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_device.h>
23 #include <linux/of_reserved_mem.h>
24 #include <linux/platform_device.h>
25 #include <linux/regmap.h>
26 #include <linux/remoteproc.h>
27 #include <linux/reset.h>
28 
29 #include "remoteproc_internal.h"
30 
31 #define ST_RPROC_VQ0		0
32 #define ST_RPROC_VQ1		1
33 #define ST_RPROC_MAX_VRING	2
34 
35 #define MBOX_RX			0
36 #define MBOX_TX			1
37 #define MBOX_MAX		2
38 
39 struct st_rproc_config {
40 	bool			sw_reset;
41 	bool			pwr_reset;
42 	unsigned long		bootaddr_mask;
43 };
44 
45 struct st_rproc {
46 	struct st_rproc_config	*config;
47 	struct reset_control	*sw_reset;
48 	struct reset_control	*pwr_reset;
49 	struct clk		*clk;
50 	u32			clk_rate;
51 	struct regmap		*boot_base;
52 	u32			boot_offset;
53 	struct mbox_chan	*mbox_chan[ST_RPROC_MAX_VRING * MBOX_MAX];
54 	struct mbox_client mbox_client_vq0;
55 	struct mbox_client mbox_client_vq1;
56 };
57 
58 static void st_rproc_mbox_callback(struct device *dev, u32 msg)
59 {
60 	struct rproc *rproc = dev_get_drvdata(dev);
61 
62 	if (rproc_vq_interrupt(rproc, msg) == IRQ_NONE)
63 		dev_dbg(dev, "no message was found in vqid %d\n", msg);
64 }
65 
66 static
67 void st_rproc_mbox_callback_vq0(struct mbox_client *mbox_client, void *data)
68 {
69 	st_rproc_mbox_callback(mbox_client->dev, 0);
70 }
71 
72 static
73 void st_rproc_mbox_callback_vq1(struct mbox_client *mbox_client, void *data)
74 {
75 	st_rproc_mbox_callback(mbox_client->dev, 1);
76 }
77 
78 static void st_rproc_kick(struct rproc *rproc, int vqid)
79 {
80 	struct st_rproc *ddata = rproc->priv;
81 	struct device *dev = rproc->dev.parent;
82 	int ret;
83 
84 	/* send the index of the triggered virtqueue in the mailbox payload */
85 	if (WARN_ON(vqid >= ST_RPROC_MAX_VRING))
86 		return;
87 
88 	ret = mbox_send_message(ddata->mbox_chan[vqid * MBOX_MAX + MBOX_TX],
89 				(void *)&vqid);
90 	if (ret < 0)
91 		dev_err(dev, "failed to send message via mbox: %d\n", ret);
92 }
93 
94 static int st_rproc_start(struct rproc *rproc)
95 {
96 	struct st_rproc *ddata = rproc->priv;
97 	int err;
98 
99 	regmap_update_bits(ddata->boot_base, ddata->boot_offset,
100 			   ddata->config->bootaddr_mask, rproc->bootaddr);
101 
102 	err = clk_enable(ddata->clk);
103 	if (err) {
104 		dev_err(&rproc->dev, "Failed to enable clock\n");
105 		return err;
106 	}
107 
108 	if (ddata->config->sw_reset) {
109 		err = reset_control_deassert(ddata->sw_reset);
110 		if (err) {
111 			dev_err(&rproc->dev, "Failed to deassert S/W Reset\n");
112 			goto sw_reset_fail;
113 		}
114 	}
115 
116 	if (ddata->config->pwr_reset) {
117 		err = reset_control_deassert(ddata->pwr_reset);
118 		if (err) {
119 			dev_err(&rproc->dev, "Failed to deassert Power Reset\n");
120 			goto pwr_reset_fail;
121 		}
122 	}
123 
124 	dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
125 
126 	return 0;
127 
128 
129 pwr_reset_fail:
130 	if (ddata->config->pwr_reset)
131 		reset_control_assert(ddata->sw_reset);
132 sw_reset_fail:
133 	clk_disable(ddata->clk);
134 
135 	return err;
136 }
137 
138 static int st_rproc_stop(struct rproc *rproc)
139 {
140 	struct st_rproc *ddata = rproc->priv;
141 	int sw_err = 0, pwr_err = 0;
142 
143 	if (ddata->config->sw_reset) {
144 		sw_err = reset_control_assert(ddata->sw_reset);
145 		if (sw_err)
146 			dev_err(&rproc->dev, "Failed to assert S/W Reset\n");
147 	}
148 
149 	if (ddata->config->pwr_reset) {
150 		pwr_err = reset_control_assert(ddata->pwr_reset);
151 		if (pwr_err)
152 			dev_err(&rproc->dev, "Failed to assert Power Reset\n");
153 	}
154 
155 	clk_disable(ddata->clk);
156 
157 	return sw_err ?: pwr_err;
158 }
159 
160 static const struct rproc_ops st_rproc_ops = {
161 	.kick		= st_rproc_kick,
162 	.start		= st_rproc_start,
163 	.stop		= st_rproc_stop,
164 };
165 
166 /*
167  * Fetch state of the processor: 0 is off, 1 is on.
