1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ST's Remote Processor Control Driver
4  *
5  * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
6  *
7  * Author: Ludovic Barre <ludovic.barre@st.com>
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/mailbox_client.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/of_device.h>
21 #include <linux/of_reserved_mem.h>
22 #include <linux/platform_device.h>
23 #include <linux/regmap.h>
24 #include <linux/remoteproc.h>
25 #include <linux/reset.h>
26 
27 #include "remoteproc_internal.h"
28 
29 #define ST_RPROC_VQ0		0
30 #define ST_RPROC_VQ1		1
31 #define ST_RPROC_MAX_VRING	2
32 
33 #define MBOX_RX			0
34 #define MBOX_TX			1
35 #define MBOX_MAX		2
36 
37 struct st_rproc_config {
38 	bool			sw_reset;
39 	bool			pwr_reset;
40 	unsigned long		bootaddr_mask;
41 };
42 
43 struct st_rproc {
44 	struct st_rproc_config	*config;
45 	struct reset_control	*sw_reset;
46 	struct reset_control	*pwr_reset;
47 	struct clk		*clk;
48 	u32			clk_rate;
49 	struct regmap		*boot_base;
50 	u32			boot_offset;
51 	struct mbox_chan	*mbox_chan[ST_RPROC_MAX_VRING * MBOX_MAX];
52 	struct mbox_client mbox_client_vq0;
53 	struct mbox_client mbox_client_vq1;
54 };
55 
56 static void st_rproc_mbox_callback(struct device *dev, u32 msg)
57 {
58 	struct rproc *rproc = dev_get_drvdata(dev);
59 
60 	if (rproc_vq_interrupt(rproc, msg) == IRQ_NONE)
61 		dev_dbg(dev, "no message was found in vqid %d\n", msg);
62 }
63 
64 static
65 void st_rproc_mbox_callback_vq0(struct mbox_client *mbox_client, void *data)
66 {
67 	st_rproc_mbox_callback(mbox_client->dev, 0);
68 }
69 
70 static
71 void st_rproc_mbox_callback_vq1(struct mbox_client *mbox_client, void *data)
72 {
73 	st_rproc_mbox_callback(mbox_client->dev, 1);
74 }
75 
76 static void st_rproc_kick(struct rproc *rproc, int vqid)
77 {
78 	struct st_rproc *ddata = rproc->priv;
79 	struct device *dev = rproc->dev.parent;
80 	int ret;
81 
82 	/* send the index of the triggered virtqueue in the mailbox payload */
83 	if (WARN_ON(vqid >= ST_RPROC_MAX_VRING))
84 		return;
85 
86 	ret = mbox_send_message(ddata->mbox_chan[vqid * MBOX_MAX + MBOX_TX],
87 				(void *)&vqid);
88 	if (ret < 0)
89 		dev_err(dev, "failed to send message via mbox: %d\n", ret);
90 }
91 
92 static int st_rproc_mem_alloc(struct rproc *rproc,
93 			      struct rproc_mem_entry *mem)
94 {
95 	struct device *dev = rproc->dev.parent;
96 	void *va;
97 
98 	va = ioremap_wc(mem->dma, mem->len);
99 	if (!va) {
100 		dev_err(dev, "Unable to map memory region: %pa+%zx\n",
101 			&mem->dma, mem->len);
102 		return -ENOMEM;
103 	}
104 
105 	/* Update memory entry va */
106 	mem->va = va;
107 
108 	return 0;
109 }
110 
111 static int st_rproc_mem_release(struct rproc *rproc,
112 				struct rproc_mem_entry *mem)
113 {
114 	iounmap(mem->va);
115 
116 	return 0;
117 }
118 
119 static int st_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
120 {
121 	struct device *dev = rproc->dev.parent;
122 	struct device_node *np = dev->of_node;
123 	struct rproc_mem_entry *mem;
124 	struct reserved_mem *rmem;
125 	struct of_phandle_iterator it;
126 	int index = 0;
127 
