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 ACK error\n",
  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 ACK error\n",
 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 ACK error on writing to addr 0x%02x\n",
 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
 230         if (ret == 0x02 || ret == 0x04) {
 231                 /* NOTE: these errors seem to be related to clock stretching */
 232                 if (i2c_debug)
 233                         em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n",
 234                                     addr, ret);
 235                 return -ETIMEDOUT;
 236         }
 237
 238         em28xx_warn("write to i2c device at 0x%x failed with unknown error (status=%i)\n",
 239                     addr, ret);
 240         return -EIO;
 241 }
 242
 243 /*
 244  * em28xx_i2c_recv_bytes()
 245  * read a byte from the i2c device
 246  */
 247 static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
 248 {
 249         int ret;
 250
 251         if (len < 1 || len > 64)
 252                 return -EOPNOTSUPP;
 253         /*
 254          * NOTE: limited by the USB ctrl message constraints
 255          * Zero length reads always succeed, even if no device is connected
 256          */
 257
 258         /* Read data from i2c device */
 259         ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
 260         if (ret < 0) {
 261                 em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
 262                             addr, ret);
 263                 return ret;
 264         }
 265         /*
 266          * NOTE: some devices with two i2c busses have the bad habit to return 0
 267          * bytes if we are on bus B AND there was no write attempt to the
 268          * specified slave address before AND no device is present at the
 269          * requested slave address.
 270          * Anyway, the next check will fail with -ENXIO in this case, so avoid
 271          * spamming the system log on device probing and do nothing here.
 272          */
 273
 274         /* Check success of the i2c operation */
 275         ret = dev->em28xx_read_reg(dev, 0x05);
 276         if (ret == 0) /* success */
 277                 return len;
 278         if (ret < 0) {
 279                 em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
 280                             ret);
 281                 return ret;
 282         }
 283         if (ret == 0x10) {
 284                 if (i2c_debug == 1)
 285                         em28xx_warn("I2C ACK error on writing to addr 0x%02x\n",
 286                                     addr);
 287                 return -ENXIO;
 288         }
 289
 290         if (ret == 0x02 || ret == 0x04) {
 291                 /* NOTE: these errors seem to be related to clock stretching */
 292                 if (i2c_debug)
 293                         em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n",
 294                                     addr, ret);
 295                 return -ETIMEDOUT;
 296         }
 297
 298         em28xx_warn("write to i2c device at 0x%x failed with unknown error (status=%i)\n",
 299                     addr, ret);
 300         return -EIO;
 301 }
 302
 303 /*
 304  * em28xx_i2c_check_for_device()
 305  * check if there is a i2c_device at the supplied address
 306  */
 307 static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
 308 {
 309         int ret;
 310         u8 buf;
 311
 312         ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1);
 313         if (ret == 1)
 314                 return 0;
 315         return (ret < 0) ? ret : -EIO;
 316 }
 317
 318 /*
 319  * em25xx_bus_B_send_bytes
 320  * write bytes to the i2c device
 321  */
 322 static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 323                                    u16 len)
 324 {
 325         int ret;
 326
 327         if (len < 1 || len > 64)
 328                 return -EOPNOTSUPP;
 329         /*
 330          * NOTE: limited by the USB ctrl message constraints
 331          * Zero length reads always succeed, even if no device is connected
 332          */
 333
 334         /* Set register and write value */
 335         ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
 336         if (ret != len) {
 337                 if (ret < 0) {
 338                         em28xx_warn("writing to i2c device at 0x%x failed (error=%i)\n",
 339                                     addr, ret);
 340                         return ret;
 341                 } else {
 342                         em28xx_warn("%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
 343                                     len, addr, ret);
 344                         return -EIO;
 345                 }
 346         }
 347         /* Check success */
 348         ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
 349         /*
 350          * NOTE: the only error we've seen so far is
 351          * 0x01 when the slave device is not present
 352          */
 353         if (!ret)
 354                 return len;
 355         else if (ret > 0) {
 356                 if (i2c_debug == 1)
 357                         em28xx_warn("Bus B R08 returned 0x%02x: I2C ACK error\n",
 358                                     ret);
 359                 return -ENXIO;
 360         }
 361
 362         return ret;
 363         /*
 364          * NOTE: With chip types (other chip IDs) which actually don't support
 365          * this operation, it seems to succeed ALWAYS ! (even if there is no
 366          * slave device or even no second i2c bus provided)
 367          */
 368 }
 369
 370 /*
 371  * em25xx_bus_B_recv_bytes
 372  * read bytes from the i2c device
 373  */
 374 static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 375                                    u16 len)
 376 {
 377         int ret;
 378
 379         if (len < 1 || len > 64)
 380                 return -EOPNOTSUPP;
 381         /*
 382          * NOTE: limited by the USB ctrl message constraints
 383          * Zero length reads always succeed, even if no device is connected
 384          */
 385
 386         /* Read value */
 387         ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
 388         if (ret < 0) {
 389                 em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
 390                             addr, ret);
 391                 return ret;
 392         }
 393         /*
 394          * NOTE: some devices with two i2c busses have the bad habit to return 0
 395          * bytes if we are on bus B AND there was no write attempt to the
 396          * specified slave address before AND no device is present at the
 397          * requested slave address.
