linux/drivers/media/usb/em28xx/em28xx-i2c.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2//
   3// em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
   4//
   5// Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
   6//                    Markus Rechberger <mrechberger@gmail.com>
   7//                    Mauro Carvalho Chehab <mchehab@kernel.org>
   8//                    Sascha Sommer <saschasommer@freenet.de>
   9// Copyright (C) 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
  10//
  11// This program is free software; you can redistribute it and/or modify
  12// it under the terms of the GNU General Public License as published by
  13// the Free Software Foundation; either version 2 of the License, or
  14// (at your option) any later version.
  15//
  16// This program is distributed in the hope that it will be useful,
  17// but WITHOUT ANY WARRANTY; without even the implied warranty of
  18// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19// GNU General Public License for more details.
  20
  21#include "em28xx.h"
  22
  23#include <linux/module.h>
  24#include <linux/kernel.h>
  25#include <linux/usb.h>
  26#include <linux/i2c.h>
  27#include <linux/jiffies.h>
  28
  29#include "tuner-xc2028.h"
  30#include <media/v4l2-common.h>
  31#include <media/tuner.h>
  32
  33/* ----------------------------------------------------------- */
  34
  35static unsigned int i2c_scan;
  36module_param(i2c_scan, int, 0444);
  37MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  38
  39static unsigned int i2c_debug;
  40module_param(i2c_debug, int, 0644);
  41MODULE_PARM_DESC(i2c_debug, "i2c debug message level (1: normal debug, 2: show I2C transfers)");
  42
  43#define dprintk(level, fmt, arg...) do {                                \
  44        if (i2c_debug > level)                                          \
  45                dev_printk(KERN_DEBUG, &dev->intf->dev,                 \
  46                           "i2c: %s: " fmt, __func__, ## arg);          \
  47} while (0)
  48
  49/*
  50 * Time in msecs to wait for i2c xfers to finish.
  51 * 35ms is the maximum time a SMBUS device could wait when
  52 * clock stretching is used. As the transfer itself will take
  53 * some time to happen, set it to 35 ms.
  54 *
  55 * Ok, I2C doesn't specify any limit. So, eventually, we may need
  56 * to increase this timeout.
  57 */
  58#define EM28XX_I2C_XFER_TIMEOUT         35 /* ms */
  59
  60static int em28xx_i2c_timeout(struct em28xx *dev)
  61{
  62        int time = EM28XX_I2C_XFER_TIMEOUT;
  63
  64        switch (dev->i2c_speed & 0x03) {
  65        case EM28XX_I2C_FREQ_25_KHZ:
  66                time += 4;              /* Assume 4 ms for transfers */
  67                break;
  68        case EM28XX_I2C_FREQ_100_KHZ:
  69        case EM28XX_I2C_FREQ_400_KHZ:
  70                time += 1;              /* Assume 1 ms for transfers */
  71                break;
  72        default: /* EM28XX_I2C_FREQ_1_5_MHZ */
  73                break;
  74        }
  75
  76        return msecs_to_jiffies(time);
  77}
  78
  79/*
  80 * em2800_i2c_send_bytes()
  81 * send up to 4 bytes to the em2800 i2c device
  82 */
  83static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
  84{
  85        unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
  86        int ret;
  87        u8 b2[6];
  88
  89        if (len < 1 || len > 4)
  90                return -EOPNOTSUPP;
  91
  92        b2[5] = 0x80 + len - 1;
  93        b2[4] = addr;
  94        b2[3] = buf[0];
  95        if (len > 1)
  96                b2[2] = buf[1];
  97        if (len > 2)
  98                b2[1] = buf[2];
  99        if (len > 3)
 100                b2[0] = buf[3];
 101
 102        /* trigger write */
 103        ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
 104        if (ret != 2 + len) {
 105                dev_warn(&dev->intf->dev,
 106                         "failed to trigger write to i2c address 0x%x (error=%i)\n",
 107                            addr, ret);
 108                return (ret < 0) ? ret : -EIO;
 109        }
 110        /* wait for completion */
 111        while (time_is_after_jiffies(timeout)) {
 112                ret = dev->em28xx_read_reg(dev, 0x05);
 113                if (ret == 0x80 + len - 1)
 114                        return len;
 115                if (ret == 0x94 + len - 1) {
 116                        dprintk(1, "R05 returned 0x%02x: I2C ACK error\n", ret);
 117                        return -ENXIO;
 118                }
 119                if (ret < 0) {
 120                        dev_warn(&dev->intf->dev,
 121                                 "failed to get i2c transfer status from bridge register (error=%i)\n",
 122                                ret);
 123                        return ret;
 124                }
 125                usleep_range(5000, 6000);
 126        }
