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
st_rproc_mbox_callback(struct device * dev,u32 msg)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
st_rproc_mbox_callback_vq0(struct mbox_client * mbox_client,void * data)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
st_rproc_mbox_callback_vq1(struct mbox_client * mbox_client,void * data)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
st_rproc_kick(struct rproc * rproc,int vqid)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
st_rproc_start(struct rproc * rproc)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
st_rproc_stop(struct rproc * rproc)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 */
st_rproc_state(struct platform_device * pdev)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
st_rproc_parse_dt(struct platform_device * pdev)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
st_rproc_probe(struct platform_device * pdev)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
st_rproc_remove(struct platform_device * pdev)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
