summaryrefslogtreecommitdiffstats
path: root/drivers/media/video/em28xx/em28xx-i2c.c
blob: 1683bd9d51eed67ecaef8832832bd1eafeaa1ca5 (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
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
/*
   em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices

   Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
		      Markus Rechberger <mrechberger@gmail.com>
		      Mauro Carvalho Chehab <mchehab@infradead.org>
		      Sascha Sommer <saschasommer@freenet.de>

   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 <linux/module.h>
#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/i2c.h>

#include "em28xx.h"
#include "tuner-xc2028.h"
#include <media/v4l2-common.h>
#include <media/tuner.h>

/* ----------------------------------------------------------- */

static unsigned int i2c_scan;
module_param(i2c_scan, int, 0444);
MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");

static unsigned int i2c_debug;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");

#define dprintk2(lvl, fmt, args...)			\
do {							\
	if (i2c_debug >= lvl) {				\
		printk(KERN_DEBUG "%s at %s: " fmt,	\
		       dev->name, __func__ , ##args);	\
      } 						\
} while (0)

/*
 * em2800_i2c_send_max4()
 * send up to 4 bytes to the i2c device
 */
static int em2800_i2c_send_max4(struct em28xx *dev, unsigned char addr,
				char *buf, int len)
{
	int ret;
	int write_timeout;
	unsigned char b2[6];
	BUG_ON(len < 1 || len > 4);
	b2[5] = 0x80 + len - 1;
	b2[4] = addr;
	b2[3] = buf[0];
	if (len > 1)
		b2[2] = buf[1];
	if (len > 2)
		b2[1] = buf[2];
	if (len > 3)
		b2[0] = buf[3];

	ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
	if (ret != 2 + len) {
		em28xx_warn("writing to i2c device failed (error=%i)\n", ret);
		return -EIO;
	}
	for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
	     write_timeout -= 5) {
		ret = dev->em28xx_read_reg(dev, 0x05);
		if (ret == 0x80 + len - 1)
			return len;
		msleep(5);
	}
	em28xx_warn("i2c write timed out\n");
	return -EIO;
}

/*
 * em2800_i2c_send_bytes()
 */
static int em2800_i2c_send_bytes(void *data, unsigned char addr, char *buf,
				 short len)
{
	char *bufPtr = buf;
	int ret;
	int wrcount = 0;
	int count;
	int maxLen = 4;
	struct em28xx *dev = (struct em28xx *)data;
	while (len > 0) {
		count = (len > maxLen) ? maxLen : len;
		ret = em2800_i2c_send_max4(dev, addr, bufPtr, count);
		if (ret > 0) {
			len -= count;
			bufPtr += count;
			wrcount += count;
		} else
			return (ret < 0) ? ret : -EFAULT;
	}
	return wrcount;
}

/*
 * em2800_i2c_check_for_device()
 * check if there is a i2c_device at the supplied address
 */
static int em2800_i2c_check_for_device(struct em28xx *dev, unsigned char addr)
{
	char msg;
	int ret;
	int write_timeout;
	msg = addr;
	ret = dev->em28xx_write_regs(dev, 0x04, &msg, 1);
	if (ret < 0) {
		em28xx_warn("setting i2c device address failed (error=%i)\n",
			    ret);
		return ret;
	}
	msg = 0x84;
	ret = dev->em28xx_write_regs(dev, 0x05, &msg, 1);
	if (ret < 0) {
		em28xx_warn("preparing i2c read failed (error=%i)\n", ret);
		return ret;
	}
	for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
	     write_timeout -= 5) {
		unsigned reg = dev->em28xx_read_reg(dev, 0x5);

		if (reg == 0x94)
			return -ENODEV;
		else if (reg == 0x84)
			return 0;
		msleep(5);
	}
	return -ENODEV;
}