 127        dprintk(0, "write to i2c device at 0x%x timed out\n", addr);
 128        return -ETIMEDOUT;
 129}
 130
 131/*
 132 * em2800_i2c_recv_bytes()
 133 * read up to 4 bytes from the em2800 i2c device
 134 */
 135static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
 136{
 137        unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
 138        u8 buf2[4];
 139        int ret;
 140        int i;
 141
 142        if (len < 1 || len > 4)
 143                return -EOPNOTSUPP;
 144
 145        /* trigger read */
 146        buf2[1] = 0x84 + len - 1;
 147        buf2[0] = addr;
 148        ret = dev->em28xx_write_regs(dev, 0x04, buf2, 2);
 149        if (ret != 2) {
 150                dev_warn(&dev->intf->dev,
 151                         "failed to trigger read from i2c address 0x%x (error=%i)\n",
 152                         addr, ret);
 153                return (ret < 0) ? ret : -EIO;
 154        }
 155
 156        /* wait for completion */
 157        while (time_is_after_jiffies(timeout)) {
 158                ret = dev->em28xx_read_reg(dev, 0x05);
 159                if (ret == 0x84 + len - 1)
 160                        break;
 161                if (ret == 0x94 + len - 1) {
 162                        dprintk(1, "R05 returned 0x%02x: I2C ACK error\n",
 163                                ret);
 164                        return -ENXIO;
 165                }
 166                if (ret < 0) {
 167                        dev_warn(&dev->intf->dev,
 168                                 "failed to get i2c transfer status from bridge register (error=%i)\n",
 169                                 ret);
 170                        return ret;
 171                }
 172                usleep_range(5000, 6000);
 173        }
 174        if (ret != 0x84 + len - 1)
 175                dprintk(0, "read from i2c device at 0x%x timed out\n", addr);
 176
 177        /* get the received message */
 178        ret = dev->em28xx_read_reg_req_len(dev, 0x00, 4 - len, buf2, len);
 179        if (ret != len) {
 180                dev_warn(&dev->intf->dev,
 181                         "reading from i2c device at 0x%x failed: couldn't get the received message from the bridge (error=%i)\n",
 182                         addr, ret);
 183                return (ret < 0) ? ret : -EIO;
 184        }
 185        for (i = 0; i < len; i++)
 186                buf[i] = buf2[len - 1 - i];
 187
 188        return ret;
 189}
 190
 191/*
 192 * em2800_i2c_check_for_device()
 193 * check if there is an i2c device at the supplied address
 194 */
 195static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr)
 196{
 197        u8 buf;
 198        int ret;
 199
 200        ret = em2800_i2c_recv_bytes(dev, addr, &buf, 1);
 201        if (ret == 1)
 202                return 0;
 203        return (ret < 0) ? ret : -EIO;
 204}
 205
 206/*
 207 * em28xx_i2c_send_bytes()
 208 */
 209static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 210                                 u16 len, int stop)
 211{
 212        unsigned long timeout = jiffies + em28xx_i2c_timeout(dev);
 213        int ret;
 214
 215        if (len < 1 || len > 64)
 216                return -EOPNOTSUPP;
 217        /*
 218         * NOTE: limited by the USB ctrl message constraints
 219         * Zero length reads always succeed, even if no device is connected
 220         */
 221
 222        /* Write to i2c device */
 223        ret = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
 224        if (ret != len) {
 225                if (ret < 0) {
 226                        dev_warn(&dev->intf->dev,
 227                                 "writing to i2c device at 0x%x failed (error=%i)\n",
 228                                 addr, ret);
 229                        return ret;
 230                }
 231                dev_warn(&dev->intf->dev,
 232                         "%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
 233                                len, addr, ret);
 234                return -EIO;
 235        }
 236
 237        /* wait for completion */
 238        while (time_is_after_jiffies(timeout)) {
 239                ret = dev->em28xx_read_reg(dev, 0x05);
 240                if (ret == 0) /* success */
 241                        return len;
 242                if (ret == 0x10) {
 243                        dprintk(1, "I2C ACK error on writing to addr 0x%02x\n",
 244                                addr);
 245                        return -ENXIO;
 246                }
 247                if (ret < 0) {
 248                        dev_warn(&dev->intf->dev,
 249                                 "failed to get i2c transfer status from bridge register (error=%i)\n",
 250                                 ret);
 251                        return ret;
 252                }
 253                usleep_range(5000, 6000);
 254                /*
 255                 * NOTE: do we really have to wait for success ?
