xref: /optee_os/core/drivers/stm32_iwdg.c (revision 0960b6765c51598643bdb226a3bfaeab1b0e608f) 
1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * Copyright (c) 2017-2025, STMicroelectronics - All Rights Reserved
4  */
5 
6 #include <assert.h>
7 #include <drivers/clk.h>
8 #include <drivers/clk_dt.h>
9 #include <drivers/rstctrl.h>
10 #include <drivers/wdt.h>
11 #include <io.h>
12 #include <keep.h>
13 #include <kernel/boot.h>
14 #include <kernel/delay.h>
15 #include <kernel/dt.h>
16 #include <kernel/dt_driver.h>
17 #include <kernel/interrupt.h>
18 #include <kernel/misc.h>
19 #include <kernel/panic.h>
20 #include <kernel/pm.h>
21 #include <kernel/spinlock.h>
22 #include <kernel/tee_time.h>
23 #include <libfdt.h>
24 #include <mm/core_memprot.h>
25 #include <sm/sm.h>
26 #include <stdint.h>
27 #include <stm32_util.h>
28 #include <string.h>
29 #include <trace.h>
30 
31 /* IWDG Compatibility */
32 #define IWDG_TIMEOUT_US		U(40000)
33 #define IWDG_CNT_MASK		GENMASK_32(11, 0)
34 #define IWDG_ONF_MIN_VER	U(0x31)
35 #define IWDG_ICR_MIN_VER	U(0x40)
36 
37 /* IWDG registers offsets */
38 #define IWDG_KR_OFFSET		U(0x00)
39 #define IWDG_PR_OFFSET		U(0x04)
40 #define IWDG_RLR_OFFSET		U(0x08)
41 #define IWDG_SR_OFFSET		U(0x0C)
42 #define IWDG_EWCR_OFFSET	U(0x14)
43 #define IWDG_ICR_OFFSET		U(0x18)
44 #define IWDG_VERR_OFFSET	U(0x3F4)
45 
46 #define IWDG_KR_WPROT_KEY	U(0x0000)
47 #define IWDG_KR_ACCESS_KEY	U(0x5555)
48 #define IWDG_KR_RELOAD_KEY	U(0xAAAA)
49 #define IWDG_KR_START_KEY	U(0xCCCC)
50 
51 /* Use a fixed prescaler divider of 1024 */
52 #define IWDG_PRESCALER_1024	U(1024)
53 #define IWDG_PR_DIV_1024	U(0x8)
54 #define IWDG_PR_DIV_MASK	GENMASK_32(3, 0)
55 
56 #define IWDG_SR_PVU		BIT(0)
57 #define IWDG_SR_RVU		BIT(1)
58 #define IWDG_SR_WVU		BIT(2)
59 #define IWDG_SR_EWU		BIT(3)
60 #define IWDG_SR_UPDATE_MASK	(IWDG_SR_PVU | IWDG_SR_RVU | IWDG_SR_WVU | \
61 				 IWDG_SR_EWU)
62 #define IWDG_SR_ONF		BIT(8)
63 #define IWDG_SR_EWIF		BIT(14)
64 #define IWDG_SR_EWIF_V40	BIT(15)
65 
66 #define IWDG_EWCR_EWIE		BIT(15)
67 #define IWDG_EWCR_EWIC		BIT(14)
68 
69 #define IWDG_ICR_EWIC		BIT(15)
70 
71 #define IWDG_VERR_REV_MASK	GENMASK_32(7, 0)
72 
73 /* Define default early timeout delay to 5 sec before timeout */
74 #define IWDG_ETIMEOUT_SEC	U(5)
75 
76 /*
77  * Values for struct stm32_iwdg_device::flags
78  * IWDG_FLAGS_ENABLED			Watchdog has been enabled
79  */
80 #define IWDG_FLAGS_ENABLED			BIT(0)
81 
82 /*
83  * IWDG watch instance data
84  * @base - IWDG interface IOMEM base address
85  * @clk_pclk - Bus clock
86  * @clk_lsi - IWDG source clock
87  * @itr_chip - Interrupt chip device
88  * @itr_num - Interrupt number for the IWDG instance
89  * @itr_handler - Interrupt handler
90  * @reset - Reset controller device used to control the ability of the watchdog
91  *          to reset the system
92  * @flags - Property flags for the IWDG instance
93  * @timeout - Watchdog elaspure timeout
94  * @saved_nb_int - Saved number of interrupts before panic
95  * @nb_int - Remaining number of interrupts before panic
