summaryrefslogtreecommitdiffstats
path: root/drivers/media/pci/saa7134/saa7134-i2c.c
blob: 8a1128c60680b928835da0601fdc51d06383b593 (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
/*
 *
 * device driver for philips saa7134 based TV cards
 * i2c interface support
 *
 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
 *
 *  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.
 */

#include "saa7134.h"
#include "saa7134-reg.h"

#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>

#include <media/v4l2-common.h>

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

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

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

#define i2c_dbg(level, fmt, arg...) do { \
	if (i2c_debug == level) \
		printk(KERN_DEBUG pr_fmt("i2c: " fmt), ## arg); \
	} while (0)

#define i2c_cont(level, fmt, arg...) do { \
	if (i2c_debug == level) \
		pr_cont(fmt, ## arg); \
	} while (0)

#define I2C_WAIT_DELAY  32
#define I2C_WAIT_RETRY  16

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

static char *str_i2c_status[] = {
	"IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
	"DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
	"NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
};

enum i2c_status {
	IDLE          = 0,  // no I2C command pending
	DONE_STOP     = 1,  // I2C command done and STOP executed
	BUSY          = 2,  // executing I2C command
	TO_SCL        = 3,  // executing I2C command, time out on clock stretching
	TO_ARB        = 4,  // time out on arbitration trial, still trying
	DONE_WRITE    = 5,  // I2C command done and awaiting next write command
	DONE_READ     = 6,  // I2C command done and awaiting next read command
	DONE_WRITE_TO = 7,  // see 5, and time out on status echo
	DONE_READ_TO  = 8,  // see 6, and time out on status echo
	NO_DEVICE     = 9,  // no acknowledge on device slave address
	NO_ACKN       = 10, // no acknowledge after data byte transfer
	BUS_ERR       = 11, // bus error
	ARB_LOST      = 12, // arbitration lost during transfer
	SEQ_ERR       = 13, // erroneous programming sequence
	ST_ERR        = 14, // wrong status echoing
	SW_ERR        = 15  // software error
};

static char *str_i2c_attr[] = {
	"NOP", "STOP", "CONTINUE", "START"
};

enum i2c_attr {
	NOP           = 0,  // no operation on I2C bus
	STOP          = 1,  // stop condition, no associated byte transfer
	CONTINUE      = 2,  // continue with byte transfer
	START         = 3   // start condition with byte transfer
};

static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
{
	enum i2c_status status;

	status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
	i2c_dbg(2, "i2c stat <= %s\n", str_i2c_status[status]);
	return status;
}

static inline void i2c_set_status(struct saa7134_dev *dev,
				  enum i2c_status status)
{
	i2c_dbg(2, "i2c stat => %s\n", str_i2c_status[status]);
	saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
}

static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
{
	i2c_dbg(2, "i2c attr => %s\n", str_i2c_attr[attr]);
	saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
}

static inline int i2c_is_error(enum i2c_status status)
{
	switch (status) {
	case NO_DEVICE:
	case NO_ACKN:
	case BUS_ERR:
	case ARB_LOST:
	case SEQ_ERR:
	case ST_ERR:
		return true;
	default:
		return false;
	}
}

static inline int i2c_is_idle(enum i2c_status status)
{
	switch (status) {
	case IDLE:
	case DONE_STOP:
		return true;
	default:
		return false;
	}
}

static inline int i2c_is_busy(enum i2c_status status)
{
	switch (status) {
	case BUSY:
	case TO_SCL:
	case TO_ARB:
		return true;
	default:
		return false;
	}
}

static int i2c_is_busy_wait(struct saa7134_dev *dev)
{
	enum i2c_status status;
	int count;

	for (count = 0; count < I2C_WAIT_RETRY; count++) {
		status = i2c_get_status(dev);
		if (!i2c_is_busy(status))
			break;
		saa_wait(I2C_WAIT_DELAY);
	}
	if (I2C_WAIT_RETRY == count)
		return false;
	return true;
}

static int i2c_reset(struct saa7134_dev *dev)
{
	enum i2c_status status;
	int count;

	i2c_dbg(2, "i2c reset\n");
	status = i2c_get_status(dev);
	if (!i2c_is_error(status))
		return true;
	i2c_set_status(dev,status);

	for (count = 0; count < I2C_WAIT_RETRY; count++) {
		status = i2c_get_status(dev);
		if (!i2c_is_error(status))
			break;
		udelay(I2C_WAIT_DELAY);
	}
	if (I2C_WAIT_RETRY == count)
		return false;

	if (!i2c_is_idle(status))
		return false;

	i2c_set_attr(dev,NOP);
	return true;
}

static inline int i2c_send_byte(struct saa7134_dev *dev,
				enum i2c_attr attr,
				unsigned char data)
{
	enum i2c_status status;
	__u32 dword;

