1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
4  * Authors: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
5  *          Fabien Dessenne <fabien.dessenne@st.com> for STMicroelectronics.
6  */
7 
8 #include <linux/arm-smccc.h>
9 #include <linux/dma-mapping.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/mailbox_client.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/module.h>
15 #include <linux/of_address.h>
16 #include <linux/of_device.h>
17 #include <linux/of_reserved_mem.h>
18 #include <linux/pm_wakeirq.h>
19 #include <linux/regmap.h>
20 #include <linux/remoteproc.h>
21 #include <linux/reset.h>
22 #include <linux/slab.h>
23 #include <linux/workqueue.h>
24 
25 #include "remoteproc_internal.h"
26 
27 #define HOLD_BOOT		0
28 #define RELEASE_BOOT		1
29 
30 #define MBOX_NB_VQ		2
31 #define MBOX_NB_MBX		3
32 
33 #define STM32_SMC_RCC		0x82001000
34 #define STM32_SMC_REG_WRITE	0x1
35 
36 #define STM32_MBX_VQ0		"vq0"
37 #define STM32_MBX_VQ0_ID	0
38 #define STM32_MBX_VQ1		"vq1"
39 #define STM32_MBX_VQ1_ID	1
40 #define STM32_MBX_SHUTDOWN	"shutdown"
41 
42 #define RSC_TBL_SIZE		1024
43 
44 #define M4_STATE_OFF		0
45 #define M4_STATE_INI		1
46 #define M4_STATE_CRUN		2
47 #define M4_STATE_CSTOP		3
48 #define M4_STATE_STANDBY	4
49 #define M4_STATE_CRASH		5
50 
51 struct stm32_syscon {
52 	struct regmap *map;
53 	u32 reg;
54 	u32 mask;
55 };
56 
57 struct stm32_rproc_mem {
58 	char name[20];
59 	void __iomem *cpu_addr;
60 	phys_addr_t bus_addr;
61 	u32 dev_addr;
62 	size_t size;
63 };
64 
65 struct stm32_rproc_mem_ranges {
66 	u32 dev_addr;
67 	u32 bus_addr;
68 	u32 size;
69 };
70 
71 struct stm32_mbox {
72 	const unsigned char name[10];
73 	struct mbox_chan *chan;
74 	struct mbox_client client;
75 	struct work_struct vq_work;
76 	int vq_id;
77 };
78 
79 struct stm32_rproc {
80 	struct reset_control *rst;
81 	struct stm32_syscon hold_boot;
82 	struct stm32_syscon pdds;
83 	struct stm32_syscon m4_state;
84 	struct stm32_syscon rsctbl;
85 	int wdg_irq;
86 	u32 nb_rmems;
87 	struct stm32_rproc_mem *rmems;
88 	struct stm32_mbox mb[MBOX_NB_MBX];
89 	struct workqueue_struct *workqueue;
90 	bool secured_soc;
91 	void __iomem *rsc_va;
92 };
93 
94 static int stm32_rproc_pa_to_da(struct rproc *rproc, phys_addr_t pa, u64 *da)
95 {
96 	unsigned int i;
97 	struct stm32_rproc *ddata = rproc->priv;
98 	struct stm32_rproc_mem *p_mem;
99 
100 	for (i = 0; i < ddata->nb_rmems; i++) {
101 		p_mem = &ddata->rmems[i];
102 
103 		if (pa < p_mem->bus_addr ||
104 		    pa >= p_mem->bus_addr + p_mem->size)
105 			continue;
106 		*da = pa - p_mem->bus_addr + p_mem->dev_addr;
107 		dev_dbg(rproc->dev.parent, "pa %pa to da %llx\n", &pa, *da);
108 		return 0;
109 	}
110 
111 	return -EINVAL;
112 }
113 
114 static int stm32_rproc_mem_alloc(struct rproc *rproc,
115 				 struct rproc_mem_entry *mem)
116 {
117 	struct device *dev = rproc->dev.parent;
118 	void *va;
119 
120 	dev_dbg(dev, "map memory: %pa+%x\n", &mem->dma, mem->len);
121 	va = ioremap_wc(mem->dma, mem->len);
122 	if (IS_ERR_OR_NULL(va)) {
123 		dev_err(dev, "Unable to map memory region: %pa+%x\n",
124 			&mem->dma, mem->len);
