drivers/media/pci/ivtv/ivtv-i2c.c

   1 /*
   2     I2C functions
   3     Copyright (C) 2003-2004  Kevin Thayer <nufan_wfk at yahoo.com>
   4     Copyright (C) 2005-2007  Hans Verkuil <hverkuil@xs4all.nl>
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /*
  22     This file includes an i2c implementation that was reverse engineered
  23     from the Hauppauge windows driver.  Older ivtv versions used i2c-algo-bit,
  24     which whilst fine under most circumstances, had trouble with the Zilog
  25     CPU on the PVR-150 which handles IR functions (occasional inability to
  26     communicate with the chip until it was reset) and also with the i2c
  27     bus being completely unreachable when multiple PVR cards were present.
  28
  29     The implementation is very similar to i2c-algo-bit, but there are enough
  30     subtle differences that the two are hard to merge.  The general strategy
  31     employed by i2c-algo-bit is to use udelay() to implement the timing
  32     when putting out bits on the scl/sda lines.  The general strategy taken
  33     here is to poll the lines for state changes (see ivtv_waitscl and
  34     ivtv_waitsda).  In addition there are small delays at various locations
  35     which poll the SCL line 5 times (ivtv_scldelay).  I would guess that
  36     since this is memory mapped I/O that the length of those delays is tied
  37     to the PCI bus clock.  There is some extra code to do with recovery
  38     and retries.  Since it is not known what causes the actual i2c problems
  39     in the first place, the only goal if one was to attempt to use
  40     i2c-algo-bit would be to try to make it follow the same code path.
  41     This would be a lot of work, and I'm also not convinced that it would
  42     provide a generic benefit to i2c-algo-bit.  Therefore consider this
  43     an engineering solution -- not pretty, but it works.
  44
  45     Some more general comments about what we are doing:
  46
  47     The i2c bus is a 2 wire serial bus, with clock (SCL) and data (SDA)
  48     lines.  To communicate on the bus (as a master, we don't act as a slave),
  49     we first initiate a start condition (ivtv_start).  We then write the
  50     address of the device that we want to communicate with, along with a flag
  51     that indicates whether this is a read or a write.  The slave then issues
  52     an ACK signal (ivtv_ack), which tells us that it is ready for reading /
  53     writing.  We then proceed with reading or writing (ivtv_read/ivtv_write),
  54     and finally issue a stop condition (ivtv_stop) to make the bus available
  55     to other masters.
  56
  57     There is an additional form of transaction where a write may be
  58     immediately followed by a read.  In this case, there is no intervening
  59     stop condition.  (Only the msp3400 chip uses this method of data transfer).
  60  */
  61
  62 #include "ivtv-driver.h"
  63 #include "ivtv-cards.h"
  64 #include "ivtv-gpio.h"
  65 #include "ivtv-i2c.h"
  66 #include <media/cx25840.h>
  67
  68 /* i2c implementation for cx23415/6 chip, ivtv project.