 256                 * Never seen anything else than 0x00 or 0x10
 257                 * (even with high payload) ...
 258                 */
 259        }
 260
 261        if (ret == 0x02 || ret == 0x04) {
 262                /* NOTE: these errors seem to be related to clock stretching */
 263                dprintk(0,
 264                        "write to i2c device at 0x%x timed out (status=%i)\n",
 265                        addr, ret);
 266                return -ETIMEDOUT;
 267        }
 268
 269        dev_warn(&dev->intf->dev,
 270                 "write to i2c device at 0x%x failed with unknown error (status=%i)\n",
 271                 addr, ret);
 272        return -EIO;
 273}
 274
 275/*
 276 * em28xx_i2c_recv_bytes()
 277 * read a byte from the i2c device
 278 */
 279static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
 280{
 281        int ret;
 282
 283        if (len < 1 || len > 64)
 284                return -EOPNOTSUPP;
 285        /*
 286         * NOTE: limited by the USB ctrl message constraints
 287         * Zero length reads always succeed, even if no device is connected
 288         */
 289
 290        /* Read data from i2c device */
 291        ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
 292        if (ret < 0) {
 293                dev_warn(&dev->intf->dev,
 294                         "reading from i2c device at 0x%x failed (error=%i)\n",
 295                         addr, ret);
 296                return ret;
 297        }
 298        /*
 299         * NOTE: some devices with two i2c buses have the bad habit to return 0
 300         * bytes if we are on bus B AND there was no write attempt to the
 301         * specified slave address before AND no device is present at the
 302         * requested slave address.
 303         * Anyway, the next check will fail with -ENXIO in this case, so avoid
 304         * spamming the system log on device probing and do nothing here.
 305         */
 306
 307        /* Check success of the i2c operation */
 308        ret = dev->em28xx_read_reg(dev, 0x05);
 309        if (ret == 0) /* success */
 310                return len;
 311        if (ret < 0) {
 312                dev_warn(&dev->intf->dev,
 313                         "failed to get i2c transfer status from bridge register (error=%i)\n",
 314                         ret);
 315                return ret;
 316        }
 317        if (ret == 0x10) {
 318                dprintk(1, "I2C ACK error on writing to addr 0x%02x\n",
 319                        addr);
 320                return -ENXIO;
 321        }
 322
 323        if (ret == 0x02 || ret == 0x04) {
 324                /* NOTE: these errors seem to be related to clock stretching */
 325                dprintk(0,
 326                        "write to i2c device at 0x%x timed out (status=%i)\n",
 327                        addr, ret);
 328                return -ETIMEDOUT;
 329        }
 330
 331        dev_warn(&dev->intf->dev,
 332                 "write to i2c device at 0x%x failed with unknown error (status=%i)\n",
 333                 addr, ret);
 334        return -EIO;
 335}
 336
 337/*
 338 * em28xx_i2c_check_for_device()
 339 * check if there is a i2c_device at the supplied address
 340 */
 341static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
 342{
 343        int ret;
 344        u8 buf;
 345
 346        ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1);
 347        if (ret == 1)
 348                return 0;
 349        return (ret < 0) ? ret : -EIO;
 350}
 351
 352/*
 353 * em25xx_bus_B_send_bytes
 354 * write bytes to the i2c device
 355 */
 356static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 357                                   u16 len)
 358{
 359        int ret;
 360
 361        if (len < 1 || len > 64)
 362                return -EOPNOTSUPP;
 363        /*
 364         * NOTE: limited by the USB ctrl message constraints
 365         * Zero length reads always succeed, even if no device is connected
 366         */
 367
 368        /* Set register and write value */
 369        ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
 370        if (ret != len) {
 371                if (ret < 0) {
 372                        dev_warn(&dev->intf->dev,
 373                                 "writing to i2c device at 0x%x failed (error=%i)\n",
 374                                 addr, ret);
 375                        return ret;
 376                }
 377
 378                dev_warn(&dev->intf->dev,
 379                         "%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
 380                         len, addr, ret);
 381                return -EIO;
 382        }
 383        /* Check success */
 384        ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
 385        /*
 386         * NOTE: the only error we've seen so far is
 387         * 0x01 when the slave device is not present
 388         */
 389        if (!ret)
 390                return len;
 391
 392        if (ret > 0) {
 393                dprintk(1, "Bus B R08 returned 0x%02x: I2C ACK error\n", ret);
 394                return -ENXIO;
 395        }
 396
 397        return ret;
 398        /*
 399         * NOTE: With chip types (other chip IDs) which actually don't support
 400         * this operation, it seems to succeed ALWAYS ! (even if there is no
 401         * slave device or even no second i2c bus provided)
 402         */
 403}
 404
 405/*
 406 * em25xx_bus_B_recv_bytes
 407 * read bytes from the i2c device
 408 */
 409static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
 410                                   u16 len)
 411{
 412        int ret;
 413
 414        if (len < 1 || len > 64)
 415                return -EOPNOTSUPP;
 416        /*
 417         * NOTE: limited by the USB ctrl message constraints
 418         * Zero length reads always succeed, even if no device is connected
 419         */
 420
 421        /* Read value */
 422        ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
 423        if (ret < 0) {
 424                dev_warn(&dev->intf->dev,
 425                         "reading from i2c device at 0x%x failed (error=%i)\n",
 426                         addr, ret);
 427                return ret;
 428        }
 429        /*
 430         * NOTE: some devices with two i2c buses have the bad habit to return 0
 431         * bytes if we are on bus B AND there was no write attempt to the
 432         * specified slave address before AND no device is present at the
 433         * requested slave address.