125 		return -ENOMEM;
126 	}
127 
128 	/* Update memory entry va */
129 	mem->va = va;
130 
131 	return 0;
132 }
133 
134 static int stm32_rproc_mem_release(struct rproc *rproc,
135 				   struct rproc_mem_entry *mem)
136 {
137 	dev_dbg(rproc->dev.parent, "unmap memory: %pa\n", &mem->dma);
138 	iounmap(mem->va);
139 
140 	return 0;
141 }
142 
143 static int stm32_rproc_of_memory_translations(struct platform_device *pdev,
144 					      struct stm32_rproc *ddata)
145 {
146 	struct device *parent, *dev = &pdev->dev;
147 	struct device_node *np;
148 	struct stm32_rproc_mem *p_mems;
149 	struct stm32_rproc_mem_ranges *mem_range;
150 	int cnt, array_size, i, ret = 0;
151 
152 	parent = dev->parent;
153 	np = parent->of_node;
154 
155 	cnt = of_property_count_elems_of_size(np, "dma-ranges",
156 					      sizeof(*mem_range));
157 	if (cnt <= 0) {
158 		dev_err(dev, "%s: dma-ranges property not defined\n", __func__);
159 		return -EINVAL;
160 	}
161 
162 	p_mems = devm_kcalloc(dev, cnt, sizeof(*p_mems), GFP_KERNEL);
163 	if (!p_mems)
164 		return -ENOMEM;
165 	mem_range = kcalloc(cnt, sizeof(*mem_range), GFP_KERNEL);
166 	if (!mem_range)
167 		return -ENOMEM;
168 
169 	array_size = cnt * sizeof(struct stm32_rproc_mem_ranges) / sizeof(u32);
170 
171 	ret = of_property_read_u32_array(np, "dma-ranges",
172 					 (u32 *)mem_range, array_size);
173 	if (ret) {
174 		dev_err(dev, "error while get dma-ranges property: %x\n", ret);
175 		goto free_mem;
176 	}
177 
178 	for (i = 0; i < cnt; i++) {
179 		p_mems[i].bus_addr = mem_range[i].bus_addr;
180 		p_mems[i].dev_addr = mem_range[i].dev_addr;
181 		p_mems[i].size     = mem_range[i].size;
182 
183 		dev_dbg(dev, "memory range[%i]: da %#x, pa %pa, size %#zx:\n",
184 			i, p_mems[i].dev_addr, &p_mems[i].bus_addr,
185 			p_mems[i].size);
186 	}
187 
188 	ddata->rmems = p_mems;
189 	ddata->nb_rmems = cnt;
190 
191 free_mem:
192 	kfree(mem_range);
193 	return ret;
194 }
195 
196 static int stm32_rproc_mbox_idx(struct rproc *rproc, const unsigned char *name)
197 {
198 	struct stm32_rproc *ddata = rproc->priv;
199 	int i;
200 
201 	for (i = 0; i < ARRAY_SIZE(ddata->mb); i++) {
202 		if (!strncmp(ddata->mb[i].name, name, strlen(name)))
203 			return i;
204 	}
205 	dev_err(&rproc->dev, "mailbox %s not found\n", name);
206 
207 	return -EINVAL;
208 }
209 
210 static int stm32_rproc_elf_load_rsc_table(struct rproc *rproc,
211 					  const struct firmware *fw)
212 {
213 	if (rproc_elf_load_rsc_table(rproc, fw))
214 		dev_warn(&rproc->dev, "no resource table found for this firmware\n");
215 
216 	return 0;
217 }
218 
219 static int stm32_rproc_parse_memory_regions(struct rproc *rproc)
220 {
221 	struct device *dev = rproc->dev.parent;
222 	struct device_node *np = dev->of_node;
223 	struct of_phandle_iterator it;
224 	struct rproc_mem_entry *mem;
225 	struct reserved_mem *rmem;
226 	u64 da;
227 	int index = 0;
228 
229 	/* Register associated reserved memory regions */
230 	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
231 	while (of_phandle_iterator_next(&it) == 0) {
232 		rmem = of_reserved_mem_lookup(it.node);
233 		if (!rmem) {