  69  * Author: Kevin Thayer (nufan_wfk at yahoo.com)
  70  */
  71 /* i2c stuff */
  72 #define IVTV_REG_I2C_SETSCL_OFFSET 0x7000
  73 #define IVTV_REG_I2C_SETSDA_OFFSET 0x7004
  74 #define IVTV_REG_I2C_GETSCL_OFFSET 0x7008
  75 #define IVTV_REG_I2C_GETSDA_OFFSET 0x700c
  76
  77 #define IVTV_CS53L32A_I2C_ADDR          0x11
  78 #define IVTV_M52790_I2C_ADDR            0x48
  79 #define IVTV_CX25840_I2C_ADDR           0x44
  80 #define IVTV_SAA7115_I2C_ADDR           0x21
  81 #define IVTV_SAA7127_I2C_ADDR           0x44
  82 #define IVTV_SAA717x_I2C_ADDR           0x21
  83 #define IVTV_MSP3400_I2C_ADDR           0x40
  84 #define IVTV_HAUPPAUGE_I2C_ADDR         0x50
  85 #define IVTV_WM8739_I2C_ADDR            0x1a
  86 #define IVTV_WM8775_I2C_ADDR            0x1b
  87 #define IVTV_TEA5767_I2C_ADDR           0x60
  88 #define IVTV_UPD64031A_I2C_ADDR         0x12
  89 #define IVTV_UPD64083_I2C_ADDR          0x5c
  90 #define IVTV_VP27SMPX_I2C_ADDR          0x5b
  91 #define IVTV_M52790_I2C_ADDR            0x48
  92 #define IVTV_AVERMEDIA_IR_RX_I2C_ADDR   0x40
  93 #define IVTV_HAUP_EXT_IR_RX_I2C_ADDR    0x1a
  94 #define IVTV_HAUP_INT_IR_RX_I2C_ADDR    0x18
  95 #define IVTV_Z8F0811_IR_TX_I2C_ADDR     0x70
  96 #define IVTV_Z8F0811_IR_RX_I2C_ADDR     0x71
  97 #define IVTV_ADAPTEC_IR_ADDR            0x6b
  98
  99 /* This array should match the IVTV_HW_ defines */
 100 static const u8 hw_addrs[] = {
 101         IVTV_CX25840_I2C_ADDR,
 102         IVTV_SAA7115_I2C_ADDR,
 103         IVTV_SAA7127_I2C_ADDR,
 104         IVTV_MSP3400_I2C_ADDR,
 105         0,
 106         IVTV_WM8775_I2C_ADDR,
 107         IVTV_CS53L32A_I2C_ADDR,
 108         0,
 109         IVTV_SAA7115_I2C_ADDR,
 110         IVTV_UPD64031A_I2C_ADDR,
 111         IVTV_UPD64083_I2C_ADDR,
 112         IVTV_SAA717x_I2C_ADDR,
 113         IVTV_WM8739_I2C_ADDR,
 114         IVTV_VP27SMPX_I2C_ADDR,
 115         IVTV_M52790_I2C_ADDR,
 116         0,                              /* IVTV_HW_GPIO dummy driver ID */
 117         IVTV_AVERMEDIA_IR_RX_I2C_ADDR,  /* IVTV_HW_I2C_IR_RX_AVER */
 118         IVTV_HAUP_EXT_IR_RX_I2C_ADDR,   /* IVTV_HW_I2C_IR_RX_HAUP_EXT */
 119         IVTV_HAUP_INT_IR_RX_I2C_ADDR,   /* IVTV_HW_I2C_IR_RX_HAUP_INT */
 120         IVTV_Z8F0811_IR_TX_I2C_ADDR,    /* IVTV_HW_Z8F0811_IR_TX_HAUP */
 121         IVTV_Z8F0811_IR_RX_I2C_ADDR,    /* IVTV_HW_Z8F0811_IR_RX_HAUP */
 122         IVTV_ADAPTEC_IR_ADDR,           /* IVTV_HW_I2C_IR_RX_ADAPTEC */
 123 };
 124
 125 /* This array should match the IVTV_HW_ defines */
 126 static const char * const hw_devicenames[] = {
 127         "cx25840",
 128         "saa7115",
 129         "saa7127_auto", /* saa7127 or saa7129 */
 130         "msp3400",
 131         "tuner",
 132         "wm8775",
 133         "cs53l32a",
 134         "tveeprom",
 135         "saa7114",
 136         "upd64031a",
 137         "upd64083",
 138         "saa717x",
 139         "wm8739",
 140         "vp27smpx",
 141         "m52790",
 142         "gpio",
 143         "ir_video",             /* IVTV_HW_I2C_IR_RX_AVER */
 144         "ir_video",             /* IVTV_HW_I2C_IR_RX_HAUP_EXT */
 145         "ir_video",             /* IVTV_HW_I2C_IR_RX_HAUP_INT */
 146         "ir_tx_z8f0811_haup",   /* IVTV_HW_Z8F0811_IR_TX_HAUP */
 147         "ir_rx_z8f0811_haup",   /* IVTV_HW_Z8F0811_IR_RX_HAUP */
 148         "ir_video",             /* IVTV_HW_I2C_IR_RX_ADAPTEC */
 149 };
 150
 151 static int get_key_adaptec(struct IR_i2c *ir, u32 *ir_key, u32 *ir_raw)
 152 {
 153         unsigned char keybuf[4];