 434         * Anyway, the next check will fail with -ENXIO in this case, so avoid
 435         * spamming the system log on device probing and do nothing here.
 436         */
 437
 438        /* Check success */
 439        ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
 440        /*
 441         * NOTE: the only error we've seen so far is
 442         * 0x01 when the slave device is not present
 443         */
 444        if (!ret)
 445                return len;
 446
 447        if (ret > 0) {
 448                dprintk(1, "Bus B R08 returned 0x%02x: I2C ACK error\n", ret);
 449                return -ENXIO;
 450        }
 451
 452        return ret;
 453        /*
 454         * NOTE: With chip types (other chip IDs) which actually don't support
 455         * this operation, it seems to succeed ALWAYS ! (even if there is no
 456         * slave device or even no second i2c bus provided)
 457         */
 458}
 459
 460/*
 461 * em25xx_bus_B_check_for_device()
 462 * check if there is a i2c device at the supplied address
 463 */
 464static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
 465{
 466        u8 buf;
 467        int ret;
 468
 469        ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
 470        if (ret < 0)
 471                return ret;
 472
 473        return 0;
 474        /*
 475         * NOTE: With chips which do not support this operation,
 476         * it seems to succeed ALWAYS ! (even if no device connected)
 477         */
 478}
 479
 480static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
 481{
 482        struct em28xx *dev = i2c_bus->dev;
 483        int rc = -EOPNOTSUPP;
 484
 485        if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 486                rc = em28xx_i2c_check_for_device(dev, addr);
 487        else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 488                rc = em2800_i2c_check_for_device(dev, addr);
 489        else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 490                rc = em25xx_bus_B_check_for_device(dev, addr);
 491        return rc;
 492}
 493
 494static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
 495                                 struct i2c_msg msg)
 496{
 497        struct em28xx *dev = i2c_bus->dev;
 498        u16 addr = msg.addr << 1;
 499        int rc = -EOPNOTSUPP;
 500
 501        if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 502                rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
 503        else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 504                rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
 505        else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 506                rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
 507        return rc;
 508}
 509
 510static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
 511                                 struct i2c_msg msg, int stop)
 512{
 513        struct em28xx *dev = i2c_bus->dev;
 514        u16 addr = msg.addr << 1;
 515        int rc = -EOPNOTSUPP;
 516
 517        if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
 518                rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
 519        else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
 520                rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
 521        else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
 522                rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
 523        return rc;
 524}
 525
 526/*
 527 * em28xx_i2c_xfer()
 528 * the main i2c transfer function
 529 */
 530static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 531                           struct i2c_msg msgs[], int num)
 532{
 533        struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
 534        struct em28xx *dev = i2c_bus->dev;
 535        unsigned int bus = i2c_bus->bus;
 536        int addr, rc, i;
 537        u8 reg;
 538
 539        /*
 540         * prevent i2c xfer attempts after device is disconnected
 541         * some fe's try to do i2c writes/reads from their release
 542         * interfaces when called in disconnect path
 543         */
 544        if (dev->disconnected)
 545                return -ENODEV;
 546
 547        if (!rt_mutex_trylock(&dev->i2c_bus_lock))
 548                return -EAGAIN;
 549
 550        /* Switch I2C bus if needed */
 551        if (bus != dev->cur_i2c_bus &&
 552            i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
 553                if (bus == 1)
 554                        reg = EM2874_I2C_SECONDARY_BUS_SELECT;
 555                else
 556                        reg = 0;
 557                em28xx_write_reg_bits(dev, EM28XX_R06_I2C_CLK, reg,
 558                                      EM2874_I2C_SECONDARY_BUS_SELECT);
 559                dev->cur_i2c_bus = bus;
 560        }
 561
 562        for (i = 0; i < num; i++) {
 563                addr = msgs[i].addr << 1;
 564                if (!msgs[i].len) {
 565                        /*
 566                         * no len: check only for device presence
 567                         * This code is only called during device probe.
