xref: /linux/drivers/media/usb/dvb-usb-v2/mxl111sf-i2c.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  *  mxl111sf-i2c.c - driver for the MaxLinear MXL111SF
3  *
4  *  Copyright (C) 2010-2014 Michael Krufky <mkrufky@linuxtv.org>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  */
16 
17 #include "mxl111sf-i2c.h"
18 #include "mxl111sf.h"
19 
20 /* SW-I2C ----------------------------------------------------------------- */
21 
22 #define SW_I2C_ADDR		0x1a
23 #define SW_I2C_EN		0x02
24 #define SW_SCL_OUT		0x04
25 #define SW_SDA_OUT		0x08
26 #define SW_SDA_IN		0x04
27 
28 #define SW_I2C_BUSY_ADDR	0x2f
29 #define SW_I2C_BUSY		0x02
30 
31 static int mxl111sf_i2c_bitbang_sendbyte(struct mxl111sf_state *state,
32 					 u8 byte)
33 {
34 	int i, ret;
35 	u8 data = 0;
36 
37 	mxl_i2c("(0x%02x)", byte);
38 
39 	ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &data);
40 	if (mxl_fail(ret))
41 		goto fail;
42 
43 	for (i = 0; i < 8; i++) {
44 
45 		data = (byte & (0x80 >> i)) ? SW_SDA_OUT : 0;
46 
47 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
48 					 0x10 | SW_I2C_EN | data);
49 		if (mxl_fail(ret))
50 			goto fail;
51 
52 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
53 					 0x10 | SW_I2C_EN | data | SW_SCL_OUT);
54 		if (mxl_fail(ret))
55 			goto fail;
56 
57 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
58 					 0x10 | SW_I2C_EN | data);
59 		if (mxl_fail(ret))
60 			goto fail;
61 	}
62 
63 	/* last bit was 0 so we need to release SDA */
64 	if (!(byte & 1)) {
65 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
66 					 0x10 | SW_I2C_EN | SW_SDA_OUT);
67 		if (mxl_fail(ret))
68 			goto fail;
69 	}
70 
71 	/* CLK high for ACK readback */
72 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
73 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
74 	if (mxl_fail(ret))
75 		goto fail;
76 
77 	ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &data);
78 	if (mxl_fail(ret))
79 		goto fail;
80 
81 	/* drop the CLK after getting ACK, SDA will go high right away */
82 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
83 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
84 	if (mxl_fail(ret))
85 		goto fail;
86 
87 	if (data & SW_SDA_IN)
88 		ret = -EIO;
89 fail:
90 	return ret;
91 }
92 
93 static int mxl111sf_i2c_bitbang_recvbyte(struct mxl111sf_state *state,
94 					 u8 *pbyte)
95 {
96 	int i, ret;
97 	u8 byte = 0;
98 	u8 data = 0;
99 
100 	mxl_i2c("()");
101 
102 	*pbyte = 0;
103 
104 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
105 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
106 	if (mxl_fail(ret))
107 		goto fail;
108 
109 	for (i = 0; i < 8; i++) {
110 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
111 					 0x10 | SW_I2C_EN |
112 					 SW_SCL_OUT | SW_SDA_OUT);
113 		if (mxl_fail(ret))
114 			goto fail;
115 
116 		ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &data);
117 		if (mxl_fail(ret))
118 			goto fail;
119 
120 		if (data & SW_SDA_IN)
121 			byte |= (0x80 >> i);
122 
123 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
