1 /*
2  * ST's Remote Processor Control Driver
3  *
4  * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
5  *
6  * Author: Ludovic Barre <ludovic.barre@st.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/err.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/mailbox_client.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/of_device.h>
24 #include <linux/of_reserved_mem.h>
25 #include <linux/platform_device.h>
26 #include <linux/regmap.h>
27 #include <linux/remoteproc.h>
28 #include <linux/reset.h>
29 
30 #include "remoteproc_internal.h"
31 
32 #define ST_RPROC_VQ0		0
33 #define ST_RPROC_VQ1		1
34 #define ST_RPROC_MAX_VRING	2
35 
36 #define MBOX_RX			0
37 #define MBOX_TX			1
38 #define MBOX_MAX		2
39 
40 struct st_rproc_config {
41 	bool			sw_reset;
42 	bool			pwr_reset;
43 	unsigned long		bootaddr_mask;
44 };
45 
46 struct st_rproc {
47 	struct st_rproc_config	*config;
48 	struct reset_control	*sw_reset;
49 	struct reset_control	*pwr_reset;
50 	struct clk		*clk;
51 	u32			clk_rate;
52 	struct regmap		*boot_base;
53 	u32			boot_offset;
54 	struct mbox_chan	*mbox_chan[ST_RPROC_MAX_VRING * MBOX_MAX];
55 	struct mbox_client mbox_client_vq0;
56 	struct mbox_client mbox_client_vq1;
57 };
58 
59 static void st_rproc_mbox_callback(struct device *dev, u32 msg)
60 {
61 	struct rproc *rproc = dev_get_drvdata(dev);
62 
63 	if (rproc_vq_interrupt(rproc, msg) == IRQ_NONE)
64 		dev_dbg(dev, "no message was found in vqid %d\n", msg);
65 }
66 
67 static
68 void st_rproc_mbox_callback_vq0(struct mbox_client *mbox_client, void *data)
69 {
70 	st_rproc_mbox_callback(mbox_client->dev, 0);
71 }
72 
73 static
74 void st_rproc_mbox_callback_vq1(struct mbox_client *mbox_client, void *data)
75 {
76 	st_rproc_mbox_callback(mbox_client->dev, 1);
77 }
78 
79 static void st_rproc_kick(struct rproc *rproc, int vqid)
80 {
81 	struct st_rproc *ddata = rproc->priv;
82 	struct device *dev = rproc->dev.parent;
83 	int ret;
84 
85 	/* send the index of the triggered virtqueue in the mailbox payload */
86 	if (WARN_ON(vqid >= ST_RPROC_MAX_VRING))
87 		return;
88 
89 	ret = mbox_send_message(ddata->mbox_chan[vqid * MBOX_MAX + MBOX_TX],
90 				(void *)&vqid);
91 	if (ret < 0)
92 		dev_err(dev, "failed to send message via mbox: %d\n", ret);
93 }
94 
95 static int st_rproc_mem_alloc(struct rproc *rproc,
96 			      struct rproc_mem_entry *mem)
97 {
98 	struct device *dev = rproc->dev.parent;
99 	void *va;
100 
101 	va = ioremap_wc(mem->dma, mem->len);
102 	if (!va) {
103 		dev_err(dev, "Unable to map memory region: %pa+%zx\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 st_rproc_mem_release(struct rproc *rproc,
115 				struct rproc_mem_entry *mem)
116 {
117 	iounmap(mem->va);
118 
119 	return 0;
120 }
121 
122 static int st_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
123 {
124 	struct device *dev = rproc->dev.parent;
125 	struct device_node *np = dev->of_node;
126 	struct rproc_mem_entry *mem;
127 	struct reserved_mem *rmem;
128 	struct of_phandle_iterator it;
129 	int index = 0;
130 
131 	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