 398          * Anyway, the next check will fail with -ENXIO in this case, so avoid
 399          * spamming the system log on device probing and do nothing here.
 400          */
 401
 402         /* Check success */
 403         ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
 404         /*
 405          * NOTE: the only error we've seen so far is
 406          * 0x01 when the slave device is not present
 407          */
 408         if (!ret)
 409                 return len;
 410         else if (ret > 0) {
 411                 if (i2c_debug == 1)
 412                         em28xx_warn("Bus B R08 returned 0x%02x: I2C ACK error\n",
 413                                     ret);
 414                 return -ENXIO;
 415         }
 416
 417         return ret;
 418         /*
 419          * NOTE: With chip types (other chip IDs) which actually don't support
 420          * this operation, it seems to succeed ALWAYS ! (even if there is no
 421          * slave device or even no second i2c bus provided)
 422          */
 423 }
 424
 425 /*
 426  * em25xx_bus_B_check_for_device()
 427  * check if there is a i2c device at the supplied address
 428  */
 429 static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
 430 {
 431         u8 buf;
 432         int ret;
 433
 434         ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
 435         if (ret < 0)
 436                 return ret;
 437
 438         return 0;
 439         /*
 440          * NOTE: With chips which do not support this operation,
 441          * it seems to succeed ALWAYS ! (even if no device connected)
 442          */
 443 }
 444
 445 static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
 446 {
 447         struct em28xx *dev = i2c_bus->dev;
 448         int rc = -EOPNOTSUPP;
 449
 450         if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 451                 rc = em28xx_i2c_check_for_device(dev, addr);
 452         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 453                 rc = em2800_i2c_check_for_device(dev, addr);
 454         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 455                 rc = em25xx_bus_B_check_for_device(dev, addr);
 456         return rc;
 457 }
 458
 459 static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
 460                                  struct i2c_msg msg)
 461 {
 462         struct em28xx *dev = i2c_bus->dev;
 463         u16 addr = msg.addr << 1;
 464         int rc = -EOPNOTSUPP;
 465
 466         if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 467                 rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
 468         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 469                 rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
 470         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 471                 rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
 472         return rc;
 473 }
 474
 475 static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
 476                                  struct i2c_msg msg, int stop)
 477 {
 478         struct em28xx *dev = i2c_bus->dev;
 479         u16 addr = msg.addr << 1;
 480         int rc = -EOPNOTSUPP;
 481
 482         if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 483                 rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
 484         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 485                 rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
 486         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 487                 rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
 488         return rc;
 489 }
 490
 491 /*
 492  * em28xx_i2c_xfer()
 493  * the main i2c transfer function
 494  */
 495 static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 496                            struct i2c_msg msgs[], int num)
 497 {
 498         struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
 499         struct em28xx *dev = i2c_bus->dev;
 500         unsigned bus = i2c_bus->bus;
 501         int addr, rc, i;
 502         u8 reg;
 503
 504         /* prevent i2c xfer attempts after device is disconnected
 505            some fe's try to do i2c writes/reads from their release
 506            interfaces when called in disconnect path */
 507         if (dev->disconnected)
 508                 return -ENODEV;
 509
 510         if (!rt_mutex_trylock(&dev->i2c_bus_lock))
 511                 return -EAGAIN;
 512
 513         /* Switch I2C bus if needed */
 514         if (bus != dev->cur_i2c_bus &&
 515             i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
 516                 if (bus == 1)
 517                         reg = EM2874_I2C_SECONDARY_BUS_SELECT;
 518                 else
 519                         reg = 0;
 520                 em28xx_write_reg_bits(dev, EM28XX_R06_I2C_CLK, reg,
 521                                       EM2874_I2C_SECONDARY_BUS_SELECT);
 522                 dev->cur_i2c_bus = bus;
 523         }
 524
 525         if (num <= 0) {
 526                 rt_mutex_unlock(&dev->i2c_bus_lock);
 527                 return 0;
 528         }
 529         for (i = 0; i < num; i++) {
 530                 addr = msgs[i].addr << 1;
 531                 if (i2c_debug > 1)
 532                         printk(KERN_DEBUG "%s at %s: %s %s addr=%02x len=%d:",
 533                                dev->name, __func__ ,
 534                                (msgs[i].flags & I2C_M_RD) ? "read" : "write",
 535                                i == num - 1 ? "stop" : "nonstop",
 536                                addr, msgs[i].len);
 537                 if (!msgs[i].len) {
 538                         /*
 539                          * no len: check only for device presence
 540                          * This code is only called during device probe.
