drivers/media/usb/dvb-usb-v2/mxl111sf-i2c.c

   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, 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, 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
 520                 mxl_i2c("block_len %d, left_over_len %d",
 521                         block_len, left_over_len);
 522
 523                 for (index = 0; index < block_len; index++) {
 524                         for (i = 0; i < 8; i++) {
 525                                 /* write data on I2C interface */
 526                                 buf[2+(i*3)] = I2C_DATA_REG;
 527                                 buf[3+(i*3)] = msg->buf[(index*8)+i];
 528                                 buf[4+(i*3)] = 0x00;
 529                         }
 530
 531                         ret = mxl111sf_i2c_send_data(state, 0, buf);
 532
 533                         /* check for I2C NACK status */
 534                         if (mxl111sf_i2c_check_status(state) == 1) {
 535                                 mxl_i2c("NACK writing slave address %02x",
 536                                         msg->addr);
 537
 538                                 /* if NACK, stop I2C bus and exit */
 539                                 buf[2] = I2C_CONTROL_REG;
 540                                 buf[3] = 0x4E;
 541                                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 542                                 ret = -EIO;
 543                                 goto exit;
 544                         }
 545
 546                 }
 547
 548                 if (left_over_len) {
 549                         for (k = 0; k < 26; k++)
 550                                 buf[k] = USB_END_I2C_CMD;
 551
 552                         buf[0] = 0x99;
 553                         buf[1] = 0x00;
 554
 555                         for (i = 0; i < left_over_len; i++) {
 556                                 buf[2+(i*3)] = I2C_DATA_REG;
 557                                 buf[3+(i*3)] = msg->buf[(index*8)+i];
 558                                 mxl_i2c("index = %d %d data %d",
 559                                         index, i, msg->buf[(index*8)+i]);
 560                                 buf[4+(i*3)] = 0x00;
 561                         }
 562                         ret = mxl111sf_i2c_send_data(state, 0, buf);
 563
 564                         /* check for I2C NACK status */
 565                         if (mxl111sf_i2c_check_status(state) == 1) {
 566                                 mxl_i2c("NACK writing slave address %02x",
 567                                         msg->addr);
 568
 569                                 /* if NACK, stop I2C bus and exit */
 570                                 buf[2] = I2C_CONTROL_REG;
 571                                 buf[3] = 0x4E;
 572                                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 573                                 ret = -EIO;
 574                                 goto exit;
 575                         }
 576
 577                 }
 578
 579                 /* issue I2C STOP after write */
 580                 buf[2] = I2C_CONTROL_REG;
 581                 buf[3] = 0x4E;
 582                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 583
 584         }
 585
 586         /* read data from I2C bus */
 587         if ((msg->flags & I2C_M_RD) && (msg->len > 0)) {
 588                 mxl_i2c("read buf len %d", msg->len);
 589
 590                 /* command to indicate data payload is
 591                    destined for I2C interface */
 592                 buf[2] = I2C_CONTROL_REG;
 593                 buf[3] = 0xDF;
 594                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 595
 596                 /* I2C xfer length */
 597                 buf[5] = 0x14;
 598                 buf[6] = (msg->len & 0xFF);
 599                 buf[7] = 0;
 600
 601                 /* I2C slave device Address */
 602                 buf[8] = I2C_SLAVE_ADDR_REG;
 603                 buf[9] = msg->addr;
 604                 buf[10] = 0x00;
 605                 buf[11] = USB_END_I2C_CMD;
 606                 ret = mxl111sf_i2c_send_data(state, 0, buf);
 607
 608                 /* check for I2C NACK status */
 609                 if (mxl111sf_i2c_check_status(state) == 1) {
 610                         mxl_i2c("NACK reading slave address %02x",
 611                                 msg->addr);
 612
 613                         /* if NACK, stop I2C bus and exit */
 614                         buf[2] = I2C_CONTROL_REG;
 615                         buf[3] = 0xC7;
 616                         buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 617                         ret = -EIO;
 618                         goto exit;
 619                 }
 620
 621                 /* I2C interface can do I2C operations in block of 8 bytes of
