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  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 
21 #include "mxl111sf-i2c.h"
22 #include "mxl111sf.h"
23 
24 /* SW-I2C ----------------------------------------------------------------- */
25 
26 #define SW_I2C_ADDR		0x1a
27 #define SW_I2C_EN		0x02
28 #define SW_SCL_OUT		0x04
29 #define SW_SDA_OUT		0x08
30 #define SW_SDA_IN		0x04
31 
32 #define SW_I2C_BUSY_ADDR	0x2f
33 #define SW_I2C_BUSY		0x02
34 
35 static int mxl111sf_i2c_bitbang_sendbyte(struct mxl111sf_state *state,
36 					 u8 byte)
37 {
38 	int i, ret;
39 	u8 data = 0;
40 
41 	mxl_i2c("(0x%02x)", byte);
42 
43 	ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &data);
44 	if (mxl_fail(ret))
45 		goto fail;
46 
47 	for (i = 0; i < 8; i++) {
48 
49 		data = (byte & (0x80 >> i)) ? SW_SDA_OUT : 0;
50 
51 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
52 					 0x10 | SW_I2C_EN | data);
53 		if (mxl_fail(ret))
54 			goto fail;
55 
56 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
57 					 0x10 | SW_I2C_EN | data | SW_SCL_OUT);
58 		if (mxl_fail(ret))
59 			goto fail;
60 
61 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
62 					 0x10 | SW_I2C_EN | data);
63 		if (mxl_fail(ret))
64 			goto fail;
65 	}
66 
67 	/* last bit was 0 so we need to release SDA */
68 	if (!(byte & 1)) {
69 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
70 					 0x10 | SW_I2C_EN | SW_SDA_OUT);
71 		if (mxl_fail(ret))
72 			goto fail;
73 	}
74 
75 	/* CLK high for ACK readback */
76 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
77 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
78 	if (mxl_fail(ret))
79 		goto fail;
80 
81 	ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &data);
82 	if (mxl_fail(ret))
83 		goto fail;
84 
85 	/* drop the CLK after getting ACK, SDA will go high right away */
86 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
87 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
88 	if (mxl_fail(ret))
89 		goto fail;
90 
91 	if (data & SW_SDA_IN)
92 		ret = -EIO;
93 fail:
94 	return ret;
95 }
96 
97 static int mxl111sf_i2c_bitbang_recvbyte(struct mxl111sf_state *state,
98 					 u8 *pbyte)
99 {
100 	int i, ret;
101 	u8 byte = 0;
102 	u8 data = 0;
103 
104 	mxl_i2c("()");
105 
106 	*pbyte = 0;
107 
108 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
109 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
110 	if (mxl_fail(ret))
111 		goto fail;
112 
113 	for (i = 0; i < 8; i++) {
114 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
115 					 0x10 | SW_I2C_EN |
116 					 SW_SCL_OUT | SW_SDA_OUT);
117 		if (mxl_fail(ret))
118 			goto fail;
119 
120 		ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &data);
121 		if (mxl_fail(ret))
122 			goto fail;
123 
124 		if (data & SW_SDA_IN)
125 			byte |= (0x80 >> i);
126 
127 		ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
128 					 0x10 | SW_I2C_EN | SW_SDA_OUT);
129 		if (mxl_fail(ret))
130 			goto fail;
131 	}
132 	*pbyte = byte;
133 fail:
134 	return ret;
135 }
136 
