1 /*
2 * Driver for the NXP SAA7164 PCIe bridge
3 *
4 * Copyright (c) 2010 Steven Toth <stoth@kernellabs.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 *
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22 #include "saa7164.h"
23
24 /* The message bus to/from the firmware is a ring buffer in PCI address
25 * space. Establish the defaults.
26 */
saa7164_bus_setup(struct saa7164_dev * dev)27 int saa7164_bus_setup(struct saa7164_dev *dev)
28 {
29 struct tmComResBusInfo *b = &dev->bus;
30
31 mutex_init(&b->lock);
32
33 b->Type = TYPE_BUS_PCIe;
34 b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE;
35
36 b->m_pdwSetRing = (u8 *)(dev->bmmio +
37 ((u32)dev->busdesc.CommandRing));
38
39 b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
40
41 b->m_pdwGetRing = (u8 *)(dev->bmmio +
42 ((u32)dev->busdesc.ResponseRing));
43
44 b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE;
45
46 b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) +
47 (2 * sizeof(u64));
48 b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32));
49
50 b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32));
51 b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32));
52
53 return 0;
54 }
55
saa7164_bus_dump(struct saa7164_dev * dev)56 void saa7164_bus_dump(struct saa7164_dev *dev)
57 {
58 struct tmComResBusInfo *b = &dev->bus;
59
60 dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
61 dprintk(DBGLVL_BUS, " .type = %d\n", b->Type);
62 dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio);
63 dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize);
64 dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing);
65 dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing);
66 dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing);
67 dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing);
68
69 dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n",
70 b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));
71
72 dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n",
73 b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));
74
75 dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n",
76 b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));
77
78 dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n",
79 b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
80
81 }
82
83 /* Intensionally throw a BUG() if the state of the message bus looks corrupt */
saa7164_bus_verify(struct saa7164_dev * dev)84 void saa7164_bus_verify(struct saa7164_dev *dev)
85 {
86 struct tmComResBusInfo *b = &dev->bus;
87 int bug = 0;
88
89 if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
90 bug++;
91
92 if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
93 bug++;
94
95 if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
96 bug++;
97
98 if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
99 bug++;
100
101 if (bug) {
102 saa_debug = 0xffff; /* Ensure we get the bus dump */
103 saa7164_bus_dump(dev);
104 saa_debug = 1024; /* Ensure we get the bus dump */
105 BUG();
106 }
107 }
108
saa7164_bus_dumpmsg(struct saa7164_dev * dev,struct tmComResInfo * m,void * buf)109 void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo* m,
110 void *buf)
111 {
112 dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
113 dprintk(DBGLVL_BUS, " .id = %d\n", m->id);
114 dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags);
115 dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size);
116 dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command);
117 dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector);
118 dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno);
119 if (buf)
120 dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
121 }
122
123 /*
124 * Places a command or a response on the bus. The implementation does not
125 * know if it is a command or a response it just places the data on the
126 * bus depending on the bus information given in the struct tmComResBusInfo
127 * structure. If the command or response does not fit into the bus ring
128 * buffer it will be refused.
129 *
130 * Return Value:
131 * SAA_OK The function executed successfully.
132 * < 0 One or more members are not initialized.
133 */
saa7164_bus_set(struct saa7164_dev * dev,struct tmComResInfo * msg,void * buf)134 int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg,
135 void *buf)
136 {
137 struct tmComResBusInfo *bus = &dev->bus;
138 u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
139 u32 new_swp, space_rem;
140 int ret = SAA_ERR_BAD_PARAMETER;
141
142 if (!msg) {
143 printk(KERN_ERR "%s() !msg\n", __func__);
144 return SAA_ERR_BAD_PARAMETER;
145 }
146
147 dprintk(DBGLVL_BUS, "%s()\n", __func__);
148
149 saa7164_bus_verify(dev);
150
151 msg->size = cpu_to_le16(msg->size);
152 msg->command = cpu_to_le16(msg->command);
153 msg->controlselector = cpu_to_le16(msg->controlselector);
154
155 if (msg->size > dev->bus.m_wMaxReqSize) {
156 printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
157 __func__);
158 return SAA_ERR_BAD_PARAMETER;
159 }
160
161 if ((msg->size > 0) && (buf == NULL)) {
162 printk(KERN_ERR "%s() Missing message buffer\n", __func__);
163 return SAA_ERR_BAD_PARAMETER;
164 }
165
166 /* Lock the bus from any other access */
167 mutex_lock(&bus->lock);