 541                          */
 542                         rc = i2c_check_for_device(i2c_bus, addr);
 543                         if (rc < 0) {
 544                                 if (rc == -ENXIO) {
 545                                         if (i2c_debug > 1)
 546                                                 printk(KERN_CONT " no device\n");
 547                                         rc = -ENODEV;
 548                                 } else {
 549                                         if (i2c_debug > 1)
 550                                                 printk(KERN_CONT " ERROR: %i\n", rc);
 551                                 }
 552                                 rt_mutex_unlock(&dev->i2c_bus_lock);
 553                                 return rc;
 554                         }
 555                 } else if (msgs[i].flags & I2C_M_RD) {
 556                         /* read bytes */
 557                         rc = i2c_recv_bytes(i2c_bus, msgs[i]);
 558
 559                         if (i2c_debug > 1 && rc >= 0)
 560                                 printk(KERN_CONT " %*ph",
 561                                        msgs[i].len, msgs[i].buf);
 562                 } else {
 563                         if (i2c_debug > 1)
 564                                 printk(KERN_CONT " %*ph",
 565                                        msgs[i].len, msgs[i].buf);
 566
 567                         /* write bytes */
 568                         rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
 569                 }
 570                 if (rc < 0) {
 571                         if (i2c_debug > 1)
 572                                 printk(KERN_CONT " ERROR: %i\n", rc);
 573                         rt_mutex_unlock(&dev->i2c_bus_lock);
 574                         return rc;
 575                 }
 576                 if (i2c_debug > 1)
 577                         printk(KERN_CONT "\n");
 578         }
 579
 580         rt_mutex_unlock(&dev->i2c_bus_lock);
 581         return num;
 582 }
 583
 584 /*
 585  * based on linux/sunrpc/svcauth.h and linux/hash.h
 586  * The original hash function returns a different value, if arch is x86_64
 587  * or i386.
 588  */
 589 static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
 590 {
 591         unsigned long hash = 0;
 592         unsigned long l = 0;
 593         int len = 0;
 594         unsigned char c;
 595
 596         do {
 597                 if (len == length) {
 598                         c = (char)len;
 599                         len = -1;
 600                 } else
 601                         c = *buf++;
 602                 l = (l << 8) | c;
 603                 len++;
 604                 if ((len & (32 / 8 - 1)) == 0)
 605                         hash = ((hash^l) * 0x9e370001UL);
 606         } while (len);
 607
 608         return (hash >> (32 - bits)) & 0xffffffffUL;
 609 }
 610
 611 /*
 612  * Helper function to read data blocks from i2c clients with 8 or 16 bit
 613  * address width, 8 bit register width and auto incrementation been activated
 614  */
 615 static int em28xx_i2c_read_block(struct em28xx *dev, unsigned bus, u16 addr,
 616                                  bool addr_w16, u16 len, u8 *data)
 617 {
 618         int remain = len, rsize, rsize_max, ret;
 619         u8 buf[2];
 620
 621         /* Sanity check */
 622         if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))
 623                 return -EINVAL;
 624         /* Select address */
 625         buf[0] = addr >> 8;
 626         buf[1] = addr & 0xff;
 627         ret = i2c_master_send(&dev->i2c_client[bus], buf + !addr_w16, 1 + addr_w16);
 628         if (ret < 0)
 629                 return ret;
 630         /* Read data */
 631         if (dev->board.is_em2800)
 632                 rsize_max = 4;
 633         else
 634                 rsize_max = 64;
 635         while (remain > 0) {
 636                 if (remain > rsize_max)
 637                         rsize = rsize_max;
 638                 else
 639                         rsize = remain;
 640
 641                 ret = i2c_master_recv(&dev->i2c_client[bus], data, rsize);
 642                 if (ret < 0)
 643                         return ret;
 644
 645                 remain -= rsize;
 646                 data += rsize;
 647         }
 648
 649         return len;
 650 }
 651
 652 static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned bus,
 653                              u8 **eedata, u16 *eedata_len)
 654 {
 655         const u16 len = 256;
 656         /*
 657          * FIXME common length/size for bytes to read, to display, hash
 658          * calculation and returned device dataset. Simplifies the code a lot,
 659          * but we might have to deal with multiple sizes in the future !