132 	while (of_phandle_iterator_next(&it) == 0) {
133 		rmem = of_reserved_mem_lookup(it.node);
134 		if (!rmem) {
135 			dev_err(dev, "unable to acquire memory-region\n");
136 			return -EINVAL;
137 		}
138 
139 		/*  No need to map vdev buffer */
140 		if (strcmp(it.node->name, "vdev0buffer")) {
141 			/* Register memory region */
142 			mem = rproc_mem_entry_init(dev, NULL,
143 						   (dma_addr_t)rmem->base,
144 						   rmem->size, rmem->base,
145 						   st_rproc_mem_alloc,
146 						   st_rproc_mem_release,
147 						   it.node->name);
148 		} else {
149 			/* Register reserved memory for vdev buffer allocation */
150 			mem = rproc_of_resm_mem_entry_init(dev, index,
151 							   rmem->size,
152 							   rmem->base,
153 							   it.node->name);
154 		}
155 
156 		if (!mem)
157 			return -ENOMEM;
158 
159 		rproc_add_carveout(rproc, mem);
160 		index++;
161 	}
162 
163 	return rproc_elf_load_rsc_table(rproc, fw);
164 }
165 
166 static int st_rproc_start(struct rproc *rproc)
167 {
168 	struct st_rproc *ddata = rproc->priv;
169 	int err;
170 
171 	regmap_update_bits(ddata->boot_base, ddata->boot_offset,
172 			   ddata->config->bootaddr_mask, rproc->bootaddr);
173 
174 	err = clk_enable(ddata->clk);
175 	if (err) {
176 		dev_err(&rproc->dev, "Failed to enable clock\n");
177 		return err;
178 	}
179 
180 	if (ddata->config->sw_reset) {
181 		err = reset_control_deassert(ddata->sw_reset);
182 		if (err) {
183 			dev_err(&rproc->dev, "Failed to deassert S/W Reset\n");
184 			goto sw_reset_fail;
185 		}
186 	}
187 
188 	if (ddata->config->pwr_reset) {
189 		err = reset_control_deassert(ddata->pwr_reset);
190 		if (err) {
191 			dev_err(&rproc->dev, "Failed to deassert Power Reset\n");
192 			goto pwr_reset_fail;
193 		}
194 	}
195 
196 	dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
197 
198 	return 0;
199 
200 
201 pwr_reset_fail:
202 	if (ddata->config->pwr_reset)
203 		reset_control_assert(ddata->sw_reset);
204 sw_reset_fail:
205 	clk_disable(ddata->clk);
206 
207 	return err;
208 }
209 
210 static int st_rproc_stop(struct rproc *rproc)
211 {
212 	struct st_rproc *ddata = rproc->priv;
213 	int sw_err = 0, pwr_err = 0;
214 
215 	if (ddata->config->sw_reset) {
216 		sw_err = reset_control_assert(ddata->sw_reset);
217 		if (sw_err)
218 			dev_err(&rproc->dev, "Failed to assert S/W Reset\n");
219 	}
220 
221 	if (ddata->config->pwr_reset) {
222 		pwr_err = reset_control_assert(ddata->pwr_reset);
223 		if (pwr_err)
224 			dev_err(&rproc->dev, "Failed to assert Power Reset\n");
225 	}
226 
227 	clk_disable(ddata->clk);
228 
229 	return sw_err ?: pwr_err;
230 }
231 
232 static const struct rproc_ops st_rproc_ops = {
233 	.kick			= st_rproc_kick,
234 	.start			= st_rproc_start,
235 	.stop			= st_rproc_stop,
236 	.parse_fw		= st_rproc_parse_fw,
237 	.load			= rproc_elf_load_segments,
238 	.find_loaded_rsc_table	= rproc_elf_find_loaded_rsc_table,
239 	.sanity_check		= rproc_elf_sanity_check,
240 	.get_boot_addr		= rproc_elf_get_boot_addr,
241 };
242 
243 /*
244  * Fetch state of the processor: 0 is off, 1 is on.
