_data_exynos7 },
277 { .compatible = "samsung,exynos850-wdt",
278 .data = &drv_data_exynos850_cl0 },
279 { .compatible = "samsung,exynosautov9-wdt",
280 .data = &drv_data_exynosautov9_cl0 },
281 {},
282 };
283 MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
284 #endif
285
286 static const struct platform_device_id s3c2410_wdt_ids[] = {
287 {
288 .name = "s3c2410-wdt",
289 .driver_data = (unsigned long)&drv_data_s3c2410,
290 },
291 {}
292 };
293 MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
294
295 /* functions */
296
s3c2410wdt_get_freq(struct s3c2410_wdt * wdt)297 static inline unsigned long s3c2410wdt_get_freq(struct s3c2410_wdt *wdt)
298 {
299 return clk_get_rate(wdt->src_clk ? wdt->src_clk : wdt->bus_clk);
300 }
301
s3c2410wdt_max_timeout(struct s3c2410_wdt * wdt)302 static inline unsigned int s3c2410wdt_max_timeout(struct s3c2410_wdt *wdt)
303 {
304 const unsigned long freq = s3c2410wdt_get_freq(wdt);
305
306 return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1)
307 / S3C2410_WTCON_MAXDIV);
308 }
309
s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt * wdt,bool mask)310 static int s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
311 {
312 const u32 mask_val = BIT(wdt->drv_data->mask_bit);
313 const u32 val = mask ? mask_val : 0;
314 int ret;
315
316 ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->disable_reg,
317 mask_val, val);
318 if (ret < 0)
319 dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
320
321 return ret;
322 }
323
s3c2410wdt_mask_wdt_reset(struct s3c2410_wdt * wdt,bool mask)324 static int s3c2410wdt_mask_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
325 {
326 const u32 mask_val = BIT(wdt->drv_data->mask_bit);
327 const bool val_inv = wdt->drv_data->mask_reset_inv;
328 const u32 val = (mask ^ val_inv) ? mask_val : 0;
329 int ret;
330
331 ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->mask_reset_reg,
332 mask_val, val);
333 if (ret < 0)
334 dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
335
336 return ret;
337 }
338
s3c2410wdt_enable_counter(struct s3c2410_wdt * wdt,bool en)339 static int s3c2410wdt_enable_counter(struct s3c2410_wdt *wdt, bool en)
340 {
341 const u32 mask_val = BIT(wdt->drv_data->cnt_en_bit);
342 const u32 val = en ? mask_val : 0;
343 int ret;
344
345 ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->cnt_en_reg,
346 mask_val, val);
347 if (ret < 0)
348 dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
349
350 return ret;
351 }
352
s3c2410wdt_enable(struct s3c2410_wdt * wdt,bool en)353 static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en)
354 {
355 int ret;
356
357 if (wdt->drv_data->quirks & QUIRK_HAS_PMU_AUTO_DISABLE) {
358 ret = s3c2410wdt_disable_wdt_reset(wdt, !en);
359 if (ret < 0)
360 return ret;
361 }
362
363 if (wdt->drv_data->quirks & QUIRK_HAS_PMU_MASK_RESET) {
364 ret = s3c2410wdt_mask_wdt_reset(wdt, !en);
365 if (ret < 0)
366 return ret;
367 }
368
369 if (wdt->drv_data->quirks & QUIRK_HAS_PMU_CNT_EN) {
370 ret = s3c2410wdt_enable_counter(wdt, en);
371 if (ret < 0)
372 return ret;
373 }
374
375 return 0;
376 }
377
s3c2410wdt_keepalive(struct watchdog_device * wdd)378 static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
379 {
380 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
381 unsigned long flags;
382
383 spin_lock_irqsave(&wdt->lock, flags);
384 writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
385 spin_unlock_irqrestore(&wdt->lock, flags);
386
387 return 0;
388 }
389
__s3c2410wdt_stop(struct s3c2410_wdt * wdt)390 static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
391 {
392 unsigned long wtcon;
393
394 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
395 wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
396 writel(wtcon, wdt->reg_base + S3C2410_WTCON);
397 }
398
s3c2410wdt_stop(struct watchdog_device * wdd)399 static int s3c2410wdt_stop(struct watchdog_device *wdd)
400 {
