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/regmap.h>
19 #include <linux/remoteproc.h>
20 #include <linux/reset.h>
21 
22 #include "remoteproc_internal.h"
23 
24 #define HOLD_BOOT		0
25 #define RELEASE_BOOT		1
26 
27 #define MBOX_NB_VQ		2
28 #define MBOX_NB_MBX		3
29 
30 #define STM32_SMC_RCC		0x82001000
31 #define STM32_SMC_REG_WRITE	0x1
32 
33 #define STM32_MBX_VQ0		"vq0"
34 #define STM32_MBX_VQ1		"vq1"
35 #define STM32_MBX_SHUTDOWN	"shutdown"
36 
37 struct stm32_syscon {
38 	struct regmap *map;
39 	u32 reg;
40 	u32 mask;
41 };
42 
43 struct stm32_rproc_mem {
44 	char name[20];
45 	void __iomem *cpu_addr;
46 	phys_addr_t bus_addr;
47 	u32 dev_addr;
48 	size_t size;
49 };
50 
51 struct stm32_rproc_mem_ranges {
52 	u32 dev_addr;
53 	u32 bus_addr;
54 	u32 size;
55 };
56 
57 struct stm32_mbox {
58 	const unsigned char name[10];
59 	struct mbox_chan *chan;
60 	struct mbox_client client;
61 	int vq_id;
62 };
63 
64 struct stm32_rproc {
65 	struct reset_control *rst;
66 	struct stm32_syscon hold_boot;
67 	struct stm32_syscon pdds;
68 	u32 nb_rmems;
69 	struct stm32_rproc_mem *rmems;
70 	struct stm32_mbox mb[MBOX_NB_MBX];
71 	bool secured_soc;
72 };
73 
74 static int stm32_rproc_pa_to_da(struct rproc *rproc, phys_addr_t pa, u64 *da)
75 {
76 	unsigned int i;
77 	struct stm32_rproc *ddata = rproc->priv;
78 	struct stm32_rproc_mem *p_mem;
79 
80 	for (i = 0; i < ddata->nb_rmems; i++) {
81 		p_mem = &ddata->rmems[i];
82 
83 		if (pa < p_mem->bus_addr ||
84 		    pa >= p_mem->bus_addr + p_mem->size)
85 			continue;
86 		*da = pa - p_mem->bus_addr + p_mem->dev_addr;
87 		dev_dbg(rproc->dev.parent, "pa %pa to da %llx\n", &pa, *da);
88 		return 0;
89 	}
90 
91 	return -EINVAL;
92 }
93 
94 static int stm32_rproc_mem_alloc(struct rproc *rproc,
95 				 struct rproc_mem_entry *mem)
96 {
97 	struct device *dev = rproc->dev.parent;
98 	void *va;
99 
100 	dev_dbg(dev, "map memory: %pa+%x\n", &mem->dma, mem->len);
101 	va = ioremap_wc(mem->dma, mem->len);
102 	if (IS_ERR_OR_NULL(va)) {
103 		dev_err(dev, "Unable to map memory region: %pa+%x\n",
104 			&mem->dma, mem->len);
105 		return -ENOMEM;
106 	}
107 
108 	/* Update memory entry va */
109 	mem->va = va;
110 
111 	return 0;
112 }
113 
114 static int stm32_rproc_mem_release(struct rproc *rproc,
115 				   struct rproc_mem_entry *mem)
116 {
117 	dev_dbg(rproc->dev.parent, "unmap memory: %pa\n", &mem->dma);
118 	iounmap(mem->va);
119 
120 	return 0;
121 }
122 
123 static int stm32_rproc_of_memory_translations(struct rproc *rproc)
124 {
125 	struct device *parent, *dev = rproc->dev.parent;
126 	struct stm32_rproc *ddata = rproc->priv;
127 	struct device_node *np;
128 	struct stm32_rproc_mem *p_mems;
129 	struct stm32_rproc_mem_ranges *mem_range;
130 	int cnt, array_size, i, ret = 0;
131 
132 	parent = dev->parent;
133 	np = parent->of_node;
134 
135 	cnt = of_property_count_elems_of_size(np, "dma-ranges",
136 					      sizeof(*mem_range));
137 	if (cnt <= 0) {
138 		dev_err(dev, "%s: dma-ranges property not defined\n", __func__);
139 		return -EINVAL;
140 	}
141 
142 	p_mems = devm_kcalloc(dev, cnt, sizeof(*p_mems), GFP_KERNEL);
143 	if (!p_mems)
144 		return -ENOMEM;
145 	mem_range = kcalloc(cnt, sizeof(*mem_range), GFP_KERNEL);
146 	if (!mem_range)
147 		return -ENOMEM;
148 
149 	array_size = cnt * sizeof(struct stm32_rproc_mem_ranges) / sizeof(u32);
150 
151 	ret = of_property_read_u32_array(np, "dma-ranges",
152 					 (u32 *)mem_range, array_size);
153 	if (ret) {
154 		dev_err(dev, "error while get dma-ranges property: %x\n", ret);
155 		goto free_mem;