234 			dev_err(dev, "unable to acquire memory-region\n");
235 			return -EINVAL;
236 		}
237 
238 		if (stm32_rproc_pa_to_da(rproc, rmem->base, &da) < 0) {
239 			dev_err(dev, "memory region not valid %pa\n",
240 				&rmem->base);
241 			return -EINVAL;
242 		}
243 
244 		/*  No need to map vdev buffer */
245 		if (strcmp(it.node->name, "vdev0buffer")) {
246 			/* Register memory region */
247 			mem = rproc_mem_entry_init(dev, NULL,
248 						   (dma_addr_t)rmem->base,
249 						   rmem->size, da,
250 						   stm32_rproc_mem_alloc,
251 						   stm32_rproc_mem_release,
252 						   it.node->name);
253 
254 			if (mem)
255 				rproc_coredump_add_segment(rproc, da,
256 							   rmem->size);
257 		} else {
258 			/* Register reserved memory for vdev buffer alloc */
259 			mem = rproc_of_resm_mem_entry_init(dev, index,
260 							   rmem->size,
261 							   rmem->base,
262 							   it.node->name);
263 		}
264 
265 		if (!mem)
266 			return -ENOMEM;
267 
268 		rproc_add_carveout(rproc, mem);
269 		index++;
270 	}
271 
272 	return 0;
273 }
274 
275 static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
276 {
277 	int ret = stm32_rproc_parse_memory_regions(rproc);
278 
279 	if (ret)
280 		return ret;
281 
282 	return stm32_rproc_elf_load_rsc_table(rproc, fw);
283 }
284 
285 static irqreturn_t stm32_rproc_wdg(int irq, void *data)
286 {
287 	struct platform_device *pdev = data;
288 	struct rproc *rproc = platform_get_drvdata(pdev);
289 
290 	rproc_report_crash(rproc, RPROC_WATCHDOG);
291 
292 	return IRQ_HANDLED;
293 }
294 
295 static void stm32_rproc_mb_vq_work(struct work_struct *work)
296 {
297 	struct stm32_mbox *mb = container_of(work, struct stm32_mbox, vq_work);
298 	struct rproc *rproc = dev_get_drvdata(mb->client.dev);
299 
300 	if (rproc_vq_interrupt(rproc, mb->vq_id) == IRQ_NONE)
301 		dev_dbg(&rproc->dev, "no message found in vq%d\n", mb->vq_id);
302 }
303 
304 static void stm32_rproc_mb_callback(struct mbox_client *cl, void *data)
305 {
306 	struct rproc *rproc = dev_get_drvdata(cl->dev);
307 	struct stm32_mbox *mb = container_of(cl, struct stm32_mbox, client);
308 	struct stm32_rproc *ddata = rproc->priv;
309 
310 	queue_work(ddata->workqueue, &mb->vq_work);
311 }
312 
313 static void stm32_rproc_free_mbox(struct rproc *rproc)
314 {
315 	struct stm32_rproc *ddata = rproc->priv;
316 	unsigned int i;
317 
318 	for (i = 0; i < ARRAY_SIZE(ddata->mb); i++) {
319 		if (ddata->mb[i].chan)
320 			mbox_free_channel(ddata->mb[i].chan);
321 		ddata->mb[i].chan = NULL;
322 	}
323 }
324 
325 static const struct stm32_mbox stm32_rproc_mbox[MBOX_NB_MBX] = {
326 	{
327 		.name = STM32_MBX_VQ0,
328 		.vq_id = STM32_MBX_VQ0_ID,
329 		.client = {
330 			.rx_callback = stm32_rproc_mb_callback,
331 			.tx_block = false,
332 		},
333 	},
334 	{
335 		.name = STM32_MBX_VQ1,
336 		.vq_id = STM32_MBX_VQ1_ID,
337 		.client = {
338 			.rx_callback = stm32_rproc_mb_callback,
339 			.tx_block = false,
340 		},
341 	},
342 	{
343 		.name = STM32_MBX_SHUTDOWN,
344 		.vq_id = -1,
345 		.client = {
346 			.tx_block = true,
347 			.tx_done = NULL,
348 			.tx_tout = 500, /* 500 ms time out */
349 		},