 568                         */
 569                        rc = i2c_check_for_device(i2c_bus, addr);
 570
 571                        if (rc == -ENXIO)
 572                                rc = -ENODEV;
 573                } else if (msgs[i].flags & I2C_M_RD) {
 574                        /* read bytes */
 575                        rc = i2c_recv_bytes(i2c_bus, msgs[i]);
 576                } else {
 577                        /* write bytes */
 578                        rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
 579                }
 580
 581                if (rc < 0)
 582                        goto error;
 583
 584                dprintk(2, "%s %s addr=%02x len=%d: %*ph\n",
 585                        (msgs[i].flags & I2C_M_RD) ? "read" : "write",
 586                        i == num - 1 ? "stop" : "nonstop",
 587                        addr, msgs[i].len,
 588                        msgs[i].len, msgs[i].buf);
 589        }
 590
 591        rt_mutex_unlock(&dev->i2c_bus_lock);
 592        return num;
 593
 594error:
 595        dprintk(2, "%s %s addr=%02x len=%d: %sERROR: %i\n",
 596                (msgs[i].flags & I2C_M_RD) ? "read" : "write",
 597                i == num - 1 ? "stop" : "nonstop",
 598                addr, msgs[i].len,
 599                (rc == -ENODEV) ? "no device " : "",
 600                rc);
 601
 602        rt_mutex_unlock(&dev->i2c_bus_lock);
 603        return rc;
 604}
 605
 606/*
 607 * based on linux/sunrpc/svcauth.h and linux/hash.h
 608 * The original hash function returns a different value, if arch is x86_64
 609 * or i386.
 610 */
 611static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
 612{
 613        unsigned long hash = 0;
 614        unsigned long l = 0;
 615        int len = 0;
 616        unsigned char c;
 617
 618        do {
 619                if (len == length) {
 620                        c = (char)len;
 621                        len = -1;
 622                } else {
 623                        c = *buf++;
 624                }
 625                l = (l << 8) | c;
 626                len++;
 627                if ((len & (32 / 8 - 1)) == 0)
 628                        hash = ((hash ^ l) * 0x9e370001UL);
 629        } while (len);
 630
 631        return (hash >> (32 - bits)) & 0xffffffffUL;
 632}
 633
 634/*
 635 * Helper function to read data blocks from i2c clients with 8 or 16 bit
 636 * address width, 8 bit register width and auto incrementation been activated
 637 */
 638static int em28xx_i2c_read_block(struct em28xx *dev, unsigned int bus, u16 addr,
 639                                 bool addr_w16, u16 len, u8 *data)
 640{
 641        int remain = len, rsize, rsize_max, ret;
 642        u8 buf[2];
 643
 644        /* Sanity check */
 645        if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))
 646                return -EINVAL;
 647        /* Select address */
 648        buf[0] = addr >> 8;
 649        buf[1] = addr & 0xff;
 650        ret = i2c_master_send(&dev->i2c_client[bus],
 651                              buf + !addr_w16, 1 + addr_w16);
 652        if (ret < 0)
 653                return ret;
 654        /* Read data */
 655        if (dev->board.is_em2800)
 656                rsize_max = 4;
 657        else
 658                rsize_max = 64;
 659        while (remain > 0) {
 660                if (remain > rsize_max)
 661                        rsize = rsize_max;
 662                else
 663                        rsize = remain;
 664
 665                ret = i2c_master_recv(&dev->i2c_client[bus], data, rsize);
 666                if (ret < 0)
 667                        return ret;
 668
 669                remain -= rsize;
 670                data += rsize;
 671        }
 672
 673        return len;
 674}
 675
 676static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned int bus,
 677                             u8 **eedata, u16 *eedata_len)
 678{
 679        const u16 len = 256;
 680        /*
 681         * FIXME common length/size for bytes to read, to display, hash
 682         * calculation and returned device dataset. Simplifies the code a lot,
 683         * but we might have to deal with multiple sizes in the future !