156 	}
157 
158 	for (i = 0; i < cnt; i++) {
159 		p_mems[i].bus_addr = mem_range[i].bus_addr;
160 		p_mems[i].dev_addr = mem_range[i].dev_addr;
161 		p_mems[i].size     = mem_range[i].size;
162 
163 		dev_dbg(dev, "memory range[%i]: da %#x, pa %pa, size %#zx:\n",
164 			i, p_mems[i].dev_addr, &p_mems[i].bus_addr,
165 			p_mems[i].size);
166 	}
167 
168 	ddata->rmems = p_mems;
169 	ddata->nb_rmems = cnt;
170 
171 free_mem:
172 	kfree(mem_range);
173 	return ret;
174 }
175 
176 static int stm32_rproc_mbox_idx(struct rproc *rproc, const unsigned char *name)
177 {
178 	struct stm32_rproc *ddata = rproc->priv;
179 	int i;
180 
181 	for (i = 0; i < ARRAY_SIZE(ddata->mb); i++) {
182 		if (!strncmp(ddata->mb[i].name, name, strlen(name)))
183 			return i;
184 	}
185 	dev_err(&rproc->dev, "mailbox %s not found\n", name);
186 
187 	return -EINVAL;
188 }
189 
190 static int stm32_rproc_elf_load_rsc_table(struct rproc *rproc,
191 					  const struct firmware *fw)
192 {
193 	if (rproc_elf_load_rsc_table(rproc, fw))
194 		dev_warn(&rproc->dev, "no resource table found for this firmware\n");
195 
196 	return 0;
197 }
198 
199 static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
200 {
201 	struct device *dev = rproc->dev.parent;
202 	struct device_node *np = dev->of_node;
203 	struct of_phandle_iterator it;
204 	struct rproc_mem_entry *mem;
205 	struct reserved_mem *rmem;
206 	u64 da;
207 	int index = 0;
208 
209 	/* Register associated reserved memory regions */
210 	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
211 	while (of_phandle_iterator_next(&it) == 0) {
212 		rmem = of_reserved_mem_lookup(it.node);
213 		if (!rmem) {
214 			dev_err(dev, "unable to acquire memory-region\n");
215 			return -EINVAL;
216 		}
217 
218 		if (stm32_rproc_pa_to_da(rproc, rmem->base, &da) < 0) {
219 			dev_err(dev, "memory region not valid %pa\n",
220 				&rmem->base);
221 			return -EINVAL;
222 		}
223 
224 		/*  No need to map vdev buffer */
225 		if (strcmp(it.node->name, "vdev0buffer")) {
226 			/* Register memory region */
227 			mem = rproc_mem_entry_init(dev, NULL,
228 						   (dma_addr_t)rmem->base,
229 						   rmem->size, da,
230 						   stm32_rproc_mem_alloc,
231 						   stm32_rproc_mem_release,
232 						   it.node->name);
233 
234 			if (mem)
235 				rproc_coredump_add_segment(rproc, da,
236 							   rmem->size);
237 		} else {
238 			/* Register reserved memory for vdev buffer alloc */
239 			mem = rproc_of_resm_mem_entry_init(dev, index,
240 							   rmem->size,
241 							   rmem->base,
242 							   it.node->name);
243 		}
244 
245 		if (!mem)
246 			return -ENOMEM;
247 
248 		rproc_add_carveout(rproc, mem);
249 		index++;
250 	}
251 
252 	return stm32_rproc_elf_load_rsc_table(rproc, fw);
253 }
254 
255 static irqreturn_t stm32_rproc_wdg(int irq, void *data)
256 {
257 	struct rproc *rproc = data;
258 
259 	rproc_report_crash(rproc, RPROC_WATCHDOG);
260 
261 	return IRQ_HANDLED;
262 }
263 
264 static void stm32_rproc_mb_callback(struct mbox_client *cl, void *data)
265 {
266 	struct rproc *rproc = dev_get_drvdata(cl->dev);
267 	struct stm32_mbox *mb = container_of(cl, struct stm32_mbox, client);
268 
269 	if (rproc_vq_interrupt(rproc, mb->vq_id) == IRQ_NONE)
270 		dev_dbg(&rproc->dev, "no message found in vq%d\n", mb->vq_id);
271 }
272 
273 static void stm32_rproc_free_mbox(struct rproc *rproc)
274 {
275 	struct stm32_rproc *ddata = rproc->priv;
276 	unsigned int i;
277 
278 	for (i = 0; i < ARRAY_SIZE(ddata->mb); i++) {
279 		if (ddata->mb[i].chan)
280 			mbox_free_channel(ddata->mb[i].chan);