96  * @hw_version - Watchdog HW version
97  * @last_refresh - Time of last watchdog refresh
98  * @wdt_chip - Wathcdog chip instance
99  * @max_hw_timeout - Maximum hardware timeout
100  */
101 struct stm32_iwdg_device {
102 	struct io_pa_va base;
103 	struct clk *clk_pclk;
104 	struct clk *clk_lsi;
105 	struct itr_chip *itr_chip;
106 	size_t itr_num;
107 	struct itr_handler *itr_handler;
108 	struct rstctrl *reset;
109 	uint32_t flags;
110 	unsigned long timeout;
111 	unsigned long early_timeout;
112 	unsigned long saved_nb_int;
113 	unsigned long nb_int;
114 	unsigned int hw_version;
115 	TEE_Time last_refresh;
116 	struct wdt_chip wdt_chip;
117 	unsigned long max_hw_timeout;
118 };
119 
120 static uint32_t sr_ewif_mask(struct stm32_iwdg_device *iwdg)
121 {
122 	if (iwdg->hw_version >= IWDG_ICR_MIN_VER)
123 		return IWDG_SR_EWIF_V40;
124 	else
125 		return IWDG_SR_EWIF;
126 }
127 
128 static vaddr_t get_base(struct stm32_iwdg_device *iwdg)
129 {
130 	return io_pa_or_va(&iwdg->base, 1);
131 }
132 
133 static void iwdg_wdt_set_enabled(struct stm32_iwdg_device *iwdg)
134 {
135 	iwdg->flags |= IWDG_FLAGS_ENABLED;
136 }
137 
138 static bool iwdg_wdt_is_enabled(struct stm32_iwdg_device *iwdg)
139 {
140 	return iwdg->flags & IWDG_FLAGS_ENABLED;
141 }
142 
143 /* Return counter value to related to input timeout in seconds, or 0 on error */
144 static uint32_t iwdg_timeout_cnt(struct stm32_iwdg_device *iwdg,
145 				 unsigned long to_sec)
146 {
147 	uint64_t reload = (uint64_t)to_sec * clk_get_rate(iwdg->clk_lsi);
148 	uint64_t cnt = (reload / IWDG_PRESCALER_1024) - 1;
149 
150 	/* Be safe and expect any counter to be above 2 */
151 	if (cnt > IWDG_CNT_MASK || cnt < 3)
152 		return 0;
153 
154 	return cnt;
155 }
156 
157 /* Wait IWDG programming completes */
158 static TEE_Result iwdg_wait_sync(struct stm32_iwdg_device *iwdg)
159 {
160 	uint64_t timeout_ref = timeout_init_us(IWDG_TIMEOUT_US);
161 	vaddr_t iwdg_base = get_base(iwdg);
162 
163 	while (io_read32(iwdg_base + IWDG_SR_OFFSET) & IWDG_SR_UPDATE_MASK)
164 		if (timeout_elapsed(timeout_ref))
165 			break;
166 
167 	if (io_read32(iwdg_base + IWDG_SR_OFFSET) & IWDG_SR_UPDATE_MASK)
168 		return TEE_ERROR_GENERIC;
169 
170 	return TEE_SUCCESS;
171 }
172 
173 static void stm32_iwdg_it_ack(struct stm32_iwdg_device *iwdg)
174 {
175 	vaddr_t iwdg_base = get_base(iwdg);
176 
177 	if (iwdg->hw_version >= IWDG_ICR_MIN_VER)
178 		io_setbits32(iwdg_base + IWDG_ICR_OFFSET, IWDG_ICR_EWIC);
179 	else
180 		io_setbits32(iwdg_base + IWDG_EWCR_OFFSET, IWDG_EWCR_EWIC);
181 }
182 
183 static enum itr_return stm32_iwdg_it_handler(struct itr_handler *h)
184 {
185 	unsigned int __maybe_unused cpu = get_core_pos();
186 	struct stm32_iwdg_device *iwdg = h->data;
187 	vaddr_t iwdg_base = get_base(iwdg);
188 
189 	DMSG("CPU %u IT Watchdog %#"PRIxPA, cpu, iwdg->base.pa);
190 
191 	/* Check for spurious interrupt */
192 	if (!(io_read32(iwdg_base + IWDG_SR_OFFSET) & sr_ewif_mask(iwdg)))
193 		return ITRR_NONE;
194 
195 	/*
196 	 * Writing IWDG_EWCR_EWIT triggers a watchdog refresh.