124 					 0x10 | SW_I2C_EN | SW_SDA_OUT);
125 		if (mxl_fail(ret))
126 			goto fail;
127 	}
128 	*pbyte = byte;
129 fail:
130 	return ret;
131 }
132 
133 static int mxl111sf_i2c_start(struct mxl111sf_state *state)
134 {
135 	int ret;
136 
137 	mxl_i2c("()");
138 
139 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
140 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
141 	if (mxl_fail(ret))
142 		goto fail;
143 
144 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
145 				 0x10 | SW_I2C_EN | SW_SCL_OUT);
146 	if (mxl_fail(ret))
147 		goto fail;
148 
149 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
150 				 0x10 | SW_I2C_EN); /* start */
151 	mxl_fail(ret);
152 fail:
153 	return ret;
154 }
155 
156 static int mxl111sf_i2c_stop(struct mxl111sf_state *state)
157 {
158 	int ret;
159 
160 	mxl_i2c("()");
161 
162 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
163 				 0x10 | SW_I2C_EN); /* stop */
164 	if (mxl_fail(ret))
165 		goto fail;
166 
167 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
168 				 0x10 | SW_I2C_EN | SW_SCL_OUT);
169 	if (mxl_fail(ret))
170 		goto fail;
171 
172 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
173 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
174 	if (mxl_fail(ret))
175 		goto fail;
176 
177 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
178 				 0x10 | SW_SCL_OUT | SW_SDA_OUT);
179 	mxl_fail(ret);
180 fail:
181 	return ret;
182 }
183 
184 static int mxl111sf_i2c_ack(struct mxl111sf_state *state)
185 {
186 	int ret;
187 	u8 b = 0;
188 
189 	mxl_i2c("()");
190 
191 	ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &b);
192 	if (mxl_fail(ret))
193 		goto fail;
194 
195 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
196 				 0x10 | SW_I2C_EN);
197 	if (mxl_fail(ret))
198 		goto fail;
199 
200 	/* pull SDA low */
201 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
202 				 0x10 | SW_I2C_EN | SW_SCL_OUT);
203 	if (mxl_fail(ret))
204 		goto fail;
205 
206 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
207 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
208 	mxl_fail(ret);
209 fail:
210 	return ret;
211 }
212 
213 static int mxl111sf_i2c_nack(struct mxl111sf_state *state)
214 {
215 	int ret;
216 
217 	mxl_i2c("()");
218 
219 	/* SDA high to signal last byte read from slave */
220 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
221 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
222 	if (mxl_fail(ret))
223 		goto fail;
224 
225 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
226 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
227 	mxl_fail(ret);
228 fail:
229 	return ret;
230 }
231 
232 /* ------------------------------------------------------------------------ */
233 
234 static int mxl111sf_i2c_sw_xfer_msg(struct mxl111sf_state *state,
235 				    struct i2c_msg *msg)
236 {
237 	int i, ret;
238 
239 	mxl_i2c("()");
240 
241 	if (msg->flags & I2C_M_RD) {
242 
243 		ret = mxl111sf_i2c_start(state);
244 		if (mxl_fail(ret))
245 			goto fail;
246 
247 		ret = mxl111sf_i2c_bitbang_sendbyte(state,