245  */
246 static int st_rproc_state(struct platform_device *pdev)
247 {
248 	struct rproc *rproc = platform_get_drvdata(pdev);
249 	struct st_rproc *ddata = rproc->priv;
250 	int reset_sw = 0, reset_pwr = 0;
251 
252 	if (ddata->config->sw_reset)
253 		reset_sw = reset_control_status(ddata->sw_reset);
254 
255 	if (ddata->config->pwr_reset)
256 		reset_pwr = reset_control_status(ddata->pwr_reset);
257 
258 	if (reset_sw < 0 || reset_pwr < 0)
259 		return -EINVAL;
260 
261 	return !reset_sw && !reset_pwr;
262 }
263 
264 static const struct st_rproc_config st40_rproc_cfg = {
265 	.sw_reset = true,
266 	.pwr_reset = true,
267 	.bootaddr_mask = GENMASK(28, 1),
268 };
269 
270 static const struct st_rproc_config st231_rproc_cfg = {
271 	.sw_reset = true,
272 	.pwr_reset = false,
273 	.bootaddr_mask = GENMASK(31, 6),
274 };
275 
276 static const struct of_device_id st_rproc_match[] = {
277 	{ .compatible = "st,st40-rproc", .data = &st40_rproc_cfg },
278 	{ .compatible = "st,st231-rproc", .data = &st231_rproc_cfg },
279 	{},
280 };
281 MODULE_DEVICE_TABLE(of, st_rproc_match);
282 
283 static int st_rproc_parse_dt(struct platform_device *pdev)
284 {
285 	struct device *dev = &pdev->dev;
286 	struct rproc *rproc = platform_get_drvdata(pdev);
287 	struct st_rproc *ddata = rproc->priv;
288 	struct device_node *np = dev->of_node;
289 	int err;
290 
291 	if (ddata->config->sw_reset) {
292 		ddata->sw_reset = devm_reset_control_get_exclusive(dev,
293 								   "sw_reset");
294 		if (IS_ERR(ddata->sw_reset)) {
295 			dev_err(dev, "Failed to get S/W Reset\n");
296 			return PTR_ERR(ddata->sw_reset);
297 		}
298 	}
299 
300 	if (ddata->config->pwr_reset) {
301 		ddata->pwr_reset = devm_reset_control_get_exclusive(dev,
302 								    "pwr_reset");
303 		if (IS_ERR(ddata->pwr_reset)) {
304 			dev_err(dev, "Failed to get Power Reset\n");
305 			return PTR_ERR(ddata->pwr_reset);
306 		}
307 	}
308 
309 	ddata->clk = devm_clk_get(dev, NULL);
310 	if (IS_ERR(ddata->clk)) {
311 		dev_err(dev, "Failed to get clock\n");
312 		return PTR_ERR(ddata->clk);
313 	}
314 
315 	err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
316 	if (err) {
317 		dev_err(dev, "failed to get clock frequency\n");
318 		return err;
319 	}
320 
321 	ddata->boot_base = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
322 	if (IS_ERR(ddata->boot_base)) {
323 		dev_err(dev, "Boot base not found\n");
324 		return PTR_ERR(ddata->boot_base);
325 	}
326 
327 	err = of_property_read_u32_index(np, "st,syscfg", 1,
328 					 &ddata->boot_offset);
329 	if (err) {
330 		dev_err(dev, "Boot offset not found\n");
331 		return -EINVAL;
332 	}
333 
334 	err = clk_prepare(ddata->clk);
335 	if (err)
336 		dev_err(dev, "failed to get clock\n");
337 
338 	return err;
339 }
340 
341 static int st_rproc_probe(struct platform_device *pdev)
342 {
343 	struct device *dev = &pdev->dev;
344 	const struct of_device_id *match;
345 	struct st_rproc *ddata;
346 	struct device_node *np = dev->of_node;
347 	struct rproc *rproc;
348 	struct mbox_chan *chan;
349 	int enabled;
350 	int ret, i;
351 
352 	match = of_match_device(st_rproc_match, dev);
353 	if (!match || !match->data) {
354 		dev_err(dev, "No device match found\n");
355 		return -ENODEV;
356 	}
357 
358 	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
359 	if (!rproc)
360 		return -ENOMEM;
361 
362 	rproc->has_iommu = false;
363 	ddata = rproc->priv;
364 	ddata->config = (struct st_rproc_config *)match->data;