 660          */
 661         int err;
 662         struct em28xx_eeprom *dev_config;
 663         u8 buf, *data;
 664
 665         *eedata = NULL;
 666         *eedata_len = 0;
 667
 668         /* EEPROM is always on i2c bus 0 on all known devices. */
 669
 670         dev->i2c_client[bus].addr = 0xa0 >> 1;
 671
 672         /* Check if board has eeprom */
 673         err = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
 674         if (err < 0) {
 675                 em28xx_info("board has no eeprom\n");
 676                 return -ENODEV;
 677         }
 678
 679         data = kzalloc(len, GFP_KERNEL);
 680         if (data == NULL)
 681                 return -ENOMEM;
 682
 683         /* Read EEPROM content */
 684         err = em28xx_i2c_read_block(dev, bus, 0x0000,
 685                                     dev->eeprom_addrwidth_16bit,
 686                                     len, data);
 687         if (err != len) {
 688                 em28xx_errdev("failed to read eeprom (err=%d)\n", err);
 689                 goto error;
 690         }
 691
 692         if (i2c_debug) {
 693                 /* Display eeprom content */
 694                 print_hex_dump(KERN_INFO, "eeprom ", DUMP_PREFIX_OFFSET,
 695                                16, 1, data, len, true);
 696
 697                 if (dev->eeprom_addrwidth_16bit)
 698                         em28xx_info("eeprom %06x: ... (skipped)\n", 256);
 699         }
 700
 701         if (dev->eeprom_addrwidth_16bit &&
 702             data[0] == 0x26 && data[3] == 0x00) {
 703                 /* new eeprom format; size 4-64kb */
 704                 u16 mc_start;
 705                 u16 hwconf_offset;
 706
 707                 dev->hash = em28xx_hash_mem(data, len, 32);
 708                 mc_start = (data[1] << 8) + 4;  /* usually 0x0004 */
 709
 710                 em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
 711                             data[0], data[1], data[2], data[3], dev->hash);
 712                 em28xx_info("EEPROM info:\n");
 713                 em28xx_info("\tmicrocode start address = 0x%04x, boot configuration = 0x%02x\n",
 714                             mc_start, data[2]);
 715                 /*
 716                  * boot configuration (address 0x0002):
 717                  * [0]   microcode download speed: 1 = 400 kHz; 0 = 100 kHz
 718                  * [1]   always selects 12 kb RAM
 719                  * [2]   USB device speed: 1 = force Full Speed; 0 = auto detect
 720                  * [4]   1 = force fast mode and no suspend for device testing
 721                  * [5:7] USB PHY tuning registers; determined by device
 722                  *       characterization
 723                  */
 724
 725                 /*
 726                  * Read hardware config dataset offset from address
 727                  * (microcode start + 46)
 728                  */
 729                 err = em28xx_i2c_read_block(dev, bus, mc_start + 46, 1, 2,
 730                                             data);
 731                 if (err != 2) {
 732                         em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
 733                                       err);
 734                         goto error;
 735                 }
 736
 737                 /* Calculate hardware config dataset start address */
 738                 hwconf_offset = mc_start + data[0] + (data[1] << 8);
 739
 740                 /* Read hardware config dataset */
 741                 /*
 742                  * NOTE: the microcode copy can be multiple pages long, but
 743                  * we assume the hardware config dataset is the same as in
 744                  * the old eeprom and not longer than 256 bytes.
 745                  * tveeprom is currently also limited to 256 bytes.