350 	}
351 };
352 
353 static int stm32_rproc_request_mbox(struct rproc *rproc)
354 {
355 	struct stm32_rproc *ddata = rproc->priv;
356 	struct device *dev = &rproc->dev;
357 	unsigned int i;
358 	int j;
359 	const unsigned char *name;
360 	struct mbox_client *cl;
361 
362 	/* Initialise mailbox structure table */
363 	memcpy(ddata->mb, stm32_rproc_mbox, sizeof(stm32_rproc_mbox));
364 
365 	for (i = 0; i < MBOX_NB_MBX; i++) {
366 		name = ddata->mb[i].name;
367 
368 		cl = &ddata->mb[i].client;
369 		cl->dev = dev->parent;
370 
371 		ddata->mb[i].chan = mbox_request_channel_byname(cl, name);
372 		if (IS_ERR(ddata->mb[i].chan)) {
373 			if (PTR_ERR(ddata->mb[i].chan) == -EPROBE_DEFER)
374 				goto err_probe;
375 			dev_warn(dev, "cannot get %s mbox\n", name);
376 			ddata->mb[i].chan = NULL;
377 		}
378 		if (ddata->mb[i].vq_id >= 0) {
379 			INIT_WORK(&ddata->mb[i].vq_work,
380 				  stm32_rproc_mb_vq_work);
381 		}
382 	}
383 
384 	return 0;
385 
386 err_probe:
387 	for (j = i - 1; j >= 0; j--)
388 		if (ddata->mb[j].chan)
389 			mbox_free_channel(ddata->mb[j].chan);
390 	return -EPROBE_DEFER;
391 }
392 
393 static int stm32_rproc_set_hold_boot(struct rproc *rproc, bool hold)
394 {
395 	struct stm32_rproc *ddata = rproc->priv;
396 	struct stm32_syscon hold_boot = ddata->hold_boot;
397 	struct arm_smccc_res smc_res;
398 	int val, err;
399 
400 	val = hold ? HOLD_BOOT : RELEASE_BOOT;
401 
402 	if (IS_ENABLED(CONFIG_HAVE_ARM_SMCCC) && ddata->secured_soc) {
403 		arm_smccc_smc(STM32_SMC_RCC, STM32_SMC_REG_WRITE,
404 			      hold_boot.reg, val, 0, 0, 0, 0, &smc_res);
405 		err = smc_res.a0;
406 	} else {
407 		err = regmap_update_bits(hold_boot.map, hold_boot.reg,
408 					 hold_boot.mask, val);
409 	}
410 
411 	if (err)
412 		dev_err(&rproc->dev, "failed to set hold boot\n");
413 
414 	return err;
415 }
416 
417 static void stm32_rproc_add_coredump_trace(struct rproc *rproc)
418 {
419 	struct rproc_debug_trace *trace;
420 	struct rproc_dump_segment *segment;
421 	bool already_added;
422 
423 	list_for_each_entry(trace, &rproc->traces, node) {
424 		already_added = false;
425 
426 		list_for_each_entry(segment, &rproc->dump_segments, node) {
427 			if (segment->da == trace->trace_mem.da) {
428 				already_added = true;
429 				break;
430 			}
431 		}
432 
433 		if (!already_added)
434 			rproc_coredump_add_segment(rproc, trace->trace_mem.da,
435 						   trace->trace_mem.len);
436 	}
437 }
438 
439 static int stm32_rproc_start(struct rproc *rproc)
440 {
441 	struct stm32_rproc *ddata = rproc->priv;
442 	int err;
443 
444 	stm32_rproc_add_coredump_trace(rproc);
445 
446 	/* clear remote proc Deep Sleep */
447 	if (ddata->pdds.map) {
448 		err = regmap_update_bits(ddata->pdds.map, ddata->pdds.reg,
449 					 ddata->pdds.mask, 0);
450 		if (err) {
451 			dev_err(&rproc->dev, "failed to clear pdds\n");
452 			return err;
453 		}
454 	}
455 
456 	err = stm32_rproc_set_hold_boot(rproc, false);
457 	if (err)
458 		return err;
459 
460 	return stm32_rproc_set_hold_boot(rproc, true);
461 }
462 
463 static int stm32_rproc_attach(struct rproc *rproc)
464 {
465 	stm32_rproc_add_coredump_trace(rproc);