365 
366 	platform_set_drvdata(pdev, rproc);
367 
368 	ret = st_rproc_parse_dt(pdev);
369 	if (ret)
370 		goto free_rproc;
371 
372 	enabled = st_rproc_state(pdev);
373 	if (enabled < 0) {
374 		ret = enabled;
375 		goto free_clk;
376 	}
377 
378 	if (enabled) {
379 		atomic_inc(&rproc->power);
380 		rproc->state = RPROC_RUNNING;
381 	} else {
382 		clk_set_rate(ddata->clk, ddata->clk_rate);
383 	}
384 
385 	if (of_get_property(np, "mbox-names", NULL)) {
386 		ddata->mbox_client_vq0.dev		= dev;
387 		ddata->mbox_client_vq0.tx_done		= NULL;
388 		ddata->mbox_client_vq0.tx_block	= false;
389 		ddata->mbox_client_vq0.knows_txdone	= false;
390 		ddata->mbox_client_vq0.rx_callback	= st_rproc_mbox_callback_vq0;
391 
392 		ddata->mbox_client_vq1.dev		= dev;
393 		ddata->mbox_client_vq1.tx_done		= NULL;
394 		ddata->mbox_client_vq1.tx_block	= false;
395 		ddata->mbox_client_vq1.knows_txdone	= false;
396 		ddata->mbox_client_vq1.rx_callback	= st_rproc_mbox_callback_vq1;
397 
398 		/*
399 		 * To control a co-processor without IPC mechanism.
400 		 * This driver can be used without mbox and rpmsg.
401 		 */
402 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_rx");
403 		if (IS_ERR(chan)) {
404 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
405 			ret = PTR_ERR(chan);
406 			goto free_clk;
407 		}
408 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_RX] = chan;
409 
410 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_tx");
411 		if (IS_ERR(chan)) {
412 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
413 			ret = PTR_ERR(chan);
414 			goto free_mbox;
415 		}
416 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_TX] = chan;
417 
418 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_rx");
419 		if (IS_ERR(chan)) {
420 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
421 			ret = PTR_ERR(chan);
422 			goto free_mbox;
423 		}
424 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_RX] = chan;
425 
426 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_tx");
427 		if (IS_ERR(chan)) {
428 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
429 			ret = PTR_ERR(chan);
430 			goto free_mbox;
431 		}
432 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_TX] = chan;
433 	}
434 
435 	ret = rproc_add(rproc);
436 	if (ret)
437 		goto free_mbox;
438 
439 	return 0;
440 
441 free_mbox:
442 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
443 		mbox_free_channel(ddata->mbox_chan[i]);
444 free_clk:
445 	clk_unprepare(ddata->clk);
446 free_rproc:
447 	rproc_free(rproc);
448 	return ret;
449 }
450 
451 static int st_rproc_remove(struct platform_device *pdev)
452 {
453 	struct rproc *rproc = platform_get_drvdata(pdev);
454 	struct st_rproc *ddata = rproc->priv;
455 	int i;
456 
457 	rproc_del(rproc);
458 
459 	clk_disable_unprepare(ddata->clk);
460 
461 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
462 		mbox_free_channel(ddata->mbox_chan[i]);
463 
464 	rproc_free(rproc);
465 
466 	return 0;
467 }
468 
469 static struct platform_driver st_rproc_driver = {
470 	.probe = st_rproc_probe,
471 	.remove = st_rproc_remove,
472 	.driver = {
473 		.name = "st-rproc",
474 		.of_match_table = of_match_ptr(st_rproc_match),
475 	},
476 };
477 module_platform_driver(st_rproc_driver);
478 
479 MODULE_DESCRIPTION("ST Remote Processor Control Driver");
480 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
481 MODULE_LICENSE("GPL v2");
482