summaryrefslogtreecommitdiffstats
path: root/drivers/media/video/saa7164/saa7164-bus.c
blob: 466e1b02f91f42c38c9a8af77d0eb1f9794c55f5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
/*
 *  Driver for the NXP SAA7164 PCIe bridge
 *
 *  Copyright (c) 2010 Steven Toth <stoth@kernellabs.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "saa7164.h"

/* The message bus to/from the firmware is a ring buffer in PCI address
 * space. Establish the defaults.
 */
int saa7164_bus_setup(struct saa7164_dev *dev)
{
	struct tmComResBusInfo *b	= &dev->bus;

	mutex_init(&b->lock);

	b->Type			= TYPE_BUS_PCIe;
	b->m_wMaxReqSize	= SAA_DEVICE_MAXREQUESTSIZE;

	b->m_pdwSetRing		= (u8 *)(dev->bmmio +
		((u32)dev->busdesc.CommandRing));

	b->m_dwSizeSetRing	= SAA_DEVICE_BUFFERBLOCKSIZE;

	b->m_pdwGetRing		= (u8 *)(dev->bmmio +
		((u32)dev->busdesc.ResponseRing));

	b->m_dwSizeGetRing	= SAA_DEVICE_BUFFERBLOCKSIZE;

	b->m_dwSetWritePos	= ((u32)dev->intfdesc.BARLocation) +
		(2 * sizeof(u64));
	b->m_dwSetReadPos	= b->m_dwSetWritePos + (1 * sizeof(u32));

	b->m_dwGetWritePos	= b->m_dwSetWritePos + (2 * sizeof(u32));
	b->m_dwGetReadPos	= b->m_dwSetWritePos + (3 * sizeof(u32));

	return 0;
}

void saa7164_bus_dump(struct saa7164_dev *dev)
{
	struct tmComResBusInfo *b = &dev->bus;

	dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
	dprintk(DBGLVL_BUS, " .type             = %d\n", b->Type);
	dprintk(DBGLVL_BUS, " .dev->bmmio       = 0x%p\n", dev->bmmio);
	dprintk(DBGLVL_BUS, " .m_wMaxReqSize    = 0x%x\n", b->m_wMaxReqSize);
	dprintk(DBGLVL_BUS, " .m_pdwSetRing     = 0x%p\n", b->m_pdwSetRing);
	dprintk(DBGLVL_BUS, " .m_dwSizeSetRing  = 0x%x\n", b->m_dwSizeSetRing);
	dprintk(DBGLVL_BUS, " .m_pdwGetRing     = 0x%p\n", b->m_pdwGetRing);
	dprintk(DBGLVL_BUS, " .m_dwSizeGetRing  = 0x%x\n", b->m_dwSizeGetRing);

	dprintk(DBGLVL_BUS, " .m_dwSetReadPos   = 0x%x (0x%08x)\n",
		b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));

	dprintk(DBGLVL_BUS, " .m_dwSetWritePos  = 0x%x (0x%08x)\n",
		b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));

	dprintk(DBGLVL_BUS, " .m_dwGetReadPos   = 0x%x (0x%08x)\n",
		b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));

	dprintk(DBGLVL_BUS, " .m_dwGetWritePos  = 0x%x (0x%08x)\n",
		b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));

}

/* Intensionally throw a BUG() if the state of the message bus looks corrupt */
void saa7164_bus_verify(struct saa7164_dev *dev)
{
	struct tmComResBusInfo *b = &dev->bus;
	int bug = 0;

	if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
		bug++;

	if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
		bug++;

	if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
		bug++;

	if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
		bug++;

	if (bug) {
		saa_debug = 0xffff; /* Ensure we get the bus dump */
		saa7164_bus_dump(dev);
		saa_debug = 1024; /* Ensure we get the bus dump */
		BUG();
	}
}

void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo* m,
	void *buf)
{
	dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
	dprintk(DBGLVL_BUS, " .id               = %d\n",   m->id);
	dprintk(DBGLVL_BUS, " .flags            = 0x%x\n", m->flags);
	dprintk(DBGLVL_BUS, " .size             = 0x%x\n", m->size);
	dprintk(DBGLVL_BUS, " .command          = 0x%x\n", m->command);
	dprintk(DBGLVL_BUS, " .controlselector  = 0x%x\n", m->controlselector);
	dprintk(DBGLVL_BUS, " .seqno            = %d\n",   m->seqno);
	if (buf)
		dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
}

