1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2016-2017, Linaro Ltd
4 */
5
6 #include <linux/idr.h>
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/list.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <linux/of_irq.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/rpmsg.h>
18 #include <linux/slab.h>
19 #include <linux/workqueue.h>
20 #include <linux/mailbox_client.h>
21
22 #include "rpmsg_internal.h"
23 #include "qcom_glink_native.h"
24
25 #define RPM_TOC_SIZE 256
26 #define RPM_TOC_MAGIC 0x67727430 /* grt0 */
27 #define RPM_TOC_MAX_ENTRIES ((RPM_TOC_SIZE - sizeof(struct rpm_toc)) / \
28 sizeof(struct rpm_toc_entry))
29
30 #define RPM_TX_FIFO_ID 0x61703272 /* ap2r */
31 #define RPM_RX_FIFO_ID 0x72326170 /* r2ap */
32
33 #define to_rpm_pipe(p) container_of(p, struct glink_rpm_pipe, native)
34
35 struct rpm_toc_entry {
36 __le32 id;
37 __le32 offset;
38 __le32 size;
39 } __packed;
40
41 struct rpm_toc {
42 __le32 magic;
43 __le32 count;
44
45 struct rpm_toc_entry entries[];
46 } __packed;
47
48 struct glink_rpm_pipe {
49 struct qcom_glink_pipe native;
50
51 void __iomem *tail;
52 void __iomem *head;
53
54 void __iomem *fifo;
55 };
56
57 struct glink_rpm {
58 struct qcom_glink *glink;
59
60 int irq;
61
62 struct mbox_client mbox_client;
63 struct mbox_chan *mbox_chan;
64
65 struct glink_rpm_pipe rx_pipe;
66 struct glink_rpm_pipe tx_pipe;
67 };
68
glink_rpm_rx_avail(struct qcom_glink_pipe * glink_pipe)69 static size_t glink_rpm_rx_avail(struct qcom_glink_pipe *glink_pipe)
70 {
71 struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
72 unsigned int head;
73 unsigned int tail;
74
75 head = readl(pipe->head);
76 tail = readl(pipe->tail);
77
78 if (head < tail)
79 return pipe->native.length - tail + head;
80 else
81 return head - tail;
82 }
83
glink_rpm_rx_peek(struct qcom_glink_pipe * glink_pipe,void * data,unsigned int offset,size_t count)84 static void glink_rpm_rx_peek(struct qcom_glink_pipe *glink_pipe,
85 void *data, unsigned int offset, size_t count)
86 {
87 struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
88 unsigned int tail;
89 size_t len;
90
91 tail = readl(pipe->tail);
92 tail += offset;
93 if (tail >= pipe->native.length)
94 tail -= pipe->native.length;
95
96 len = min_t(size_t, count, pipe->native.length - tail);
97 if (len) {
98 __ioread32_copy(data, pipe->fifo + tail,
99 len / sizeof(u32));
100 }
101
102 if (len != count) {
103 __ioread32_copy(data + len, pipe->fifo,
104 (count - len) / sizeof(u32));
105 }
106 }
107
glink_rpm_rx_advance(struct qcom_glink_pipe * glink_pipe,size_t count)108 static void glink_rpm_rx_advance(struct qcom_glink_pipe *glink_pipe,
109 size_t count)
110 {
111 struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
112 unsigned int tail;
113
114 tail = readl(pipe->tail);
115
116 tail += count;
117 if (tail >= pipe->native.length)
118 tail -= pipe->native.length;
119
120 writel(tail, pipe->tail);
121 }
122
glink_rpm_tx_avail(struct qcom_glink_pipe * glink_pipe)123 static size_t glink_rpm_tx_avail(struct qcom_glink_pipe *glink_pipe)
124 {
125 struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
126 unsigned int head;
127 unsigned int tail;
128
129 head = readl(pipe->head);
130 tail = readl(pipe->tail);
131
132 if (tail <= head)
133 return pipe->native.length - head + tail;
134 else
135 return tail - head;
136 }
137
glink_rpm_tx_write_one(struct glink_rpm_pipe * pipe,unsigned int head,const void * data,size_t count)138 static unsigned int glink_rpm_tx_write_one(struct glink_rpm_pipe *pipe,
139 unsigned int head,
140 const void *data, size_t count)
141 {
142 size_t len;
143
144 len = min_t(size_t, count, pipe->native.length - head);
145 if (len) {