168
169 bytes_to_write = sizeof(*msg) + msg->size;
170 free_write_space = 0;
171 timeout = SAA_BUS_TIMEOUT;
172 curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
173 curr_swp = le32_to_cpu(saa7164_readl(bus->m_dwSetWritePos));
174
175 /* Deal with ring wrapping issues */
176 if (curr_srp > curr_swp)
177 /* Deal with the wrapped ring */
178 free_write_space = curr_srp - curr_swp;
179 else
180 /* The ring has not wrapped yet */
181 free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
182
183 dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
184 bytes_to_write);
185
186 dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
187 free_write_space);
188
189 dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
190 dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);
191
192 /* Process the msg and write the content onto the bus */
193 while (bytes_to_write >= free_write_space) {
194
195 if (timeout-- == 0) {
196 printk(KERN_ERR "%s() bus timeout\n", __func__);
197 ret = SAA_ERR_NO_RESOURCES;
198 goto out;
199 }
200
201 /* TODO: Review this delay, efficient? */
202 /* Wait, allowing the hardware fetch time */
203 mdelay(1);
204
205 /* Check the space usage again */
206 curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
207
208 /* Deal with ring wrapping issues */
209 if (curr_srp > curr_swp)
210 /* Deal with the wrapped ring */
211 free_write_space = curr_srp - curr_swp;
212 else
213 /* Read didn't wrap around the buffer */
214 free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
215 curr_swp;
216
217 }
218
219 /* Calculate the new write position */
220 new_swp = curr_swp + bytes_to_write;
221
222 dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
223 dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
224 bus->m_dwSizeSetRing);
225
226 /* Mental Note: line 462 tmmhComResBusPCIe.cpp */
227
228 /* Check if we're going to wrap again */
229 if (new_swp > bus->m_dwSizeSetRing) {
230
231 /* Ring wraps */
232 new_swp -= bus->m_dwSizeSetRing;
233
234 space_rem = bus->m_dwSizeSetRing - curr_swp;
235
236 dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
237 space_rem);
238
239 dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
240 (u32)sizeof(*msg));
241
242 if (space_rem < sizeof(*msg)) {
243 dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);
244
245 /* Split the msg into pieces as the ring wraps */
246 memcpy(bus->m_pdwSetRing + curr_swp, msg, space_rem);
247 memcpy(bus->m_pdwSetRing, (u8 *)msg + space_rem,
248 sizeof(*msg) - space_rem);
249
250 memcpy(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
251 buf, msg->size);
252
253 } else if (space_rem == sizeof(*msg)) {
254 dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
255
256 /* Additional data at the beginning of the ring */
257 memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
258 memcpy(bus->m_pdwSetRing, buf, msg->size);
259
260 } else {
261 /* Additional data wraps around the ring */
262 memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
263 if (msg->size > 0) {
264 memcpy(bus->m_pdwSetRing + curr_swp +
265 sizeof(*msg), buf, space_rem -
266 sizeof(*msg));
267 memcpy(bus->m_pdwSetRing, (u8 *)buf +
268 space_rem - sizeof(*msg),
269 bytes_to_write - space_rem);
270 }
271
272 }
273
274 } /* (new_swp > bus->m_dwSizeSetRing) */
275 else {
276 dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);
277
278 /* The ring buffer doesn't wrap, two simple copies */
279 memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
280 memcpy(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
281 msg->size);
282 }
283
284 dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
285
286 /* Update the bus write position */
287 saa7164_writel(bus->m_dwSetWritePos, cpu_to_le32(new_swp));
288 ret = SAA_OK;
289
290 out:
291 saa7164_bus_dump(dev);
292 mutex_unlock(&bus->lock);
293 saa7164_bus_verify(dev);
294 return ret;
295 }
296
297 /*
298 * Receive a command or a response from the bus. The implementation does not
299 * know if it is a command or a response it simply dequeues the data,
300 * depending on the bus information given in the struct tmComResBusInfo
301 * structure.
302 *
303 * Return Value:
304 * 0 The function executed successfully.
305 * < 0 One or more members are not initialized.
306 */
saa7164_bus_get(struct saa7164_dev * dev,struct tmComResInfo * msg,void * buf,int peekonly)307 int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
308 void *buf, int peekonly)
309 {
310 struct tmComResBusInfo *bus = &dev->bus;
311 u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
312 new_grp, buf_size, space_rem;
313 struct tmComResInfo msg_tmp;
314 int ret = SAA_ERR_BAD_PARAMETER;
315
316 saa7164_bus_verify(dev);
317
318 if (msg == NULL)
319 return ret;
320
321 if (msg->size > dev->bus.m_wMaxReqSize) {
322 printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
323 __func__);
324 return ret;
325 }
326
327 if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) {
328 printk(KERN_ERR
329 "%s() Missing msg buf, size should be %d bytes\n",
330 __func__, msg->size);
331 return ret;
332 }
333
334 mutex_lock(&bus->lock);
335
336 /* Peek the bus to see if a msg exists, if it's not what we're expecting
337 * then return cleanly else read the message from the bus.