401 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
402 unsigned long flags;
403
404 spin_lock_irqsave(&wdt->lock, flags);
405 __s3c2410wdt_stop(wdt);
406 spin_unlock_irqrestore(&wdt->lock, flags);
407
408 return 0;
409 }
410
s3c2410wdt_start(struct watchdog_device * wdd)411 static int s3c2410wdt_start(struct watchdog_device *wdd)
412 {
413 unsigned long wtcon;
414 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
415 unsigned long flags;
416
417 spin_lock_irqsave(&wdt->lock, flags);
418
419 __s3c2410wdt_stop(wdt);
420
421 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
422 wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
423
424 if (soft_noboot) {
425 wtcon |= S3C2410_WTCON_INTEN;
426 wtcon &= ~S3C2410_WTCON_RSTEN;
427 } else {
428 wtcon &= ~S3C2410_WTCON_INTEN;
429 wtcon |= S3C2410_WTCON_RSTEN;
430 }
431
432 dev_dbg(wdt->dev, "Starting watchdog: count=0x%08x, wtcon=%08lx\n",
433 wdt->count, wtcon);
434
435 writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
436 writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
437 writel(wtcon, wdt->reg_base + S3C2410_WTCON);
438 spin_unlock_irqrestore(&wdt->lock, flags);
439
440 return 0;
441 }
442
s3c2410wdt_set_heartbeat(struct watchdog_device * wdd,unsigned int timeout)443 static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd,
444 unsigned int timeout)
445 {
446 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
447 unsigned long freq = s3c2410wdt_get_freq(wdt);
448 unsigned int count;
449 unsigned int divisor = 1;
450 unsigned long wtcon;
451
452 if (timeout < 1)
453 return -EINVAL;
454
455 freq = DIV_ROUND_UP(freq, 128);
456 count = timeout * freq;
457
458 dev_dbg(wdt->dev, "Heartbeat: count=%d, timeout=%d, freq=%lu\n",
459 count, timeout, freq);
460
461 /* if the count is bigger than the watchdog register,
462 then work out what we need to do (and if) we can
463 actually make this value
464 */
465
466 if (count >= 0x10000) {
467 divisor = DIV_ROUND_UP(count, 0xffff);
468
469 if (divisor > 0x100) {
470 dev_err(wdt->dev, "timeout %d too big\n", timeout);
471 return -EINVAL;
472 }
473 }
474
475 dev_dbg(wdt->dev, "Heartbeat: timeout=%d, divisor=%d, count=%d (%08x)\n",
476 timeout, divisor, count, DIV_ROUND_UP(count, divisor));
477
478 count = DIV_ROUND_UP(count, divisor);
479 wdt->count = count;
480
481 /* update the pre-scaler */
482 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
483 wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
484 wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
485
486 writel(count, wdt->reg_base + S3C2410_WTDAT);
487 writel(wtcon, wdt->reg_base + S3C2410_WTCON);
488
489 wdd->timeout = (count * divisor) / freq;
490
491 return 0;
492 }
493
s3c2410wdt_restart(struct watchdog_device * wdd,unsigned long action,void * data)494 static int s3c2410wdt_restart(struct watchdog_device *wdd, unsigned long action,
495 void *data)
496 {
497 struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
498 void __iomem *wdt_base = wdt->reg_base;
499
500 /* disable watchdog, to be safe */
501 writel(0, wdt_base + S3C2410_WTCON);
502
503 /* put initial values into count and data */
504 writel(0x80, wdt_base + S3C2410_WTCNT);
505 writel(0x80, wdt_base + S3C2410_WTDAT);
506
507 /* set the watchdog to go and reset... */
508 writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
509 S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
510 wdt_base + S3C2410_WTCON);
511
512 /* wait for reset to assert... */
513 mdelay(500);
514
515 return 0;
516 }
517
518 #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
519
520 static const struct watchdog_info s3c2410_wdt_ident = {
521 .options = OPTIONS,
522 .firmware_version = 0,
523 .identity = "S3C2410 Watchdog",
524 };
525
526 static const struct watchdog_ops s3c2410wdt_ops = {
527 .owner = THIS_MODULE,
528 .start = s3c2410wdt_start,
529 .stop = s3c2410wdt_stop,
530 .ping = s3c2410wdt_keepalive,
531 .set_timeout = s3c2410wdt_set_heartbeat,