	/* have to write both attr + data in one 32bit word */
	dword  = saa_readl(SAA7134_I2C_ATTR_STATUS >> 2);
	dword &= 0x0f;
	dword |= (attr << 6);
	dword |= ((__u32)data << 8);
	dword |= 0x00 << 16;  /* 100 kHz */
//	dword |= 0x40 << 16;  /* 400 kHz */
	dword |= 0xf0 << 24;
	saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
	i2c_dbg(2, "i2c data => 0x%x\n", data);

	if (!i2c_is_busy_wait(dev))
		return -EIO;
	status = i2c_get_status(dev);
	if (i2c_is_error(status))
		return -EIO;
	return 0;
}

static inline int i2c_recv_byte(struct saa7134_dev *dev)
{
	enum i2c_status status;
	unsigned char data;

	i2c_set_attr(dev,CONTINUE);
	if (!i2c_is_busy_wait(dev))
		return -EIO;
	status = i2c_get_status(dev);
	if (i2c_is_error(status))
		return -EIO;
	data = saa_readb(SAA7134_I2C_DATA);
	i2c_dbg(2, "i2c data <= 0x%x\n", data);
	return data;
}

static int saa7134_i2c_xfer(struct i2c_adapter *i2c_adap,
			    struct i2c_msg *msgs, int num)
{
	struct saa7134_dev *dev = i2c_adap->algo_data;
	enum i2c_status status;
	unsigned char data;
	int addr,rc,i,byte;

	status = i2c_get_status(dev);
	if (!i2c_is_idle(status))
		if (!i2c_reset(dev))
			return -EIO;

	i2c_dbg(2, "start xfer\n");
	i2c_dbg(1, "i2c xfer:");
	for (i = 0; i < num; i++) {
		if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
			/* send address */
			i2c_dbg(2, "send address\n");
			addr  = msgs[i].addr << 1;
			if (msgs[i].flags & I2C_M_RD)
				addr |= 1;
			if (i > 0 && msgs[i].flags &
			    I2C_M_RD && msgs[i].addr != 0x40 &&
			    msgs[i].addr != 0x41 &&
			    msgs[i].addr != 0x19) {
				/* workaround for a saa7134 i2c bug
				 * needed to talk to the mt352 demux
				 * thanks to pinnacle for the hint */
				int quirk = 0xfe;
				i2c_cont(1, " [%02x quirk]", quirk);
				i2c_send_byte(dev,START,quirk);
				i2c_recv_byte(dev);
			}
			i2c_cont(1, " < %02x", addr);
			rc = i2c_send_byte(dev,START,addr);
			if (rc < 0)
				 goto err;
		}
		if (msgs[i].flags & I2C_M_RD) {
			/* read bytes */
			i2c_dbg(2, "read bytes\n");
			for (byte = 0; byte < msgs[i].len; byte++) {
				i2c_cont(1, " =");
				rc = i2c_recv_byte(dev);
				if (rc < 0)
					goto err;
				i2c_cont(1, "%02x", rc);
				msgs[i].buf[byte] = rc;
			}
			/* discard mysterious extra byte when reading
			   from Samsung S5H1411.  i2c bus gets error
			   if we do not. */
			if (0x19 == msgs[i].addr) {
				i2c_cont(1, " ?");
				rc = i2c_recv_byte(dev);
				if (rc < 0)
					goto err;
				i2c_cont(1, "%02x", rc);
			}
		} else {
			/* write bytes */
			i2c_dbg(2, "write bytes\n");
			for (byte = 0; byte < msgs[i].len; byte++) {
				data = msgs[i].buf[byte];
				i2c_cont(1, " %02x", data);
				rc = i2c_send_byte(dev,CONTINUE,data);
				if (rc < 0)
					goto err;
			}
		}
	}
	i2c_dbg(2, "xfer done\n");
	i2c_cont(1, " >");
	i2c_set_attr(dev,STOP);
	rc = -EIO;
	if (!i2c_is_busy_wait(dev))
		goto err;
	status = i2c_get_status(dev);
	if (i2c_is_error(status))
		goto err;
	/* ensure that the bus is idle for at least one bit slot */
	msleep(1);

	i2c_cont(1, "\n");
	return num;
 err:
	if (1 == i2c_debug) {
		status = i2c_get_status(dev);
		i2c_cont(1, " ERROR: %s\n", str_i2c_status[status]);
	}
	return rc;
}