146 __iowrite32_copy(pipe->fifo + head, data,
147 len / sizeof(u32));
148 }
149
150 if (len != count) {
151 __iowrite32_copy(pipe->fifo, data + len,
152 (count - len) / sizeof(u32));
153 }
154
155 head += count;
156 if (head >= pipe->native.length)
157 head -= pipe->native.length;
158
159 return head;
160 }
161
glink_rpm_tx_write(struct qcom_glink_pipe * glink_pipe,const void * hdr,size_t hlen,const void * data,size_t dlen)162 static void glink_rpm_tx_write(struct qcom_glink_pipe *glink_pipe,
163 const void *hdr, size_t hlen,
164 const void *data, size_t dlen)
165 {
166 struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
167 size_t tlen = hlen + dlen;
168 size_t aligned_dlen;
169 unsigned int head;
170 char padding[8] = {0};
171 size_t pad;
172
173 /* Header length comes from glink native and is always 4 byte aligned */
174 if (WARN(hlen % 4, "Glink Header length must be 4 bytes aligned\n"))
175 return;
176
177 /*
178 * Move the unaligned tail of the message to the padding chunk, to
179 * ensure word aligned accesses
180 */
181 aligned_dlen = ALIGN_DOWN(dlen, 4);
182 if (aligned_dlen != dlen)
183 memcpy(padding, data + aligned_dlen, dlen - aligned_dlen);
184
185 head = readl(pipe->head);
186 head = glink_rpm_tx_write_one(pipe, head, hdr, hlen);
187 head = glink_rpm_tx_write_one(pipe, head, data, aligned_dlen);
188
189 pad = ALIGN(tlen, 8) - ALIGN_DOWN(tlen, 4);
190 if (pad)
191 head = glink_rpm_tx_write_one(pipe, head, padding, pad);
192 writel(head, pipe->head);
193 }
194
glink_rpm_tx_kick(struct qcom_glink_pipe * glink_pipe)195 static void glink_rpm_tx_kick(struct qcom_glink_pipe *glink_pipe)
196 {
197 struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
198 struct glink_rpm *rpm = container_of(pipe, struct glink_rpm, tx_pipe);
199
200 mbox_send_message(rpm->mbox_chan, NULL);
201 mbox_client_txdone(rpm->mbox_chan, 0);
202 }
203
qcom_glink_rpm_intr(int irq,void * data)204 static irqreturn_t qcom_glink_rpm_intr(int irq, void *data)
205 {
206 struct glink_rpm *rpm = data;
207
208 qcom_glink_native_rx(rpm->glink);
209
210 return IRQ_HANDLED;
211 }
212
glink_rpm_parse_toc(struct device * dev,void __iomem * msg_ram,size_t msg_ram_size,struct glink_rpm_pipe * rx,struct glink_rpm_pipe * tx)213 static int glink_rpm_parse_toc(struct device *dev,
214 void __iomem *msg_ram,
215 size_t msg_ram_size,
216 struct glink_rpm_pipe *rx,
217 struct glink_rpm_pipe *tx)
218 {
219 struct rpm_toc *toc;
220 int num_entries;
221 unsigned int id;
222 size_t offset;
223 size_t size;
224 void *buf;
225 int i;
226
227 buf = kzalloc(RPM_TOC_SIZE, GFP_KERNEL);
228 if (!buf)
229 return -ENOMEM;
230
231 __ioread32_copy(buf, msg_ram + msg_ram_size - RPM_TOC_SIZE,
232 RPM_TOC_SIZE / sizeof(u32));
233
234 toc = buf;
235
236 if (le32_to_cpu(toc->magic) != RPM_TOC_MAGIC) {
237 dev_err(dev, "RPM TOC has invalid magic\n");
238 goto err_inval;
239 }
240
241 num_entries = le32_to_cpu(toc->count);
242 if (num_entries > RPM_TOC_MAX_ENTRIES) {
243 dev_err(dev, "Invalid number of toc entries\n");
244 goto err_inval;
245 }
246
247 for (i = 0; i < num_entries; i++) {
248 id = le32_to_cpu(toc->entries[i].id);
249 offset = le32_to_cpu(toc->entries[i].offset);
250 size = le32_to_cpu(toc->entries[i].size);
251
252 if (offset > msg_ram_size || offset + size > msg_ram_size) {
253 dev_err(dev, "TOC entry with invalid size\n");
254 continue;
255 }
256
257 switch (id) {
258 case RPM_RX_FIFO_ID:
259 rx->native.length = size;
260
261 rx->tail = msg_ram + offset;
262 rx->head = msg_ram + offset + sizeof(u32);
263 rx->fifo = msg_ram + offset + 2 * sizeof(u32);
264 break;
265 case RPM_TX_FIFO_ID:
266 tx->native.length = size;
267
268 tx->tail = msg_ram + offset;