248 						    (msg->addr << 1) | 0x01);
249 		if (mxl_fail(ret)) {
250 			mxl111sf_i2c_stop(state);
251 			goto fail;
252 		}
253 
254 		for (i = 0; i < msg->len; i++) {
255 			ret = mxl111sf_i2c_bitbang_recvbyte(state,
256 							    &msg->buf[i]);
257 			if (mxl_fail(ret)) {
258 				mxl111sf_i2c_stop(state);
259 				goto fail;
260 			}
261 
262 			if (i < msg->len - 1)
263 				mxl111sf_i2c_ack(state);
264 		}
265 
266 		mxl111sf_i2c_nack(state);
267 
268 		ret = mxl111sf_i2c_stop(state);
269 		if (mxl_fail(ret))
270 			goto fail;
271 
272 	} else {
273 
274 		ret = mxl111sf_i2c_start(state);
275 		if (mxl_fail(ret))
276 			goto fail;
277 
278 		ret = mxl111sf_i2c_bitbang_sendbyte(state,
279 						    (msg->addr << 1) & 0xfe);
280 		if (mxl_fail(ret)) {
281 			mxl111sf_i2c_stop(state);
282 			goto fail;
283 		}
284 
285 		for (i = 0; i < msg->len; i++) {
286 			ret = mxl111sf_i2c_bitbang_sendbyte(state,
287 							    msg->buf[i]);
288 			if (mxl_fail(ret)) {
289 				mxl111sf_i2c_stop(state);
290 				goto fail;
291 			}
292 		}
293 
294 		/* FIXME: we only want to do this on the last transaction */
295 		mxl111sf_i2c_stop(state);
296 	}
297 fail:
298 	return ret;
299 }
300 
301 /* HW-I2C ----------------------------------------------------------------- */
302 
303 #define USB_WRITE_I2C_CMD     0x99
304 #define USB_READ_I2C_CMD      0xdd
305 #define USB_END_I2C_CMD       0xfe
306 
307 #define USB_WRITE_I2C_CMD_LEN   26
308 #define USB_READ_I2C_CMD_LEN    24
309 
310 #define I2C_MUX_REG           0x30
311 #define I2C_CONTROL_REG       0x00
312 #define I2C_SLAVE_ADDR_REG    0x08
313 #define I2C_DATA_REG          0x0c
314 #define I2C_INT_STATUS_REG    0x10
315 
316 static int mxl111sf_i2c_send_data(struct mxl111sf_state *state,
317 				  u8 index, u8 *wdata)
318 {
319 	int ret = mxl111sf_ctrl_msg(state->d, wdata[0],
320 				    &wdata[1], 25, NULL, 0);
321 	mxl_fail(ret);
322 
323 	return ret;
324 }
325 
326 static int mxl111sf_i2c_get_data(struct mxl111sf_state *state,
327 				 u8 index, u8 *wdata, u8 *rdata)
328 {
329 	int ret = mxl111sf_ctrl_msg(state->d, wdata[0],
330 				    &wdata[1], 25, rdata, 24);
331 	mxl_fail(ret);
332 
333 	return ret;
334 }
335 
336 static u8 mxl111sf_i2c_check_status(struct mxl111sf_state *state)
337 {
338 	u8 status = 0;
339 	u8 buf[26];
340 
341 	mxl_i2c_adv("()");
342 
343 	buf[0] = USB_READ_I2C_CMD;
344 	buf[1] = 0x00;
345 
346 	buf[2] = I2C_INT_STATUS_REG;
347 	buf[3] = 0x00;
348 	buf[4] = 0x00;
349 
350 	buf[5] = USB_END_I2C_CMD;
351 
352 	mxl111sf_i2c_get_data(state, 0, buf, buf);
353 
354 	if (buf[1] & 0x04)
355 		status = 1;
356 
357 	return status;
358 }
359 
360 static u8 mxl111sf_i2c_check_fifo(struct mxl111sf_state *state)
361 {
362 	u8 status = 0;
363 	u8 buf[26];
364 
365 	mxl_i2c("()");
366 
367 	buf[0] = USB_READ_I2C_CMD;
368 	buf[1] = 0x00;
369 
370 	buf[2] = I2C_MUX_REG;
371 	buf[3] = 0x00;
372 	buf[4] = 0x00;
373 
374 	buf[5] = I2C_INT_STATUS_REG;
375 	buf[6] = 0x00;
376 	buf[7] = 0x00;
377 	buf[8] = USB_END_I2C_CMD;
378 
379 	mxl111sf_i2c_get_data(state, 0, buf, buf);
380 
381 	if (0x08 == (buf[1] & 0x08))