466 
467 	return stm32_rproc_set_hold_boot(rproc, true);
468 }
469 
470 static int stm32_rproc_stop(struct rproc *rproc)
471 {
472 	struct stm32_rproc *ddata = rproc->priv;
473 	int err, dummy_data, idx;
474 
475 	/* request shutdown of the remote processor */
476 	if (rproc->state != RPROC_OFFLINE) {
477 		idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_SHUTDOWN);
478 		if (idx >= 0 && ddata->mb[idx].chan) {
479 			/* a dummy data is sent to allow to block on transmit */
480 			err = mbox_send_message(ddata->mb[idx].chan,
481 						&dummy_data);
482 			if (err < 0)
483 				dev_warn(&rproc->dev, "warning: remote FW shutdown without ack\n");
484 		}
485 	}
486 
487 	err = stm32_rproc_set_hold_boot(rproc, true);
488 	if (err)
489 		return err;
490 
491 	err = reset_control_assert(ddata->rst);
492 	if (err) {
493 		dev_err(&rproc->dev, "failed to assert the reset\n");
494 		return err;
495 	}
496 
497 	/* to allow platform Standby power mode, set remote proc Deep Sleep */
498 	if (ddata->pdds.map) {
499 		err = regmap_update_bits(ddata->pdds.map, ddata->pdds.reg,
500 					 ddata->pdds.mask, 1);
501 		if (err) {
502 			dev_err(&rproc->dev, "failed to set pdds\n");
503 			return err;
504 		}
505 	}
506 
507 	/* update coprocessor state to OFF if available */
508 	if (ddata->m4_state.map) {
509 		err = regmap_update_bits(ddata->m4_state.map,
510 					 ddata->m4_state.reg,
511 					 ddata->m4_state.mask,
512 					 M4_STATE_OFF);
513 		if (err) {
514 			dev_err(&rproc->dev, "failed to set copro state\n");
515 			return err;
516 		}
517 	}
518 
519 	return 0;
520 }
521 
522 static void stm32_rproc_kick(struct rproc *rproc, int vqid)
523 {
524 	struct stm32_rproc *ddata = rproc->priv;
525 	unsigned int i;
526 	int err;
527 
528 	if (WARN_ON(vqid >= MBOX_NB_VQ))
529 		return;
530 
531 	for (i = 0; i < MBOX_NB_MBX; i++) {
532 		if (vqid != ddata->mb[i].vq_id)
533 			continue;
534 		if (!ddata->mb[i].chan)
535 			return;
536 		err = mbox_send_message(ddata->mb[i].chan, (void *)(long)vqid);
537 		if (err < 0)
538 			dev_err(&rproc->dev, "%s: failed (%s, err:%d)\n",
539 				__func__, ddata->mb[i].name, err);
540 		return;
541 	}
542 }
543 
544 static struct rproc_ops st_rproc_ops = {
545 	.start		= stm32_rproc_start,
546 	.stop		= stm32_rproc_stop,
547 	.attach		= stm32_rproc_attach,
548 	.kick		= stm32_rproc_kick,
549 	.load		= rproc_elf_load_segments,
550 	.parse_fw	= stm32_rproc_parse_fw,
551 	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
552 	.sanity_check	= rproc_elf_sanity_check,
553 	.get_boot_addr	= rproc_elf_get_boot_addr,
554 };
555 
556 static const struct of_device_id stm32_rproc_match[] = {
557 	{ .compatible = "st,stm32mp1-m4" },
558 	{},
559 };
560 MODULE_DEVICE_TABLE(of, stm32_rproc_match);
561 
562 static int stm32_rproc_get_syscon(struct device_node *np, const char *prop,
563 				  struct stm32_syscon *syscon)
564 {
565 	int err = 0;
566 
567 	syscon->map = syscon_regmap_lookup_by_phandle(np, prop);
568 	if (IS_ERR(syscon->map)) {
569 		err = PTR_ERR(syscon->map);
570 		syscon->map = NULL;
571 		goto out;
572 	}
573 