137 static int mxl111sf_i2c_start(struct mxl111sf_state *state)
138 {
139 	int ret;
140 
141 	mxl_i2c("()");
142 
143 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
144 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
145 	if (mxl_fail(ret))
146 		goto fail;
147 
148 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
149 				 0x10 | SW_I2C_EN | SW_SCL_OUT);
150 	if (mxl_fail(ret))
151 		goto fail;
152 
153 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
154 				 0x10 | SW_I2C_EN); /* start */
155 	mxl_fail(ret);
156 fail:
157 	return ret;
158 }
159 
160 static int mxl111sf_i2c_stop(struct mxl111sf_state *state)
161 {
162 	int ret;
163 
164 	mxl_i2c("()");
165 
166 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
167 				 0x10 | SW_I2C_EN); /* stop */
168 	if (mxl_fail(ret))
169 		goto fail;
170 
171 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
172 				 0x10 | SW_I2C_EN | SW_SCL_OUT);
173 	if (mxl_fail(ret))
174 		goto fail;
175 
176 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
177 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
178 	if (mxl_fail(ret))
179 		goto fail;
180 
181 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
182 				 0x10 | SW_SCL_OUT | SW_SDA_OUT);
183 	mxl_fail(ret);
184 fail:
185 	return ret;
186 }
187 
188 static int mxl111sf_i2c_ack(struct mxl111sf_state *state)
189 {
190 	int ret;
191 	u8 b = 0;
192 
193 	mxl_i2c("()");
194 
195 	ret = mxl111sf_read_reg(state, SW_I2C_BUSY_ADDR, &b);
196 	if (mxl_fail(ret))
197 		goto fail;
198 
199 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
200 				 0x10 | SW_I2C_EN);
201 	if (mxl_fail(ret))
202 		goto fail;
203 
204 	/* pull SDA low */
205 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
206 				 0x10 | SW_I2C_EN | SW_SCL_OUT);
207 	if (mxl_fail(ret))
208 		goto fail;
209 
210 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
211 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
212 	mxl_fail(ret);
213 fail:
214 	return ret;
215 }
216 
217 static int mxl111sf_i2c_nack(struct mxl111sf_state *state)
218 {
219 	int ret;
220 
221 	mxl_i2c("()");
222 
223 	/* SDA high to signal last byte read from slave */
224 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
225 				 0x10 | SW_I2C_EN | SW_SCL_OUT | SW_SDA_OUT);
226 	if (mxl_fail(ret))
227 		goto fail;
228 
229 	ret = mxl111sf_write_reg(state, SW_I2C_ADDR,
230 				 0x10 | SW_I2C_EN | SW_SDA_OUT);
231 	mxl_fail(ret);
232 fail:
233 	return ret;
234 }
235 
236 /* ------------------------------------------------------------------------ */
237 
238 static int mxl111sf_i2c_sw_xfer_msg(struct mxl111sf_state *state,
239 				    struct i2c_msg *msg)
240 {
241 	int i, ret;
242 
243 	mxl_i2c("()");
244 
245 	if (msg->flags & I2C_M_RD) {
246 
247 		ret = mxl111sf_i2c_start(state);
248 		if (mxl_fail(ret))
249 			goto fail;
250 
251 		ret = mxl111sf_i2c_bitbang_sendbyte(state,
252 						    (msg->addr << 1) | 0x01);
253 		if (mxl_fail(ret)) {
254 			mxl111sf_i2c_stop(state);
255 			goto fail;
256 		}
257 
258 		for (i = 0; i < msg->len; i++) {