281 		ddata->mb[i].chan = NULL;
282 	}
283 }
284 
285 static const struct stm32_mbox stm32_rproc_mbox[MBOX_NB_MBX] = {
286 	{
287 		.name = STM32_MBX_VQ0,
288 		.vq_id = 0,
289 		.client = {
290 			.rx_callback = stm32_rproc_mb_callback,
291 			.tx_block = false,
292 		},
293 	},
294 	{
295 		.name = STM32_MBX_VQ1,
296 		.vq_id = 1,
297 		.client = {
298 			.rx_callback = stm32_rproc_mb_callback,
299 			.tx_block = false,
300 		},
301 	},
302 	{
303 		.name = STM32_MBX_SHUTDOWN,
304 		.vq_id = -1,
305 		.client = {
306 			.tx_block = true,
307 			.tx_done = NULL,
308 			.tx_tout = 500, /* 500 ms time out */
309 		},
310 	}
311 };
312 
313 static void stm32_rproc_request_mbox(struct rproc *rproc)
314 {
315 	struct stm32_rproc *ddata = rproc->priv;
316 	struct device *dev = &rproc->dev;
317 	unsigned int i;
318 	const unsigned char *name;
319 	struct mbox_client *cl;
320 
321 	/* Initialise mailbox structure table */
322 	memcpy(ddata->mb, stm32_rproc_mbox, sizeof(stm32_rproc_mbox));
323 
324 	for (i = 0; i < MBOX_NB_MBX; i++) {
325 		name = ddata->mb[i].name;
326 
327 		cl = &ddata->mb[i].client;
328 		cl->dev = dev->parent;
329 
330 		ddata->mb[i].chan = mbox_request_channel_byname(cl, name);
331 		if (IS_ERR(ddata->mb[i].chan)) {
332 			dev_warn(dev, "cannot get %s mbox\n", name);
333 			ddata->mb[i].chan = NULL;
334 		}
335 	}
336 }
337 
338 static int stm32_rproc_set_hold_boot(struct rproc *rproc, bool hold)
339 {
340 	struct stm32_rproc *ddata = rproc->priv;
341 	struct stm32_syscon hold_boot = ddata->hold_boot;
342 	struct arm_smccc_res smc_res;
343 	int val, err;
344 
345 	val = hold ? HOLD_BOOT : RELEASE_BOOT;
346 
347 	if (IS_ENABLED(CONFIG_HAVE_ARM_SMCCC) && ddata->secured_soc) {
348 		arm_smccc_smc(STM32_SMC_RCC, STM32_SMC_REG_WRITE,
349 			      hold_boot.reg, val, 0, 0, 0, 0, &smc_res);
350 		err = smc_res.a0;
351 	} else {
352 		err = regmap_update_bits(hold_boot.map, hold_boot.reg,
353 					 hold_boot.mask, val);
354 	}
355 
356 	if (err)
357 		dev_err(&rproc->dev, "failed to set hold boot\n");
358 
359 	return err;
360 }
361 
362 static void stm32_rproc_add_coredump_trace(struct rproc *rproc)
363 {
364 	struct rproc_debug_trace *trace;
365 	struct rproc_dump_segment *segment;
366 	bool already_added;
367 
368 	list_for_each_entry(trace, &rproc->traces, node) {
369 		already_added = false;
370 
371 		list_for_each_entry(segment, &rproc->dump_segments, node) {
372 			if (segment->da == trace->trace_mem.da) {
373 				already_added = true;
374 				break;
375 			}
376 		}
377 
378 		if (!already_added)
379 			rproc_coredump_add_segment(rproc, trace->trace_mem.da,
380 						   trace->trace_mem.len);
381 	}
382 }
383 
384 static int stm32_rproc_start(struct rproc *rproc)
385 {
386 	struct stm32_rproc *ddata = rproc->priv;
387 	int err;
388 
389 	stm32_rproc_add_coredump_trace(rproc);
390 
391 	/* clear remote proc Deep Sleep */
392 	if (ddata->pdds.map) {
393 		err = regmap_update_bits(ddata->pdds.map, ddata->pdds.reg,
394 					 ddata->pdds.mask, 0);
395 		if (err) {
396 			dev_err(&rproc->dev, "failed to clear pdds\n");
397 			return err;
398 		}
399 	}
400 
401 	err = stm32_rproc_set_hold_boot(rproc, false);
402 	if (err)
403 		return err;
404 
405 	return stm32_rproc_set_hold_boot(rproc, true);
406 }
407 
408 static int stm32_rproc_stop(struct rproc *rproc)
409 {
410 	struct stm32_rproc *ddata = rproc->priv;
411 	int err, dummy_data, idx;
412 
413 	/* request shutdown of the remote processor */
414 	if (rproc->state != RPROC_OFFLINE) {
415 		idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_SHUTDOWN);
