Free Electrons

Embedded Linux Experts

  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
/*
 *  Driver for the Conexant CX25821 PCIe bridge
 *
 *  Copyright (C) 2009 Conexant Systems Inc.
 *  Authors  <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
 *	Based on Steven Toth <stoth@linuxtv.org> cx23885 driver
 *
 *  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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/i2c.h>
#include "cx25821.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 dprintk(level, fmt, arg...)					\
do {									\
	if (i2c_debug >= level)						\
		printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg);	\
} while (0)

#define I2C_WAIT_DELAY 32
#define I2C_WAIT_RETRY 64

#define I2C_EXTEND  (1 << 3)
#define I2C_NOSTOP  (1 << 4)

static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
{
	struct cx25821_i2c *bus = i2c_adap->algo_data;
	struct cx25821_dev *dev = bus->dev;
	return cx_read(bus->reg_stat) & 0x01;
}

static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
{
	struct cx25821_i2c *bus = i2c_adap->algo_data;
	struct cx25821_dev *dev = bus->dev;
	return cx_read(bus->reg_stat) & 0x02 ? 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;
}

static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
			 const struct i2c_msg *msg, int joined_rlen)
{
	struct cx25821_i2c *bus = i2c_adap->algo_data;
	struct cx25821_dev *dev = bus->dev;
	u32 wdata, addr, ctrl;
	int retval, cnt;

	if (joined_rlen)
		dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
			msg->len, joined_rlen);
	else
		dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

	/* Deal with i2c probe functions with zero payload */
	if (msg->len == 0) {
		cx_write(bus->reg_addr, msg->addr << 25);
		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));

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

		if (!i2c_slave_did_ack(i2c_adap))
			return -EIO;

		dprintk(1, "%s(): returns 0\n", __func__);
		return 0;
	}

	/* dev, reg + first byte */
	addr = (msg->addr << 25) | msg->buf[0];
	wdata = msg->buf[0];

	ctrl = bus->i2c_period | (1 << 12) | (1 << 2);

	if (msg->len > 1)
		ctrl |= I2C_NOSTOP | I2C_EXTEND;
	else if (joined_rlen)
		ctrl |= I2C_NOSTOP;

	cx_write(bus->reg_addr, addr);
	cx_write(bus->reg_wdata, wdata);
	cx_write(bus->reg_ctrl, ctrl);

	retval = i2c_wait_done(i2c_adap);
	if (retval < 0)
		goto err;

	if (retval == 0)
		goto eio;

	if (i2c_debug) {
		if (!(ctrl & I2C_NOSTOP))
			printk(" >\n");
	}

	for (cnt = 1; cnt < msg->len; cnt++) {
		/* following bytes */
		wdata = msg->buf[cnt];
		ctrl = bus->i2c_period | (1 << 12) | (1 << 2);

		if (cnt < msg->len - 1)
			ctrl |= I2C_NOSTOP | I2C_EXTEND;
		else if (joined_rlen)
			ctrl |= I2C_NOSTOP;

		cx_write(bus->reg_addr, addr);
		cx_write(bus->reg_wdata, wdata);
		cx_write(bus->reg_ctrl, ctrl);

		retval = i2c_wait_done(i2c_adap);
		if (retval < 0)
			goto err;

		if (retval == 0)
			goto eio;

		if (i2c_debug) {
			dprintk(1, " %02x", msg->buf[cnt]);
			if (!(ctrl & I2C_NOSTOP))
				dprintk(1, " >\n");
		}
	}

	return msg->len;

eio:
	retval = -EIO;
err:
	if (i2c_debug)
		pr_err(" ERR: %d\n", retval);
	return retval;
}

static int i2c_readbytes(struct i2c_adapter *i2c_adap,
			 const struct i2c_msg *msg, int joined)
{
	struct cx25821_i2c *bus = i2c_adap->algo_data;
	struct cx25821_dev *dev = bus->dev;
	u32 ctrl, cnt;
	int retval;

	if (i2c_debug && !joined)
		dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len);

	/* Deal with i2c probe functions with zero payload */
	if (msg->len == 0) {
		cx_write(bus->reg_addr, msg->addr << 25);
		cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
		if (!i2c_wait_done(i2c_adap))
			return -EIO;
		if (!i2c_slave_did_ack(i2c_adap))
			return -EIO;

		dprintk(1, "%s(): returns 0\n", __func__);
		return 0;
	}

	if (i2c_debug) {
		if (joined)
			dprintk(1, " R");
		else
			dprintk(1, " <R %02x", (msg->addr << 1) + 1);
	}