 684         */
 685        int err;
 686        struct em28xx_eeprom *dev_config;
 687        u8 buf, *data;
 688
 689        *eedata = NULL;
 690        *eedata_len = 0;
 691
 692        /* EEPROM is always on i2c bus 0 on all known devices. */
 693
 694        dev->i2c_client[bus].addr = 0xa0 >> 1;
 695
 696        /* Check if board has eeprom */
 697        err = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
 698        if (err < 0) {
 699                dev_info(&dev->intf->dev, "board has no eeprom\n");
 700                return -ENODEV;
 701        }
 702
 703        data = kzalloc(len, GFP_KERNEL);
 704        if (!data)
 705                return -ENOMEM;
 706
 707        /* Read EEPROM content */
 708        err = em28xx_i2c_read_block(dev, bus, 0x0000,
 709                                    dev->eeprom_addrwidth_16bit,
 710                                    len, data);
 711        if (err != len) {
 712                dev_err(&dev->intf->dev,
 713                        "failed to read eeprom (err=%d)\n", err);
 714                goto error;
 715        }
 716
 717        if (i2c_debug) {
 718                /* Display eeprom content */
 719                print_hex_dump(KERN_DEBUG, "em28xx eeprom ", DUMP_PREFIX_OFFSET,
 720                               16, 1, data, len, true);
 721
 722                if (dev->eeprom_addrwidth_16bit)
 723                        dev_info(&dev->intf->dev,
 724                                 "eeprom %06x: ... (skipped)\n", 256);
 725        }
 726
 727        if (dev->eeprom_addrwidth_16bit &&
 728            data[0] == 0x26 && data[3] == 0x00) {
 729                /* new eeprom format; size 4-64kb */
 730                u16 mc_start;
 731                u16 hwconf_offset;
 732
 733                dev->hash = em28xx_hash_mem(data, len, 32);
 734                mc_start = (data[1] << 8) + 4;  /* usually 0x0004 */
 735
 736                dev_info(&dev->intf->dev,
 737                         "EEPROM ID = %4ph, EEPROM hash = 0x%08lx\n",
 738                         data, dev->hash);
 739                dev_info(&dev->intf->dev,
 740                         "EEPROM info:\n");
 741                dev_info(&dev->intf->dev,
 742                         "\tmicrocode start address = 0x%04x, boot configuration = 0x%02x\n",
 743                         mc_start, data[2]);
 744                /*
 745                 * boot configuration (address 0x0002):
 746                 * [0]   microcode download speed: 1 = 400 kHz; 0 = 100 kHz
 747                 * [1]   always selects 12 kb RAM
 748                 * [2]   USB device speed: 1 = force Full Speed; 0 = auto detect
 749                 * [4]   1 = force fast mode and no suspend for device testing
 750                 * [5:7] USB PHY tuning registers; determined by device
 751                 *       characterization
 752                 */
 753
 754                /*
 755                 * Read hardware config dataset offset from address
 756                 * (microcode start + 46)
 757                 */
 758                err = em28xx_i2c_read_block(dev, bus, mc_start + 46, 1, 2,
 759                                            data);
 760                if (err != 2) {
 761                        dev_err(&dev->intf->dev,
 762                                "failed to read hardware configuration data from eeprom (err=%d)\n",
 763                                err);
 764                        goto error;
 765                }
 766
 767                /* Calculate hardware config dataset start address */
 768                hwconf_offset = mc_start + data[0] + (data[1] << 8);
 769
 770                /* Read hardware config dataset */
 771                /*
 772                 * NOTE: the microcode copy can be multiple pages long, but
 773                 * we assume the hardware config dataset is the same as in
 774                 * the old eeprom and not longer than 256 bytes.
 775                 * tveeprom is currently also limited to 256 bytes.
