drivers/media/usb/em28xx/em28xx-i2c.c

   1 /*
   2    em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
   3
   4    Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
   5                       Markus Rechberger <mrechberger@gmail.com>
   6                       Mauro Carvalho Chehab <mchehab@infradead.org>
   7                       Sascha Sommer <saschasommer@freenet.de>
   8    Copyright (C) 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/usb.h>
  28 #include <linux/i2c.h>
  29 #include <linux/jiffies.h>
  30
  31 #include "em28xx.h"
  32 #include "tuner-xc2028.h"
  33 #include <media/v4l2-common.h>
  34 #include <media/tuner.h>
  35
  36 /* ----------------------------------------------------------- */
  37
  38 static unsigned int i2c_scan;
  39 module_param(i2c_scan, int, 0444);
  40 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  41
  42 static unsigned int i2c_debug;
  43 module_param(i2c_debug, int, 0644);
  44 MODULE_PARM_DESC(i2c_debug, "i2c debug message level (1: normal debug, 2: show I2C transfers)");
  45
  46 /*
  47  * em2800_i2c_send_bytes()
  48  * send up to 4 bytes to the em2800 i2c device
  49  */
  50 static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
  51 {
  52         unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_I2C_XFER_TIMEOUT);
  53         int ret;
  54         u8 b2[6];
  55
  56         if (len < 1 || len > 4)
  57                 return -EOPNOTSUPP;
  58
  59         BUG_ON(len < 1 || len > 4);
  60         b2[5] = 0x80 + len - 1;
  61         b2[4] = addr;
  62         b2[3] = buf[0];
  63         if (len > 1)
  64                 b2[2] = buf[1];
  65         if (len > 2)
  66                 b2[1] = buf[2];
  67         if (len > 3)
  68                 b2[0] = buf[3];
  69
  70         /* trigger write */
  71         ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
  72         if (ret != 2 + len) {
  73                 em28xx_warn("failed to trigger write to i2c address 0x%x (error=%i)\n",
  74                             addr, ret);
  75                 return (ret < 0) ? ret : -EIO;
  76         }
  77         /* wait for completion */
  78         while (time_is_after_jiffies(timeout)) {
  79                 ret = dev->em28xx_read_reg(dev, 0x05);
  80                 if (ret == 0x80 + len - 1)
  81                         return len;
  82                 if (ret == 0x94 + len - 1) {
  83                         if (i2c_debug == 1)
  84                                 em28xx_warn("R05 returned 0x%02x: I2C timeout",
  85                                             ret);
  86                         return -ENXIO;
  87                 }
  88                 if (ret < 0) {
  89                         em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
  90                                     ret);
  91                         return ret;
  92                 }
  93                 msleep(5);
  94         }
  95         if (i2c_debug)
  96                 em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
  97         return -ETIMEDOUT;
  98 }
  99
 100 /*
 101  * em2800_i2c_recv_bytes()
 102  * read up to 4 bytes from the em2800 i2c device
 103  */
 104 static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
 105 {
 106         unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_I2C_XFER_TIMEOUT);
 107         u8 buf2[4];
 108         int ret;
 109         int i;
 110
 111         if (len < 1 || len > 4)
 112                 return -EOPNOTSUPP;
 113
 114         /* trigger read */
 115         buf2[1] = 0x84 + len - 1;
 116         buf2[0] = addr;
 117         ret = dev->em28xx_write_regs(dev, 0x04, buf2, 2);
 118         if (ret != 2) {
 119                 em28xx_warn("failed to trigger read from i2c address 0x%x (error=%i)\n",
 120                             addr, ret);
 121                 return (ret < 0) ? ret : -EIO;
 122         }
 123
 124         /* wait for completion */
 125         while (time_is_after_jiffies(timeout)) {
 126                 ret = dev->em28xx_read_reg(dev, 0x05);
 127                 if (ret == 0x84 + len - 1)
 128                         break;
 129                 if (ret == 0x94 + len - 1) {
 130                         if (i2c_debug == 1)
 131                                 em28xx_warn("R05 returned 0x%02x: I2C timeout",
 132                                             ret);
 133                         return -ENXIO;
 134                 }
 135                 if (ret < 0) {
 136                         em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
 137                                     ret);
 138                         return ret;
 139                 }
 140                 msleep(5);