259 			ret = mxl111sf_i2c_bitbang_recvbyte(state,
260 							    &msg->buf[i]);
261 			if (mxl_fail(ret)) {
262 				mxl111sf_i2c_stop(state);
263 				goto fail;
264 			}
265 
266 			if (i < msg->len - 1)
267 				mxl111sf_i2c_ack(state);
268 		}
269 
270 		mxl111sf_i2c_nack(state);
271 
272 		ret = mxl111sf_i2c_stop(state);
273 		if (mxl_fail(ret))
274 			goto fail;
275 
276 	} else {
277 
278 		ret = mxl111sf_i2c_start(state);
279 		if (mxl_fail(ret))
280 			goto fail;
281 
282 		ret = mxl111sf_i2c_bitbang_sendbyte(state,
283 						    (msg->addr << 1) & 0xfe);
284 		if (mxl_fail(ret)) {
285 			mxl111sf_i2c_stop(state);
286 			goto fail;
287 		}
288 
289 		for (i = 0; i < msg->len; i++) {
290 			ret = mxl111sf_i2c_bitbang_sendbyte(state,
291 							    msg->buf[i]);
292 			if (mxl_fail(ret)) {
293 				mxl111sf_i2c_stop(state);
294 				goto fail;
295 			}
296 		}
297 
298 		/* FIXME: we only want to do this on the last transaction */
299 		mxl111sf_i2c_stop(state);
300 	}
301 fail:
302 	return ret;
303 }
304 
305 /* HW-I2C ----------------------------------------------------------------- */
306 
307 #define USB_WRITE_I2C_CMD     0x99
308 #define USB_READ_I2C_CMD      0xdd
309 #define USB_END_I2C_CMD       0xfe
310 
311 #define USB_WRITE_I2C_CMD_LEN   26
312 #define USB_READ_I2C_CMD_LEN    24
313 
314 #define I2C_MUX_REG           0x30
315 #define I2C_CONTROL_REG       0x00
316 #define I2C_SLAVE_ADDR_REG    0x08
317 #define I2C_DATA_REG          0x0c
318 #define I2C_INT_STATUS_REG    0x10
319 
320 static int mxl111sf_i2c_send_data(struct mxl111sf_state *state,
321 				  u8 index, u8 *wdata)
322 {
323 	int ret = mxl111sf_ctrl_msg(state->d, wdata[0],
324 				    &wdata[1], 25, NULL, 0);
325 	mxl_fail(ret);
326 
327 	return ret;
328 }
329 
330 static int mxl111sf_i2c_get_data(struct mxl111sf_state *state,
331 				 u8 index, u8 *wdata, u8 *rdata)
332 {
333 	int ret = mxl111sf_ctrl_msg(state->d, wdata[0],
334 				    &wdata[1], 25, rdata, 24);
335 	mxl_fail(ret);
336 
337 	return ret;
338 }
339 
340 static u8 mxl111sf_i2c_check_status(struct mxl111sf_state *state)
341 {
342 	u8 status = 0;
343 	u8 buf[26];
344 
345 	mxl_i2c_adv("()");
346 
347 	buf[0] = USB_READ_I2C_CMD;
348 	buf[1] = 0x00;
349 
350 	buf[2] = I2C_INT_STATUS_REG;
351 	buf[3] = 0x00;
352 	buf[4] = 0x00;
353 
354 	buf[5] = USB_END_I2C_CMD;
355 
356 	mxl111sf_i2c_get_data(state, 0, buf, buf);
357 
358 	if (buf[1] & 0x04)
359 		status = 1;
360 
361 	return status;
362 }
363 
364 static u8 mxl111sf_i2c_check_fifo(struct mxl111sf_state *state)
365 {
366 	u8 status = 0;
367 	u8 buf[26];
368 
369 	mxl_i2c("()");
370 
371 	buf[0] = USB_READ_I2C_CMD;
372 	buf[1] = 0x00;
373 
374 	buf[2] = I2C_MUX_REG;
375 	buf[3] = 0x00;
376 	buf[4] = 0x00;
377 
378 	buf[5] = I2C_INT_STATUS_REG;
379 	buf[6] = 0x00;
380 	buf[7] = 0x00;
381 	buf[8] = USB_END_I2C_CMD;
382 
383 	mxl111sf_i2c_get_data(state, 0, buf, buf);
384 
385 	if (0x08 == (buf[1] & 0x08))
386 		status = 1;
387 
388 	if ((buf[5] & 0x02) == 0x02)
389 		mxl_i2c("(buf[5] & 0x02) == 0x02"); /* FIXME */