 746                  */
 747                 err = em28xx_i2c_read_block(dev, bus, hwconf_offset, 1, len,
 748                                             data);
 749                 if (err != len) {
 750                         em28xx_errdev("failed to read hardware configuration data from eeprom (err=%d)\n",
 751                                       err);
 752                         goto error;
 753                 }
 754
 755                 /* Verify hardware config dataset */
 756                 /* NOTE: not all devices provide this type of dataset */
 757                 if (data[0] != 0x1a || data[1] != 0xeb ||
 758                     data[2] != 0x67 || data[3] != 0x95) {
 759                         em28xx_info("\tno hardware configuration dataset found in eeprom\n");
 760                         kfree(data);
 761                         return 0;
 762                 }
 763
 764                 /* TODO: decrypt eeprom data for camera bridges (em25xx, em276x+) */
 765
 766         } else if (!dev->eeprom_addrwidth_16bit &&
 767                    data[0] == 0x1a && data[1] == 0xeb &&
 768                    data[2] == 0x67 && data[3] == 0x95) {
 769                 dev->hash = em28xx_hash_mem(data, len, 32);
 770                 em28xx_info("EEPROM ID = %02x %02x %02x %02x, EEPROM hash = 0x%08lx\n",
 771                             data[0], data[1], data[2], data[3], dev->hash);
 772                 em28xx_info("EEPROM info:\n");
 773         } else {
 774                 em28xx_info("unknown eeprom format or eeprom corrupted !\n");
 775                 err = -ENODEV;
 776                 goto error;
 777         }
 778
 779         *eedata = data;
 780         *eedata_len = len;
 781         dev_config = (void *)*eedata;
 782
 783         switch (le16_to_cpu(dev_config->chip_conf) >> 4 & 0x3) {
 784         case 0:
 785                 em28xx_info("\tNo audio on board.\n");
 786                 break;
 787         case 1:
 788                 em28xx_info("\tAC97 audio (5 sample rates)\n");
 789                 break;
 790         case 2:
 791                 if (dev->chip_id < CHIP_ID_EM2860)
 792                         em28xx_info("\tI2S audio, sample rate=32k\n");
 793                 else
 794                         em28xx_info("\tI2S audio, 3 sample rates\n");
 795                 break;
 796         case 3:
 797                 if (dev->chip_id < CHIP_ID_EM2860)
 798                         em28xx_info("\tI2S audio, 3 sample rates\n");
 799                 else
 800                         em28xx_info("\tI2S audio, 5 sample rates\n");
 801                 break;
 802         }
 803
 804         if (le16_to_cpu(dev_config->chip_conf) & 1 << 3)
 805                 em28xx_info("\tUSB Remote wakeup capable\n");
 806
 807         if (le16_to_cpu(dev_config->chip_conf) & 1 << 2)
 808                 em28xx_info("\tUSB Self power capable\n");
 809
 810         switch (le16_to_cpu(dev_config->chip_conf) & 0x3) {
 811         case 0:
 812                 em28xx_info("\t500mA max power\n");
 813                 break;
 814         case 1:
 815                 em28xx_info("\t400mA max power\n");
 816                 break;
 817         case 2:
 818                 em28xx_info("\t300mA max power\n");
 819                 break;
 820         case 3:
 821                 em28xx_info("\t200mA max power\n");
 822                 break;
 823         }
 824         em28xx_info("\tTable at offset 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
 825                     dev_config->string_idx_table,
 826                     le16_to_cpu(dev_config->string1),
 827                     le16_to_cpu(dev_config->string2),
 828                     le16_to_cpu(dev_config->string3));
 829
 830         return 0;
 831
 832 error:
 833         kfree(data);
 834         return err;
 835 }
 836
 837 /* ----------------------------------------------------------- */
 838
 839 /*
 840  * functionality()
 841  */
 842 static u32 functionality(struct i2c_adapter *i2c_adap)
 843 {
 844         struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
 845
 846         if ((i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) ||
 847             (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)) {
 848                 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 849         } else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)  {
 850                 return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
 851                         ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
 852         }
 853
 854         WARN(1, "Unknown i2c bus algorithm.\n");