 776                 */
 777                err = em28xx_i2c_read_block(dev, bus, hwconf_offset, 1, len,
 778                                            data);
 779                if (err != len) {
 780                        dev_err(&dev->intf->dev,
 781                                "failed to read hardware configuration data from eeprom (err=%d)\n",
 782                                err);
 783                        goto error;
 784                }
 785
 786                /* Verify hardware config dataset */
 787                /* NOTE: not all devices provide this type of dataset */
 788                if (data[0] != 0x1a || data[1] != 0xeb ||
 789                    data[2] != 0x67 || data[3] != 0x95) {
 790                        dev_info(&dev->intf->dev,
 791                                 "\tno hardware configuration dataset found in eeprom\n");
 792                        kfree(data);
 793                        return 0;
 794                }
 795
 796                /*
 797                 * TODO: decrypt eeprom data for camera bridges
 798                 * (em25xx, em276x+)
 799                 */
 800
 801        } else if (!dev->eeprom_addrwidth_16bit &&
 802                   data[0] == 0x1a && data[1] == 0xeb &&
 803                   data[2] == 0x67 && data[3] == 0x95) {
 804                dev->hash = em28xx_hash_mem(data, len, 32);
 805                dev_info(&dev->intf->dev,
 806                         "EEPROM ID = %4ph, EEPROM hash = 0x%08lx\n",
 807                         data, dev->hash);
 808                dev_info(&dev->intf->dev,
 809                         "EEPROM info:\n");
 810        } else {
 811                dev_info(&dev->intf->dev,
 812                         "unknown eeprom format or eeprom corrupted !\n");
 813                err = -ENODEV;
 814                goto error;
 815        }
 816
 817        *eedata = data;
 818        *eedata_len = len;
 819        dev_config = (void *)*eedata;
 820
 821        switch (le16_to_cpu(dev_config->chip_conf) >> 4 & 0x3) {
 822        case 0:
 823                dev_info(&dev->intf->dev, "\tNo audio on board.\n");
 824                break;
 825        case 1:
 826                dev_info(&dev->intf->dev, "\tAC97 audio (5 sample rates)\n");
 827                break;
 828        case 2:
 829                if (dev->chip_id < CHIP_ID_EM2860)
 830                        dev_info(&dev->intf->dev,
 831                                 "\tI2S audio, sample rate=32k\n");
 832                else
 833                        dev_info(&dev->intf->dev,
 834                                 "\tI2S audio, 3 sample rates\n");
 835                break;
 836        case 3:
 837                if (dev->chip_id < CHIP_ID_EM2860)
 838                        dev_info(&dev->intf->dev,
 839                                 "\tI2S audio, 3 sample rates\n");
 840                else
 841                        dev_info(&dev->intf->dev,
 842                                 "\tI2S audio, 5 sample rates\n");
 843                break;
 844        }
 845
 846        if (le16_to_cpu(dev_config->chip_conf) & 1 << 3)
 847                dev_info(&dev->intf->dev, "\tUSB Remote wakeup capable\n");
 848
 849        if (le16_to_cpu(dev_config->chip_conf) & 1 << 2)
 850                dev_info(&dev->intf->dev, "\tUSB Self power capable\n");
 851
 852        switch (le16_to_cpu(dev_config->chip_conf) & 0x3) {
 853        case 0:
 854                dev_info(&dev->intf->dev, "\t500mA max power\n");
 855                break;
 856        case 1:
 857                dev_info(&dev->intf->dev, "\t400mA max power\n");
 858                break;
 859        case 2:
 860                dev_info(&dev->intf->dev, "\t300mA max power\n");
 861                break;
 862        case 3:
 863                dev_info(&dev->intf->dev, "\t200mA max power\n");
 864                break;
 865        }
 866        dev_info(&dev->intf->dev,
 867                 "\tTable at offset 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
 868                 dev_config->string_idx_table,
 869                 le16_to_cpu(dev_config->string1),
 870                 le16_to_cpu(dev_config->string2),
 871                 le16_to_cpu(dev_config->string3));
 872
 873        return 0;
 874
 875error:
 876        kfree(data);
 877        return err;
 878}
 879
 880/* ----------------------------------------------------------- */
 881
 882/*
 883 * functionality()
 884 */
 885static u32 functionality(struct i2c_adapter *i2c_adap)
 886{
 887        struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
 888
 889        if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX ||
 890            i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B) {
 891                return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 892        } else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)  {