390 
391 	return status;
392 }
393 
394 static int mxl111sf_i2c_readagain(struct mxl111sf_state *state,
395 				  u8 count, u8 *rbuf)
396 {
397 	u8 i2c_w_data[26];
398 	u8 i2c_r_data[24];
399 	u8 i = 0;
400 	u8 fifo_status = 0;
401 	int status = 0;
402 
403 	mxl_i2c("read %d bytes", count);
404 
405 	while ((fifo_status == 0) && (i++ < 5))
406 		fifo_status = mxl111sf_i2c_check_fifo(state);
407 
408 	i2c_w_data[0] = 0xDD;
409 	i2c_w_data[1] = 0x00;
410 
411 	for (i = 2; i < 26; i++)
412 		i2c_w_data[i] = 0xFE;
413 
414 	for (i = 0; i < count; i++) {
415 		i2c_w_data[2+(i*3)] = 0x0C;
416 		i2c_w_data[3+(i*3)] = 0x00;
417 		i2c_w_data[4+(i*3)] = 0x00;
418 	}
419 
420 	mxl111sf_i2c_get_data(state, 0, i2c_w_data, i2c_r_data);
421 
422 	/* Check for I2C NACK status */
423 	if (mxl111sf_i2c_check_status(state) == 1) {
424 		mxl_i2c("error!");
425 	} else {
426 		for (i = 0; i < count; i++) {
427 			rbuf[i] = i2c_r_data[(i*3)+1];
428 			mxl_i2c("%02x\t %02x",
429 				i2c_r_data[(i*3)+1],
430 				i2c_r_data[(i*3)+2]);
431 		}
432 
433 		status = 1;
434 	}
435 
436 	return status;
437 }
438 
439 #define HWI2C400 1
440 static int mxl111sf_i2c_hw_xfer_msg(struct mxl111sf_state *state,
441 				    struct i2c_msg *msg)
442 {
443 	int i, k, ret = 0;
444 	u16 index = 0;
445 	u8 buf[26];
446 	u8 i2c_r_data[24];
447 	u16 block_len;
448 	u16 left_over_len;
449 	u8 rd_status[8];
450 	u8 ret_status;
451 	u8 readbuff[26];
452 
453 	mxl_i2c("addr: 0x%02x, read buff len: %d, write buff len: %d",
454 		msg->addr, (msg->flags & I2C_M_RD) ? msg->len : 0,
455 		(!(msg->flags & I2C_M_RD)) ? msg->len : 0);
456 
457 	for (index = 0; index < 26; index++)
458 		buf[index] = USB_END_I2C_CMD;
459 
460 	/* command to indicate data payload is destined for I2C interface */
461 	buf[0] = USB_WRITE_I2C_CMD;
462 	buf[1] = 0x00;
463 
464 	/* enable I2C interface */
465 	buf[2] = I2C_MUX_REG;
466 	buf[3] = 0x80;
467 	buf[4] = 0x00;
468 
469 	/* enable I2C interface */
470 	buf[5] = I2C_MUX_REG;
471 	buf[6] = 0x81;
472 	buf[7] = 0x00;
473 
474 	/* set Timeout register on I2C interface */
475 	buf[8] = 0x14;
476 	buf[9] = 0xff;
477 	buf[10] = 0x00;
478 #if 0
479 	/* enable Interrupts on I2C interface */
480 	buf[8] = 0x24;
481 	buf[9] = 0xF7;
482 	buf[10] = 0x00;
483 #endif
484 	buf[11] = 0x24;
485 	buf[12] = 0xF7;
486 	buf[13] = 0x00;
487 
488 	ret = mxl111sf_i2c_send_data(state, 0, buf);
489 
490 	/* write data on I2C bus */
491 	if (!(msg->flags & I2C_M_RD) && (msg->len > 0)) {
492 		mxl_i2c("%d\t%02x", msg->len, msg->buf[0]);
493 
494 		/* control register on I2C interface to initialize I2C bus */
495 		buf[2] = I2C_CONTROL_REG;
496 		buf[3] = 0x5E;
497 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
498 
499 		/* I2C Slave device Address */
500 		buf[5] = I2C_SLAVE_ADDR_REG;
501 		buf[6] = (msg->addr);
502 		buf[7] = 0x00;
503 		buf[8] = USB_END_I2C_CMD;
504 		ret = mxl111sf_i2c_send_data(state, 0, buf);
505 
506 		/* check for slave device status */
507 		if (mxl111sf_i2c_check_status(state) == 1) {