 622                    I2C data. calculation to figure out number of blocks of
 623                    i2c data required to program */
 624                 block_len = ((msg->len) / 8);
 625                 left_over_len = ((msg->len) % 8);
 626                 index = 0;
 627
 628                 mxl_i2c("block_len %d, left_over_len %d",
 629                         block_len, left_over_len);
 630
 631                 /* command to read data from I2C interface */
 632                 buf[0] = USB_READ_I2C_CMD;
 633                 buf[1] = 0x00;
 634
 635                 for (index = 0; index < block_len; index++) {
 636                         /* setup I2C read request packet on I2C interface */
 637                         for (i = 0; i < 8; i++) {
 638                                 buf[2+(i*3)] = I2C_DATA_REG;
 639                                 buf[3+(i*3)] = 0x00;
 640                                 buf[4+(i*3)] = 0x00;
 641                         }
 642
 643                         ret = mxl111sf_i2c_get_data(state, 0, buf, i2c_r_data);
 644
 645                         /* check for I2C NACK status */
 646                         if (mxl111sf_i2c_check_status(state) == 1) {
 647                                 mxl_i2c("NACK reading slave address %02x",
 648                                         msg->addr);
 649
 650                                 /* if NACK, stop I2C bus and exit */
 651                                 buf[2] = I2C_CONTROL_REG;
 652                                 buf[3] = 0xC7;
 653                                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 654                                 ret = -EIO;
 655                                 goto exit;
 656                         }
 657
 658                         /* copy data from i2c data payload to read buffer */
 659                         for (i = 0; i < 8; i++) {
 660                                 rd_status[i] = i2c_r_data[(i*3)+2];
 661
 662                                 if (rd_status[i] == 0x04) {
 663                                         if (i < 7) {
 664                                                 mxl_i2c("i2c fifo empty! @ %d",
 665                                                         i);
 666                                                 msg->buf[(index*8)+i] =
 667                                                         i2c_r_data[(i*3)+1];
 668                                                 /* read again */
 669                                                 ret_status =
 670                                                         mxl111sf_i2c_readagain(
 671                                                                 state, 8-(i+1),
 672                                                                 readbuff);
 673                                                 if (ret_status == 1) {
 674                                                         for (k = 0;
 675                                                              k < 8-(i+1);
 676                                                              k++) {
 677
 678                                         msg->buf[(index*8)+(k+i+1)] =
 679                                                 readbuff[k];
 680                                         mxl_i2c("read data: %02x\t %02x",
 681                                                 msg->buf[(index*8)+(k+i)],
 682                                                 (index*8)+(k+i));
 683                                         mxl_i2c("read data: %02x\t %02x",
 684                                                 msg->buf[(index*8)+(k+i+1)],
 685                                                 readbuff[k]);
 686
 687                                                         }
 688                                                         goto stop_copy;
 689                                                 } else {
 690                                                         mxl_i2c("readagain ERROR!");
 691                                                 }
 692                                         } else {
 693                                                 msg->buf[(index*8)+i] =
 694                                                         i2c_r_data[(i*3)+1];
 695                                         }
 696                                 } else {
 697                                         msg->buf[(index*8)+i] =
 698                                                 i2c_r_data[(i*3)+1];
 699                                 }
 700                         }
 701 stop_copy:
 702                         ;
 703
 704                 }
 705
 706                 if (left_over_len) {
 707                         for (k = 0; k < 26; k++)
 708                                 buf[k] = USB_END_I2C_CMD;
 709
 710                         buf[0] = 0xDD;
 711                         buf[1] = 0x00;