574 	err = of_property_read_u32_index(np, prop, 1, &syscon->reg);
575 	if (err)
576 		goto out;
577 
578 	err = of_property_read_u32_index(np, prop, 2, &syscon->mask);
579 
580 out:
581 	return err;
582 }
583 
584 static int stm32_rproc_parse_dt(struct platform_device *pdev,
585 				struct stm32_rproc *ddata, bool *auto_boot)
586 {
587 	struct device *dev = &pdev->dev;
588 	struct device_node *np = dev->of_node;
589 	struct stm32_syscon tz;
590 	unsigned int tzen;
591 	int err, irq;
592 
593 	irq = platform_get_irq(pdev, 0);
594 	if (irq == -EPROBE_DEFER)
595 		return -EPROBE_DEFER;
596 
597 	if (irq > 0) {
598 		err = devm_request_irq(dev, irq, stm32_rproc_wdg, 0,
599 				       dev_name(dev), pdev);
600 		if (err) {
601 			dev_err(dev, "failed to request wdg irq\n");
602 			return err;
603 		}
604 
605 		ddata->wdg_irq = irq;
606 
607 		if (of_property_read_bool(np, "wakeup-source")) {
608 			device_init_wakeup(dev, true);
609 			dev_pm_set_wake_irq(dev, irq);
610 		}
611 
612 		dev_info(dev, "wdg irq registered\n");
613 	}
614 
615 	ddata->rst = devm_reset_control_get_by_index(dev, 0);
616 	if (IS_ERR(ddata->rst)) {
617 		dev_err(dev, "failed to get mcu reset\n");
618 		return PTR_ERR(ddata->rst);
619 	}
620 
621 	/*
622 	 * if platform is secured the hold boot bit must be written by
623 	 * smc call and read normally.
624 	 * if not secure the hold boot bit could be read/write normally
625 	 */
626 	err = stm32_rproc_get_syscon(np, "st,syscfg-tz", &tz);
627 	if (err) {
628 		dev_err(dev, "failed to get tz syscfg\n");
629 		return err;
630 	}
631 
632 	err = regmap_read(tz.map, tz.reg, &tzen);
633 	if (err) {
634 		dev_err(dev, "failed to read tzen\n");
635 		return err;
636 	}
637 	ddata->secured_soc = tzen & tz.mask;
638 
639 	err = stm32_rproc_get_syscon(np, "st,syscfg-holdboot",
640 				     &ddata->hold_boot);
641 	if (err) {
642 		dev_err(dev, "failed to get hold boot\n");
643 		return err;
644 	}
645 
646 	err = stm32_rproc_get_syscon(np, "st,syscfg-pdds", &ddata->pdds);
647 	if (err)
648 		dev_info(dev, "failed to get pdds\n");
649 
650 	*auto_boot = of_property_read_bool(np, "st,auto-boot");
651 
652 	/*
653 	 * See if we can check the M4 status, i.e if it was started
654 	 * from the boot loader or not.
655 	 */
656 	err = stm32_rproc_get_syscon(np, "st,syscfg-m4-state",
657 				     &ddata->m4_state);
658 	if (err) {
659 		/* remember this */
660 		ddata->m4_state.map = NULL;
661 		/* no coprocessor state syscon (optional) */
662 		dev_warn(dev, "m4 state not supported\n");
663 
664 		/* no need to go further */
665 		return 0;
666 	}
667 
668 	/* See if we can get the resource table */
669 	err = stm32_rproc_get_syscon(np, "st,syscfg-rsc-tbl",
670 				     &ddata->rsctbl);
671 	if (err) {
672 		/* no rsc table syscon (optional) */
673 		dev_warn(dev, "rsc tbl syscon not supported\n");
674 	}
675 
676 	return 0;
677 }
678 
679 static int stm32_rproc_get_m4_status(struct stm32_rproc *ddata,
680 				     unsigned int *state)
681 {
682 	/* See stm32_rproc_parse_dt() */
683 	if (!ddata->m4_state.map) {
684 		/*
685 		 * We couldn't get the coprocessor's state, assume
686 		 * it is not running.