508 			mxl_i2c("NACK writing slave address %02x",
509 				msg->addr);
510 			/* if NACK, stop I2C bus and exit */
511 			buf[2] = I2C_CONTROL_REG;
512 			buf[3] = 0x4E;
513 			buf[4] = (HWI2C400) ? 0x03 : 0x0D;
514 			ret = -EIO;
515 			goto exit;
516 		}
517 
518 		/* I2C interface can do I2C operations in block of 8 bytes of
519 		   I2C data. calculation to figure out number of blocks of i2c
520 		   data required to program */
521 		block_len = (msg->len / 8);
522 		left_over_len = (msg->len % 8);
523 		index = 0;
524 
525 		mxl_i2c("block_len %d, left_over_len %d",
526 			block_len, left_over_len);
527 
528 		for (index = 0; index < block_len; index++) {
529 			for (i = 0; i < 8; i++) {
530 				/* write data on I2C interface */
531 				buf[2+(i*3)] = I2C_DATA_REG;
532 				buf[3+(i*3)] = msg->buf[(index*8)+i];
533 				buf[4+(i*3)] = 0x00;
534 			}
535 
536 			ret = mxl111sf_i2c_send_data(state, 0, buf);
537 
538 			/* check for I2C NACK status */
539 			if (mxl111sf_i2c_check_status(state) == 1) {
540 				mxl_i2c("NACK writing slave address %02x",
541 					msg->addr);
542 
543 				/* if NACK, stop I2C bus and exit */
544 				buf[2] = I2C_CONTROL_REG;
545 				buf[3] = 0x4E;
546 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
547 				ret = -EIO;
548 				goto exit;
549 			}
550 
551 		}
552 
553 		if (left_over_len) {
554 			for (k = 0; k < 26; k++)
555 				buf[k] = USB_END_I2C_CMD;
556 
557 			buf[0] = 0x99;
558 			buf[1] = 0x00;
559 
560 			for (i = 0; i < left_over_len; i++) {
561 				buf[2+(i*3)] = I2C_DATA_REG;
562 				buf[3+(i*3)] = msg->buf[(index*8)+i];
563 				mxl_i2c("index = %d %d data %d",
564 					index, i, msg->buf[(index*8)+i]);
565 				buf[4+(i*3)] = 0x00;
566 			}
567 			ret = mxl111sf_i2c_send_data(state, 0, buf);
568 
569 			/* check for I2C NACK status */
570 			if (mxl111sf_i2c_check_status(state) == 1) {
571 				mxl_i2c("NACK writing slave address %02x",
572 					msg->addr);
573 
574 				/* if NACK, stop I2C bus and exit */
575 				buf[2] = I2C_CONTROL_REG;
576 				buf[3] = 0x4E;
577 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
578 				ret = -EIO;
579 				goto exit;
580 			}
581 
582 		}
583 
584 		/* issue I2C STOP after write */
585 		buf[2] = I2C_CONTROL_REG;
586 		buf[3] = 0x4E;
587 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
588 
589 	}
590 
591 	/* read data from I2C bus */
592 	if ((msg->flags & I2C_M_RD) && (msg->len > 0)) {
593 		mxl_i2c("read buf len %d", msg->len);
594 
595 		/* command to indicate data payload is
596 		   destined for I2C interface */
597 		buf[2] = I2C_CONTROL_REG;
598 		buf[3] = 0xDF;
599 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
600 
601 		/* I2C xfer length */
602 		buf[5] = 0x14;
603 		buf[6] = (msg->len & 0xFF);
604 		buf[7] = 0;
605 
606 		/* I2C slave device Address */
607 		buf[8] = I2C_SLAVE_ADDR_REG;
608 		buf[9] = msg->addr;
609 		buf[10] = 0x00;
610 		buf[11] = USB_END_I2C_CMD;
611 		ret = mxl111sf_i2c_send_data(state, 0, buf);
612 
613 		/* check for I2C NACK status */
614 		if (mxl111sf_i2c_check_status(state) == 1) {