532 .restart = s3c2410wdt_restart,
533 };
534
535 static const struct watchdog_device s3c2410_wdd = {
536 .info = &s3c2410_wdt_ident,
537 .ops = &s3c2410wdt_ops,
538 .timeout = S3C2410_WATCHDOG_DEFAULT_TIME,
539 };
540
541 /* interrupt handler code */
542
s3c2410wdt_irq(int irqno,void * param)543 static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
544 {
545 struct s3c2410_wdt *wdt = platform_get_drvdata(param);
546
547 dev_info(wdt->dev, "watchdog timer expired (irq)\n");
548
549 s3c2410wdt_keepalive(&wdt->wdt_device);
550
551 if (wdt->drv_data->quirks & QUIRK_HAS_WTCLRINT_REG)
552 writel(0x1, wdt->reg_base + S3C2410_WTCLRINT);
553
554 return IRQ_HANDLED;
555 }
556
s3c2410wdt_get_bootstatus(struct s3c2410_wdt * wdt)557 static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
558 {
559 unsigned int rst_stat;
560 int ret;
561
562 if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_RST_STAT))
563 return 0;
564
565 ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
566 if (ret)
567 dev_warn(wdt->dev, "Couldn't get RST_STAT register\n");
568 else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit))
569 return WDIOF_CARDRESET;
570
571 return 0;
572 }
573
574 static inline int
s3c2410_get_wdt_drv_data(struct platform_device * pdev,struct s3c2410_wdt * wdt)575 s3c2410_get_wdt_drv_data(struct platform_device *pdev, struct s3c2410_wdt *wdt)
576 {
577 const struct s3c2410_wdt_variant *variant;
578 struct device *dev = &pdev->dev;
579
580 variant = of_device_get_match_data(dev);
581 if (!variant) {
582 /* Device matched by platform_device_id */
583 variant = (struct s3c2410_wdt_variant *)
584 platform_get_device_id(pdev)->driver_data;
585 }
586
587 #ifdef CONFIG_OF
588 /* Choose Exynos850/ExynosAutov9 driver data w.r.t. cluster index */
589 if (variant == &drv_data_exynos850_cl0 ||
590 variant == &drv_data_exynosautov9_cl0) {
591 u32 index;
592 int err;
593
594 err = of_property_read_u32(dev->of_node,
595 "samsung,cluster-index", &index);
596 if (err)
597 return dev_err_probe(dev, -EINVAL, "failed to get cluster index\n");
598
599 switch (index) {
600 case 0:
601 break;
602 case 1:
603 variant = (variant == &drv_data_exynos850_cl0) ?
604 &drv_data_exynos850_cl1 :
605 &drv_data_exynosautov9_cl1;
606 break;
607 default:
608 return dev_err_probe(dev, -EINVAL, "wrong cluster index: %u\n", index);
609 }
610 }
611 #endif
612
613 wdt->drv_data = variant;
614 return 0;
615 }
616
s3c2410wdt_wdt_disable_action(void * data)617 static void s3c2410wdt_wdt_disable_action(void *data)
618 {
619 s3c2410wdt_enable(data, false);
620 }
621
s3c2410wdt_probe(struct platform_device * pdev)622 static int s3c2410wdt_probe(struct platform_device *pdev)
623 {
624 struct device *dev = &pdev->dev;
625 struct s3c2410_wdt *wdt;
626 unsigned int wtcon;
627 int wdt_irq;
628 int ret;
629
630 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
631 if (!wdt)
632 return -ENOMEM;
633
634 wdt->dev = dev;
635 spin_lock_init(&wdt->lock);
636 wdt->wdt_device = s3c2410_wdd;
637
638 ret = s3c2410_get_wdt_drv_data(pdev, wdt);
639 if (ret)
640 return ret;
641
642 if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
643 wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
644 "samsung,syscon-phandle");
645 if (IS_ERR(wdt->pmureg))
646 return dev_err_probe(dev, PTR_ERR(wdt->pmureg),
647 "syscon regmap lookup failed.\n");
648 }
649
650 wdt_irq = platform_get_irq(pdev, 0);
651 if (wdt_irq < 0)
652 return wdt_irq;
653
654 /* get the memory region for the watchdog timer */
655 wdt->reg_base = devm_platform_ioremap_resource(pdev, 0);
656 if (IS_ERR(wdt->reg_base))
657 return PTR_ERR(wdt->reg_base);
658
659 wdt->bus_clk = devm_clk_get_enabled(dev, "watchdog");
660 if (IS_ERR(wdt->bus_clk))
661 return dev_err_probe(dev, PTR_ERR(wdt->bus_clk), "failed to get bus clock\n");
662
663 /*
664 * "watchdog_src" clock is optional; if it's not present -- just skip it
665 * and use "watchdog" clock as both bus and source clock.