382 		status = 1;
383 
384 	if ((buf[5] & 0x02) == 0x02)
385 		mxl_i2c("(buf[5] & 0x02) == 0x02"); /* FIXME */
386 
387 	return status;
388 }
389 
390 static int mxl111sf_i2c_readagain(struct mxl111sf_state *state,
391 				  u8 count, u8 *rbuf)
392 {
393 	u8 i2c_w_data[26];
394 	u8 i2c_r_data[24];
395 	u8 i = 0;
396 	u8 fifo_status = 0;
397 	int status = 0;
398 
399 	mxl_i2c("read %d bytes", count);
400 
401 	while ((fifo_status == 0) && (i++ < 5))
402 		fifo_status = mxl111sf_i2c_check_fifo(state);
403 
404 	i2c_w_data[0] = 0xDD;
405 	i2c_w_data[1] = 0x00;
406 
407 	for (i = 2; i < 26; i++)
408 		i2c_w_data[i] = 0xFE;
409 
410 	for (i = 0; i < count; i++) {
411 		i2c_w_data[2+(i*3)] = 0x0C;
412 		i2c_w_data[3+(i*3)] = 0x00;
413 		i2c_w_data[4+(i*3)] = 0x00;
414 	}
415 
416 	mxl111sf_i2c_get_data(state, 0, i2c_w_data, i2c_r_data);
417 
418 	/* Check for I2C NACK status */
419 	if (mxl111sf_i2c_check_status(state) == 1) {
420 		mxl_i2c("error!");
421 	} else {
422 		for (i = 0; i < count; i++) {
423 			rbuf[i] = i2c_r_data[(i*3)+1];
424 			mxl_i2c("%02x\t %02x",
425 				i2c_r_data[(i*3)+1],
426 				i2c_r_data[(i*3)+2]);
427 		}
428 
429 		status = 1;
430 	}
431 
432 	return status;
433 }
434 
435 #define HWI2C400 1
436 static int mxl111sf_i2c_hw_xfer_msg(struct mxl111sf_state *state,
437 				    struct i2c_msg *msg)
438 {
439 	int i, k, ret = 0;
440 	u16 index = 0;
441 	u8 buf[26];
442 	u8 i2c_r_data[24];
443 	u16 block_len;
444 	u16 left_over_len;
445 	u8 rd_status[8];
446 	u8 ret_status;
447 	u8 readbuff[26];
448 
449 	mxl_i2c("addr: 0x%02x, read buff len: %d, write buff len: %d",
450 		msg->addr, (msg->flags & I2C_M_RD) ? msg->len : 0,
451 		(!(msg->flags & I2C_M_RD)) ? msg->len : 0);
452 
453 	for (index = 0; index < 26; index++)
454 		buf[index] = USB_END_I2C_CMD;
455 
456 	/* command to indicate data payload is destined for I2C interface */
457 	buf[0] = USB_WRITE_I2C_CMD;
458 	buf[1] = 0x00;
459 
460 	/* enable I2C interface */
461 	buf[2] = I2C_MUX_REG;
462 	buf[3] = 0x80;
463 	buf[4] = 0x00;
464 
465 	/* enable I2C interface */
466 	buf[5] = I2C_MUX_REG;
467 	buf[6] = 0x81;
468 	buf[7] = 0x00;
469 
470 	/* set Timeout register on I2C interface */
471 	buf[8] = 0x14;
472 	buf[9] = 0xff;
473 	buf[10] = 0x00;
474 #if 0
475 	/* enable Interrupts on I2C interface */
476 	buf[8] = 0x24;
477 	buf[9] = 0xF7;
478 	buf[10] = 0x00;
479 #endif
480 	buf[11] = 0x24;
481 	buf[12] = 0xF7;
482 	buf[13] = 0x00;
483 
484 	ret = mxl111sf_i2c_send_data(state, 0, buf);
485 
486 	/* write data on I2C bus */
487 	if (!(msg->flags & I2C_M_RD) && (msg->len > 0)) {
488 		mxl_i2c("%d\t%02x", msg->len, msg->buf[0]);
489 
490 		/* control register on I2C interface to initialize I2C bus */
491 		buf[2] = I2C_CONTROL_REG;
492 		buf[3] = 0x5E;
493 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
494 
495 		/* I2C Slave device Address */
496 		buf[5] = I2C_SLAVE_ADDR_REG;
497 		buf[6] = (msg->addr);
498 		buf[7] = 0x00;
499 		buf[8] = USB_END_I2C_CMD;
500 		ret = mxl111sf_i2c_send_data(state, 0, buf);
501 
502 		/* check for slave device status */