615 			mxl_i2c("NACK reading slave address %02x",
616 				msg->addr);
617 
618 			/* if NACK, stop I2C bus and exit */
619 			buf[2] = I2C_CONTROL_REG;
620 			buf[3] = 0xC7;
621 			buf[4] = (HWI2C400) ? 0x03 : 0x0D;
622 			ret = -EIO;
623 			goto exit;
624 		}
625 
626 		/* I2C interface can do I2C operations in block of 8 bytes of
627 		   I2C data. calculation to figure out number of blocks of
628 		   i2c data required to program */
629 		block_len = ((msg->len) / 8);
630 		left_over_len = ((msg->len) % 8);
631 		index = 0;
632 
633 		mxl_i2c("block_len %d, left_over_len %d",
634 			block_len, left_over_len);
635 
636 		/* command to read data from I2C interface */
637 		buf[0] = USB_READ_I2C_CMD;
638 		buf[1] = 0x00;
639 
640 		for (index = 0; index < block_len; index++) {
641 			/* setup I2C read request packet on I2C interface */
642 			for (i = 0; i < 8; i++) {
643 				buf[2+(i*3)] = I2C_DATA_REG;
644 				buf[3+(i*3)] = 0x00;
645 				buf[4+(i*3)] = 0x00;
646 			}
647 
648 			ret = mxl111sf_i2c_get_data(state, 0, buf, i2c_r_data);
649 
650 			/* check for I2C NACK status */
651 			if (mxl111sf_i2c_check_status(state) == 1) {
652 				mxl_i2c("NACK reading slave address %02x",
653 					msg->addr);
654 
655 				/* if NACK, stop I2C bus and exit */
656 				buf[2] = I2C_CONTROL_REG;
657 				buf[3] = 0xC7;
658 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
659 				ret = -EIO;
660 				goto exit;
661 			}
662 
663 			/* copy data from i2c data payload to read buffer */
664 			for (i = 0; i < 8; i++) {
665 				rd_status[i] = i2c_r_data[(i*3)+2];
666 
667 				if (rd_status[i] == 0x04) {
668 					if (i < 7) {
669 						mxl_i2c("i2c fifo empty! @ %d",
670 							i);
671 						msg->buf[(index*8)+i] =
672 							i2c_r_data[(i*3)+1];
673 						/* read again */
674 						ret_status =
675 							mxl111sf_i2c_readagain(
676 								state, 8-(i+1),
677 								readbuff);
678 						if (ret_status == 1) {
679 							for (k = 0;
680 							     k < 8-(i+1);
681 							     k++) {
682 
683 					msg->buf[(index*8)+(k+i+1)] =
684 						readbuff[k];
685 					mxl_i2c("read data: %02x\t %02x",
686 						msg->buf[(index*8)+(k+i)],
687 						(index*8)+(k+i));
688 					mxl_i2c("read data: %02x\t %02x",
689 						msg->buf[(index*8)+(k+i+1)],
690 						readbuff[k]);
691 
692 							}
693 							goto stop_copy;
694 						} else {
695 							mxl_i2c("readagain ERROR!");
696 						}
697 					} else {
698 						msg->buf[(index*8)+i] =
699 							i2c_r_data[(i*3)+1];
700 					}
701 				} else {
702 					msg->buf[(index*8)+i] =
703 						i2c_r_data[(i*3)+1];
704 				}
705 			}
706 stop_copy:
707 			;
708 
709 		}
710 
711 		if (left_over_len) {
712 			for (k = 0; k < 26; k++)
713 				buf[k] = USB_END_I2C_CMD;
714 
715 			buf[0] = 0xDD;
716 			buf[1] = 0x00;
717 
718 			for (i = 0; i < left_over_len; i++) {
719 				buf[2+(i*3)] = I2C_DATA_REG;
720 				buf[3+(i*3)] = 0x00;
721 				buf[4+(i*3)] = 0x00;
722 			}
723 			ret = mxl111sf_i2c_get_data(state, 0, buf,
724 						    i2c_r_data);
725 
726 			/* check for I2C NACK status */