/*
 * Places a command or a response on the bus. The implementation does not
 * know if it is a command or a response it just places the data on the
 * bus depending on the bus information given in the struct tmComResBusInfo
 * structure. If the command or response does not fit into the bus ring
 * buffer it will be refused.
 *
 * Return Value:
 *  SAA_OK     The function executed successfully.
 *  < 0        One or more members are not initialized.
 */
int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg,
	void *buf)
{
	struct tmComResBusInfo *bus = &dev->bus;
	u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
	u32 new_swp, space_rem;
	int ret = SAA_ERR_BAD_PARAMETER;

	if (!msg) {
		printk(KERN_ERR "%s() !msg\n", __func__);
		return SAA_ERR_BAD_PARAMETER;
	}

	dprintk(DBGLVL_BUS, "%s()\n", __func__);

	saa7164_bus_verify(dev);

	msg->size = cpu_to_le16(msg->size);
	msg->command = cpu_to_le16(msg->command);
	msg->controlselector = cpu_to_le16(msg->controlselector);

	if (msg->size > dev->bus.m_wMaxReqSize) {
		printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
			__func__);
		return SAA_ERR_BAD_PARAMETER;
	}

	if ((msg->size > 0) && (buf == NULL)) {
		printk(KERN_ERR "%s() Missing message buffer\n", __func__);
		return SAA_ERR_BAD_PARAMETER;
	}

	/* Lock the bus from any other access */
	mutex_lock(&bus->lock);

	bytes_to_write = sizeof(*msg) + msg->size;
	free_write_space = 0;
	timeout = SAA_BUS_TIMEOUT;
	curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
	curr_swp = le32_to_cpu(saa7164_readl(bus->m_dwSetWritePos));

	/* Deal with ring wrapping issues */
	if (curr_srp > curr_swp)
		/* Deal with the wrapped ring */
		free_write_space = curr_srp - curr_swp;
	else
		/* The ring has not wrapped yet */
		free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;

	dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
		bytes_to_write);

	dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
		free_write_space);

	dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
	dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);

	/* Process the msg and write the content onto the bus */
	while (bytes_to_write >= free_write_space) {

		if (timeout-- == 0) {
			printk(KERN_ERR "%s() bus timeout\n", __func__);
			ret = SAA_ERR_NO_RESOURCES;
			goto out;
		}

		/* TODO: Review this delay, efficient? */
		/* Wait, allowing the hardware fetch time */
		mdelay(1);

		/* Check the space usage again */
		curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));

		/* Deal with ring wrapping issues */
		if (curr_srp > curr_swp)
			/* Deal with the wrapped ring */
			free_write_space = curr_srp - curr_swp;
		else
			/* Read didn't wrap around the buffer */
			free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
				curr_swp;

	}

	/* Calculate the new write position */
	new_swp = curr_swp + bytes_to_write;

	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
	dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
		bus->m_dwSizeSetRing);

	/* Mental Note: line 462 tmmhComResBusPCIe.cpp */

	/* Check if we're going to wrap again */
	if (new_swp > bus->m_dwSizeSetRing) {

		/* Ring wraps */
		new_swp -= bus->m_dwSizeSetRing;

		space_rem = bus->m_dwSizeSetRing - curr_swp;

		dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
			space_rem);

		dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
			(u32)sizeof(*msg));

		if (space_rem < sizeof(*msg)) {
			dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);

			/* Split the msg into pieces as the ring wraps */
			memcpy(bus->m_pdwSetRing + curr_swp, msg, space_rem);
			memcpy(bus->m_pdwSetRing, (u8 *)msg + space_rem,
				sizeof(*msg) - space_rem);

			memcpy(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
				buf, msg->size);

		} else if (space_rem == sizeof(*msg)) {
			dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);

			/* Additional data at the beginning of the ring */
			memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
			memcpy(bus->m_pdwSetRing, buf, msg->size);

		} else {
			/* Additional data wraps around the ring */
			memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
			if (msg->size > 0) {
				memcpy(bus->m_pdwSetRing + curr_swp +
					sizeof(*msg), buf, space_rem -
					sizeof(*msg));
				memcpy(bus->m_pdwSetRing, (u8 *)buf +
					space_rem - sizeof(*msg),
					bytes_to_write - space_rem);
			}

		}

	} /* (new_swp > bus->m_dwSizeSetRing) */
	else {
		dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);

		/* The ring buffer doesn't wrap, two simple copies */
		memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
		memcpy(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
			msg->size);
	}

	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);

	/* Update the bus write position */
	saa7164_writel(bus->m_dwSetWritePos, cpu_to_le32(new_swp));
	ret = SAA_OK;

out:
	saa7164_bus_dump(dev);
	mutex_unlock(&bus->lock);
	saa7164_bus_verify(dev);
	return ret;
}