 141         }
 142         if (ret != 0x84 + len - 1) {
 143                 if (i2c_debug)
 144                         em28xx_warn("read from i2c device at 0x%x timed out\n",
 145                                     addr);
 146         }
 147
 148         /* get the received message */
 149         ret = dev->em28xx_read_reg_req_len(dev, 0x00, 4-len, buf2, len);
 150         if (ret != len) {
 151                 em28xx_warn("reading from i2c device at 0x%x failed: couldn't get the received message from the bridge (error=%i)\n",
 152                             addr, ret);
 153                 return (ret < 0) ? ret : -EIO;
 154         }
 155         for (i = 0; i < len; i++)
 156                 buf[i] = buf2[len - 1 - i];
 157
 158         return ret;
 159 }
 160
 161 /*
 162  * em2800_i2c_check_for_device()
 163  * check if there is an i2c device at the supplied address
 164  */
 165 static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr)
 166 {
 167         u8 buf;
 168         int ret;
 169
 170         ret = em2800_i2c_recv_bytes(dev, addr, &buf, 1);
 171         if (ret == 1)
 172                 return 0;
 173         return (ret < 0) ? ret : -EIO;
 174 }
 175
 176 /*
 177  * em28xx_i2c_send_bytes()
 178  */
 179 static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 180                                  u16 len, int stop)
 181 {
 182         unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_I2C_XFER_TIMEOUT);
 183         int ret;
 184
 185         if (len < 1 || len > 64)
 186                 return -EOPNOTSUPP;
 187         /*
 188          * NOTE: limited by the USB ctrl message constraints
 189          * Zero length reads always succeed, even if no device is connected
 190          */
 191
 192         /* Write to i2c device */
 193         ret = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
 194         if (ret != len) {
 195                 if (ret < 0) {
 196                         em28xx_warn("writing to i2c device at 0x%x failed (error=%i)\n",
 197                                     addr, ret);
 198                         return ret;
 199                 } else {
 200                         em28xx_warn("%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
 201                                     len, addr, ret);
 202                         return -EIO;
 203                 }
 204         }
 205
 206         /* wait for completion */
 207         while (time_is_after_jiffies(timeout)) {
 208                 ret = dev->em28xx_read_reg(dev, 0x05);
 209                 if (ret == 0) /* success */
 210                         return len;
 211                 if (ret == 0x10) {
 212                         if (i2c_debug == 1)
 213                                 em28xx_warn("I2C transfer timeout on writing to addr 0x%02x",
 214                                             addr);
 215                         return -ENXIO;
 216                 }
 217                 if (ret < 0) {
 218                         em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
 219                                     ret);
 220                         return ret;
 221                 }
 222                 msleep(5);
 223                 /*
 224                  * NOTE: do we really have to wait for success ?
 225                  * Never seen anything else than 0x00 or 0x10
 226                  * (even with high payload) ...
 227                  */
 228         }
 229         if (i2c_debug)
 230                 em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n",
 231                             addr, ret);
 232         return -ETIMEDOUT;
 233 }
 234
 235 /*
 236  * em28xx_i2c_recv_bytes()
 237  * read a byte from the i2c device
 238  */
 239 static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
 240 {
 241         int ret;
 242
 243         if (len < 1 || len > 64)
 244                 return -EOPNOTSUPP;
 245         /*
 246          * NOTE: limited by the USB ctrl message constraints
 247          * Zero length reads always succeed, even if no device is connected
 248          */
 249
 250         /* Read data from i2c device */
 251         ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
 252         if (ret < 0) {
 253                 em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
 254                             addr, ret);
 255                 return ret;
 256         }
 257         /*
 258          * NOTE: some devices with two i2c busses have the bad habit to return 0
 259          * bytes if we are on bus B AND there was no write attempt to the
 260          * specified slave address before AND no device is present at the
 261          * requested slave address.
