summaryrefslogtreecommitdiffstats
path: root/drivers/media/video/au0828/au0828-i2c.c
blob: cbdb65c34f219081387fce62731b1f74e0b05f41 (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
/*
 *  Driver for the Auvitek AU0828 USB bridge
 *
 *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
 *
 *  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/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/io.h>

#include "au0828.h"

#include <media/v4l2-common.h>

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

#define I2C_WAIT_DELAY 512
#define I2C_WAIT_RETRY 64

static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
{
	struct au0828_dev *dev = i2c_adap->algo_data;
	return au0828_read(dev, AU0828_I2C_STATUS_201) &
		AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
}

static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
{
	struct au0828_dev *dev = i2c_adap->algo_data;
	return au0828_read(dev, AU0828_I2C_STATUS_201) &
		AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
}

static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
{
	int count;

	for (count = 0; count < I2C_WAIT_RETRY; count++) {
		if (!i2c_slave_did_read_ack(i2c_adap))
			break;
		udelay(I2C_WAIT_DELAY);
	}

	if (I2C_WAIT_RETRY == count)
		return 0;

	return 1;
}

static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
{
	struct au0828_dev *dev = i2c_adap->algo_data;
	return au0828_read(dev, AU0828_I2C_STATUS_201) &
		AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
}

static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
{
	int count;

	for (count = 0; count < I2C_WAIT_RETRY; count++) {
		if (!i2c_is_read_busy(i2c_adap))
			break;
		udelay(I2C_WAIT_DELAY);
	}

	if (I2C_WAIT_RETRY == count)
		return 0;

	return 1;
}

static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
{
	struct au0828_dev *dev = i2c_adap->algo_data;
	return au0828_read(dev, AU0828_I2C_STATUS_201) &
		AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
}

static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
{
	int count;

	for (count = 0; count < I2C_WAIT_RETRY; count++) {
		if (i2c_is_write_done(i2c_adap))
			break;
		udelay(I2C_WAIT_DELAY);
	}

	if (I2C_WAIT_RETRY == count)
		return 0;

	return 1;
}

static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
{
	struct au0828_dev *dev = i2c_adap->algo_data;
	return au0828_read(dev, AU0828_I2C_STATUS_201) &
		AU0828_I2C_STATUS_BUSY ? 1 : 0;
}

static int i2c_wait_done(struct i2c_adapter *i2c_adap)
{
	int count;

	for (count = 0; count < I2C_WAIT_RETRY; count++) {
		if (!i2c_is_busy(i2c_adap))
			break;
		udelay(I2C_WAIT_DELAY);
	}

	if (I2C_WAIT_RETRY == count)
		return 0;

	return 1;
}

/* FIXME: Implement join handling correctly */
static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
	const struct i2c_msg *msg, int joined_rlen)
{
	int i, strobe = 0;
	struct au0828_dev *dev = i2c_adap->algo_data;

	dprintk(4, "%s()\n", __func__);

	au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);

	/* Set the I2C clock */
	au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
		     dev->board.i2c_clk_divider);

	/* Hardware needs 8 bit addresses */
	au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);

	dprintk(4, "SEND: %02x\n", msg->addr);

	/* Deal with i2c_scan */
	if (msg->len == 0) {
		/* The analog tuner detection code makes use of the SMBUS_QUICK
		   message (which involves a zero length i2c write).  To avoid
		   checking the status register when we didn't strobe out any
		   actual bytes to the bus, just do a read check.  This is
		   consistent with how I saw i2c device checking done in the
		   USB trace of the Windows driver */
		au0828_write(dev, AU0828_I2C_TRIGGER_200,
			     AU0828_I2C_TRIGGER_READ);

		if (!i2c_wait_done(i2c_adap))
			return -EIO;

		if (i2c_wait_read_ack(i2c_adap))
			return -EIO;

		return 0;
	}

	for (i = 0; i < msg->len;) {

		dprintk(4, " %02x\n", msg->buf[i]);

		au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);

		strobe++;
		i++;

		if ((strobe >= 4) || (i >= msg->len)) {

			/* Strobe the byte into the bus */
			if (i < msg->len)
				au0828_write(dev, AU0828_I2C_TRIGGER_200,
					     AU0828_I2C_TRIGGER_WRITE |
					     AU0828_I2C_TRIGGER_HOLD);
			else
				au0828_write(dev, AU0828_I2C_TRIGGER_200,
					     AU0828_I2C_TRIGGER_WRITE);

			/* Reset strobe trigger */
			strobe = 0;

			if (!i2c_wait_write_done(i2c_adap))
				return -EIO;