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

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

static const struct i2c_algorithm saa7134_algo = {
	.master_xfer   = saa7134_i2c_xfer,
	.functionality = functionality,
};

static const struct i2c_adapter saa7134_adap_template = {
	.owner         = THIS_MODULE,
	.name          = "saa7134",
	.algo          = &saa7134_algo,
};

static const struct i2c_client saa7134_client_template = {
	.name	= "saa7134 internal",
};

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

/*
 * On Medion 7134 reading the SAA7134 chip config EEPROM needs DVB-T
 * demod i2c gate closed due to an address clash between this EEPROM
 * and the demod one.
 */
static void saa7134_i2c_eeprom_md7134_gate(struct saa7134_dev *dev)
{
	u8 subaddr = 0x7, dmdregval;
	u8 data[2];
	int ret;
	struct i2c_msg i2cgatemsg_r[] = { {.addr = 0x08, .flags = 0,
					   .buf = &subaddr, .len = 1},
					  {.addr = 0x08,
					   .flags = I2C_M_RD,
					   .buf = &dmdregval, .len = 1}
					};
	struct i2c_msg i2cgatemsg_w[] = { {.addr = 0x08, .flags = 0,
					   .buf = data, .len = 2} };

	ret = i2c_transfer(&dev->i2c_adap, i2cgatemsg_r, 2);
	if ((ret == 2) && (dmdregval & 0x2)) {
		pr_debug("%s: DVB-T demod i2c gate was left open\n",
			 dev->name);

		data[0] = subaddr;
		data[1] = (dmdregval & ~0x2);
		if (i2c_transfer(&dev->i2c_adap, i2cgatemsg_w, 1) != 1)
			pr_err("%s: EEPROM i2c gate close failure\n",
			       dev->name);
	}
}

static int
saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
{
	unsigned char buf;
	int i,err;

	if (dev->board == SAA7134_BOARD_MD7134)
		saa7134_i2c_eeprom_md7134_gate(dev);

	dev->i2c_client.addr = 0xa0 >> 1;
	buf = 0;
	if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
		pr_info("%s: Huh, no eeprom present (err=%d)?\n",
		       dev->name,err);
		return -1;
	}
	if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
		pr_warn("%s: i2c eeprom read error (err=%d)\n",
		       dev->name,err);
		return -1;
	}

	for (i = 0; i < len; i += 16) {
		int size = (len - i) > 16 ? 16 : len - i;

		pr_info("i2c eeprom %02x: %*ph\n", i, size, &eedata[i]);
	}

	return 0;
}

static char *i2c_devs[128] = {
	[ 0x20      ] = "mpeg encoder (saa6752hs)",
	[ 0xa0 >> 1 ] = "eeprom",
	[ 0xc0 >> 1 ] = "tuner (analog)",
	[ 0x86 >> 1 ] = "tda9887",
	[ 0x5a >> 1 ] = "remote control",
};

static void do_i2c_scan(struct i2c_client *c)
{
	unsigned char buf;
	int i,rc;

	for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
		c->addr = i;
		rc = i2c_master_recv(c,&buf,0);
		if (rc < 0)
			continue;
		pr_info("i2c scan: found device @ 0x%x  [%s]\n",
			 i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
	}
}

int saa7134_i2c_register(struct saa7134_dev *dev)
{
	dev->i2c_adap = saa7134_adap_template;
	dev->i2c_adap.dev.parent = &dev->pci->dev;
	strcpy(dev->i2c_adap.name,dev->name);
	dev->i2c_adap.algo_data = dev;
	i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
	i2c_add_adapter(&dev->i2c_adap);

	dev->i2c_client = saa7134_client_template;
	dev->i2c_client.adapter = &dev->i2c_adap;

	saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
	if (i2c_scan)
		do_i2c_scan(&dev->i2c_client);

	/* Instantiate the IR receiver device, if present */
	saa7134_probe_i2c_ir(dev);
	return 0;
}

int saa7134_i2c_unregister(struct saa7134_dev *dev)
{
	i2c_del_adapter(&dev->i2c_adap);
	return 0;
}