503 		if (mxl111sf_i2c_check_status(state) == 1) {
504 			mxl_i2c("NACK writing slave address %02x",
505 				msg->addr);
506 			/* if NACK, stop I2C bus and exit */
507 			buf[2] = I2C_CONTROL_REG;
508 			buf[3] = 0x4E;
509 			buf[4] = (HWI2C400) ? 0x03 : 0x0D;
510 			ret = -EIO;
511 			goto exit;
512 		}
513 
514 		/* I2C interface can do I2C operations in block of 8 bytes of
515 		   I2C data. calculation to figure out number of blocks of i2c
516 		   data required to program */
517 		block_len = (msg->len / 8);
518 		left_over_len = (msg->len % 8);
519 		index = 0;
520 
521 		mxl_i2c("block_len %d, left_over_len %d",
522 			block_len, left_over_len);
523 
524 		for (index = 0; index < block_len; index++) {
525 			for (i = 0; i < 8; i++) {
526 				/* write data on I2C interface */
527 				buf[2+(i*3)] = I2C_DATA_REG;
528 				buf[3+(i*3)] = msg->buf[(index*8)+i];
529 				buf[4+(i*3)] = 0x00;
530 			}
531 
532 			ret = mxl111sf_i2c_send_data(state, 0, buf);
533 
534 			/* check for I2C NACK status */
535 			if (mxl111sf_i2c_check_status(state) == 1) {
536 				mxl_i2c("NACK writing slave address %02x",
537 					msg->addr);
538 
539 				/* if NACK, stop I2C bus and exit */
540 				buf[2] = I2C_CONTROL_REG;
541 				buf[3] = 0x4E;
542 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
543 				ret = -EIO;
544 				goto exit;
545 			}
546 
547 		}
548 
549 		if (left_over_len) {
550 			for (k = 0; k < 26; k++)
551 				buf[k] = USB_END_I2C_CMD;
552 
553 			buf[0] = 0x99;
554 			buf[1] = 0x00;
555 
556 			for (i = 0; i < left_over_len; i++) {
557 				buf[2+(i*3)] = I2C_DATA_REG;
558 				buf[3+(i*3)] = msg->buf[(index*8)+i];
559 				mxl_i2c("index = %d %d data %d",
560 					index, i, msg->buf[(index*8)+i]);
561 				buf[4+(i*3)] = 0x00;
562 			}
563 			ret = mxl111sf_i2c_send_data(state, 0, buf);
564 
565 			/* check for I2C NACK status */
566 			if (mxl111sf_i2c_check_status(state) == 1) {
567 				mxl_i2c("NACK writing slave address %02x",
568 					msg->addr);
569 
570 				/* if NACK, stop I2C bus and exit */
571 				buf[2] = I2C_CONTROL_REG;
572 				buf[3] = 0x4E;
573 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
574 				ret = -EIO;
575 				goto exit;
576 			}
577 
578 		}
579 
580 		/* issue I2C STOP after write */
581 		buf[2] = I2C_CONTROL_REG;
582 		buf[3] = 0x4E;
583 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
584 
585 	}
586 
587 	/* read data from I2C bus */
588 	if ((msg->flags & I2C_M_RD) && (msg->len > 0)) {
589 		mxl_i2c("read buf len %d", msg->len);
590 
591 		/* command to indicate data payload is
592 		   destined for I2C interface */
593 		buf[2] = I2C_CONTROL_REG;
594 		buf[3] = 0xDF;
595 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
596 
597 		/* I2C xfer length */
598 		buf[5] = 0x14;
599 		buf[6] = (msg->len & 0xFF);
600 		buf[7] = 0;
601 
602 		/* I2C slave device Address */
603 		buf[8] = I2C_SLAVE_ADDR_REG;
604 		buf[9] = msg->addr;
605 		buf[10] = 0x00;
606 		buf[11] = USB_END_I2C_CMD;
607 		ret = mxl111sf_i2c_send_data(state, 0, buf);
608 
609 		/* check for I2C NACK status */