 855         return 0;
 856 }
 857
 858 static const struct i2c_algorithm em28xx_algo = {
 859         .master_xfer   = em28xx_i2c_xfer,
 860         .functionality = functionality,
 861 };
 862
 863 static struct i2c_adapter em28xx_adap_template = {
 864         .owner = THIS_MODULE,
 865         .name = "em28xx",
 866         .algo = &em28xx_algo,
 867 };
 868
 869 static struct i2c_client em28xx_client_template = {
 870         .name = "em28xx internal",
 871 };
 872
 873 /* ----------------------------------------------------------- */
 874
 875 /*
 876  * i2c_devs
 877  * incomplete list of known devices
 878  */
 879 static char *i2c_devs[128] = {
 880        [0x1c >> 1] = "lgdt330x",
 881         [0x3e >> 1] = "remote IR sensor",
 882         [0x4a >> 1] = "saa7113h",
 883         [0x52 >> 1] = "drxk",
 884         [0x60 >> 1] = "remote IR sensor",
 885         [0x8e >> 1] = "remote IR sensor",
 886         [0x86 >> 1] = "tda9887",
 887         [0x80 >> 1] = "msp34xx",
 888         [0x88 >> 1] = "msp34xx",
 889         [0xa0 >> 1] = "eeprom",
 890         [0xb0 >> 1] = "tda9874",
 891         [0xb8 >> 1] = "tvp5150a",
 892         [0xba >> 1] = "webcam sensor or tvp5150a",
 893         [0xc0 >> 1] = "tuner (analog)",
 894         [0xc2 >> 1] = "tuner (analog)",
 895         [0xc4 >> 1] = "tuner (analog)",
 896         [0xc6 >> 1] = "tuner (analog)",
 897 };
 898
 899 /*
 900  * do_i2c_scan()
 901  * check i2c address range for devices
 902  */
 903 void em28xx_do_i2c_scan(struct em28xx *dev, unsigned bus)
 904 {
 905         u8 i2c_devicelist[128];
 906         unsigned char buf;
 907         int i, rc;
 908
 909         memset(i2c_devicelist, 0, ARRAY_SIZE(i2c_devicelist));
 910
 911         for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 912                 dev->i2c_client[bus].addr = i;
 913                 rc = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
 914                 if (rc < 0)
 915                         continue;
 916                 i2c_devicelist[i] = i;
 917                 em28xx_info("found i2c device @ 0x%x on bus %d [%s]\n",
 918                             i << 1, bus, i2c_devs[i] ? i2c_devs[i] : "???");
 919         }
 920
 921         if (bus == dev->def_i2c_bus)
 922                 dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
 923                                                 ARRAY_SIZE(i2c_devicelist), 32);
 924 }
 925
 926 /*
 927  * em28xx_i2c_register()
 928  * register i2c bus
 929  */
 930 int em28xx_i2c_register(struct em28xx *dev, unsigned bus,
 931                         enum em28xx_i2c_algo_type algo_type)
 932 {
 933         int retval;
 934
 935         BUG_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg);
 936         BUG_ON(!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req);
 937
 938         if (bus >= NUM_I2C_BUSES)
 939                 return -ENODEV;
 940
 941         dev->i2c_adap[bus] = em28xx_adap_template;
 942         dev->i2c_adap[bus].dev.parent = &dev->udev->dev;
 943         strcpy(dev->i2c_adap[bus].name, dev->name);
 944
 945         dev->i2c_bus[bus].bus = bus;
 946         dev->i2c_bus[bus].algo_type = algo_type;
 947         dev->i2c_bus[bus].dev = dev;
 948         dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
 949
 950         retval = i2c_add_adapter(&dev->i2c_adap[bus]);
 951         if (retval < 0) {
 952                 em28xx_errdev("%s: i2c_add_adapter failed! retval [%d]\n",
 953                               __func__, retval);
 954                 return retval;
 955         }
 956
 957         dev->i2c_client[bus] = em28xx_client_template;
 958         dev->i2c_client[bus].adapter = &dev->i2c_adap[bus];
 959
 960         /* Up to now, all eeproms are at bus 0 */
 961         if (!bus) {
 962                 retval = em28xx_i2c_eeprom(dev, bus, &dev->eedata, &dev->eedata_len);
 963                 if ((retval < 0) && (retval != -ENODEV)) {
 964                         em28xx_errdev("%s: em28xx_i2_eeprom failed! retval [%d]\n",
 965                                       __func__, retval);
 966
 967                         return retval;
 968                 }
 969         }
 970
 971         if (i2c_scan)
 972                 em28xx_do_i2c_scan(dev, bus);
 973
 974         return 0;
 975 }
 976
 977 /*
 978  * em28xx_i2c_unregister()
 979  * unregister i2c_bus
 980  */
 981 int em28xx_i2c_unregister(struct em28xx *dev, unsigned bus)
 982 {
 983         if (bus >= NUM_I2C_BUSES)
 984                 return -ENODEV;
 985
 986         i2c_del_adapter(&dev->i2c_adap[bus]);
 987         return 0;
 988 }