197 	 * To prevent the watchdog refresh, write-protect all the registers;
198 	 * this makes read-only all IWDG_EWCR fields except IWDG_EWCR_EWIC.
199 	 */
200 	io_write32(iwdg_base + IWDG_KR_OFFSET, IWDG_KR_WPROT_KEY);
201 
202 	/* Disable early interrupt */
203 	stm32_iwdg_it_ack(iwdg);
204 
205 	if (iwdg->nb_int > 0) {
206 		/* Decrease interrupt counter when watchdog is not stopped*/
207 		if (iwdg->nb_int < ULONG_MAX)
208 			iwdg->nb_int--;
209 		io_write32(get_base(iwdg) + IWDG_KR_OFFSET, IWDG_KR_RELOAD_KEY);
210 	} else {
211 		panic("Watchdog");
212 	}
213 
214 	return ITRR_HANDLED;
215 }
216 DECLARE_KEEP_PAGER(stm32_iwdg_it_handler);
217 
218 static TEE_Result configure_timeout(struct stm32_iwdg_device *iwdg)
219 {
220 	TEE_Result res = TEE_ERROR_GENERIC;
221 	vaddr_t iwdg_base = get_base(iwdg);
222 	uint32_t rlr_value = 0;
223 	uint32_t ewie_value = 0;
224 
225 	assert(iwdg_wdt_is_enabled(iwdg));
226 
227 	rlr_value = iwdg_timeout_cnt(iwdg, iwdg->timeout);
228 	if (!rlr_value)
229 		return TEE_ERROR_GENERIC;
230 
231 	if (iwdg->itr_handler) {
232 		ewie_value = iwdg_timeout_cnt(iwdg, iwdg->early_timeout);
233 		interrupt_enable(iwdg->itr_chip, iwdg->itr_num);
234 	}
235 
236 	io_write32(iwdg_base + IWDG_KR_OFFSET, IWDG_KR_ACCESS_KEY);
237 	io_write32(iwdg_base + IWDG_PR_OFFSET, IWDG_PR_DIV_1024);
238 	io_write32(iwdg_base + IWDG_RLR_OFFSET, rlr_value);
239 	if (ewie_value &&
240 	    !(io_read32(iwdg_base + IWDG_EWCR_OFFSET) & IWDG_EWCR_EWIE))
241 		io_write32(iwdg_base + IWDG_EWCR_OFFSET,
242 			   ewie_value | IWDG_EWCR_EWIE);
243 
244 	res = iwdg_wait_sync(iwdg);
245 
246 	io_write32(iwdg_base + IWDG_KR_OFFSET, IWDG_KR_RELOAD_KEY);
247 
248 	return res;
249 }
250 
251 static void iwdg_start(struct stm32_iwdg_device *iwdg)
252 {
253 	TEE_Result res = TEE_ERROR_GENERIC;
254 
255 	res = tee_time_get_sys_time(&iwdg->last_refresh);
256 	if (res)
257 		panic();
258 
259 	io_write32(get_base(iwdg) + IWDG_KR_OFFSET, IWDG_KR_START_KEY);
260 
261 	iwdg_wdt_set_enabled(iwdg);
262 }
263 
264 static void iwdg_refresh(struct stm32_iwdg_device *iwdg)
265 {
266 	TEE_Result res = TEE_ERROR_GENERIC;
267 
268 	res = tee_time_get_sys_time(&iwdg->last_refresh);
269 	if (res)
270 		panic();
271 
272 	io_write32(get_base(iwdg) + IWDG_KR_OFFSET, IWDG_KR_RELOAD_KEY);
273 }
274 
275 /* Operators for watchdog OP-TEE interface */
276 static struct stm32_iwdg_device *wdt_chip_to_iwdg(struct wdt_chip *chip)
277 {
278 	return container_of(chip, struct stm32_iwdg_device, wdt_chip);
279 }
280 
281 static TEE_Result iwdg_wdt_init(struct wdt_chip *chip,
282 				unsigned long *min_timeout,
283 				unsigned long *max_timeout)
284 {
285 	struct stm32_iwdg_device *iwdg = wdt_chip_to_iwdg(chip);
286 	unsigned long rate = clk_get_rate(iwdg->clk_lsi);
287 
288 	if (!rate)
289 		return TEE_ERROR_GENERIC;
290 
291 	/* Be safe and expect any counter to be above 2 */