687 		 */
688 		*state = M4_STATE_OFF;
689 		return 0;
690 	}
691 
692 	return regmap_read(ddata->m4_state.map, ddata->m4_state.reg, state);
693 }
694 
695 static int stm32_rproc_da_to_pa(struct platform_device *pdev,
696 				struct stm32_rproc *ddata,
697 				u64 da, phys_addr_t *pa)
698 {
699 	struct device *dev = &pdev->dev;
700 	struct stm32_rproc_mem *p_mem;
701 	unsigned int i;
702 
703 	for (i = 0; i < ddata->nb_rmems; i++) {
704 		p_mem = &ddata->rmems[i];
705 
706 		if (da < p_mem->dev_addr ||
707 		    da >= p_mem->dev_addr + p_mem->size)
708 			continue;
709 
710 		*pa = da - p_mem->dev_addr + p_mem->bus_addr;
711 		dev_dbg(dev, "da %llx to pa %#x\n", da, *pa);
712 
713 		return 0;
714 	}
715 
716 	dev_err(dev, "can't translate da %llx\n", da);
717 
718 	return -EINVAL;
719 }
720 
721 static int stm32_rproc_get_loaded_rsc_table(struct platform_device *pdev,
722 					    struct rproc *rproc,
723 					    struct stm32_rproc *ddata)
724 {
725 	struct device *dev = &pdev->dev;
726 	phys_addr_t rsc_pa;
727 	u32 rsc_da;
728 	int err;
729 
730 	err = regmap_read(ddata->rsctbl.map, ddata->rsctbl.reg, &rsc_da);
731 	if (err) {
732 		dev_err(dev, "failed to read rsc tbl addr\n");
733 		return err;
734 	}
735 
736 	if (!rsc_da)
737 		/* no rsc table */
738 		return 0;
739 
740 	err = stm32_rproc_da_to_pa(pdev, ddata, rsc_da, &rsc_pa);
741 	if (err)
742 		return err;
743 
744 	ddata->rsc_va = devm_ioremap_wc(dev, rsc_pa, RSC_TBL_SIZE);
745 	if (IS_ERR_OR_NULL(ddata->rsc_va)) {
746 		dev_err(dev, "Unable to map memory region: %pa+%zx\n",
747 			&rsc_pa, RSC_TBL_SIZE);
748 		ddata->rsc_va = NULL;
749 		return -ENOMEM;
750 	}
751 
752 	/*
753 	 * The resource table is already loaded in device memory, no need
754 	 * to work with a cached table.