666 */
667 wdt->src_clk = devm_clk_get_optional_enabled(dev, "watchdog_src");
668 if (IS_ERR(wdt->src_clk))
669 return dev_err_probe(dev, PTR_ERR(wdt->src_clk), "failed to get source clock\n");
670
671 wdt->wdt_device.min_timeout = 1;
672 wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt);
673
674 watchdog_set_drvdata(&wdt->wdt_device, wdt);
675
676 /* see if we can actually set the requested timer margin, and if
677 * not, try the default value */
678
679 watchdog_init_timeout(&wdt->wdt_device, tmr_margin, dev);
680 ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
681 wdt->wdt_device.timeout);
682 if (ret) {
683 ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
684 S3C2410_WATCHDOG_DEFAULT_TIME);
685 if (ret == 0)
686 dev_warn(dev, "tmr_margin value out of range, default %d used\n",
687 S3C2410_WATCHDOG_DEFAULT_TIME);
688 else
689 return dev_err_probe(dev, ret, "failed to use default timeout\n");
690 }
691
692 ret = devm_request_irq(dev, wdt_irq, s3c2410wdt_irq, 0,
693 pdev->name, pdev);
694 if (ret != 0)
695 return dev_err_probe(dev, ret, "failed to install irq (%d)\n", ret);
696
697 watchdog_set_nowayout(&wdt->wdt_device, nowayout);
698 watchdog_set_restart_priority(&wdt->wdt_device, 128);
699
700 wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
701 wdt->wdt_device.parent = dev;
702
703 /*
704 * If "tmr_atboot" param is non-zero, start the watchdog right now. Also
705 * set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
706 *
707 * If we're not enabling the watchdog, then ensure it is disabled if it
708 * has been left running from the bootloader or other source.
709 */
710 if (tmr_atboot) {
711 dev_info(dev, "starting watchdog timer\n");
712 s3c2410wdt_start(&wdt->wdt_device);
713 set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
714 } else {
715 s3c2410wdt_stop(&wdt->wdt_device);
716 }
717
718 ret = devm_watchdog_register_device(dev, &wdt->wdt_device);
719 if (ret)
720 return ret;
721
722 ret = s3c2410wdt_enable(wdt, true);
723 if (ret < 0)
724 return ret;
725
726 ret = devm_add_action_or_reset(dev, s3c2410wdt_wdt_disable_action, wdt);
727 if (ret)
728 return ret;
729
730 platform_set_drvdata(pdev, wdt);
731
732 /* print out a statement of readiness */
733
734 wtcon = readl(wdt->reg_base + S3C2410_WTCON);
735
736 dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
737 (wtcon & S3C2410_WTCON_ENABLE) ? "" : "in",
738 (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
739 (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
740
741 return 0;
742 }
743
s3c2410wdt_shutdown(struct platform_device * dev)744 static void s3c2410wdt_shutdown(struct platform_device *dev)
745 {
746 struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
747
748 s3c2410wdt_enable(wdt, false);
749 s3c2410wdt_stop(&wdt->wdt_device);
750 }
751
s3c2410wdt_suspend(struct device * dev)752 static int s3c2410wdt_suspend(struct device *dev)
753 {
754 int ret;
755 struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
756
757 /* Save watchdog state, and turn it off. */
758 wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
759 wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
760
761 ret = s3c2410wdt_enable(wdt, false);
762 if (ret < 0)
763 return ret;
764
765 /* Note that WTCNT doesn't need to be saved. */
766 s3c2410wdt_stop(&wdt->wdt_device);
767
768 return 0;
769 }
770
s3c2410wdt_resume(struct device * dev)771 static int s3c2410wdt_resume(struct device *dev)
772 {
773 int ret;
774 struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
775
776 /* Restore watchdog state. */
777 writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
778 writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
779 writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
780
781 ret = s3c2410wdt_enable(wdt, true);
782 if (ret < 0)
783 return ret;
784
785 dev_info(dev, "watchdog %sabled\n",
786 (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
787
788 return 0;
789 }
790
791 static DEFINE_SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops,
792 s3c2410wdt_suspend, s3c2410wdt_resume);
793
794 static struct platform_driver s3c2410wdt_driver = {
795 .probe = s3c2410wdt_probe,
796 .shutdown = s3c2410wdt_shutdown,
797 .id_table = s3c2410_wdt_ids,
798 .driver = {
799 .name = "s3c2410-wdt",
800 .pm = pm_sleep_ptr(&s3c2410wdt_pm_ops),
801 .of_match_table = of_match_ptr(s3c2410_wdt_match),
802 },
803 };
804
805 module_platform_driver(s3c2410wdt_driver);
806
807 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, Dimitry Andric <dimitry.andric@tomtom.com>");
808 MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
809 MODULE_LICENSE("GPL");
810