/*
 * Receive a command or a response from the bus. The implementation does not
 * know if it is a command or a response it simply dequeues the data,
 * depending on the bus information given in the struct tmComResBusInfo
 * structure.
 *
 * Return Value:
 *  0          The function executed successfully.
 *  < 0        One or more members are not initialized.
 */
int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
	void *buf, int peekonly)
{
	struct tmComResBusInfo *bus = &dev->bus;
	u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
		new_grp, buf_size, space_rem;
	struct tmComResInfo msg_tmp;
	int ret = SAA_ERR_BAD_PARAMETER;

	saa7164_bus_verify(dev);

	if (msg == NULL)
		return ret;

	if (msg->size > dev->bus.m_wMaxReqSize) {
		printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
			__func__);
		return ret;
	}

	if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) {
		printk(KERN_ERR
			"%s() Missing msg buf, size should be %d bytes\n",
			__func__, msg->size);
		return ret;
	}

	mutex_lock(&bus->lock);

	/* Peek the bus to see if a msg exists, if it's not what we're expecting
	 * then return cleanly else read the message from the bus.
	 */
	curr_gwp = le32_to_cpu(saa7164_readl(bus->m_dwGetWritePos));
	curr_grp = le32_to_cpu(saa7164_readl(bus->m_dwGetReadPos));

	if (curr_gwp == curr_grp) {
		ret = SAA_ERR_EMPTY;
		goto out;
	}

	bytes_to_read = sizeof(*msg);

	/* Calculate write distance to current read position */
	write_distance = 0;
	if (curr_gwp >= curr_grp)
		/* Write doesn't wrap around the ring */
		write_distance = curr_gwp - curr_grp;
	else
		/* Write wraps around the ring */
		write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;

	if (bytes_to_read > write_distance) {
		printk(KERN_ERR "%s() No message/response found\n", __func__);
		ret = SAA_ERR_INVALID_COMMAND;
		goto out;
	}

	/* Calculate the new read position */
	new_grp = curr_grp + bytes_to_read;
	if (new_grp > bus->m_dwSizeGetRing) {

		/* Ring wraps */
		new_grp -= bus->m_dwSizeGetRing;
		space_rem = bus->m_dwSizeGetRing - curr_grp;

		memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
		memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
			bytes_to_read - space_rem);

	} else {
		/* No wrapping */
		memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
	}

	/* No need to update the read positions, because this was a peek */
	/* If the caller specifically want to peek, return */
	if (peekonly) {
		memcpy(msg, &msg_tmp, sizeof(*msg));
		goto peekout;
	}

	/* Check if the command/response matches what is expected */
	if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) ||
		(msg_tmp.controlselector != msg->controlselector) ||
		(msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) {

		printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
		saa7164_bus_dumpmsg(dev, msg, buf);
		saa7164_bus_dumpmsg(dev, &msg_tmp, NULL);
		ret = SAA_ERR_INVALID_COMMAND;
		goto out;
	}

	/* Get the actual command and response from the bus */
	buf_size = msg->size;

	bytes_to_read = sizeof(*msg) + msg->size;
	/* Calculate write distance to current read position */
	write_distance = 0;
	if (curr_gwp >= curr_grp)
		/* Write doesn't wrap around the ring */
		write_distance = curr_gwp - curr_grp;
	else
		/* Write wraps around the ring */
		write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;

	if (bytes_to_read > write_distance) {
		printk(KERN_ERR "%s() Invalid bus state, missing msg "
			"or mangled ring, faulty H/W / bad code?\n", __func__);
		ret = SAA_ERR_INVALID_COMMAND;
		goto out;
	}

	/* Calculate the new read position */
	new_grp = curr_grp + bytes_to_read;
	if (new_grp > bus->m_dwSizeGetRing) {

		/* Ring wraps */
		new_grp -= bus->m_dwSizeGetRing;
		space_rem = bus->m_dwSizeGetRing - curr_grp;

		if (space_rem < sizeof(*msg)) {
			/* msg wraps around the ring */
			memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem);
			memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing,
				sizeof(*msg) - space_rem);
			if (buf)
				memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) -
					space_rem, buf_size);

		} else if (space_rem == sizeof(*msg)) {
			memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
			if (buf)
				memcpy(buf, bus->m_pdwGetRing, buf_size);
		} else {
			/* Additional data wraps around the ring */
			memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
			if (buf) {
				memcpy(buf, bus->m_pdwGetRing + curr_grp +
					sizeof(*msg), space_rem - sizeof(*msg));
				memcpy(buf + space_rem - sizeof(*msg),
					bus->m_pdwGetRing, bytes_to_read -
					space_rem);
			}

		}

	} else {
		/* No wrapping */
		memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
		if (buf)
			memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
				buf_size);
	}

	/* Update the read positions, adjusting the ring */
	saa7164_writel(bus->m_dwGetReadPos, cpu_to_le32(new_grp));

peekout:
	msg->size = le16_to_cpu(msg->size);
	msg->command = le16_to_cpu(msg->command);
	msg->controlselector = le16_to_cpu(msg->controlselector);
	ret = SAA_OK;
out:
	mutex_unlock(&bus->lock);
	saa7164_bus_verify(dev);
	return ret;
}

OpenPOWER on IntegriCloud