610 		if (mxl111sf_i2c_check_status(state) == 1) {
611 			mxl_i2c("NACK reading slave address %02x",
612 				msg->addr);
613 
614 			/* if NACK, stop I2C bus and exit */
615 			buf[2] = I2C_CONTROL_REG;
616 			buf[3] = 0xC7;
617 			buf[4] = (HWI2C400) ? 0x03 : 0x0D;
618 			ret = -EIO;
619 			goto exit;
620 		}
621 
622 		/* I2C interface can do I2C operations in block of 8 bytes of
623 		   I2C data. calculation to figure out number of blocks of
624 		   i2c data required to program */
625 		block_len = ((msg->len) / 8);
626 		left_over_len = ((msg->len) % 8);
627 		index = 0;
628 
629 		mxl_i2c("block_len %d, left_over_len %d",
630 			block_len, left_over_len);
631 
632 		/* command to read data from I2C interface */
633 		buf[0] = USB_READ_I2C_CMD;
634 		buf[1] = 0x00;
635 
636 		for (index = 0; index < block_len; index++) {
637 			/* setup I2C read request packet on I2C interface */
638 			for (i = 0; i < 8; i++) {
639 				buf[2+(i*3)] = I2C_DATA_REG;
640 				buf[3+(i*3)] = 0x00;
641 				buf[4+(i*3)] = 0x00;
642 			}
643 
644 			ret = mxl111sf_i2c_get_data(state, 0, buf, i2c_r_data);
645 
646 			/* check for I2C NACK status */
647 			if (mxl111sf_i2c_check_status(state) == 1) {
648 				mxl_i2c("NACK reading slave address %02x",
649 					msg->addr);
650 
651 				/* if NACK, stop I2C bus and exit */
652 				buf[2] = I2C_CONTROL_REG;
653 				buf[3] = 0xC7;
654 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
655 				ret = -EIO;
656 				goto exit;
657 			}
658 
659 			/* copy data from i2c data payload to read buffer */
660 			for (i = 0; i < 8; i++) {
661 				rd_status[i] = i2c_r_data[(i*3)+2];
662 
663 				if (rd_status[i] == 0x04) {
664 					if (i < 7) {
665 						mxl_i2c("i2c fifo empty! @ %d",
666 							i);
667 						msg->buf[(index*8)+i] =
668 							i2c_r_data[(i*3)+1];
669 						/* read again */
670 						ret_status =
671 							mxl111sf_i2c_readagain(
672 								state, 8-(i+1),
673 								readbuff);
674 						if (ret_status == 1) {
675 							for (k = 0;
676 							     k < 8-(i+1);
677 							     k++) {
678 
679 					msg->buf[(index*8)+(k+i+1)] =
680 						readbuff[k];
681 					mxl_i2c("read data: %02x\t %02x",
682 						msg->buf[(index*8)+(k+i)],
683 						(index*8)+(k+i));
684 					mxl_i2c("read data: %02x\t %02x",
685 						msg->buf[(index*8)+(k+i+1)],
686 						readbuff[k]);
687 
688 							}
689 							goto stop_copy;
690 						} else {
691 							mxl_i2c("readagain ERROR!");
692 						}
693 					} else {
694 						msg->buf[(index*8)+i] =
695 							i2c_r_data[(i*3)+1];
696 					}
697 				} else {
698 					msg->buf[(index*8)+i] =
699 						i2c_r_data[(i*3)+1];
700 				}
701 			}
702 stop_copy:
703 			;
704 
705 		}
706 
707 		if (left_over_len) {
708 			for (k = 0; k < 26; k++)
709 				buf[k] = USB_END_I2C_CMD;
710 
711 			buf[0] = 0xDD;
712 			buf[1] = 0x00;
713 
714 			for (i = 0; i < left_over_len; i++) {
715 				buf[2+(i*3)] = I2C_DATA_REG;
716 				buf[3+(i*3)] = 0x00;
717 				buf[4+(i*3)] = 0x00;
718 			}
719 			ret = mxl111sf_i2c_get_data(state, 0, buf,
720 						    i2c_r_data);
721 
722 			/* check for I2C NACK status */
