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 	int err;
387 
388 	stm32_rproc_add_coredump_trace(rproc);
389 
390 	err = stm32_rproc_set_hold_boot(rproc, false);
391 	if (err)
392 		return err;
393 
394 	return stm32_rproc_set_hold_boot(rproc, true);
395 }
396 
397 static int stm32_rproc_stop(struct rproc *rproc)
398 {
399 	struct stm32_rproc *ddata = rproc->priv;
400 	int err, dummy_data, idx;
401 
402 	/* request shutdown of the remote processor */
403 	if (rproc->state != RPROC_OFFLINE) {
404 		idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_SHUTDOWN);
405 		if (idx >= 0 && ddata->mb[idx].chan) {
406 			/* a dummy data is sent to allow to block on transmit */
407 			err = mbox_send_message(ddata->mb[idx].chan,
408 						&dummy_data);
409 			if (err < 0)
410 				dev_warn(&rproc->dev, "warning: remote FW shutdown without ack\n");
411 		}
412 	}
413 
414 	err = stm32_rproc_set_hold_boot(rproc, true);
415 	if (err)
416 		return err;
417 
418 	err = reset_control_assert(ddata->rst);
419 	if (err) {
420 		dev_err(&rproc->dev, "failed to assert the reset\n");
421 		return err;
422 	}
423 
424 	/* to allow platform Standby power mode, set remote proc Deep Sleep */
425 	if (ddata->pdds.map) {
426 		err = regmap_update_bits(ddata->pdds.map, ddata->pdds.reg,
427 					 ddata->pdds.mask, 1);
428 		if (err) {
429 			dev_err(&rproc->dev, "failed to set pdds\n");
430 			return err;
431 		}
432 	}
433 
434 	return 0;
435 }
436 
437 static void stm32_rproc_kick(struct rproc *rproc, int vqid)
438 {
439 	struct stm32_rproc *ddata = rproc->priv;
440 	unsigned int i;
441 	int err;
442 
443 	if (WARN_ON(vqid >= MBOX_NB_VQ))
444 		return;
445 
446 	for (i = 0; i < MBOX_NB_MBX; i++) {
447 		if (vqid != ddata->mb[i].vq_id)
448 			continue;
449 		if (!ddata->mb[i].chan)
450 			return;
451 		err = mbox_send_message(ddata->mb[i].chan, (void *)(long)vqid);
452 		if (err < 0)
453 			dev_err(&rproc->dev, "%s: failed (%s, err:%d)\n",
454 				__func__, ddata->mb[i].name, err);
455 		return;
456 	}
457 }
458 
459 static struct rproc_ops st_rproc_ops = {
460 	.start		= stm32_rproc_start,
461 	.stop		= stm32_rproc_stop,
462 	.kick		= stm32_rproc_kick,
463 	.load		= rproc_elf_load_segments,
464 	.parse_fw	= stm32_rproc_parse_fw,
465 	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
466 	.sanity_check	= rproc_elf_sanity_check,
467 	.get_boot_addr	= rproc_elf_get_boot_addr,
468 };
469 
470 static const struct of_device_id stm32_rproc_match[] = {
471 	{ .compatible = "st,stm32mp1-m4" },
472 	{},
473 };
474 MODULE_DEVICE_TABLE(of, stm32_rproc_match);
475 
476 static int stm32_rproc_get_syscon(struct device_node *np, const char *prop,
477 				  struct stm32_syscon *syscon)
478 {
479 	int err = 0;
480 
481 	syscon->map = syscon_regmap_lookup_by_phandle(np, prop);
482 	if (IS_ERR(syscon->map)) {
483 		err = PTR_ERR(syscon->map);
484 		syscon->map = NULL;
485 		goto out;
486 	}
487 
488 	err = of_property_read_u32_index(np, prop, 1, &syscon->reg);
489 	if (err)
490 		goto out;
491 
492 	err = of_property_read_u32_index(np, prop, 2, &syscon->mask);
493 
494 out:
495 	return err;
496 }
497 
498 static int stm32_rproc_parse_dt(struct platform_device *pdev)
499 {
500 	struct device *dev = &pdev->dev;
501 	struct device_node *np = dev->of_node;
502 	struct rproc *rproc = platform_get_drvdata(pdev);
503 	struct stm32_rproc *ddata = rproc->priv;
504 	struct stm32_syscon tz;
505 	unsigned int tzen;
506 	int err, irq;
507 
508 	irq = platform_get_irq(pdev, 0);
509 	if (irq > 0) {
510 		err = devm_request_irq(dev, irq, stm32_rproc_wdg, 0,
511 				       dev_name(dev), rproc);
512 		if (err) {
513 			dev_err(dev, "failed to request wdg irq\n");
514 			return err;
515 		}
516 
517 		dev_info(dev, "wdg irq registered\n");
518 	}
519 
520 	ddata->rst = devm_reset_control_get_by_index(dev, 0);
521 	if (IS_ERR(ddata->rst)) {
522 		dev_err(dev, "failed to get mcu reset\n");
523 		return PTR_ERR(ddata->rst);
524 	}
525 
526 	/*
527 	 * if platform is secured the hold boot bit must be written by
528 	 * smc call and read normally.