 262          * Anyway, the next check will fail with -ENXIO in this case, so avoid
 263          * spamming the system log on device probing and do nothing here.
 264          */
 265
 266         /* Check success of the i2c operation */
 267         ret = dev->em28xx_read_reg(dev, 0x05);
 268         if (ret == 0) /* success */
 269                 return len;
 270         if (ret < 0) {
 271                 em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
 272                             ret);
 273                 return ret;
 274         }
 275         if (ret == 0x10) {
 276                 if (i2c_debug == 1)
 277                         em28xx_warn("I2C transfer timeout on writing to addr 0x%02x",
 278                                     addr);
 279                 return -ENXIO;
 280         }
 281
 282         em28xx_warn("unknown i2c error (status=%i)\n", ret);
 283         return -ETIMEDOUT;
 284 }
 285
 286 /*
 287  * em28xx_i2c_check_for_device()
 288  * check if there is a i2c_device at the supplied address
 289  */
 290 static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
 291 {
 292         int ret;
 293         u8 buf;
 294
 295         ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1);
 296         if (ret == 1)
 297                 return 0;
 298         return (ret < 0) ? ret : -EIO;
 299 }
 300
 301 /*
 302  * em25xx_bus_B_send_bytes
 303  * write bytes to the i2c device
 304  */
 305 static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 306                                    u16 len)
 307 {
 308         int ret;
 309
 310         if (len < 1 || len > 64)
 311                 return -EOPNOTSUPP;
 312         /*
 313          * NOTE: limited by the USB ctrl message constraints
 314          * Zero length reads always succeed, even if no device is connected
 315          */
 316
 317         /* Set register and write value */
 318         ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
 319         if (ret != len) {
 320                 if (ret < 0) {
 321                         em28xx_warn("writing to i2c device at 0x%x failed (error=%i)\n",
 322                                     addr, ret);
 323                         return ret;
 324                 } else {
 325                         em28xx_warn("%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
 326                                     len, addr, ret);
 327                         return -EIO;
 328                 }
 329         }
 330         /* Check success */
 331         ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
 332         /*
 333          * NOTE: the only error we've seen so far is
 334          * 0x01 when the slave device is not present
 335          */
 336         if (!ret)
 337                 return len;
 338         else if (ret > 0) {
 339                 if (i2c_debug == 1)
 340                         em28xx_warn("Bus B R08 returned 0x%02x: I2C timeout",
 341                                     ret);
 342                 return -ENXIO;
 343         }
 344
 345         return ret;
 346         /*
 347          * NOTE: With chip types (other chip IDs) which actually don't support
 348          * this operation, it seems to succeed ALWAYS ! (even if there is no
 349          * slave device or even no second i2c bus provided)
 350          */
 351 }
 352
 353 /*
 354  * em25xx_bus_B_recv_bytes
 355  * read bytes from the i2c device
 356  */
 357 static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 358                                    u16 len)
 359 {
 360         int ret;
 361
 362         if (len < 1 || len > 64)
 363                 return -EOPNOTSUPP;
 364         /*
 365          * NOTE: limited by the USB ctrl message constraints
 366          * Zero length reads always succeed, even if no device is connected
 367          */
 368
 369         /* Read value */
 370         ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
 371         if (ret < 0) {
 372                 em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
 373                             addr, ret);
 374                 return ret;
 375         }
 376         /*
 377          * NOTE: some devices with two i2c busses have the bad habit to return 0
 378          * bytes if we are on bus B AND there was no write attempt to the
 379          * specified slave address before AND no device is present at the
 380          * requested slave address.
 381          * Anyway, the next check will fail with -ENXIO in this case, so avoid
 382          * spamming the system log on device probing and do nothing here.