416 		if (idx >= 0 && ddata->mb[idx].chan) {
417 			/* a dummy data is sent to allow to block on transmit */
418 			err = mbox_send_message(ddata->mb[idx].chan,
419 						&dummy_data);
420 			if (err < 0)
421 				dev_warn(&rproc->dev, "warning: remote FW shutdown without ack\n");
422 		}
423 	}
424 
425 	err = stm32_rproc_set_hold_boot(rproc, true);
426 	if (err)
427 		return err;
428 
429 	err = reset_control_assert(ddata->rst);
430 	if (err) {
431 		dev_err(&rproc->dev, "failed to assert the reset\n");
432 		return err;
433 	}
434 
435 	/* to allow platform Standby power mode, set remote proc Deep Sleep */
436 	if (ddata->pdds.map) {
437 		err = regmap_update_bits(ddata->pdds.map, ddata->pdds.reg,
438 					 ddata->pdds.mask, 1);
439 		if (err) {
440 			dev_err(&rproc->dev, "failed to set pdds\n");
441 			return err;
442 		}
443 	}
444 
445 	return 0;
446 }
447 
448 static void stm32_rproc_kick(struct rproc *rproc, int vqid)
449 {
450 	struct stm32_rproc *ddata = rproc->priv;
451 	unsigned int i;
452 	int err;
453 
454 	if (WARN_ON(vqid >= MBOX_NB_VQ))
455 		return;
456 
457 	for (i = 0; i < MBOX_NB_MBX; i++) {
458 		if (vqid != ddata->mb[i].vq_id)
459 			continue;
460 		if (!ddata->mb[i].chan)
461 			return;
462 		err = mbox_send_message(ddata->mb[i].chan, (void *)(long)vqid);
463 		if (err < 0)
464 			dev_err(&rproc->dev, "%s: failed (%s, err:%d)\n",
465 				__func__, ddata->mb[i].name, err);
466 		return;
467 	}
468 }
469 
470 static struct rproc_ops st_rproc_ops = {
471 	.start		= stm32_rproc_start,
472 	.stop		= stm32_rproc_stop,
473 	.kick		= stm32_rproc_kick,
474 	.load		= rproc_elf_load_segments,
475 	.parse_fw	= stm32_rproc_parse_fw,
476 	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
477 	.sanity_check	= rproc_elf_sanity_check,
478 	.get_boot_addr	= rproc_elf_get_boot_addr,
479 };
480 
481 static const struct of_device_id stm32_rproc_match[] = {
482 	{ .compatible = "st,stm32mp1-m4" },
483 	{},
484 };
485 MODULE_DEVICE_TABLE(of, stm32_rproc_match);
486 
487 static int stm32_rproc_get_syscon(struct device_node *np, const char *prop,
488 				  struct stm32_syscon *syscon)
489 {
490 	int err = 0;
491 
492 	syscon->map = syscon_regmap_lookup_by_phandle(np, prop);
493 	if (IS_ERR(syscon->map)) {
494 		err = PTR_ERR(syscon->map);
495 		syscon->map = NULL;
496 		goto out;
497 	}
498 
499 	err = of_property_read_u32_index(np, prop, 1, &syscon->reg);
500 	if (err)
501 		goto out;
502 
503 	err = of_property_read_u32_index(np, prop, 2, &syscon->mask);
504 
505 out:
506 	return err;
507 }
508 
509 static int stm32_rproc_parse_dt(struct platform_device *pdev)
510 {
511 	struct device *dev = &pdev->dev;
512 	struct device_node *np = dev->of_node;
513 	struct rproc *rproc = platform_get_drvdata(pdev);
514 	struct stm32_rproc *ddata = rproc->priv;
515 	struct stm32_syscon tz;
516 	unsigned int tzen;
517 	int err, irq;
518 
519 	irq = platform_get_irq(pdev, 0);
520 	if (irq == -EPROBE_DEFER)
521 		return -EPROBE_DEFER;
522 
523 	if (irq > 0) {
524 		err = devm_request_irq(dev, irq, stm32_rproc_wdg, 0,
525 				       dev_name(dev), rproc);
526 		if (err) {
527 			dev_err(dev, "failed to request wdg irq\n");
528 			return err;
529 		}
530 
531 		dev_info(dev, "wdg irq registered\n");
532 	}
533 
534 	ddata->rst = devm_reset_control_get_by_index(dev, 0);
535 	if (IS_ERR(ddata->rst)) {
536 		dev_err(dev, "failed to get mcu reset\n");
537 		return PTR_ERR(ddata->rst);
538 	}
539 
540 	/*
541 	 * if platform is secured the hold boot bit must be written by
542 	 * smc call and read normally.