168  */
169 static int st_rproc_state(struct platform_device *pdev)
170 {
171 	struct rproc *rproc = platform_get_drvdata(pdev);
172 	struct st_rproc *ddata = rproc->priv;
173 	int reset_sw = 0, reset_pwr = 0;
174 
175 	if (ddata->config->sw_reset)
176 		reset_sw = reset_control_status(ddata->sw_reset);
177 
178 	if (ddata->config->pwr_reset)
179 		reset_pwr = reset_control_status(ddata->pwr_reset);
180 
181 	if (reset_sw < 0 || reset_pwr < 0)
182 		return -EINVAL;
183 
184 	return !reset_sw && !reset_pwr;
185 }
186 
187 static const struct st_rproc_config st40_rproc_cfg = {
188 	.sw_reset = true,
189 	.pwr_reset = true,
190 	.bootaddr_mask = GENMASK(28, 1),
191 };
192 
193 static const struct st_rproc_config st231_rproc_cfg = {
194 	.sw_reset = true,
195 	.pwr_reset = false,
196 	.bootaddr_mask = GENMASK(31, 6),
197 };
198 
199 static const struct of_device_id st_rproc_match[] = {
200 	{ .compatible = "st,st40-rproc", .data = &st40_rproc_cfg },
201 	{ .compatible = "st,st231-rproc", .data = &st231_rproc_cfg },
202 	{},
203 };
204 MODULE_DEVICE_TABLE(of, st_rproc_match);
205 
206 static int st_rproc_parse_dt(struct platform_device *pdev)
207 {
208 	struct device *dev = &pdev->dev;
209 	struct rproc *rproc = platform_get_drvdata(pdev);
210 	struct st_rproc *ddata = rproc->priv;
211 	struct device_node *np = dev->of_node;
212 	int err;
213 
214 	if (ddata->config->sw_reset) {
215 		ddata->sw_reset = devm_reset_control_get_exclusive(dev,
216 								   "sw_reset");
217 		if (IS_ERR(ddata->sw_reset)) {
218 			dev_err(dev, "Failed to get S/W Reset\n");
219 			return PTR_ERR(ddata->sw_reset);
220 		}
221 	}
222 
223 	if (ddata->config->pwr_reset) {
224 		ddata->pwr_reset = devm_reset_control_get_exclusive(dev,
225 								    "pwr_reset");
226 		if (IS_ERR(ddata->pwr_reset)) {
227 			dev_err(dev, "Failed to get Power Reset\n");
228 			return PTR_ERR(ddata->pwr_reset);
229 		}
230 	}
231 
232 	ddata->clk = devm_clk_get(dev, NULL);
233 	if (IS_ERR(ddata->clk)) {
234 		dev_err(dev, "Failed to get clock\n");
235 		return PTR_ERR(ddata->clk);
236 	}
237 
238 	err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
239 	if (err) {
240 		dev_err(dev, "failed to get clock frequency\n");
241 		return err;
242 	}
243 
244 	ddata->boot_base = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
245 	if (IS_ERR(ddata->boot_base)) {
246 		dev_err(dev, "Boot base not found\n");
247 		return PTR_ERR(ddata->boot_base);
248 	}
249 
250 	err = of_property_read_u32_index(np, "st,syscfg", 1,
251 					 &ddata->boot_offset);
252 	if (err) {
253 		dev_err(dev, "Boot offset not found\n");
254 		return -EINVAL;
255 	}
256 
257 	err = of_reserved_mem_device_init(dev);
258 	if (err) {
259 		dev_err(dev, "Failed to obtain shared memory\n");
260 		return err;
261 	}
262 
263 	err = clk_prepare(ddata->clk);
264 	if (err)
265 		dev_err(dev, "failed to get clock\n");
266 
267 	return err;
268 }
269 
270 static int st_rproc_probe(struct platform_device *pdev)
271 {
272 	struct device *dev = &pdev->dev;
273 	const struct of_device_id *match;
274 	struct st_rproc *ddata;
275 	struct device_node *np = dev->of_node;
276 	struct rproc *rproc;
277 	struct mbox_chan *chan;
278 	int enabled;
279 	int ret, i;
280 
281 	match = of_match_device(st_rproc_match, dev);
282 	if (!match || !match->data) {
283 		dev_err(dev, "No device match found\n");
284 		return -ENODEV;
285 	}
286 
287 	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
288 	if (!rproc)
289 		return -ENOMEM;
290 
291 	rproc->has_iommu = false;
292 	ddata = rproc->priv;