755 	 */
756 	rproc->cached_table = NULL;
757 	/* Assuming the resource table fits in 1kB is fair */
758 	rproc->table_sz = RSC_TBL_SIZE;
759 	rproc->table_ptr = (struct resource_table *)ddata->rsc_va;
760 
761 	return 0;
762 }
763 
764 static int stm32_rproc_probe(struct platform_device *pdev)
765 {
766 	struct device *dev = &pdev->dev;
767 	struct stm32_rproc *ddata;
768 	struct device_node *np = dev->of_node;
769 	struct rproc *rproc;
770 	unsigned int state;
771 	int ret;
772 
773 	ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
774 	if (ret)
775 		return ret;
776 
777 	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
778 	if (!rproc)
779 		return -ENOMEM;
780 
781 	ddata = rproc->priv;
782 
783 	rproc_coredump_set_elf_info(rproc, ELFCLASS32, EM_NONE);
784 
785 	ret = stm32_rproc_parse_dt(pdev, ddata, &rproc->auto_boot);
786 	if (ret)
787 		goto free_rproc;
788 
789 	ret = stm32_rproc_of_memory_translations(pdev, ddata);
790 	if (ret)
791 		goto free_rproc;
792 
793 	ret = stm32_rproc_get_m4_status(ddata, &state);
794 	if (ret)
795 		goto free_rproc;
796 
797 	if (state == M4_STATE_CRUN) {
798 		rproc->state = RPROC_DETACHED;
799 
800 		ret = stm32_rproc_parse_memory_regions(rproc);
801 		if (ret)
802 			goto free_resources;
803 
804 		ret = stm32_rproc_get_loaded_rsc_table(pdev, rproc, ddata);
805 		if (ret)
806 			goto free_resources;
807 	}
808 
809 	rproc->has_iommu = false;
810 	ddata->workqueue = create_workqueue(dev_name(dev));
811 	if (!ddata->workqueue) {
812 		dev_err(dev, "cannot create workqueue\n");
813 		ret = -ENOMEM;
814 		goto free_resources;
815 	}
816 
817 	platform_set_drvdata(pdev, rproc);
818 
819 	ret = stm32_rproc_request_mbox(rproc);
820 	if (ret)
821 		goto free_wkq;
822 
823 	ret = rproc_add(rproc);
824 	if (ret)
825 		goto free_mb;
826 
827 	return 0;
828 
829 free_mb:
830 	stm32_rproc_free_mbox(rproc);
831 free_wkq:
832 	destroy_workqueue(ddata->workqueue);
833 free_resources:
834 	rproc_resource_cleanup(rproc);
835 free_rproc:
836 	if (device_may_wakeup(dev)) {
837 		dev_pm_clear_wake_irq(dev);
838 		device_init_wakeup(dev, false);
839 	}
840 	rproc_free(rproc);
841 	return ret;
842 }
843 
844 static int stm32_rproc_remove(struct platform_device *pdev)
845 {
846 	struct rproc *rproc = platform_get_drvdata(pdev);
847 	struct stm32_rproc *ddata = rproc->priv;
848 	struct device *dev = &pdev->dev;
849 
850 	if (atomic_read(&rproc->power) > 0)
851 		rproc_shutdown(rproc);
852 
853 	rproc_del(rproc);
854 	stm32_rproc_free_mbox(rproc);
855 	destroy_workqueue(ddata->workqueue);
856 
857 	if (device_may_wakeup(dev)) {
858 		dev_pm_clear_wake_irq(dev);
859 		device_init_wakeup(dev, false);
860 	}
861 	rproc_free(rproc);
862 
863 	return 0;
864 }
865 
866 static int __maybe_unused stm32_rproc_suspend(struct device *dev)
867 {
868 	struct rproc *rproc = dev_get_drvdata(dev);
869 	struct stm32_rproc *ddata = rproc->priv;
870 
871 	if (device_may_wakeup(dev))
872 		return enable_irq_wake(ddata->wdg_irq);
873 
874 	return 0;
875 }
876 
877 static int __maybe_unused stm32_rproc_resume(struct device *dev)
878 {
879 	struct rproc *rproc = dev_get_drvdata(dev);
880 	struct stm32_rproc *ddata = rproc->priv;
881 
882 	if (device_may_wakeup(dev))
883 		return disable_irq_wake(ddata->wdg_irq);
884 
885 	return 0;
886 }
887 
888 static SIMPLE_DEV_PM_OPS(stm32_rproc_pm_ops,
889 			 stm32_rproc_suspend, stm32_rproc_resume);
890 
891 static struct platform_driver stm32_rproc_driver = {
892 	.probe = stm32_rproc_probe,
893 	.remove = stm32_rproc_remove,
894 	.driver = {
895 		.name = "stm32-rproc",
896 		.pm = &stm32_rproc_pm_ops,
897 		.of_match_table = of_match_ptr(stm32_rproc_match),
898 	},
899 };
900 module_platform_driver(stm32_rproc_driver);
901 
902 MODULE_DESCRIPTION("STM32 Remote Processor Control Driver");
903 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
904 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
905 MODULE_LICENSE("GPL v2");
906 
907