292 	*min_timeout = 3 * IWDG_PRESCALER_1024 / rate;
293 	*max_timeout = (IWDG_CNT_MASK + 1) * IWDG_PRESCALER_1024 / rate;
294 
295 	return TEE_SUCCESS;
296 }
297 
298 static void iwdg_wdt_start(struct wdt_chip *chip)
299 {
300 	struct stm32_iwdg_device *iwdg = wdt_chip_to_iwdg(chip);
301 
302 	iwdg_start(iwdg);
303 	if (iwdg->reset && iwdg->itr_handler)
304 		stm32_iwdg_it_ack(iwdg);
305 
306 	if (configure_timeout(iwdg))
307 		panic();
308 
309 	if (iwdg->reset)
310 		if (rstctrl_assert(iwdg->reset))
311 			panic();
312 }
313 
314 static void iwdg_wdt_stop(struct wdt_chip *chip)
315 {
316 	struct stm32_iwdg_device *iwdg = wdt_chip_to_iwdg(chip);
317 
318 	if (iwdg->reset) {
319 		if (rstctrl_deassert(iwdg->reset))
320 			panic();
321 		if (iwdg->itr_handler)
322 			interrupt_disable(iwdg->itr_chip, iwdg->itr_num);
323 	}
324 
325 	/* Reload on early interrupt and no more panic */
326 	iwdg->saved_nb_int = ULONG_MAX;
327 	iwdg->nb_int = ULONG_MAX;
328 }
329 
330 static void iwdg_wdt_refresh(struct wdt_chip *chip)
331 {
332 	struct stm32_iwdg_device *iwdg = wdt_chip_to_iwdg(chip);
333 
334 	iwdg->nb_int = iwdg->saved_nb_int;
335 	iwdg_refresh(iwdg);
336 }
337 
338 static void stm32_iwdg_handle_timeouts(struct stm32_iwdg_device *iwdg,
339 				       unsigned long timeout_sec)
340 {
341 	unsigned long interval = 0;
342 	unsigned long rate = 0;
343 	unsigned long n = 0;
344 	long w = 0;
345 
346 	rate = clk_get_rate(iwdg->clk_lsi);
347 	iwdg->max_hw_timeout = (IWDG_CNT_MASK + 1) * IWDG_PRESCALER_1024 / rate;
348 
349 	if (timeout_sec > iwdg->max_hw_timeout) {
350 		IMSG("Timeout exceeds hardware capability, approximate it");
351 		interval = iwdg->max_hw_timeout - IWDG_ETIMEOUT_SEC;
352 		n = (timeout_sec - IWDG_ETIMEOUT_SEC) / interval;
353 		w = ((timeout_sec - IWDG_ETIMEOUT_SEC) / (n + 1)) +
354 		IWDG_ETIMEOUT_SEC;
355 		iwdg->timeout = w;
356 		iwdg->early_timeout = IWDG_ETIMEOUT_SEC;
357 	} else {
358 		iwdg->timeout = timeout_sec;
359 		if (iwdg->timeout >= 2 * IWDG_ETIMEOUT_SEC)
360 			iwdg->early_timeout = IWDG_ETIMEOUT_SEC;
361 		else
362 			iwdg->early_timeout = iwdg->timeout / 4;
363 	}
364 
365 	if (!iwdg->early_timeout)
366 		iwdg->early_timeout = 1;
367 
368 	iwdg->saved_nb_int = n;
369 	iwdg->nb_int = n;
370 }
371 
372 static TEE_Result iwdg_wdt_set_timeout(struct wdt_chip *chip,
373 				       unsigned long timeout)
374 {
375 	struct stm32_iwdg_device *iwdg = wdt_chip_to_iwdg(chip);
376 
377 	if (iwdg_wdt_is_enabled(iwdg)) {
378 		TEE_Result res = TEE_ERROR_GENERIC;
379 
380 		stm32_iwdg_handle_timeouts(iwdg, timeout);
381 
382 		res = configure_timeout(iwdg);
383 		if (res)
384 			return res;
385 	}
386 
387 	return TEE_SUCCESS;
388 }
389 
390 static TEE_Result iwdg_wdt_get_timeleft(struct wdt_chip *chip, bool *is_started,
391 					unsigned long *timeleft)
392 {
393 	struct stm32_iwdg_device *iwdg = wdt_chip_to_iwdg(chip);