293 	ddata->config = (struct st_rproc_config *)match->data;
294 
295 	platform_set_drvdata(pdev, rproc);
296 
297 	ret = st_rproc_parse_dt(pdev);
298 	if (ret)
299 		goto free_rproc;
300 
301 	enabled = st_rproc_state(pdev);
302 	if (enabled < 0) {
303 		ret = enabled;
304 		goto free_clk;
305 	}
306 
307 	if (enabled) {
308 		atomic_inc(&rproc->power);
309 		rproc->state = RPROC_RUNNING;
310 	} else {
311 		clk_set_rate(ddata->clk, ddata->clk_rate);
312 	}
313 
314 	if (of_get_property(np, "mbox-names", NULL)) {
315 		ddata->mbox_client_vq0.dev		= dev;
316 		ddata->mbox_client_vq0.tx_done		= NULL;
317 		ddata->mbox_client_vq0.tx_block	= false;
318 		ddata->mbox_client_vq0.knows_txdone	= false;
319 		ddata->mbox_client_vq0.rx_callback	= st_rproc_mbox_callback_vq0;
320 
321 		ddata->mbox_client_vq1.dev		= dev;
322 		ddata->mbox_client_vq1.tx_done		= NULL;
323 		ddata->mbox_client_vq1.tx_block	= false;
324 		ddata->mbox_client_vq1.knows_txdone	= false;
325 		ddata->mbox_client_vq1.rx_callback	= st_rproc_mbox_callback_vq1;
326 
327 		/*
328 		 * To control a co-processor without IPC mechanism.
329 		 * This driver can be used without mbox and rpmsg.
330 		 */
331 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_rx");
332 		if (IS_ERR(chan)) {
333 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
334 			ret = PTR_ERR(chan);
335 			goto free_clk;
336 		}
337 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_RX] = chan;
338 
339 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_tx");
340 		if (IS_ERR(chan)) {
341 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
342 			ret = PTR_ERR(chan);
343 			goto free_mbox;
344 		}
345 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_TX] = chan;
346 
347 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_rx");
348 		if (IS_ERR(chan)) {
349 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
350 			ret = PTR_ERR(chan);
351 			goto free_mbox;
352 		}
353 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_RX] = chan;
354 
355 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_tx");
356 		if (IS_ERR(chan)) {
357 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
358 			ret = PTR_ERR(chan);
359 			goto free_mbox;
360 		}
361 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_TX] = chan;
362 	}
363 
364 	ret = rproc_add(rproc);
365 	if (ret)
366 		goto free_mbox;
367 
368 	return 0;
369 
370 free_mbox:
371 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
372 		mbox_free_channel(ddata->mbox_chan[i]);
373 free_clk:
374 	clk_unprepare(ddata->clk);
375 free_rproc:
376 	rproc_free(rproc);
377 	return ret;
378 }
379 
380 static int st_rproc_remove(struct platform_device *pdev)
381 {
382 	struct rproc *rproc = platform_get_drvdata(pdev);
383 	struct st_rproc *ddata = rproc->priv;
384 	int i;
385 
386 	rproc_del(rproc);
387 
388 	clk_disable_unprepare(ddata->clk);
389 
390 	of_reserved_mem_device_release(&pdev->dev);
391 
392 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
393 		mbox_free_channel(ddata->mbox_chan[i]);
394 
395 	rproc_free(rproc);
396 
397 	return 0;
398 }
399 
400 static struct platform_driver st_rproc_driver = {
401 	.probe = st_rproc_probe,
402 	.remove = st_rproc_remove,
403 	.driver = {
404 		.name = "st-rproc",
405 		.of_match_table = of_match_ptr(st_rproc_match),
406 	},
407 };
408 module_platform_driver(st_rproc_driver);
409 
410 MODULE_DESCRIPTION("ST Remote Processor Control Driver");
411 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
412 MODULE_LICENSE("GPL v2");
413