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

		ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;

		if (cnt < msg->len - 1)
			ctrl |= I2C_NOSTOP | I2C_EXTEND;

		cx_write(bus->reg_addr, msg->addr << 25);
		cx_write(bus->reg_ctrl, ctrl);

		retval = i2c_wait_done(i2c_adap);
		if (retval < 0)
			goto err;
		if (retval == 0)
			goto eio;
		msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;

		if (i2c_debug) {
			dprintk(1, " %02x", msg->buf[cnt]);
			if (!(ctrl & I2C_NOSTOP))
				dprintk(1, " >\n");
		}
	}

	return msg->len;
eio:
	retval = -EIO;
err:
	if (i2c_debug)
		pr_err(" ERR: %d\n", retval);
	return retval;
}

static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
	struct cx25821_i2c *bus = i2c_adap->algo_data;
	struct cx25821_dev *dev = bus->dev;
	int i, retval = 0;

	dprintk(1, "%s(num = %d)\n", __func__, num);

	for (i = 0; i < num; i++) {
		dprintk(1, "%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 cx25821_functionality(struct i2c_adapter *adap)
{
	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA |
		I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA;
}

static struct i2c_algorithm cx25821_i2c_algo_template = {
	.master_xfer = i2c_xfer,
	.functionality = cx25821_functionality,
#ifdef NEED_ALGO_CONTROL
	.algo_control = dummy_algo_control,
#endif
};

static struct i2c_adapter cx25821_i2c_adap_template = {
	.name = "cx25821",
	.owner = THIS_MODULE,
	.algo = &cx25821_i2c_algo_template,
};

static struct i2c_client cx25821_i2c_client_template = {
	.name = "cx25821 internal",
};

/* init + register i2c adapter */
int cx25821_i2c_register(struct cx25821_i2c *bus)
{
	struct cx25821_dev *dev = bus->dev;

	dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);

	bus->i2c_adap = cx25821_i2c_adap_template;
	bus->i2c_client = cx25821_i2c_client_template;
	bus->i2c_adap.dev.parent = &dev->pci->dev;

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

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

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

	/* set up the I2c */
	bus->i2c_client.addr = (0x88 >> 1);

	return bus->i2c_rc;
}

int cx25821_i2c_unregister(struct cx25821_i2c *bus)
{
	i2c_del_adapter(&bus->i2c_adap);
	return 0;
}

#if 0 /* Currently unused */
static void cx25821_av_clk(struct cx25821_dev *dev, int enable)
{
	/* write 0 to bus 2 addr 0x144 via i2x_xfer() */
	char buffer[3];
	struct i2c_msg msg;
	dprintk(1, "%s(enabled = %d)\n", __func__, enable);

	/* Register 0x144 */
	buffer[0] = 0x01;
	buffer[1] = 0x44;
	if (enable == 1)
		buffer[2] = 0x05;
	else
		buffer[2] = 0x00;

	msg.addr = 0x44;
	msg.flags = I2C_M_TEN;
	msg.len = 3;
	msg.buf = buffer;

	i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1);
}
#endif

int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value)
{
	struct i2c_client *client = &bus->i2c_client;
	int v = 0;
	u8 addr[2] = { 0, 0 };
	u8 buf[4] = { 0, 0, 0, 0 };

	struct i2c_msg msgs[2] = {
		{
			.addr = client->addr,
			.flags = 0,
			.len = 2,
			.buf = addr,
		}, {
			.addr = client->addr,
			.flags = I2C_M_RD,
			.len = 4,
			.buf = buf,
		}
	};

	addr[0] = (reg_addr >> 8);
	addr[1] = (reg_addr & 0xff);
	msgs[0].addr = 0x44;
	msgs[1].addr = 0x44;

	i2c_xfer(client->adapter, msgs, 2);

	v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
	*value = v;

	return v;
}

int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value)
{
	struct i2c_client *client = &bus->i2c_client;
	int retval = 0;
	u8 buf[6] = { 0, 0, 0, 0, 0, 0 };

	struct i2c_msg msgs[1] = {
		{
			.addr = client->addr,
			.flags = 0,
			.len = 6,
			.buf = buf,
		}
	};

	buf[0] = reg_addr >> 8;
	buf[1] = reg_addr & 0xff;
	buf[5] = (value >> 24) & 0xff;
	buf[4] = (value >> 16) & 0xff;
	buf[3] = (value >> 8) & 0xff;
	buf[2] = value & 0xff;
	client->flags = 0;
	msgs[0].addr = 0x44;

	retval = i2c_xfer(client->adapter, msgs, 1);

	return retval;
}