 154
 155         keybuf[0] = 0x00;
 156         i2c_master_send(ir->c, keybuf, 1);
 157         /* poll IR chip */
 158         if (i2c_master_recv(ir->c, keybuf, sizeof(keybuf)) != sizeof(keybuf)) {
 159                 return 0;
 160         }
 161
 162         /* key pressed ? */
 163         if (keybuf[2] == 0xff)
 164                 return 0;
 165
 166         /* remove repeat bit */
 167         keybuf[2] &= 0x7f;
 168         keybuf[3] |= 0x80;
 169
 170         *ir_key = keybuf[3] | keybuf[2] << 8 | keybuf[1] << 16 |keybuf[0] << 24;
 171         *ir_raw = *ir_key;
 172
 173         return 1;
 174 }
 175
 176 static int ivtv_i2c_new_ir(struct ivtv *itv, u32 hw, const char *type, u8 addr)
 177 {
 178         struct i2c_board_info info;
 179         struct i2c_adapter *adap = &itv->i2c_adap;
 180         struct IR_i2c_init_data *init_data = &itv->ir_i2c_init_data;
 181         unsigned short addr_list[2] = { addr, I2C_CLIENT_END };
 182
 183         /* Only allow one IR transmitter to be registered per board */
 184         if (hw & IVTV_HW_IR_TX_ANY) {
 185                 if (itv->hw_flags & IVTV_HW_IR_TX_ANY)
 186                         return -1;
 187                 memset(&info, 0, sizeof(struct i2c_board_info));
 188                 strlcpy(info.type, type, I2C_NAME_SIZE);
 189                 return i2c_new_probed_device(adap, &info, addr_list, NULL)
 190                                                            == NULL ? -1 : 0;
 191         }
 192
 193         /* Only allow one IR receiver to be registered per board */
 194         if (itv->hw_flags & IVTV_HW_IR_RX_ANY)
 195                 return -1;
 196
 197         /* Our default information for ir-kbd-i2c.c to use */
 198         switch (hw) {
 199         case IVTV_HW_I2C_IR_RX_AVER:
 200                 init_data->ir_codes = RC_MAP_AVERMEDIA_CARDBUS;
 201                 init_data->internal_get_key_func =
 202                                         IR_KBD_GET_KEY_AVERMEDIA_CARDBUS;
 203                 init_data->type = RC_TYPE_OTHER;
 204                 init_data->name = "AVerMedia AVerTV card";
 205                 break;
 206         case IVTV_HW_I2C_IR_RX_HAUP_EXT:
 207         case IVTV_HW_I2C_IR_RX_HAUP_INT:
 208                 init_data->ir_codes = RC_MAP_HAUPPAUGE;
 209                 init_data->internal_get_key_func = IR_KBD_GET_KEY_HAUP;
 210                 init_data->type = RC_TYPE_RC5;
 211                 init_data->name = itv->card_name;
 212                 break;
 213         case IVTV_HW_Z8F0811_IR_RX_HAUP:
 214                 /* Default to grey remote */
 215                 init_data->ir_codes = RC_MAP_HAUPPAUGE;
 216                 init_data->internal_get_key_func = IR_KBD_GET_KEY_HAUP_XVR;
 217                 init_data->type = RC_TYPE_RC5;
 218                 init_data->name = itv->card_name;
 219                 break;
 220         case IVTV_HW_I2C_IR_RX_ADAPTEC:
 221                 init_data->get_key = get_key_adaptec;
 222                 init_data->name = itv->card_name;
 223                 /* FIXME: The protocol and RC_MAP needs to be corrected */
 224                 init_data->ir_codes = RC_MAP_EMPTY;
 225                 init_data->type = RC_TYPE_UNKNOWN;
 226                 break;
 227         }
 228
 229         memset(&info, 0, sizeof(struct i2c_board_info));
 230         info.platform_data = init_data;
 231         strlcpy(info.type, type, I2C_NAME_SIZE);
 232
 233         return i2c_new_probed_device(adap, &info, addr_list, NULL) == NULL ?