128 	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
129 	while (of_phandle_iterator_next(&it) == 0) {
130 		rmem = of_reserved_mem_lookup(it.node);
131 		if (!rmem) {
132 			dev_err(dev, "unable to acquire memory-region\n");
133 			return -EINVAL;
134 		}
135 
136 		/*  No need to map vdev buffer */
137 		if (strcmp(it.node->name, "vdev0buffer")) {
138 			/* Register memory region */
139 			mem = rproc_mem_entry_init(dev, NULL,
140 						   (dma_addr_t)rmem->base,
141 						   rmem->size, rmem->base,
142 						   st_rproc_mem_alloc,
143 						   st_rproc_mem_release,
144 						   it.node->name);
145 		} else {
146 			/* Register reserved memory for vdev buffer allocation */
147 			mem = rproc_of_resm_mem_entry_init(dev, index,
148 							   rmem->size,
149 							   rmem->base,
150 							   it.node->name);
151 		}
152 
153 		if (!mem)
154 			return -ENOMEM;
155 
156 		rproc_add_carveout(rproc, mem);
157 		index++;
158 	}
159 
160 	return rproc_elf_load_rsc_table(rproc, fw);
161 }
162 
163 static int st_rproc_start(struct rproc *rproc)
164 {
165 	struct st_rproc *ddata = rproc->priv;
166 	int err;
167 
168 	regmap_update_bits(ddata->boot_base, ddata->boot_offset,
169 			   ddata->config->bootaddr_mask, rproc->bootaddr);
170 
171 	err = clk_enable(ddata->clk);
172 	if (err) {
173 		dev_err(&rproc->dev, "Failed to enable clock\n");
174 		return err;
175 	}
176 
177 	if (ddata->config->sw_reset) {
178 		err = reset_control_deassert(ddata->sw_reset);
179 		if (err) {
180 			dev_err(&rproc->dev, "Failed to deassert S/W Reset\n");
181 			goto sw_reset_fail;
182 		}
183 	}
184 
185 	if (ddata->config->pwr_reset) {
186 		err = reset_control_deassert(ddata->pwr_reset);
187 		if (err) {
188 			dev_err(&rproc->dev, "Failed to deassert Power Reset\n");
189 			goto pwr_reset_fail;
190 		}
191 	}
192 
193 	dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
194 
195 	return 0;
196 
197 
198 pwr_reset_fail:
199 	if (ddata->config->pwr_reset)
200 		reset_control_assert(ddata->sw_reset);
201 sw_reset_fail:
202 	clk_disable(ddata->clk);
203 
204 	return err;
205 }
206 
207 static int st_rproc_stop(struct rproc *rproc)
208 {
209 	struct st_rproc *ddata = rproc->priv;
210 	int sw_err = 0, pwr_err = 0;
211 
212 	if (ddata->config->sw_reset) {
213 		sw_err = reset_control_assert(ddata->sw_reset);
214 		if (sw_err)
215 			dev_err(&rproc->dev, "Failed to assert S/W Reset\n");
216 	}
217 
218 	if (ddata->config->pwr_reset) {
219 		pwr_err = reset_control_assert(ddata->pwr_reset);
220 		if (pwr_err)
221 			dev_err(&rproc->dev, "Failed to assert Power Reset\n");
222 	}
223 
224 	clk_disable(ddata->clk);
225 
226 	return sw_err ?: pwr_err;
227 }
228 
229 static const struct rproc_ops st_rproc_ops = {
230 	.kick			= st_rproc_kick,
231 	.start			= st_rproc_start,
232 	.stop			= st_rproc_stop,
233 	.parse_fw		= st_rproc_parse_fw,
234 	.load			= rproc_elf_load_segments,
235 	.find_loaded_rsc_table	= rproc_elf_find_loaded_rsc_table,
236 	.sanity_check		= rproc_elf_sanity_check,
237 	.get_boot_addr		= rproc_elf_get_boot_addr,
238 };
239 
240 /*
241  * Fetch state of the processor: 0 is off, 1 is on.