723 			if (mxl111sf_i2c_check_status(state) == 1) {
724 				mxl_i2c("NACK reading slave address %02x",
725 					msg->addr);
726 
727 				/* if NACK, stop I2C bus and exit */
728 				buf[2] = I2C_CONTROL_REG;
729 				buf[3] = 0xC7;
730 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
731 				ret = -EIO;
732 				goto exit;
733 			}
734 
735 			for (i = 0; i < left_over_len; i++) {
736 				msg->buf[(block_len*8)+i] =
737 					i2c_r_data[(i*3)+1];
738 				mxl_i2c("read data: %02x\t %02x",
739 					i2c_r_data[(i*3)+1],
740 					i2c_r_data[(i*3)+2]);
741 			}
742 		}
743 
744 		/* indicate I2C interface to issue NACK
745 		   after next I2C read op */
746 		buf[0] = USB_WRITE_I2C_CMD;
747 		buf[1] = 0x00;
748 
749 		/* control register */
750 		buf[2] = I2C_CONTROL_REG;
751 		buf[3] = 0x17;
752 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
753 
754 		buf[5] = USB_END_I2C_CMD;
755 		ret = mxl111sf_i2c_send_data(state, 0, buf);
756 
757 		/* control register */
758 		buf[2] = I2C_CONTROL_REG;
759 		buf[3] = 0xC7;
760 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
761 
762 	}
763 exit:
764 	/* STOP and disable I2C MUX */
765 	buf[0] = USB_WRITE_I2C_CMD;
766 	buf[1] = 0x00;
767 
768 	/* de-initilize I2C BUS */
769 	buf[5] = USB_END_I2C_CMD;
770 	mxl111sf_i2c_send_data(state, 0, buf);
771 
772 	/* Control Register */
773 	buf[2] = I2C_CONTROL_REG;
774 	buf[3] = 0xDF;
775 	buf[4] = 0x03;
776 
777 	/* disable I2C interface */
778 	buf[5] = I2C_MUX_REG;
779 	buf[6] = 0x00;
780 	buf[7] = 0x00;
781 
782 	/* de-initilize I2C BUS */
783 	buf[8] = USB_END_I2C_CMD;
784 	mxl111sf_i2c_send_data(state, 0, buf);
785 
786 	/* disable I2C interface */
787 	buf[2] = I2C_MUX_REG;
788 	buf[3] = 0x81;
789 	buf[4] = 0x00;
790 
791 	/* disable I2C interface */
792 	buf[5] = I2C_MUX_REG;
793 	buf[6] = 0x00;
794 	buf[7] = 0x00;
795 
796 	/* disable I2C interface */
797 	buf[8] = I2C_MUX_REG;
798 	buf[9] = 0x00;
799 	buf[10] = 0x00;
800 
801 	buf[11] = USB_END_I2C_CMD;
802 	mxl111sf_i2c_send_data(state, 0, buf);
803 
804 	return ret;
805 }
806 
807 /* ------------------------------------------------------------------------ */
808 
809 int mxl111sf_i2c_xfer(struct i2c_adapter *adap,
810 		      struct i2c_msg msg[], int num)
811 {
812 	struct dvb_usb_device *d = i2c_get_adapdata(adap);
813 	struct mxl111sf_state *state = d->priv;
814 	int hwi2c = (state->chip_rev > MXL111SF_V6);
815 	int i, ret;
816 
817 	if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
818 		return -EAGAIN;
819 
820 	for (i = 0; i < num; i++) {
821 		ret = (hwi2c) ?
822 			mxl111sf_i2c_hw_xfer_msg(state, &msg[i]) :
823 			mxl111sf_i2c_sw_xfer_msg(state, &msg[i]);
824 		if (mxl_fail(ret)) {
825 			mxl_debug_adv("failed with error %d on i2c transaction %d of %d, %sing %d bytes to/from 0x%02x",
826 				      ret, i+1, num,
827 				      (msg[i].flags & I2C_M_RD) ?
828 				      "read" : "writ",
829 				      msg[i].len, msg[i].addr);
830 
831 			break;
832 		}
833 	}
834 
835 	mutex_unlock(&d->i2c_mutex);
836 
837 	return i == num ? num : -EREMOTEIO;
838 }
839