 234                -1 : 0;
 235 }
 236
 237 /* Instantiate the IR receiver device using probing -- undesirable */
 238 struct i2c_client *ivtv_i2c_new_ir_legacy(struct ivtv *itv)
 239 {
 240         struct i2c_board_info info;
 241         /*
 242          * The external IR receiver is at i2c address 0x34.
 243          * The internal IR receiver is at i2c address 0x30.
 244          *
 245          * In theory, both can be fitted, and Hauppauge suggests an external
 246          * overrides an internal.  That's why we probe 0x1a (~0x34) first. CB
 247          *
 248          * Some of these addresses we probe may collide with other i2c address
 249          * allocations, so this function must be called after all other i2c
 250          * devices we care about are registered.
 251          */
 252         const unsigned short addr_list[] = {
 253                 0x1a,   /* Hauppauge IR external - collides with WM8739 */
 254                 0x18,   /* Hauppauge IR internal */
 255                 I2C_CLIENT_END
 256         };
 257
 258         memset(&info, 0, sizeof(struct i2c_board_info));
 259         strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
 260         return i2c_new_probed_device(&itv->i2c_adap, &info, addr_list, NULL);
 261 }
 262
 263 int ivtv_i2c_register(struct ivtv *itv, unsigned idx)
 264 {
 265         struct v4l2_subdev *sd;
 266         struct i2c_adapter *adap = &itv->i2c_adap;
 267         const char *type = hw_devicenames[idx];
 268         u32 hw = 1 << idx;
 269
 270         if (idx >= ARRAY_SIZE(hw_addrs))
 271                 return -1;
 272         if (hw == IVTV_HW_TUNER) {
 273                 /* special tuner handling */
 274                 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0,
 275                                 itv->card_i2c->radio);
 276                 if (sd)
 277                         sd->grp_id = 1 << idx;
 278                 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0,
 279                                 itv->card_i2c->demod);
 280                 if (sd)
 281                         sd->grp_id = 1 << idx;
 282                 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0,
 283                                 itv->card_i2c->tv);
 284                 if (sd)
 285                         sd->grp_id = 1 << idx;
 286                 return sd ? 0 : -1;
 287         }
 288
 289         if (hw & IVTV_HW_IR_ANY)
 290                 return ivtv_i2c_new_ir(itv, hw, type, hw_addrs[idx]);
 291
 292         /* Is it not an I2C device or one we do not wish to register? */
 293         if (!hw_addrs[idx])
 294                 return -1;
 295
 296         /* It's an I2C device other than an analog tuner or IR chip */
 297         if (hw == IVTV_HW_UPD64031A || hw == IVTV_HW_UPD6408X) {
 298                 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
 299                                 adap, type, 0, I2C_ADDRS(hw_addrs[idx]));
 300         } else if (hw == IVTV_HW_CX25840) {
 301                 struct cx25840_platform_data pdata;
 302                 struct i2c_board_info cx25840_info = {
 303                         .type = "cx25840",
 304                         .addr = hw_addrs[idx],
 305                         .platform_data = &pdata,
 306                 };
 307
 308                 pdata.pvr150_workaround = itv->pvr150_workaround;
 309                 sd = v4l2_i2c_new_subdev_board(&itv->v4l2_dev, adap,
 310                                 &cx25840_info, NULL);
 311         } else {