 712
 713                         for (i = 0; i < left_over_len; i++) {
 714                                 buf[2+(i*3)] = I2C_DATA_REG;
 715                                 buf[3+(i*3)] = 0x00;
 716                                 buf[4+(i*3)] = 0x00;
 717                         }
 718                         ret = mxl111sf_i2c_get_data(state, 0, buf,
 719                                                     i2c_r_data);
 720
 721                         /* check for I2C NACK status */
 722                         if (mxl111sf_i2c_check_status(state) == 1) {
 723                                 mxl_i2c("NACK reading slave address %02x",
 724                                         msg->addr);
 725
 726                                 /* if NACK, stop I2C bus and exit */
 727                                 buf[2] = I2C_CONTROL_REG;
 728                                 buf[3] = 0xC7;
 729                                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 730                                 ret = -EIO;
 731                                 goto exit;
 732                         }
 733
 734                         for (i = 0; i < left_over_len; i++) {
 735                                 msg->buf[(block_len*8)+i] =
 736                                         i2c_r_data[(i*3)+1];
 737                                 mxl_i2c("read data: %02x\t %02x",
 738                                         i2c_r_data[(i*3)+1],
 739                                         i2c_r_data[(i*3)+2]);
 740                         }
 741                 }
 742
 743                 /* indicate I2C interface to issue NACK
 744                    after next I2C read op */
 745                 buf[0] = USB_WRITE_I2C_CMD;
 746                 buf[1] = 0x00;
 747
 748                 /* control register */
 749                 buf[2] = I2C_CONTROL_REG;
 750                 buf[3] = 0x17;
 751                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 752
 753                 buf[5] = USB_END_I2C_CMD;
 754                 ret = mxl111sf_i2c_send_data(state, 0, buf);
 755
 756                 /* control register */
 757                 buf[2] = I2C_CONTROL_REG;
 758                 buf[3] = 0xC7;
 759                 buf[4] = (HWI2C400) ? 0x03 : 0x0D;
 760
 761         }
 762 exit:
 763         /* STOP and disable I2C MUX */
 764         buf[0] = USB_WRITE_I2C_CMD;
 765         buf[1] = 0x00;
 766
 767         /* de-initilize I2C BUS */
 768         buf[5] = USB_END_I2C_CMD;
 769         mxl111sf_i2c_send_data(state, 0, buf);
 770
 771         /* Control Register */
 772         buf[2] = I2C_CONTROL_REG;
 773         buf[3] = 0xDF;
 774         buf[4] = 0x03;
 775
 776         /* disable I2C interface */
 777         buf[5] = I2C_MUX_REG;
 778         buf[6] = 0x00;
 779         buf[7] = 0x00;
 780
 781         /* de-initilize I2C BUS */
 782         buf[8] = USB_END_I2C_CMD;
 783         mxl111sf_i2c_send_data(state, 0, buf);
 784
 785         /* disable I2C interface */
 786         buf[2] = I2C_MUX_REG;
 787         buf[3] = 0x81;
 788         buf[4] = 0x00;
 789
 790         /* disable I2C interface */
 791         buf[5] = I2C_MUX_REG;
 792         buf[6] = 0x00;
 793         buf[7] = 0x00;
 794
 795         /* disable I2C interface */
 796         buf[8] = I2C_MUX_REG;
 797         buf[9] = 0x00;
 798         buf[10] = 0x00;
 799
 800         buf[11] = USB_END_I2C_CMD;
 801         mxl111sf_i2c_send_data(state, 0, buf);
 802
 803         return ret;
 804 }
 805
 806 /* ------------------------------------------------------------------------ */
 807
 808 int mxl111sf_i2c_xfer(struct i2c_adapter *adap,
 809                       struct i2c_msg msg[], int num)
 810 {
 811         struct dvb_usb_device *d = i2c_get_adapdata(adap);
 812         struct mxl111sf_state *state = d->priv;
 813         int hwi2c = (state->chip_rev > MXL111SF_V6);
 814         int i, ret;
 815
 816         if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
 817                 return -EAGAIN;
 818
 819         for (i = 0; i < num; i++) {
 820                 ret = (hwi2c) ?
 821                         mxl111sf_i2c_hw_xfer_msg(state, &msg[i]) :
 822                         mxl111sf_i2c_sw_xfer_msg(state, &msg[i]);
 823                 if (mxl_fail(ret)) {
 824                         mxl_debug_adv("failed with error %d on i2c transaction %d of %d, %sing %d bytes to/from 0x%02x",
 825                                       ret, i+1, num,
 826                                       (msg[i].flags & I2C_M_RD) ?
 827                                       "read" : "writ",
 828                                       msg[i].len, msg[i].addr);
 829
 830                         break;
 831                 }
 832         }
 833
 834         mutex_unlock(&d->i2c_mutex);
 835
 836         return i == num ? num : -EREMOTEIO;
 837 }