		}

	}
	if (!i2c_wait_done(i2c_adap))
		return -EIO;

	dprintk(4, "\n");

	return msg->len;
}

/* FIXME: Implement join handling correctly */
static int i2c_readbytes(struct i2c_adapter *i2c_adap,
	const struct i2c_msg *msg, int joined)
{
	struct au0828_dev *dev = i2c_adap->algo_data;
	int i;

	dprintk(4, "%s()\n", __func__);

	au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);

	/* Set the I2C clock */
	au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
		     dev->board.i2c_clk_divider);

	/* Hardware needs 8 bit addresses */
	au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);

	dprintk(4, " RECV:\n");

	/* Deal with i2c_scan */
	if (msg->len == 0) {
		au0828_write(dev, AU0828_I2C_TRIGGER_200,
			     AU0828_I2C_TRIGGER_READ);

		if (i2c_wait_read_ack(i2c_adap))
			return -EIO;
		return 0;
	}

	for (i = 0; i < msg->len;) {

		i++;

		if (i < msg->len)
			au0828_write(dev, AU0828_I2C_TRIGGER_200,
				     AU0828_I2C_TRIGGER_READ |
				     AU0828_I2C_TRIGGER_HOLD);
		else
			au0828_write(dev, AU0828_I2C_TRIGGER_200,
				     AU0828_I2C_TRIGGER_READ);

		if (!i2c_wait_read_done(i2c_adap))
			return -EIO;

		msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
			0xff;

		dprintk(4, " %02x\n", msg->buf[i-1]);
	}
	if (!i2c_wait_done(i2c_adap))
		return -EIO;

	dprintk(4, "\n");

	return msg->len;
}

static int i2c_xfer(struct i2c_adapter *i2c_adap,
		    struct i2c_msg *msgs, int num)
{
	int i, retval = 0;

	dprintk(4, "%s(num = %d)\n", __func__, num);

	for (i = 0; i < num; i++) {
		dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
			__func__, num, msgs[i].addr, msgs[i].len);
		if (msgs[i].flags & I2C_M_RD) {
			/* read */
			retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
		} else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
			   msgs[i].addr == msgs[i + 1].addr) {
			/* write then read from same address */
			retval = i2c_sendbytes(i2c_adap, &msgs[i],
					       msgs[i + 1].len);
			if (retval < 0)
				goto err;
			i++;
			retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
		} else {
			/* write */
			retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
		}
		if (retval < 0)
			goto err;
	}
	return num;

err:
	return retval;
}

static u32 au0828_functionality(struct i2c_adapter *adap)
{
	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
}

static struct i2c_algorithm au0828_i2c_algo_template = {
	.master_xfer	= i2c_xfer,
	.functionality	= au0828_functionality,
};

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

static struct i2c_adapter au0828_i2c_adap_template = {
	.name              = DRIVER_NAME,
	.owner             = THIS_MODULE,
	.algo              = &au0828_i2c_algo_template,
};

static struct i2c_client au0828_i2c_client_template = {
	.name	= "au0828 internal",
};

static char *i2c_devs[128] = {
	[0x8e >> 1] = "au8522",
	[0xa0 >> 1] = "eeprom",
	[0xc2 >> 1] = "tuner/xc5000",
};

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

	for (i = 0; i < 128; i++) {
		c->addr = i;
		rc = i2c_master_recv(c, &buf, 0);
		if (rc < 0)
			continue;
		printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
		       name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
	}
}

/* init + register i2c algo-bit adapter */
int au0828_i2c_register(struct au0828_dev *dev)
{
	dprintk(1, "%s()\n", __func__);

	memcpy(&dev->i2c_adap, &au0828_i2c_adap_template,
	       sizeof(dev->i2c_adap));
	memcpy(&dev->i2c_algo, &au0828_i2c_algo_template,
	       sizeof(dev->i2c_algo));
	memcpy(&dev->i2c_client, &au0828_i2c_client_template,
	       sizeof(dev->i2c_client));

	dev->i2c_adap.dev.parent = &dev->usbdev->dev;

	strlcpy(dev->i2c_adap.name, DRIVER_NAME,
		sizeof(dev->i2c_adap.name));

	dev->i2c_adap.algo = &dev->i2c_algo;
	dev->i2c_adap.algo_data = dev;
	i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
	i2c_add_adapter(&dev->i2c_adap);

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

	if (0 == dev->i2c_rc) {
		printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME);
		if (i2c_scan)
			do_i2c_scan(DRIVER_NAME, &dev->i2c_client);
	} else
		printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME);

	return dev->i2c_rc;
}

int au0828_i2c_unregister(struct au0828_dev *dev)
{
	i2c_del_adapter(&dev->i2c_adap);
	return 0;
}