 312                 sd = v4l2_i2c_new_subdev(&itv->v4l2_dev,
 313                                 adap, type, hw_addrs[idx], NULL);
 314         }
 315         if (sd)
 316                 sd->grp_id = 1 << idx;
 317         return sd ? 0 : -1;
 318 }
 319
 320 struct v4l2_subdev *ivtv_find_hw(struct ivtv *itv, u32 hw)
 321 {
 322         struct v4l2_subdev *result = NULL;
 323         struct v4l2_subdev *sd;
 324
 325         spin_lock(&itv->v4l2_dev.lock);
 326         v4l2_device_for_each_subdev(sd, &itv->v4l2_dev) {
 327                 if (sd->grp_id == hw) {
 328                         result = sd;
 329                         break;
 330                 }
 331         }
 332         spin_unlock(&itv->v4l2_dev.lock);
 333         return result;
 334 }
 335
 336 /* Set the serial clock line to the desired state */
 337 static void ivtv_setscl(struct ivtv *itv, int state)
 338 {
 339         /* write them out */
 340         /* write bits are inverted */
 341         write_reg(~state, IVTV_REG_I2C_SETSCL_OFFSET);
 342 }
 343
 344 /* Set the serial data line to the desired state */
 345 static void ivtv_setsda(struct ivtv *itv, int state)
 346 {
 347         /* write them out */
 348         /* write bits are inverted */
 349         write_reg(~state & 1, IVTV_REG_I2C_SETSDA_OFFSET);
 350 }
 351
 352 /* Read the serial clock line */
 353 static int ivtv_getscl(struct ivtv *itv)
 354 {
 355         return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
 356 }
 357
 358 /* Read the serial data line */
 359 static int ivtv_getsda(struct ivtv *itv)
 360 {
 361         return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
 362 }
 363
 364 /* Implement a short delay by polling the serial clock line */
 365 static void ivtv_scldelay(struct ivtv *itv)
 366 {
 367         int i;
 368
 369         for (i = 0; i < 5; ++i)
 370                 ivtv_getscl(itv);
 371 }
 372
 373 /* Wait for the serial clock line to become set to a specific value */
 374 static int ivtv_waitscl(struct ivtv *itv, int val)
 375 {
 376         int i;
 377
 378         ivtv_scldelay(itv);
 379         for (i = 0; i < 1000; ++i) {
 380                 if (ivtv_getscl(itv) == val)
 381                         return 1;
 382         }
 383         return 0;
 384 }
 385
 386 /* Wait for the serial data line to become set to a specific value */
 387 static int ivtv_waitsda(struct ivtv *itv, int val)
 388 {
 389         int i;
 390
 391         ivtv_scldelay(itv);
 392         for (i = 0; i < 1000; ++i) {
 393                 if (ivtv_getsda(itv) == val)
 394                         return 1;
 395         }
 396         return 0;
 397 }
 398
 399 /* Wait for the slave to issue an ACK */
 400 static int ivtv_ack(struct ivtv *itv)
 401 {
 402         int ret = 0;
 403
 404         if (ivtv_getscl(itv) == 1) {
 405                 IVTV_DEBUG_HI_I2C("SCL was high starting an ack\n");
 406                 ivtv_setscl(itv, 0);
 407                 if (!ivtv_waitscl(itv, 0)) {
 408                         IVTV_DEBUG_I2C("Could not set SCL low starting an ack\n");
 409                         return -EREMOTEIO;
 410                 }
 411         }
 412         ivtv_setsda(itv, 1);
 413         ivtv_scldelay(itv);
 414         ivtv_setscl(itv, 1);
 415         if (!ivtv_waitsda(itv, 0)) {
 416                 IVTV_DEBUG_I2C("Slave did not ack\n");
 417                 ret = -EREMOTEIO;
 418         }
 419         ivtv_setscl(itv, 0);
 420         if (!ivtv_waitscl(itv, 0)) {
 421                 IVTV_DEBUG_I2C("Failed to set SCL low after ACK\n");