529 	 * if not secure the hold boot bit could be read/write normally
530 	 */
531 	err = stm32_rproc_get_syscon(np, "st,syscfg-tz", &tz);
532 	if (err) {
533 		dev_err(dev, "failed to get tz syscfg\n");
534 		return err;
535 	}
536 
537 	err = regmap_read(tz.map, tz.reg, &tzen);
538 	if (err) {
539 		dev_err(&rproc->dev, "failed to read tzen\n");
540 		return err;
541 	}
542 	ddata->secured_soc = tzen & tz.mask;
543 
544 	err = stm32_rproc_get_syscon(np, "st,syscfg-holdboot",
545 				     &ddata->hold_boot);
546 	if (err) {
547 		dev_err(dev, "failed to get hold boot\n");
548 		return err;
549 	}
550 
551 	err = stm32_rproc_get_syscon(np, "st,syscfg-pdds", &ddata->pdds);
552 	if (err)
553 		dev_warn(dev, "failed to get pdds\n");
554 
555 	rproc->auto_boot = of_property_read_bool(np, "st,auto-boot");
556 
557 	return stm32_rproc_of_memory_translations(rproc);
558 }
559 
560 static int stm32_rproc_probe(struct platform_device *pdev)
561 {
562 	struct device *dev = &pdev->dev;
563 	struct stm32_rproc *ddata;
564 	struct device_node *np = dev->of_node;
565 	struct rproc *rproc;
566 	int ret;
567 
568 	ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
569 	if (ret)
570 		return ret;
571 
572 	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
573 	if (!rproc)
574 		return -ENOMEM;
575 
576 	rproc->has_iommu = false;
577 	ddata = rproc->priv;
578 
579 	platform_set_drvdata(pdev, rproc);
580 
581 	ret = stm32_rproc_parse_dt(pdev);
582 	if (ret)
583 		goto free_rproc;
584 
585 	stm32_rproc_request_mbox(rproc);
586 
587 	ret = rproc_add(rproc);
588 	if (ret)
589 		goto free_mb;
590 
591 	return 0;
592 
593 free_mb:
594 	stm32_rproc_free_mbox(rproc);
595 free_rproc:
596 	rproc_free(rproc);
597 	return ret;
598 }
599 
600 static int stm32_rproc_remove(struct platform_device *pdev)
601 {
602 	struct rproc *rproc = platform_get_drvdata(pdev);
603 
604 	if (atomic_read(&rproc->power) > 0)
605 		rproc_shutdown(rproc);
606 
607 	rproc_del(rproc);
608 	stm32_rproc_free_mbox(rproc);
609 	rproc_free(rproc);
610 
611 	return 0;
612 }
613 
614 static struct platform_driver stm32_rproc_driver = {
615 	.probe = stm32_rproc_probe,
616 	.remove = stm32_rproc_remove,
617 	.driver = {
618 		.name = "stm32-rproc",
619 		.of_match_table = of_match_ptr(stm32_rproc_match),
620 	},
621 };
622 module_platform_driver(stm32_rproc_driver);
623 
624 MODULE_DESCRIPTION("STM32 Remote Processor Control Driver");
625 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
626 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
627 MODULE_LICENSE("GPL v2");
628 
629