727 			if (mxl111sf_i2c_check_status(state) == 1) {
728 				mxl_i2c("NACK reading slave address %02x",
729 					msg->addr);
730 
731 				/* if NACK, stop I2C bus and exit */
732 				buf[2] = I2C_CONTROL_REG;
733 				buf[3] = 0xC7;
734 				buf[4] = (HWI2C400) ? 0x03 : 0x0D;
735 				ret = -EIO;
736 				goto exit;
737 			}
738 
739 			for (i = 0; i < left_over_len; i++) {
740 				msg->buf[(block_len*8)+i] =
741 					i2c_r_data[(i*3)+1];
742 				mxl_i2c("read data: %02x\t %02x",
743 					i2c_r_data[(i*3)+1],
744 					i2c_r_data[(i*3)+2]);
745 			}
746 		}
747 
748 		/* indicate I2C interface to issue NACK
749 		   after next I2C read op */
750 		buf[0] = USB_WRITE_I2C_CMD;
751 		buf[1] = 0x00;
752 
753 		/* control register */
754 		buf[2] = I2C_CONTROL_REG;
755 		buf[3] = 0x17;
756 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
757 
758 		buf[5] = USB_END_I2C_CMD;
759 		ret = mxl111sf_i2c_send_data(state, 0, buf);
760 
761 		/* control register */
762 		buf[2] = I2C_CONTROL_REG;
763 		buf[3] = 0xC7;
764 		buf[4] = (HWI2C400) ? 0x03 : 0x0D;
765 
766 	}
767 exit:
768 	/* STOP and disable I2C MUX */
769 	buf[0] = USB_WRITE_I2C_CMD;
770 	buf[1] = 0x00;
771 
772 	/* de-initilize I2C BUS */
773 	buf[5] = USB_END_I2C_CMD;
774 	mxl111sf_i2c_send_data(state, 0, buf);
775 
776 	/* Control Register */
777 	buf[2] = I2C_CONTROL_REG;
778 	buf[3] = 0xDF;
779 	buf[4] = 0x03;
780 
781 	/* disable I2C interface */
782 	buf[5] = I2C_MUX_REG;
783 	buf[6] = 0x00;
784 	buf[7] = 0x00;
785 
786 	/* de-initilize I2C BUS */
787 	buf[8] = USB_END_I2C_CMD;
788 	mxl111sf_i2c_send_data(state, 0, buf);
789 
790 	/* disable I2C interface */
791 	buf[2] = I2C_MUX_REG;
792 	buf[3] = 0x81;
793 	buf[4] = 0x00;
794 
795 	/* disable I2C interface */
796 	buf[5] = I2C_MUX_REG;
797 	buf[6] = 0x00;
798 	buf[7] = 0x00;
799 
800 	/* disable I2C interface */
801 	buf[8] = I2C_MUX_REG;
802 	buf[9] = 0x00;
803 	buf[10] = 0x00;
804 
805 	buf[11] = USB_END_I2C_CMD;
806 	mxl111sf_i2c_send_data(state, 0, buf);
807 
808 	return ret;
809 }
810 
811 /* ------------------------------------------------------------------------ */
812 
813 int mxl111sf_i2c_xfer(struct i2c_adapter *adap,
814 		      struct i2c_msg msg[], int num)
815 {
816 	struct dvb_usb_device *d = i2c_get_adapdata(adap);
817 	struct mxl111sf_state *state = d->priv;
818 	int hwi2c = (state->chip_rev > MXL111SF_V6);
819 	int i, ret;
820 
821 	if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
822 		return -EAGAIN;
823 
824 	for (i = 0; i < num; i++) {
825 		ret = (hwi2c) ?
826 			mxl111sf_i2c_hw_xfer_msg(state, &msg[i]) :
827 			mxl111sf_i2c_sw_xfer_msg(state, &msg[i]);
828 		if (mxl_fail(ret)) {
829 			mxl_debug_adv("failed with error %d on i2c transaction %d of %d, %sing %d bytes to/from 0x%02x",
830 				      ret, i+1, num,
831 				      (msg[i].flags & I2C_M_RD) ?
832 				      "read" : "writ",
833 				      msg[i].len, msg[i].addr);
834 
835 			break;
836 		}
837 	}
838 
839 	mutex_unlock(&d->i2c_mutex);
840 
841 	return i == num ? num : -EREMOTEIO;
842 }
843