 383          */
 384
 385         /* Check success */
 386         ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
 387         /*
 388          * NOTE: the only error we've seen so far is
 389          * 0x01 when the slave device is not present
 390          */
 391         if (!ret)
 392                 return len;
 393         else if (ret > 0) {
 394                 if (i2c_debug == 1)
 395                         em28xx_warn("Bus B R08 returned 0x%02x: I2C timeout",
 396                                     ret);
 397                 return -ENXIO;
 398         }
 399
 400         return ret;
 401         /*
 402          * NOTE: With chip types (other chip IDs) which actually don't support
 403          * this operation, it seems to succeed ALWAYS ! (even if there is no
 404          * slave device or even no second i2c bus provided)
 405          */
 406 }
 407
 408 /*
 409  * em25xx_bus_B_check_for_device()
 410  * check if there is a i2c device at the supplied address
 411  */
 412 static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
 413 {
 414         u8 buf;
 415         int ret;
 416
 417         ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
 418         if (ret < 0)
 419                 return ret;
 420
 421         return 0;
 422         /*
 423          * NOTE: With chips which do not support this operation,
 424          * it seems to succeed ALWAYS ! (even if no device connected)
 425          */
 426 }
 427
 428 static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
 429 {
 430         struct em28xx *dev = i2c_bus->dev;
 431         int rc = -EOPNOTSUPP;
 432
 433         if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 434                 rc = em28xx_i2c_check_for_device(dev, addr);
 435         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 436                 rc = em2800_i2c_check_for_device(dev, addr);
 437         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 438                 rc = em25xx_bus_B_check_for_device(dev, addr);
 439         return rc;
 440 }
 441
 442 static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
 443                                  struct i2c_msg msg)
 444 {
 445         struct em28xx *dev = i2c_bus->dev;
 446         u16 addr = msg.addr << 1;
 447         int rc = -EOPNOTSUPP;
 448
 449         if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 450                 rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
 451         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 452                 rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
 453         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 454                 rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
 455         return rc;
 456 }
 457
 458 static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
 459                                  struct i2c_msg msg, int stop)
 460 {
 461         struct em28xx *dev = i2c_bus->dev;
 462         u16 addr = msg.addr << 1;
 463         int rc = -EOPNOTSUPP;
 464
 465         if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 466                 rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
 467         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 468                 rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
 469         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 470                 rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
 471         return rc;
 472 }
 473
 474 /*
 475  * em28xx_i2c_xfer()
 476  * the main i2c transfer function
 477  */
 478 static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 479                            struct i2c_msg msgs[], int num)
 480 {
 481         struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
 482         struct em28xx *dev = i2c_bus->dev;
 483         unsigned bus = i2c_bus->bus;
 484         int addr, rc, i;
 485         u8 reg;
 486
 487         rc = rt_mutex_trylock(&dev->i2c_bus_lock);
 488         if (rc < 0)
 489                 return rc;
 490
 491         /* Switch I2C bus if needed */
 492         if (bus != dev->cur_i2c_bus &&
 493             i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
 494                 if (bus == 1)
 495                         reg = EM2874_I2C_SECONDARY_BUS_SELECT;
 496                 else
 497                         reg = 0;
 498                 em28xx_write_reg_bits(dev, EM28XX_R06_I2C_CLK, reg,
 499                                       EM2874_I2C_SECONDARY_BUS_SELECT);
 500                 dev->cur_i2c_bus = bus;
 501         }
 502
 503         if (num <= 0) {
 504                 rt_mutex_unlock(&dev->i2c_bus_lock);
 505                 return 0;
 506         }
 507         for (i = 0; i < num; i++) {
 508                 addr = msgs[i].addr << 1;
 509                 if (i2c_debug > 1)
 510                         printk(KERN_DEBUG "%s at %s: %s %s addr=%02x len=%d:",
 511                                dev->name, __func__ ,
 512                                (msgs[i].flags & I2C_M_RD) ? "read" : "write",
 513                                i == num - 1 ? "stop" : "nonstop",
 514                                addr, msgs[i].len);
 515                 if (!msgs[i].len) {
 516                         /*
 517                          * no len: check only for device presence
 518                          * This code is only called during device probe.
