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(dev, "sw_reset");
216 		if (IS_ERR(ddata->sw_reset)) {
217 			dev_err(dev, "Failed to get S/W Reset\n");
218 			return PTR_ERR(ddata->sw_reset);
219 		}
220 	}
221 
222 	if (ddata->config->pwr_reset) {
223 		ddata->pwr_reset = devm_reset_control_get(dev, "pwr_reset");
224 		if (IS_ERR(ddata->pwr_reset)) {
225 			dev_err(dev, "Failed to get Power Reset\n");
226 			return PTR_ERR(ddata->pwr_reset);
227 		}
228 	}
229 
230 	ddata->clk = devm_clk_get(dev, NULL);
231 	if (IS_ERR(ddata->clk)) {
232 		dev_err(dev, "Failed to get clock\n");
233 		return PTR_ERR(ddata->clk);
234 	}
235 
236 	err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
237 	if (err) {
238 		dev_err(dev, "failed to get clock frequency\n");
239 		return err;
240 	}
241 
242 	ddata->boot_base = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
243 	if (IS_ERR(ddata->boot_base)) {
244 		dev_err(dev, "Boot base not found\n");
245 		return PTR_ERR(ddata->boot_base);
246 	}
247 
248 	err = of_property_read_u32_index(np, "st,syscfg", 1,
249 					 &ddata->boot_offset);
250 	if (err) {
251 		dev_err(dev, "Boot offset not found\n");
252 		return -EINVAL;
253 	}
254 
255 	err = of_reserved_mem_device_init(dev);
256 	if (err) {
257 		dev_err(dev, "Failed to obtain shared memory\n");
258 		return err;
259 	}
260 
261 	err = clk_prepare(ddata->clk);
262 	if (err)
263 		dev_err(dev, "failed to get clock\n");
264 
265 	return err;
266 }
267 
268 static int st_rproc_probe(struct platform_device *pdev)
269 {
270 	struct device *dev = &pdev->dev;
271 	const struct of_device_id *match;
272 	struct st_rproc *ddata;
273 	struct device_node *np = dev->of_node;
274 	struct rproc *rproc;
275 	struct mbox_chan *chan;
276 	int enabled;
277 	int ret, i;
278 
279 	match = of_match_device(st_rproc_match, dev);
280 	if (!match || !match->data) {
281 		dev_err(dev, "No device match found\n");
282 		return -ENODEV;
283 	}
284 
285 	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
286 	if (!rproc)
287 		return -ENOMEM;
288 
289 	rproc->has_iommu = false;
290 	ddata = rproc->priv;
291 	ddata->config = (struct st_rproc_config *)match->data;
292 
293 	platform_set_drvdata(pdev, rproc);
294 
295 	ret = st_rproc_parse_dt(pdev);
296 	if (ret)
297 		goto free_rproc;
298 
299 	enabled = st_rproc_state(pdev);
300 	if (enabled < 0) {
301 		ret = enabled;
302 		goto free_clk;
303 	}
304 
305 	if (enabled) {
306 		atomic_inc(&rproc->power);
307 		rproc->state = RPROC_RUNNING;
308 	} else {
309 		clk_set_rate(ddata->clk, ddata->clk_rate);
310 	}
311 
312 	if (of_get_property(np, "mbox-names", NULL)) {
313 		ddata->mbox_client_vq0.dev		= dev;
314 		ddata->mbox_client_vq0.tx_done		= NULL;
315 		ddata->mbox_client_vq0.tx_block	= false;
316 		ddata->mbox_client_vq0.knows_txdone	= false;
317 		ddata->mbox_client_vq0.rx_callback	= st_rproc_mbox_callback_vq0;
318 
319 		ddata->mbox_client_vq1.dev		= dev;
320 		ddata->mbox_client_vq1.tx_done		= NULL;
321 		ddata->mbox_client_vq1.tx_block	= false;
322 		ddata->mbox_client_vq1.knows_txdone	= false;
323 		ddata->mbox_client_vq1.rx_callback	= st_rproc_mbox_callback_vq1;
324 
325 		/*
326 		 * To control a co-processor without IPC mechanism.
327 		 * This driver can be used without mbox and rpmsg.
328 		 */
329 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_rx");
330 		if (IS_ERR(chan)) {
331 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
332 			ret = PTR_ERR(chan);
333 			goto free_clk;
334 		}
335 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_RX] = chan;
336 
337 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_tx");
338 		if (IS_ERR(chan)) {
339 			dev_err(&rproc->dev, "failed to request mbox chan 0\n");
340 			ret = PTR_ERR(chan);
341 			goto free_mbox;
342 		}
343 		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_TX] = chan;
344 
345 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_rx");
346 		if (IS_ERR(chan)) {
347 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
348 			ret = PTR_ERR(chan);
349 			goto free_mbox;
350 		}
351 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_RX] = chan;
352 
353 		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_tx");
354 		if (IS_ERR(chan)) {
355 			dev_err(&rproc->dev, "failed to request mbox chan 1\n");
356 			ret = PTR_ERR(chan);
357 			goto free_mbox;
358 		}
359 		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_TX] = chan;
360 	}
361 
362 	ret = rproc_add(rproc);
363 	if (ret)
364 		goto free_mbox;
365 
366 	return 0;
367 
368 free_mbox:
369 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
370 		mbox_free_channel(ddata->mbox_chan[i]);
371 free_clk:
372 	clk_unprepare(ddata->clk);
373 free_rproc:
374 	rproc_free(rproc);
375 	return ret;
376 }
377 
378 static int st_rproc_remove(struct platform_device *pdev)
379 {
380 	struct rproc *rproc = platform_get_drvdata(pdev);
381 	struct st_rproc *ddata = rproc->priv;
382 	int i;
383 
384 	rproc_del(rproc);
385 
386 	clk_disable_unprepare(ddata->clk);
387 
388 	of_reserved_mem_device_release(&pdev->dev);
389 
390 	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
391 		mbox_free_channel(ddata->mbox_chan[i]);
392 
393 	rproc_free(rproc);
394 
395 	return 0;
396 }
397 
398 static struct platform_driver st_rproc_driver = {
399 	.probe = st_rproc_probe,
400 	.remove = st_rproc_remove,
401 	.driver = {
402 		.name = "st-rproc",
403 		.of_match_table = of_match_ptr(st_rproc_match),
404 	},
405 };
406 module_platform_driver(st_rproc_driver);
407 
408 MODULE_DESCRIPTION("ST Remote Processor Control Driver");
409 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
410 MODULE_LICENSE("GPL v2");
411