394 	TEE_Result res = TEE_ERROR_GENERIC;
395 	TEE_Time time = { };
396 	TEE_Time now = { };
397 
398 	*is_started = iwdg_wdt_is_enabled(iwdg);
399 
400 	if (!*is_started)
401 		return TEE_SUCCESS;
402 
403 	res = tee_time_get_sys_time(&now);
404 	if (res)
405 		panic();
406 
407 	time.seconds =
408 		(iwdg->timeout - iwdg->early_timeout) * iwdg->saved_nb_int
409 		+ iwdg->early_timeout;
410 	TEE_TIME_ADD(iwdg->last_refresh, time, time);
411 	if (TEE_TIME_LE(time, now)) {
412 		*timeleft = 0;
413 	} else {
414 		TEE_TIME_SUB(time, now, time);
415 		*timeleft = time.seconds;
416 	}
417 
418 	return TEE_SUCCESS;
419 }
420 
421 static const struct wdt_ops stm32_iwdg_ops = {
422 	.init = iwdg_wdt_init,
423 	.start = iwdg_wdt_start,
424 	.stop = iwdg_wdt_stop,
425 	.ping = iwdg_wdt_refresh,
426 	.set_timeout = iwdg_wdt_set_timeout,
427 	.get_timeleft = iwdg_wdt_get_timeleft,
428 };
429 DECLARE_KEEP_PAGER(stm32_iwdg_ops);
430 
431 /* Driver initialization */
432 static TEE_Result stm32_iwdg_parse_fdt(struct stm32_iwdg_device *iwdg,
433 				       const void *fdt, int node)
434 {
435 	TEE_Result res = TEE_ERROR_GENERIC;
436 	struct dt_node_info dt_info = { };
437 	const fdt32_t *cuint = NULL;
438 
439 	fdt_fill_device_info(fdt, &dt_info, node);
440 
441 	if (dt_info.reg == DT_INFO_INVALID_REG ||
442 	    dt_info.reg_size == DT_INFO_INVALID_REG_SIZE)
443 		panic();
444 
445 	res = clk_dt_get_by_name(fdt, node, "pclk", &iwdg->clk_pclk);
446 	if (res)
447 		return res;
448 
449 	res = clk_dt_get_by_name(fdt, node, "lsi", &iwdg->clk_lsi);
450 	if (res)
451 		return res;
452 
453 	res = interrupt_dt_get(fdt, node, &iwdg->itr_chip, &iwdg->itr_num);
454 	if (res && res != TEE_ERROR_ITEM_NOT_FOUND)
455 		return res;
456 	if (!res) {
457 		res = interrupt_create_handler(iwdg->itr_chip, iwdg->itr_num,
458 					       stm32_iwdg_it_handler, iwdg, 0,
459 					       &iwdg->itr_handler);
460 		if (res)
461 			return res;
462 	}
463 
464 	res = rstctrl_dt_get_by_index(fdt, node, 0, &iwdg->reset);
465 	if (res && res != TEE_ERROR_ITEM_NOT_FOUND)
466 		goto err_itr;
467 
468 	/* Get IOMEM address */
469 	iwdg->base.pa = dt_info.reg;
470 	io_pa_or_va_secure(&iwdg->base, dt_info.reg_size);
471 	assert(iwdg->base.va);
472 
473 	/* Get and check timeout value */
474 	cuint = fdt_getprop(fdt, node, "timeout-sec", NULL);
475 	if (!cuint) {
476 		res = TEE_ERROR_BAD_PARAMETERS;
477 		goto err_itr;
478 	}
479 
480 	iwdg->timeout = (int)fdt32_to_cpu(*cuint);
481 	if (!iwdg->timeout) {
482 		res = TEE_ERROR_BAD_PARAMETERS;
483 		goto err_itr;
484 	}
485 
486 	return TEE_SUCCESS;
487 
488 err_itr:
489 	interrupt_remove_free_handler(iwdg->itr_handler);
490 
491 	return res;
492 }
493 
494 static void iwdg_wdt_get_version_and_status(struct stm32_iwdg_device *iwdg)
495 {
496 	vaddr_t iwdg_base = get_base(iwdg);
497 	uint32_t rlr_value = 0;