/*
 * em2800_i2c_recv_bytes()
 * read from the i2c device
 */
static int em2800_i2c_recv_bytes(struct em28xx *dev, unsigned char addr,
				 char *buf, int len)
{
	int ret;
	/* check for the device and set i2c read address */
	ret = em2800_i2c_check_for_device(dev, addr);
	if (ret) {
		em28xx_warn
		    ("preparing read at i2c address 0x%x failed (error=%i)\n",
		     addr, ret);
		return ret;
	}
	ret = dev->em28xx_read_reg_req_len(dev, 0x0, 0x3, buf, len);
	if (ret < 0) {
		em28xx_warn("reading from i2c device at 0x%x failed (error=%i)",
			    addr, ret);
		return ret;
	}
	return ret;
}

/*
 * em28xx_i2c_send_bytes()
 */
static int em28xx_i2c_send_bytes(void *data, unsigned char addr, char *buf,
				 short len, int stop)
{
	int wrcount = 0;
	struct em28xx *dev = (struct em28xx *)data;
	int write_timeout, ret;

	wrcount = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);

	/* Seems to be required after a write */
	for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
	     write_timeout -= 5) {
		ret = dev->em28xx_read_reg(dev, 0x05);
		if (!ret)
			break;
		msleep(5);
	}

	return wrcount;
}

/*
 * em28xx_i2c_recv_bytes()
 * read a byte from the i2c device
 */
static int em28xx_i2c_recv_bytes(struct em28xx *dev, unsigned char addr,
				 char *buf, int len)
{
	int ret;
	ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
	if (ret < 0) {
		em28xx_warn("reading i2c device failed (error=%i)\n", ret);
		return ret;
	}
	if (dev->em28xx_read_reg(dev, 0x5) != 0)
		return -ENODEV;
	return ret;
}

/*
 * em28xx_i2c_check_for_device()
 * check if there is a i2c_device at the supplied address
 */
static int em28xx_i2c_check_for_device(struct em28xx *dev, unsigned char addr)
{
	int ret;

	ret = dev->em28xx_read_reg_req(dev, 2, addr);
	if (ret < 0) {
		em28xx_warn("reading from i2c device failed (error=%i)\n", ret);
		return ret;
	}
	if (dev->em28xx_read_reg(dev, 0x5) != 0)
		return -ENODEV;
	return 0;
}

/*
 * em28xx_i2c_xfer()
 * the main i2c transfer function
 */
static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
			   struct i2c_msg msgs[], int num)
{
	struct em28xx *dev = i2c_adap->algo_data;
	int addr, rc, i, byte;

	if (num <= 0)
		return 0;
	for (i = 0; i < num; i++) {
		addr = msgs[i].addr << 1;
		dprintk2(2, "%s %s addr=%x len=%d:",
			 (msgs[i].flags & I2C_M_RD) ? "read" : "write",
			 i == num - 1 ? "stop" : "nonstop", addr, msgs[i].len);
		if (!msgs[i].len) { /* no len: check only for device presence */
			if (dev->board.is_em2800)
				rc = em2800_i2c_check_for_device(dev, addr);
			else
				rc = em28xx_i2c_check_for_device(dev, addr);
			if (rc < 0) {
				dprintk2(2, " no device\n");
				return rc;
			}

		} else if (msgs[i].flags & I2C_M_RD) {
			/* read bytes */
			if (dev->board.is_em2800)
				rc = em2800_i2c_recv_bytes(dev, addr,
							   msgs[i].buf,
							   msgs[i].len);
			else
				rc = em28xx_i2c_recv_bytes(dev, addr,
							   msgs[i].buf,
							   msgs[i].len);
			if (i2c_debug >= 2) {
				for (byte = 0; byte < msgs[i].len; byte++)
					printk(" %02x", msgs[i].buf[byte]);
			}
		} else {
			/* write bytes */
			if (i2c_debug >= 2) {
				for (byte = 0; byte < msgs[i].len; byte++)
					printk(" %02x", msgs[i].buf[byte]);
			}
			if (dev->board.is_em2800)
				rc = em2800_i2c_send_bytes(dev, addr,
							   msgs[i].buf,
							   msgs[i].len);
			else
				rc = em28xx_i2c_send_bytes(dev, addr,
							   msgs[i].buf,
							   msgs[i].len,
							   i == num - 1);
		}
		if (rc < 0)
			goto err;
		if (i2c_debug >= 2)
			printk("\n");
	}