242  */
243 static int st_rproc_state(struct platform_device *pdev)
244 {
245 	struct rproc *rproc = platform_get_drvdata(pdev);
246 	struct st_rproc *ddata = rproc->priv;
247 	int reset_sw = 0, reset_pwr = 0;
248 
249 	if (ddata->config->sw_reset)
250 		reset_sw = reset_control_status(ddata->sw_reset);
251 
252 	if (ddata->config->pwr_reset)
253 		reset_pwr = reset_control_status(ddata->pwr_reset);
254 
255 	if (reset_sw < 0 || reset_pwr < 0)
256 		return -EINVAL;
257 
258 	return !reset_sw && !reset_pwr;
259 }
260 
261 static const struct st_rproc_config st40_rproc_cfg = {
262 	.sw_reset = true,
263 	.pwr_reset = true,
264 	.bootaddr_mask = GENMASK(28, 1),
265 };
266 
267 static const struct st_rproc_config st231_rproc_cfg = {
268 	.sw_reset = true,
269 	.pwr_reset = false,
270 	.bootaddr_mask = GENMASK(31, 6),
271 };
272 
273 static const struct of_device_id st_rproc_match[] = {
274 	{ .compatible = "st,st40-rproc", .data = &st40_rproc_cfg },
275 	{ .compatible = "st,st231-rproc", .data = &st231_rproc_cfg },
276 	{},
277 };
278 MODULE_DEVICE_TABLE(of, st_rproc_match);
279 
280 static int st_rproc_parse_dt(struct platform_device *pdev)
281 {
282 	struct device *dev = &pdev->dev;
283 	struct rproc *rproc = platform_get_drvdata(pdev);
284 	struct st_rproc *ddata = rproc->priv;
285 	struct device_node *np = dev->of_node;
286 	int err;
287 
288 	if (ddata->config->sw_reset) {
289 		ddata->sw_reset = devm_reset_control_get_exclusive(dev,
290 								   "sw_reset");
291 		if (IS_ERR(ddata->sw_reset)) {
292 			dev_err(dev, "Failed to get S/W Reset\n");
293 			return PTR_ERR(ddata->sw_reset);
294 		}
295 	}
296 
297 	if (ddata->config->pwr_reset) {
298 		ddata->pwr_reset = devm_reset_control_get_exclusive(dev,
299 								    "pwr_reset");
300 		if (IS_ERR(ddata->pwr_reset)) {
301 			dev_err(dev, "Failed to get Power Reset\n");
302 			return PTR_ERR(ddata->pwr_reset);
303 		}
304 	}
305 
306 	ddata->clk = devm_clk_get(dev, NULL);
307 	if (IS_ERR(ddata->clk)) {
308 		dev_err(dev, "Failed to get clock\n");
309 		return PTR_ERR(ddata->clk);
310 	}
311 
312 	err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
313 	if (err) {
314 		dev_err(dev, "failed to get clock frequency\n");
315 		return err;
316 	}
317 
318 	ddata->boot_base = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
319 	if (IS_ERR(ddata->boot_base)) {
320 		dev_err(dev, "Boot base not found\n");
321 		return PTR_ERR(ddata->boot_base);
322 	}
323 
324 	err = of_property_read_u32_index(np, "st,syscfg", 1,
325 					 &ddata->boot_offset);
326 	if (err) {
327 		dev_err(dev, "Boot offset not found\n");
328 		return -EINVAL;
329 	}
330 
331 	err = clk_prepare(ddata->clk);
332 	if (err)
333 		dev_err(dev, "failed to get clock\n");
334 
335 	return err;
336 }
337 
338 static int st_rproc_probe(struct platform_device *pdev)
339 {
340 	struct device *dev = &pdev->dev;
341 	const struct of_device_id *match;
342 	struct st_rproc *ddata;
343 	struct device_node *np = dev->of_node;
344 	struct rproc *rproc;
345 	struct mbox_chan *chan;
346 	int enabled;
347 	int ret, i;
348 
349 	match = of_match_device(st_rproc_match, dev);
350 	if (!match || !match->data) {
351 		dev_err(dev, "No device match found\n");
352 		return -ENODEV;
353 	}
354 
355 	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
356 	if (!rproc)
357 		return -ENOMEM;
358 
359 	rproc->has_iommu = false;
360 	ddata = rproc->priv;
361 	ddata->config = (struct st_rproc_config *)match->data;