 893                return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
 894                        ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
 895        }
 896
 897        WARN(1, "Unknown i2c bus algorithm.\n");
 898        return 0;
 899}
 900
 901static const struct i2c_algorithm em28xx_algo = {
 902        .master_xfer   = em28xx_i2c_xfer,
 903        .functionality = functionality,
 904};
 905
 906static const struct i2c_adapter em28xx_adap_template = {
 907        .owner = THIS_MODULE,
 908        .name = "em28xx",
 909        .algo = &em28xx_algo,
 910};
 911
 912static const struct i2c_client em28xx_client_template = {
 913        .name = "em28xx internal",
 914};
 915
 916/* ----------------------------------------------------------- */
 917
 918/*
 919 * i2c_devs
 920 * incomplete list of known devices
 921 */
 922static char *i2c_devs[128] = {
 923        [0x1c >> 1] = "lgdt330x",
 924        [0x3e >> 1] = "remote IR sensor",
 925        [0x4a >> 1] = "saa7113h",
 926        [0x52 >> 1] = "drxk",
 927        [0x60 >> 1] = "remote IR sensor",
 928        [0x8e >> 1] = "remote IR sensor",
 929        [0x86 >> 1] = "tda9887",
 930        [0x80 >> 1] = "msp34xx",
 931        [0x88 >> 1] = "msp34xx",
 932        [0xa0 >> 1] = "eeprom",
 933        [0xb0 >> 1] = "tda9874",
 934        [0xb8 >> 1] = "tvp5150a",
 935        [0xba >> 1] = "webcam sensor or tvp5150a",
 936        [0xc0 >> 1] = "tuner (analog)",
 937        [0xc2 >> 1] = "tuner (analog)",
 938        [0xc4 >> 1] = "tuner (analog)",
 939        [0xc6 >> 1] = "tuner (analog)",
 940};
 941
 942/*
 943 * do_i2c_scan()
 944 * check i2c address range for devices
 945 */
 946void em28xx_do_i2c_scan(struct em28xx *dev, unsigned int bus)
 947{
 948        u8 i2c_devicelist[128];
 949        unsigned char buf;
 950        int i, rc;
 951
 952        memset(i2c_devicelist, 0, sizeof(i2c_devicelist));
 953
 954        for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
 955                dev->i2c_client[bus].addr = i;
 956                rc = i2c_master_recv(&dev->i2c_client[bus], &buf, 0);
 957                if (rc < 0)
 958                        continue;
 959                i2c_devicelist[i] = i;
 960                dev_info(&dev->intf->dev,
 961                         "found i2c device @ 0x%x on bus %d [%s]\n",
 962                         i << 1, bus, i2c_devs[i] ? i2c_devs[i] : "???");
 963        }
 964
 965        if (bus == dev->def_i2c_bus)
 966                dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
 967                                                sizeof(i2c_devicelist), 32);
 968}
 969
 970/*
 971 * em28xx_i2c_register()
 972 * register i2c bus
 973 */
 974int em28xx_i2c_register(struct em28xx *dev, unsigned int bus,
 975                        enum em28xx_i2c_algo_type algo_type)
 976{
 977        int retval;
 978
 979        if (WARN_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg ||
 980                    !dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req))
 981                return -ENODEV;
 982
 983        if (bus >= NUM_I2C_BUSES)
 984                return -ENODEV;
 985
 986        dev->i2c_adap[bus] = em28xx_adap_template;
 987        dev->i2c_adap[bus].dev.parent = &dev->intf->dev;
 988        strscpy(dev->i2c_adap[bus].name, dev_name(&dev->intf->dev),
 989                sizeof(dev->i2c_adap[bus].name));
 990
 991        dev->i2c_bus[bus].bus = bus;
 992        dev->i2c_bus[bus].algo_type = algo_type;
 993        dev->i2c_bus[bus].dev = dev;
 994        dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
 995
 996        retval = i2c_add_adapter(&dev->i2c_adap[bus]);
 997        if (retval < 0) {
 998                dev_err(&dev->intf->dev,
 999                        "%s: i2c_add_adapter failed! retval [%d]\n",
1000                        __func__, retval);
1001                return retval;
1002        }
1003
1004        dev->i2c_client[bus] = em28xx_client_template;
1005        dev->i2c_client[bus].adapter = &dev->i2c_adap[bus];
1006
1007        /* Up to now, all eeproms are at bus 0 */
1008        if (!bus) {
1009                retval = em28xx_i2c_eeprom(dev, bus,
1010                                           &dev->eedata, &dev->eedata_len);
1011                if (retval < 0 && retval != -ENODEV) {
1012                        dev_err(&dev->intf->dev,
1013                                "%s: em28xx_i2_eeprom failed! retval [%d]\n",
1014                                __func__, retval);
1015                }
1016        }
1017
1018        if (i2c_scan)
1019                em28xx_do_i2c_scan(dev, bus);
1020
1021        return 0;
1022}
1023
1024/*
1025 * em28xx_i2c_unregister()
1026 * unregister i2c_bus
1027 */
1028int em28xx_i2c_unregister(struct em28xx *dev, unsigned int bus)
1029{
1030        if (bus >= NUM_I2C_BUSES)
1031                return -ENODEV;
1032
1033        i2c_del_adapter(&dev->i2c_adap[bus]);
1034        return 0;
1035}
1036