338 */
339 curr_gwp = le32_to_cpu(saa7164_readl(bus->m_dwGetWritePos));
340 curr_grp = le32_to_cpu(saa7164_readl(bus->m_dwGetReadPos));
341
342 if (curr_gwp == curr_grp) {
343 ret = SAA_ERR_EMPTY;
344 goto out;
345 }
346
347 bytes_to_read = sizeof(*msg);
348
349 /* Calculate write distance to current read position */
350 write_distance = 0;
351 if (curr_gwp >= curr_grp)
352 /* Write doesn't wrap around the ring */
353 write_distance = curr_gwp - curr_grp;
354 else
355 /* Write wraps around the ring */
356 write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
357
358 if (bytes_to_read > write_distance) {
359 printk(KERN_ERR "%s() No message/response found\n", __func__);
360 ret = SAA_ERR_INVALID_COMMAND;
361 goto out;
362 }
363
364 /* Calculate the new read position */
365 new_grp = curr_grp + bytes_to_read;
366 if (new_grp > bus->m_dwSizeGetRing) {
367
368 /* Ring wraps */
369 new_grp -= bus->m_dwSizeGetRing;
370 space_rem = bus->m_dwSizeGetRing - curr_grp;
371
372 memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
373 memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
374 bytes_to_read - space_rem);
375
376 } else {
377 /* No wrapping */
378 memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
379 }
380
381 /* No need to update the read positions, because this was a peek */
382 /* If the caller specifically want to peek, return */
383 if (peekonly) {
384 memcpy(msg, &msg_tmp, sizeof(*msg));
385 goto peekout;
386 }
387
388 /* Check if the command/response matches what is expected */
389 if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) ||
390 (msg_tmp.controlselector != msg->controlselector) ||
391 (msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) {
392
393 printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
394 saa7164_bus_dumpmsg(dev, msg, buf);
395 saa7164_bus_dumpmsg(dev, &msg_tmp, NULL);
396 ret = SAA_ERR_INVALID_COMMAND;
397 goto out;
398 }
399
400 /* Get the actual command and response from the bus */
401 buf_size = msg->size;
402
403 bytes_to_read = sizeof(*msg) + msg->size;
404 /* Calculate write distance to current read position */
405 write_distance = 0;
406 if (curr_gwp >= curr_grp)
407 /* Write doesn't wrap around the ring */
408 write_distance = curr_gwp - curr_grp;
409 else
410 /* Write wraps around the ring */
411 write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
412
413 if (bytes_to_read > write_distance) {
414 printk(KERN_ERR "%s() Invalid bus state, missing msg "
415 "or mangled ring, faulty H/W / bad code?\n", __func__);
416 ret = SAA_ERR_INVALID_COMMAND;
417 goto out;
418 }
419
420 /* Calculate the new read position */
421 new_grp = curr_grp + bytes_to_read;
422 if (new_grp > bus->m_dwSizeGetRing) {
423
424 /* Ring wraps */
425 new_grp -= bus->m_dwSizeGetRing;
426 space_rem = bus->m_dwSizeGetRing - curr_grp;
427
428 if (space_rem < sizeof(*msg)) {
429 /* msg wraps around the ring */
430 memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem);
431 memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing,
432 sizeof(*msg) - space_rem);
433 if (buf)
434 memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) -
435 space_rem, buf_size);
436
437 } else if (space_rem == sizeof(*msg)) {
438 memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
439 if (buf)
440 memcpy(buf, bus->m_pdwGetRing, buf_size);
441 } else {
442 /* Additional data wraps around the ring */
443 memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
444 if (buf) {
445 memcpy(buf, bus->m_pdwGetRing + curr_grp +
446 sizeof(*msg), space_rem - sizeof(*msg));
447 memcpy(buf + space_rem - sizeof(*msg),
448 bus->m_pdwGetRing, bytes_to_read -
449 space_rem);
450 }
451
452 }
453
454 } else {
455 /* No wrapping */
456 memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
457 if (buf)
458 memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
459 buf_size);
460 }
461
462 /* Update the read positions, adjusting the ring */
463 saa7164_writel(bus->m_dwGetReadPos, cpu_to_le32(new_grp));
464
465 peekout:
466 msg->size = le16_to_cpu(msg->size);
467 msg->command = le16_to_cpu(msg->command);
468 msg->controlselector = le16_to_cpu(msg->controlselector);
469 ret = SAA_OK;
470 out:
471 mutex_unlock(&bus->lock);
472 saa7164_bus_verify(dev);
473 return ret;
474 }
475
476