 519                          */
 520                         rc = i2c_check_for_device(i2c_bus, addr);
 521                         if (rc < 0) {
 522                                 if (rc == -ENXIO) {
 523                                         if (i2c_debug > 1)
 524                                                 printk(KERN_CONT " no device\n");
 525                                         rc = -ENODEV;
 526                                 } else {
 527                                         if (i2c_debug > 1)
 528                                                 printk(KERN_CONT " ERROR: %i\n", rc);
 529                                 }
 530                                 rt_mutex_unlock(&dev->i2c_bus_lock);
 531                                 return rc;
 532                         }
 533                 } else if (msgs[i].flags & I2C_M_RD) {
 534                         /* read bytes */
 535                         rc = i2c_recv_bytes(i2c_bus, msgs[i]);
 536
 537                         if (i2c_debug > 1 && rc >= 0)
 538                                 printk(KERN_CONT " %*ph",
 539                                        msgs[i].len, msgs[i].buf);
 540                 } else {
 541                         if (i2c_debug > 1)
 542                                 printk(KERN_CONT " %*ph",
 543                                        msgs[i].len, msgs[i].buf);
 544
 545                         /* write bytes */
 546                         rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
 547                 }
 548                 if (rc < 0) {
 549                         if (i2c_debug > 1)
 550                                 printk(KERN_CONT " ERROR: %i\n", rc);
 551                         rt_mutex_unlock(&dev->i2c_bus_lock);
 552                         return rc;
 553                 }
 554                 if (i2c_debug > 1)
 555                         printk(KERN_CONT "\n");
 556         }
 557
 558         rt_mutex_unlock(&dev->i2c_bus_lock);
 559         return num;
 560 }
 561
 562 /*
 563  * based on linux/sunrpc/svcauth.h and linux/hash.h
 564  * The original hash function returns a different value, if arch is x86_64
 565  * or i386.
 566  */
 567 static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
 568 {
 569         unsigned long hash = 0;
 570         unsigned long l = 0;
 571         int len = 0;
 572         unsigned char c;
 573         do {
 574                 if (len == length) {
 575                         c = (char)len;
 576                         len = -1;
 577                 } else
 578                         c = *buf++;
 579                 l = (l << 8) | c;
 580                 len++;
 581                 if ((len & (32 / 8 - 1)) == 0)
 582                         hash = ((hash^l) * 0x9e370001UL);
 583         } while (len);
 584
 585         return (hash >> (32 - bits)) & 0xffffffffUL;
 586 }
 587
 588 /*
 589  * Helper function to read data blocks from i2c clients with 8 or 16 bit
 590  * address width, 8 bit register width and auto incrementation been activated
 591  */
 592 static int em28xx_i2c_read_block(struct em28xx *dev, unsigned bus, u16 addr,
 593                                  bool addr_w16, u16 len, u8 *data)
 594 {
 595         int remain = len, rsize, rsize_max, ret;
 596         u8 buf[2];
 597
 598         /* Sanity check */
 599         if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))
 600                 return -EINVAL;
 601         /* Select address */
 602         buf[0] = addr >> 8;
 603         buf[1] = addr & 0xff;
 604         ret = i2c_master_send(&dev->i2c_client[bus], buf + !addr_w16, 1 + addr_w16);
 605         if (ret < 0)
 606                 return ret;
 607         /* Read data */
 608         if (dev->board.is_em2800)
 609                 rsize_max = 4;
 610         else
 611                 rsize_max = 64;
 612         while (remain > 0) {
 613                 if (remain > rsize_max)
 614                         rsize = rsize_max;
 615                 else
 616                         rsize = remain;
 617
 618                 ret = i2c_master_recv(&dev->i2c_client[bus], data, rsize);
 619                 if (ret < 0)
 620                         return ret;
 621
 622                 remain -= rsize;
 623                 data += rsize;
 624         }
 625
 626         return len;
 627 }
 628
 629 static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned bus,
 630                              u8 **eedata, u16 *eedata_len)
 631 {
 632         const u16 len = 256;
 633         /*
 634          * FIXME common length/size for bytes to read, to display, hash
 635          * calculation and returned device dataset. Simplifies the code a lot,
 636          * but we might have to deal with multiple sizes in the future !