	return num;
err:
	dprintk2(2, " ERROR: %i\n", rc);
	return rc;
}

/* based on linux/sunrpc/svcauth.h and linux/hash.h
 * The original hash function returns a different value, if arch is x86_64
 *  or i386.
 */
static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
{
	unsigned long hash = 0;
	unsigned long l = 0;
	int len = 0;
	unsigned char c;
	do {
		if (len == length) {
			c = (char)len;
			len = -1;
		} else
			c = *buf++;
		l = (l << 8) | c;
		len++;
		if ((len & (32 / 8 - 1)) == 0)
			hash = ((hash^l) * 0x9e370001UL);
	} while (len);

	return (hash >> (32 - bits)) & 0xffffffffUL;
}

static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)
{
	unsigned char buf, *p = eedata;
	struct em28xx_eeprom *em_eeprom = (void *)eedata;
	int i, err, size = len, block;

	if (dev->chip_id == CHIP_ID_EM2874 ||
	    dev->chip_id == CHIP_ID_EM28174 ||
	    dev->chip_id == CHIP_ID_EM2884) {
		/* Empia switched to a 16-bit addressable eeprom in newer
		   devices.  While we could certainly write a routine to read
		   the eeprom, there is nothing of use in there that cannot be
		   accessed through registers, and there is the risk that we
		   could corrupt the eeprom (since a 16-bit read call is
		   interpreted as a write call by 8-bit eeproms).
		*/
		return 0;
	}

	dev->i2c_client.addr = 0xa0 >> 1;

	/* Check if board has eeprom */
	err = i2c_master_recv(&dev->i2c_client, &buf, 0);
	if (err < 0) {
		em28xx_errdev("board has no eeprom\n");
		memset(eedata, 0, len);
		return -ENODEV;
	}

	buf = 0;

	err = i2c_master_send(&dev->i2c_client, &buf, 1);
	if (err != 1) {
		printk(KERN_INFO "%s: Huh, no eeprom present (err=%d)?\n",
		       dev->name, err);
		return err;
	}
	while (size > 0) {
		if (size > 16)
			block = 16;
		else
			block = size;

		if (block !=
		    (err = i2c_master_recv(&dev->i2c_client, p, block))) {
			printk(KERN_WARNING
			       "%s: i2c eeprom read error (err=%d)\n",
			       dev->name, err);
			return err;
		}
		size -= block;
		p += block;
	}
	for (i = 0; i < len; i++) {
		if (0 == (i % 16))
			printk(KERN_INFO "%s: i2c eeprom %02x:", dev->name, i);
		printk(" %02x", eedata[i]);
		if (15 == (i % 16))
			printk("\n");
	}

	if (em_eeprom->id == 0x9567eb1a)
		dev->hash = em28xx_hash_mem(eedata, len, 32);

	printk(KERN_INFO "%s: EEPROM ID= 0x%08x, EEPROM hash = 0x%08lx\n",
	       dev->name, em_eeprom->id, dev->hash);

	printk(KERN_INFO "%s: EEPROM info:\n", dev->name);

	switch (em_eeprom->chip_conf >> 4 & 0x3) {
	case 0:
		printk(KERN_INFO "%s:\tNo audio on board.\n", dev->name);
		break;
	case 1:
		printk(KERN_INFO "%s:\tAC97 audio (5 sample rates)\n",
				 dev->name);
		break;
	case 2:
		printk(KERN_INFO "%s:\tI2S audio, sample rate=32k\n",
				 dev->name);
		break;
	case 3:
		printk(KERN_INFO "%s:\tI2S audio, 3 sample rates\n",
				 dev->name);
		break;
	}

	if (em_eeprom->chip_conf & 1 << 3)
		printk(KERN_INFO "%s:\tUSB Remote wakeup capable\n", dev->name);

	if (em_eeprom->chip_conf & 1 << 2)
		printk(KERN_INFO "%s:\tUSB Self power capable\n", dev->name);