362 
363 	platform_set_drvdata(pdev, rproc);
364 
365 	ret = st_rproc_parse_dt(pdev);
366 	if (ret)
367 		goto free_rproc;
368 
369 	enabled = st_rproc_state(pdev);
370 	if (enabled < 0) {
371 		ret = enabled;
372 		goto free_clk;
373 	}
374 
375 	if (enabled) {
376 		atomic_inc(&rproc->power);
377 		rproc->state = RPROC_RUNNING;
378 	} else {
379 		clk_set_rate(ddata->clk, ddata->clk_rate);
380 	}
381 
382 	if (of_get_property(np, "mbox-names", NULL)) {
383 		ddata->mbox_client_vq0.dev		= dev;
384 		ddata->mbox_client_vq0.tx_done		= NULL;
385 		ddata->mbox_client_vq0.tx_block	= false;
386 		ddata->mbox_client_vq0.knows_txdone	= false;
387 		ddata->mbox_client_vq0.rx_callback	= st_rproc_mbox_callback_vq0;
388 
389 		ddata->mbox_client_vq1.dev		= dev;
390 		ddata->mbox_client_vq1.tx_done		= NULL;
391 		ddata->mbox_client_vq1.tx_block	= false;
392 		ddata->mbox_client_vq1.knows_txdone	= false;
393 		ddata->mbox_client_vq1.rx_callback	= st_rproc_mbox_callback_vq1;
394 
395 		/*
396 		 * To control a co-processor without IPC mechanism.
397 		 * This driver can be used without mbox and rpmsg.
398 		 */
399 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_rx");
400 		if (IS_ERR(chan)) {
401 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
402 			ret = PTR_ERR(chan);
403 			goto free_clk;
404 		}
405 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_RX] = chan;
406 
407 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_tx");
408 		if (IS_ERR(chan)) {
409 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
410 			ret = PTR_ERR(chan);
411 			goto free_mbox;
412 		}
413 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_TX] = chan;
414 
415 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_rx");
416 		if (IS_ERR(chan)) {
417 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
418 			ret = PTR_ERR(chan);
419 			goto free_mbox;
420 		}
421 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_RX] = chan;
422 
423 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_tx");
424 		if (IS_ERR(chan)) {
425 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
426 			ret = PTR_ERR(chan);
427 			goto free_mbox;
428 		}
429 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_TX] = chan;
430 	}
431 
432 	ret = rproc_add(rproc);
433 	if (ret)
434 		goto free_mbox;
435 
436 	return 0;
437 
438 free_mbox:
439 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
440 		mbox_free_channel(ddata->mbox_chan[i]);
441 free_clk:
442 	clk_unprepare(ddata->clk);
443 free_rproc:
444 	rproc_free(rproc);
445 	return ret;
446 }
447 
448 static int st_rproc_remove(struct platform_device *pdev)
449 {
450 	struct rproc *rproc = platform_get_drvdata(pdev);
451 	struct st_rproc *ddata = rproc->priv;
452 	int i;
453 
454 	rproc_del(rproc);
455 
456 	clk_disable_unprepare(ddata->clk);
457 
458 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
459 		mbox_free_channel(ddata->mbox_chan[i]);
460 
461 	rproc_free(rproc);
462 
463 	return 0;
464 }
465 
466 static struct platform_driver st_rproc_driver = {
467 	.probe = st_rproc_probe,
468 	.remove = st_rproc_remove,
469 	.driver = {
470 		.name = "st-rproc",
471 		.of_match_table = of_match_ptr(st_rproc_match),
472 	},
473 };
474 module_platform_driver(st_rproc_driver);
475 
476 MODULE_DESCRIPTION("ST Remote Processor Control Driver");
477 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
478 MODULE_LICENSE("GPL v2");
479