 637          */
 638         int err;
 639         struct em28xx_eeprom *dev_config;
 640         u8 buf, *data;
 641
 642         *eedata = NULL;
 643         *eedata_len = 0;
 644
 645         /* EEPROM is always on i2c bus 0 on all known devices. */
 646
 647         dev->i2c_client[bus].addr = 0xa0 >> 1;
 648
 649         /* Check if board has eeprom */
 650         err = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
 651         if (err < 0) {
 652                 em28xx_info("board has no eeprom\n");
 653                 return -ENODEV;
 654         }
 655
 656         data = kzalloc(len, GFP_KERNEL);
 657         if (data == NULL)
 658                 return -ENOMEM;
 659
 660         /* Read EEPROM content */
 661         err = em28xx_i2c_read_block(dev, bus, 0x0000,
 662                                     dev->eeprom_addrwidth_16bit,
 663                                     len, data);
 664         if (err != len) {
 665                 em28xx_errdev("failed to read eeprom (err=%d)\n", err);
 666                 goto error;
 667         }
 668
 669         if (i2c_debug) {
 670                 /* Display eeprom content */
 671                 print_hex_dump(KERN_INFO, "eeprom ", DUMP_PREFIX_OFFSET,
 672                                16, 1, data, len, true);
 673
 674                 if (dev->eeprom_addrwidth_16bit)
 675                         em28xx_info("eeprom %06x: ... (skipped)\n", 256);
 676         }
 677
 678         if (dev->eeprom_addrwidth_16bit &&
 679             data[0] == 0x26 && data[3] == 0x00) {
 680                 /* new eeprom format; size 4-64kb */
 681                 u16 mc_start;
 682                 u16 hwconf_offset;
 683
 684                 dev->hash = em28xx_hash_mem(data, len, 32);
 685                 mc_start = (data[1] << 8) + 4;  /* usually 0x0004 */
 686
 687                 em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
 688                             data[0], data[1], data[2], data[3], dev->hash);
 689                 em28xx_info("EEPROM info:\n");
 690                 em28xx_info("\tmicrocode start address = 0x%04x, boot configuration = 0x%02x\n",
 691                             mc_start, data[2]);
 692                 /*
 693                  * boot configuration (address 0x0002):
 694                  * [0]   microcode download speed: 1 = 400 kHz; 0 = 100 kHz
 695                  * [1]   always selects 12 kb RAM
 696                  * [2]   USB device speed: 1 = force Full Speed; 0 = auto detect
 697                  * [4]   1 = force fast mode and no suspend for device testing
 698                  * [5:7] USB PHY tuning registers; determined by device
 699                  *       characterization
 700                  */
 701
 702                 /*
 703                  * Read hardware config dataset offset from address
 704                  * (microcode start + 46)
 705                  */
 706                 err = em28xx_i2c_read_block(dev, bus, mc_start + 46, 1, 2,
 707                                             data);
 708                 if (err != 2) {
 709                         em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
 710                                       err);
 711                         goto error;
 712                 }
 713
 714                 /* Calculate hardware config dataset start address */
 715                 hwconf_offset = mc_start + data[0] + (data[1] << 8);
 716
 717                 /* Read hardware config dataset */
 718                 /*
 719                  * NOTE: the microcode copy can be multiple pages long, but
 720                  * we assume the hardware config dataset is the same as in
 721                  * the old eeprom and not longer than 256 bytes.
 722                  * tveeprom is currently also limited to 256 bytes.