269 tx->head = msg_ram + offset + sizeof(u32);
270 tx->fifo = msg_ram + offset + 2 * sizeof(u32);
271 break;
272 }
273 }
274
275 if (!rx->fifo || !tx->fifo) {
276 dev_err(dev, "Unable to find rx and tx descriptors\n");
277 goto err_inval;
278 }
279
280 kfree(buf);
281 return 0;
282
283 err_inval:
284 kfree(buf);
285 return -EINVAL;
286 }
287
glink_rpm_probe(struct platform_device * pdev)288 static int glink_rpm_probe(struct platform_device *pdev)
289 {
290 struct qcom_glink *glink;
291 struct glink_rpm *rpm;
292 struct device_node *np;
293 void __iomem *msg_ram;
294 size_t msg_ram_size;
295 struct device *dev = &pdev->dev;
296 struct resource r;
297 int ret;
298
299 rpm = devm_kzalloc(&pdev->dev, sizeof(*rpm), GFP_KERNEL);
300 if (!rpm)
301 return -ENOMEM;
302
303 np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", 0);
304 ret = of_address_to_resource(np, 0, &r);
305 of_node_put(np);
306 if (ret)
307 return ret;
308
309 msg_ram = devm_ioremap(dev, r.start, resource_size(&r));
310 msg_ram_size = resource_size(&r);
311 if (!msg_ram)
312 return -ENOMEM;
313
314 ret = glink_rpm_parse_toc(dev, msg_ram, msg_ram_size,
315 &rpm->rx_pipe, &rpm->tx_pipe);
316 if (ret)
317 return ret;
318
319 rpm->irq = of_irq_get(dev->of_node, 0);
320 ret = devm_request_irq(dev, rpm->irq, qcom_glink_rpm_intr,
321 IRQF_NO_SUSPEND | IRQF_NO_AUTOEN,
322 "glink-rpm", rpm);
323 if (ret) {
324 dev_err(dev, "failed to request IRQ\n");
325 return ret;
326 }
327
328 rpm->mbox_client.dev = dev;
329 rpm->mbox_client.knows_txdone = true;
330 rpm->mbox_chan = mbox_request_channel(&rpm->mbox_client, 0);
331 if (IS_ERR(rpm->mbox_chan))
332 return dev_err_probe(dev, PTR_ERR(rpm->mbox_chan), "failed to acquire IPC channel\n");
333
334 /* Pipe specific accessors */
335 rpm->rx_pipe.native.avail = glink_rpm_rx_avail;
336 rpm->rx_pipe.native.peek = glink_rpm_rx_peek;
337 rpm->rx_pipe.native.advance = glink_rpm_rx_advance;
338 rpm->tx_pipe.native.avail = glink_rpm_tx_avail;
339 rpm->tx_pipe.native.write = glink_rpm_tx_write;
340 rpm->tx_pipe.native.kick = glink_rpm_tx_kick;
341
342 writel(0, rpm->tx_pipe.head);
343 writel(0, rpm->rx_pipe.tail);
344
345 glink = qcom_glink_native_probe(dev,
346 0,
347 &rpm->rx_pipe.native,
348 &rpm->tx_pipe.native,
349 true);
350 if (IS_ERR(glink)) {
351 mbox_free_channel(rpm->mbox_chan);
352 return PTR_ERR(glink);
353 }
354
355 rpm->glink = glink;
356
357 platform_set_drvdata(pdev, rpm);
358
359 enable_irq(rpm->irq);
360
361 return 0;
362 }
363
glink_rpm_remove(struct platform_device * pdev)364 static void glink_rpm_remove(struct platform_device *pdev)
365 {
366 struct glink_rpm *rpm = platform_get_drvdata(pdev);
367 struct qcom_glink *glink = rpm->glink;
368
369 disable_irq(rpm->irq);
370
371 qcom_glink_native_remove(glink);
372
373 mbox_free_channel(rpm->mbox_chan);
374 }
375
376 static const struct of_device_id glink_rpm_of_match[] = {
377 { .compatible = "qcom,glink-rpm" },
378 {}
379 };
380 MODULE_DEVICE_TABLE(of, glink_rpm_of_match);
381
382 static struct platform_driver glink_rpm_driver = {
383 .probe = glink_rpm_probe,
384 .remove = glink_rpm_remove,
385 .driver = {
386 .name = "qcom_glink_rpm",
387 .of_match_table = glink_rpm_of_match,
388 },
389 };
390
glink_rpm_init(void)391 static int __init glink_rpm_init(void)
392 {
393 return platform_driver_register(&glink_rpm_driver);
394 }
395 subsys_initcall(glink_rpm_init);
396
glink_rpm_exit(void)397 static void __exit glink_rpm_exit(void)
398 {
399 platform_driver_unregister(&glink_rpm_driver);
400 }
401 module_exit(glink_rpm_exit);
402
403 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
404 MODULE_DESCRIPTION("Qualcomm GLINK RPM driver");
405 MODULE_LICENSE("GPL v2");
406