543 	 * if not secure the hold boot bit could be read/write normally
544 	 */
545 	err = stm32_rproc_get_syscon(np, "st,syscfg-tz", &tz);
546 	if (err) {
547 		dev_err(dev, "failed to get tz syscfg\n");
548 		return err;
549 	}
550 
551 	err = regmap_read(tz.map, tz.reg, &tzen);
552 	if (err) {
553 		dev_err(&rproc->dev, "failed to read tzen\n");
554 		return err;
555 	}
556 	ddata->secured_soc = tzen & tz.mask;
557 
558 	err = stm32_rproc_get_syscon(np, "st,syscfg-holdboot",
559 				     &ddata->hold_boot);
560 	if (err) {
561 		dev_err(dev, "failed to get hold boot\n");
562 		return err;
563 	}
564 
565 	err = stm32_rproc_get_syscon(np, "st,syscfg-pdds", &ddata->pdds);
566 	if (err)
567 		dev_warn(dev, "failed to get pdds\n");
568 
569 	rproc->auto_boot = of_property_read_bool(np, "st,auto-boot");
570 
571 	return stm32_rproc_of_memory_translations(rproc);
572 }
573 
574 static int stm32_rproc_probe(struct platform_device *pdev)
575 {
576 	struct device *dev = &pdev->dev;
577 	struct stm32_rproc *ddata;
578 	struct device_node *np = dev->of_node;
579 	struct rproc *rproc;
580 	int ret;
581 
582 	ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
583 	if (ret)
584 		return ret;
585 
586 	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
587 	if (!rproc)
588 		return -ENOMEM;
589 
590 	rproc->has_iommu = false;
591 	ddata = rproc->priv;
592 
593 	platform_set_drvdata(pdev, rproc);
594 
595 	ret = stm32_rproc_parse_dt(pdev);
596 	if (ret)
597 		goto free_rproc;
598 
599 	stm32_rproc_request_mbox(rproc);
600 
601 	ret = rproc_add(rproc);
602 	if (ret)
603 		goto free_mb;
604 
605 	return 0;
606 
607 free_mb:
608 	stm32_rproc_free_mbox(rproc);
609 free_rproc:
610 	rproc_free(rproc);
611 	return ret;
612 }
613 
614 static int stm32_rproc_remove(struct platform_device *pdev)
615 {
616 	struct rproc *rproc = platform_get_drvdata(pdev);
617 
618 	if (atomic_read(&rproc->power) > 0)
619 		rproc_shutdown(rproc);
620 
621 	rproc_del(rproc);
622 	stm32_rproc_free_mbox(rproc);
623 	rproc_free(rproc);
624 
625 	return 0;
626 }
627 
628 static struct platform_driver stm32_rproc_driver = {
629 	.probe = stm32_rproc_probe,
630 	.remove = stm32_rproc_remove,
631 	.driver = {
632 		.name = "stm32-rproc",
633 		.of_match_table = of_match_ptr(stm32_rproc_match),
634 	},
635 };
636 module_platform_driver(stm32_rproc_driver);
637 
638 MODULE_DESCRIPTION("STM32 Remote Processor Control Driver");
639 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
640 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
641 MODULE_LICENSE("GPL v2");
642 
643