 723                  */
 724                 err = em28xx_i2c_read_block(dev, bus, hwconf_offset, 1, len,
 725                                             data);
 726                 if (err != len) {
 727                         em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
 728                                       err);
 729                         goto error;
 730                 }
 731
 732                 /* Verify hardware config dataset */
 733                 /* NOTE: not all devices provide this type of dataset */
 734                 if (data[0] != 0x1a || data[1] != 0xeb ||
 735                     data[2] != 0x67 || data[3] != 0x95) {
 736                         em28xx_info("\tno hardware configuration dataset found in eeprom\n");
 737                         kfree(data);
 738                         return 0;
 739                 }
 740
 741                 /* TODO: decrypt eeprom data for camera bridges (em25xx, em276x+) */
 742
 743         } else if (!dev->eeprom_addrwidth_16bit &&
 744                    data[0] == 0x1a && data[1] == 0xeb &&
 745                    data[2] == 0x67 && data[3] == 0x95) {
 746                 dev->hash = em28xx_hash_mem(data, len, 32);
 747                 em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
 748                             data[0], data[1], data[2], data[3], dev->hash);
 749                 em28xx_info("EEPROM info:\n");
 750         } else {
 751                 em28xx_info("unknown eeprom format or eeprom corrupted !\n");
 752                 err = -ENODEV;
 753                 goto error;
 754         }
 755
 756         *eedata = data;
 757         *eedata_len = len;
 758         dev_config = (void *)*eedata;
 759
 760         switch (le16_to_cpu(dev_config->chip_conf) >> 4 & 0x3) {
 761         case 0:
 762                 em28xx_info("\tNo audio on board.\n");
 763                 break;
 764         case 1:
 765                 em28xx_info("\tAC97 audio (5 sample rates)\n");
 766                 break;
 767         case 2:
 768                 if (dev->chip_id < CHIP_ID_EM2860)
 769                         em28xx_info("\tI2S audio, sample rate=32k\n");
 770                 else
 771                         em28xx_info("\tI2S audio, 3 sample rates\n");
 772                 break;
 773         case 3:
 774                 if (dev->chip_id < CHIP_ID_EM2860)
 775                         em28xx_info("\tI2S audio, 3 sample rates\n");
 776                 else
 777                         em28xx_info("\tI2S audio, 5 sample rates\n");
 778                 break;
 779         }
 780
 781         if (le16_to_cpu(dev_config->chip_conf) & 1 << 3)
 782                 em28xx_info("\tUSB Remote wakeup capable\n");
 783
 784         if (le16_to_cpu(dev_config->chip_conf) & 1 << 2)
 785                 em28xx_info("\tUSB Self power capable\n");
 786
 787         switch (le16_to_cpu(dev_config->chip_conf) & 0x3) {
 788         case 0:
 789                 em28xx_info("\t500mA max power\n");
 790                 break;
 791         case 1:
 792                 em28xx_info("\t400mA max power\n");
 793                 break;
 794         case 2:
 795                 em28xx_info("\t300mA max power\n");
 796                 break;
 797         case 3:
 798                 em28xx_info("\t200mA max power\n");
 799                 break;
 800         }
 801         em28xx_info("\tTable at offset 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
 802                     dev_config->string_idx_table,
 803                     le16_to_cpu(dev_config->string1),
 804                     le16_to_cpu(dev_config->string2),
 805                     le16_to_cpu(dev_config->string3));
 806
 807         return 0;
 808
 809 error:
 810         kfree(data);
 811         return err;
 812 }
 813
 814 /* ----------------------------------------------------------- */
 815
 816 /*
 817  * functionality()
 818  */
 819 static u32 functionality(struct i2c_adapter *i2c_adap)
 820 {
 821         struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
 822
 823         if ((i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) ||
 824             (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)) {
 825                 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 826         } else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)  {
 827                 return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
 828                         ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
 829         }
 830
 831         WARN(1, "Unknown i2c bus algorithm.\n");