498 
499 	iwdg->hw_version = io_read32(iwdg_base + IWDG_VERR_OFFSET) &
500 			   IWDG_VERR_REV_MASK;
501 
502 	/* Test if watchdog is already running */
503 	if (iwdg->hw_version >= IWDG_ONF_MIN_VER) {
504 		if (io_read32(iwdg_base + IWDG_SR_OFFSET) & IWDG_SR_ONF)
505 			iwdg_wdt_set_enabled(iwdg);
506 	} else {
507 		/*
508 		 * Workaround for old versions without IWDG_SR_ONF bit:
509 		 * - write in IWDG_RLR_OFFSET
510 		 * - wait for sync
511 		 * - if sync succeeds, then iwdg is running
512 		 */
513 		io_write32(iwdg_base + IWDG_KR_OFFSET, IWDG_KR_ACCESS_KEY);
514 
515 		rlr_value = io_read32(iwdg_base + IWDG_RLR_OFFSET);
516 		io_write32(iwdg_base + IWDG_RLR_OFFSET, rlr_value);
517 
518 		if (!iwdg_wait_sync(iwdg))
519 			iwdg_wdt_set_enabled(iwdg);
520 
521 		io_write32(iwdg_base + IWDG_KR_OFFSET, IWDG_KR_WPROT_KEY);
522 	}
523 
524 	DMSG("Watchdog is %sabled", iwdg_wdt_is_enabled(iwdg) ? "en" : "dis");
525 }
526 
527 static TEE_Result stm32_iwdg_pm(enum pm_op op, unsigned int pm_hint __unused,
528 				const struct pm_callback_handle *pm_handle)
529 {
530 	struct stm32_iwdg_device *iwdg = PM_CALLBACK_GET_HANDLE(pm_handle);
531 
532 	if (op == PM_OP_RESUME) {
533 		clk_enable(iwdg->clk_lsi);
534 		clk_enable(iwdg->clk_pclk);
535 	} else {
536 		clk_disable(iwdg->clk_lsi);
537 		clk_disable(iwdg->clk_pclk);
538 	}
539 
540 	return TEE_SUCCESS;
541 }
542 DECLARE_KEEP_PAGER(stm32_iwdg_pm);
543 
544 static TEE_Result stm32_iwdg_probe(const void *fdt, int node,
545 				   const void *compat_data __unused)
546 {
547 	struct stm32_iwdg_device *iwdg = NULL;
548 	TEE_Result res = TEE_SUCCESS;
549 
550 	iwdg = calloc(1, sizeof(*iwdg));
551 	if (!iwdg)
552 		return TEE_ERROR_OUT_OF_MEMORY;
553 
554 	res = stm32_iwdg_parse_fdt(iwdg, fdt, node);
555 	if (res)
556 		goto out_free;
557 
558 	/* Enable watchdog source and bus clocks once for all */
559 	if (clk_enable(iwdg->clk_lsi))
560 		panic();
561 
562 	if (clk_enable(iwdg->clk_pclk))
563 		panic();
564 
565 	iwdg_wdt_get_version_and_status(iwdg);
566 
567 	res = iwdg_wdt_set_timeout(&iwdg->wdt_chip, iwdg->timeout);
568 	if (res)
569 		panic();
570 
571 	if (iwdg_wdt_is_enabled(iwdg))
572 		iwdg_wdt_refresh(&iwdg->wdt_chip);
573 
574 	iwdg->wdt_chip.ops = &stm32_iwdg_ops;
575 
576 	register_pm_core_service_cb(stm32_iwdg_pm, iwdg, "stm32-iwdg");
577 
578 	res = watchdog_register(&iwdg->wdt_chip);
579 	if (res)
580 		goto out_pm;
581 
582 	return TEE_SUCCESS;
583 
584 out_pm:
585 	unregister_pm_core_service_cb(stm32_iwdg_pm, iwdg);
586 out_free:
587 	free(iwdg);
588 
589 	return res;
590 }
591 
592 static const struct dt_device_match stm32_iwdg_match_table[] = {
593 	{ .compatible = "st,stm32mp1-iwdg" },
594 	{ }
595 };
596 
597 DEFINE_DT_DRIVER(stm32_iwdg_dt_driver) = {
598 	.name = "stm32-iwdg",
599 	.match_table = stm32_iwdg_match_table,
600 	.probe = stm32_iwdg_probe,
601 };
602