	switch (em_eeprom->chip_conf & 0x3) {
	case 0:
		printk(KERN_INFO "%s:\t500mA max power\n", dev->name);
		break;
	case 1:
		printk(KERN_INFO "%s:\t400mA max power\n", dev->name);
		break;
	case 2:
		printk(KERN_INFO "%s:\t300mA max power\n", dev->name);
		break;
	case 3:
		printk(KERN_INFO "%s:\t200mA max power\n", dev->name);
		break;
	}
	printk(KERN_INFO "%s:\tTable at 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
				dev->name,
				em_eeprom->string_idx_table,
				em_eeprom->string1,
				em_eeprom->string2,
				em_eeprom->string3);

	return 0;
}

/* ----------------------------------------------------------- */

/*
 * functionality()
 */
static u32 functionality(struct i2c_adapter *adap)
{
	return I2C_FUNC_SMBUS_EMUL;
}

static struct i2c_algorithm em28xx_algo = {
	.master_xfer   = em28xx_i2c_xfer,
	.functionality = functionality,
};

static struct i2c_adapter em28xx_adap_template = {
	.owner = THIS_MODULE,
	.name = "em28xx",
	.algo = &em28xx_algo,
};

static struct i2c_client em28xx_client_template = {
	.name = "em28xx internal",
};

/* ----------------------------------------------------------- */

/*
 * i2c_devs
 * incomplete list of known devices
 */
static char *i2c_devs[128] = {
	[0x4a >> 1] = "saa7113h",
	[0x52 >> 1] = "drxk",
	[0x60 >> 1] = "remote IR sensor",
	[0x8e >> 1] = "remote IR sensor",
	[0x86 >> 1] = "tda9887",
	[0x80 >> 1] = "msp34xx",
	[0x88 >> 1] = "msp34xx",
	[0xa0 >> 1] = "eeprom",
	[0xb0 >> 1] = "tda9874",
	[0xb8 >> 1] = "tvp5150a",
	[0xba >> 1] = "webcam sensor or tvp5150a",
	[0xc0 >> 1] = "tuner (analog)",
	[0xc2 >> 1] = "tuner (analog)",
	[0xc4 >> 1] = "tuner (analog)",
	[0xc6 >> 1] = "tuner (analog)",
};

/*
 * do_i2c_scan()
 * check i2c address range for devices
 */
void em28xx_do_i2c_scan(struct em28xx *dev)
{
	u8 i2c_devicelist[128];
	unsigned char buf;
	int i, rc;

	memset(i2c_devicelist, 0, ARRAY_SIZE(i2c_devicelist));

	for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
		dev->i2c_client.addr = i;
		rc = i2c_master_recv(&dev->i2c_client, &buf, 0);
		if (rc < 0)
			continue;
		i2c_devicelist[i] = i;
		printk(KERN_INFO "%s: found i2c device @ 0x%x [%s]\n",
		       dev->name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
	}

	dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
					ARRAY_SIZE(i2c_devicelist), 32);
}

/*
 * em28xx_i2c_register()
 * register i2c bus
 */
int em28xx_i2c_register(struct em28xx *dev)
{
	int retval;

	BUG_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg);
	BUG_ON(!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req);
	dev->i2c_adap = em28xx_adap_template;
	dev->i2c_adap.dev.parent = &dev->udev->dev;
	strcpy(dev->i2c_adap.name, dev->name);
	dev->i2c_adap.algo_data = dev;
	i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);

	retval = i2c_add_adapter(&dev->i2c_adap);
	if (retval < 0) {
		em28xx_errdev("%s: i2c_add_adapter failed! retval [%d]\n",
			__func__, retval);
		return retval;
	}

	dev->i2c_client = em28xx_client_template;
	dev->i2c_client.adapter = &dev->i2c_adap;

	retval = em28xx_i2c_eeprom(dev, dev->eedata, sizeof(dev->eedata));
	if ((retval < 0) && (retval != -ENODEV)) {
		em28xx_errdev("%s: em28xx_i2_eeprom failed! retval [%d]\n",
			__func__, retval);

		return retval;
	}

	if (i2c_scan)
		em28xx_do_i2c_scan(dev);

	return 0;
}

/*
 * em28xx_i2c_unregister()
 * unregister i2c_bus
 */
int em28xx_i2c_unregister(struct em28xx *dev)
{
	i2c_del_adapter(&dev->i2c_adap);
	return 0;
}
OpenPOWER on IntegriCloud