 832         return 0;
 833 }
 834
 835 static struct i2c_algorithm em28xx_algo = {
 836         .master_xfer   = em28xx_i2c_xfer,
 837         .functionality = functionality,
 838 };
 839
 840 static struct i2c_adapter em28xx_adap_template = {
 841         .owner = THIS_MODULE,
 842         .name = "em28xx",
 843         .algo = &em28xx_algo,
 844 };
 845
 846 static struct i2c_client em28xx_client_template = {
 847         .name = "em28xx internal",
 848 };
 849
 850 /* ----------------------------------------------------------- */
 851
 852 /*
 853  * i2c_devs
 854  * incomplete list of known devices
 855  */
 856 static char *i2c_devs[128] = {
 857         [0x3e >> 1] = "remote IR sensor",
 858         [0x4a >> 1] = "saa7113h",
 859         [0x52 >> 1] = "drxk",
 860         [0x60 >> 1] = "remote IR sensor",
 861         [0x8e >> 1] = "remote IR sensor",
 862         [0x86 >> 1] = "tda9887",
 863         [0x80 >> 1] = "msp34xx",
 864         [0x88 >> 1] = "msp34xx",
 865         [0xa0 >> 1] = "eeprom",
 866         [0xb0 >> 1] = "tda9874",
 867         [0xb8 >> 1] = "tvp5150a",
 868         [0xba >> 1] = "webcam sensor or tvp5150a",
 869         [0xc0 >> 1] = "tuner (analog)",
 870         [0xc2 >> 1] = "tuner (analog)",
 871         [0xc4 >> 1] = "tuner (analog)",
 872         [0xc6 >> 1] = "tuner (analog)",
 873 };
 874
 875 /*
 876  * do_i2c_scan()
 877  * check i2c address range for devices
 878  */
 879 void em28xx_do_i2c_scan(struct em28xx *dev, unsigned bus)
 880 {
 881         u8 i2c_devicelist[128];
 882         unsigned char buf;
 883         int i, rc;
 884
 885         memset(i2c_devicelist, 0, ARRAY_SIZE(i2c_devicelist));
 886
 887         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 888                 dev->i2c_client[bus].addr = i;
 889                 rc = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
 890                 if (rc < 0)
 891                         continue;
 892                 i2c_devicelist[i] = i;
 893                 em28xx_info("found i2c device @ 0x%x on bus %d [%s]\n",
 894                             i << 1, bus, i2c_devs[i] ? i2c_devs[i] : "???");
 895         }
 896
 897         if (bus == dev->def_i2c_bus)
 898                 dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
 899                                                 ARRAY_SIZE(i2c_devicelist), 32);
 900 }
 901
 902 /*
 903  * em28xx_i2c_register()
 904  * register i2c bus
 905  */
 906 int em28xx_i2c_register(struct em28xx *dev, unsigned bus,
 907                         enum em28xx_i2c_algo_type algo_type)
 908 {
 909         int retval;
 910
 911         BUG_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg);
 912         BUG_ON(!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req);
 913
 914         if (bus >= NUM_I2C_BUSES)
 915                 return -ENODEV;
 916
 917         dev->i2c_adap[bus] = em28xx_adap_template;
 918         dev->i2c_adap[bus].dev.parent = &dev->udev->dev;
 919         strcpy(dev->i2c_adap[bus].name, dev->name);
 920
 921         dev->i2c_bus[bus].bus = bus;
 922         dev->i2c_bus[bus].algo_type = algo_type;
 923         dev->i2c_bus[bus].dev = dev;
 924         dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
 925         i2c_set_adapdata(&dev->i2c_adap[bus], &dev->v4l2_dev);
 926
 927         retval = i2c_add_adapter(&dev->i2c_adap[bus]);
 928         if (retval < 0) {
 929                 em28xx_errdev("%s: i2c_add_adapter failed! retval [%d]\n",
 930                         __func__, retval);
 931                 return retval;
 932         }
 933
 934         dev->i2c_client[bus] = em28xx_client_template;
 935         dev->i2c_client[bus].adapter = &dev->i2c_adap[bus];
 936
 937         /* Up to now, all eeproms are at bus 0 */
 938         if (!bus) {
 939                 retval = em28xx_i2c_eeprom(dev, bus, &dev->eedata, &dev->eedata_len);
 940                 if ((retval < 0) && (retval != -ENODEV)) {
 941                         em28xx_errdev("%s: em28xx_i2_eeprom failed! retval [%d]\n",
 942                                 __func__, retval);
 943
 944                         return retval;
 945                 }
 946         }
 947
 948         if (i2c_scan)
 949                 em28xx_do_i2c_scan(dev, bus);
 950
 951         return 0;
 952 }
 953
 954 /*
 955  * em28xx_i2c_unregister()
 956  * unregister i2c_bus
 957  */
 958 int em28xx_i2c_unregister(struct em28xx *dev, unsigned bus)
 959 {
 960         if (bus >= NUM_I2C_BUSES)
 961                 return -ENODEV;
 962
 963         i2c_del_adapter(&dev->i2c_adap[bus]);
 964         return 0;
 965 }