 422                 ret = -EREMOTEIO;
 423         }
 424         return ret;
 425 }
 426
 427 /* Write a single byte to the i2c bus and wait for the slave to ACK */
 428 static int ivtv_sendbyte(struct ivtv *itv, unsigned char byte)
 429 {
 430         int i, bit;
 431
 432         IVTV_DEBUG_HI_I2C("write %x\n",byte);
 433         for (i = 0; i < 8; ++i, byte<<=1) {
 434                 ivtv_setscl(itv, 0);
 435                 if (!ivtv_waitscl(itv, 0)) {
 436                         IVTV_DEBUG_I2C("Error setting SCL low\n");
 437                         return -EREMOTEIO;
 438                 }
 439                 bit = (byte>>7)&1;
 440                 ivtv_setsda(itv, bit);
 441                 if (!ivtv_waitsda(itv, bit)) {
 442                         IVTV_DEBUG_I2C("Error setting SDA\n");
 443                         return -EREMOTEIO;
 444                 }
 445                 ivtv_setscl(itv, 1);
 446                 if (!ivtv_waitscl(itv, 1)) {
 447                         IVTV_DEBUG_I2C("Slave not ready for bit\n");
 448                         return -EREMOTEIO;
 449                 }
 450         }
 451         ivtv_setscl(itv, 0);
 452         if (!ivtv_waitscl(itv, 0)) {
 453                 IVTV_DEBUG_I2C("Error setting SCL low\n");
 454                 return -EREMOTEIO;
 455         }
 456         return ivtv_ack(itv);
 457 }
 458
 459 /* Read a byte from the i2c bus and send a NACK if applicable (i.e. for the
 460    final byte) */
 461 static int ivtv_readbyte(struct ivtv *itv, unsigned char *byte, int nack)
 462 {
 463         int i;
 464
 465         *byte = 0;
 466
 467         ivtv_setsda(itv, 1);
 468         ivtv_scldelay(itv);
 469         for (i = 0; i < 8; ++i) {
 470                 ivtv_setscl(itv, 0);
 471                 ivtv_scldelay(itv);
 472                 ivtv_setscl(itv, 1);
 473                 if (!ivtv_waitscl(itv, 1)) {
 474                         IVTV_DEBUG_I2C("Error setting SCL high\n");
 475                         return -EREMOTEIO;
 476                 }
 477                 *byte = ((*byte)<<1)|ivtv_getsda(itv);
 478         }
 479         ivtv_setscl(itv, 0);
 480         ivtv_scldelay(itv);
 481         ivtv_setsda(itv, nack);
 482         ivtv_scldelay(itv);
 483         ivtv_setscl(itv, 1);
 484         ivtv_scldelay(itv);
 485         ivtv_setscl(itv, 0);
 486         ivtv_scldelay(itv);
 487         IVTV_DEBUG_HI_I2C("read %x\n",*byte);
 488         return 0;
 489 }
 490
 491 /* Issue a start condition on the i2c bus to alert slaves to prepare for
 492    an address write */
 493 static int ivtv_start(struct ivtv *itv)
 494 {
 495         int sda;
 496
 497         sda = ivtv_getsda(itv);
 498         if (sda != 1) {
 499                 IVTV_DEBUG_HI_I2C("SDA was low at start\n");
 500                 ivtv_setsda(itv, 1);
 501                 if (!ivtv_waitsda(itv, 1)) {
 502                         IVTV_DEBUG_I2C("SDA stuck low\n");
 503                         return -EREMOTEIO;
 504                 }
 505         }
 506         if (ivtv_getscl(itv) != 1) {
 507                 ivtv_setscl(itv, 1);
 508                 if (!ivtv_waitscl(itv, 1)) {
 509                         IVTV_DEBUG_I2C("SCL stuck low at start\n");
 510                         return -EREMOTEIO;
 511                 }
 512         }
 513         ivtv_setsda(itv, 0);
 514         ivtv_scldelay(itv);
 515         return 0;
 516 }
 517
 518 /* Issue a stop condition on the i2c bus to release it */
 519 static int ivtv_stop(struct ivtv *itv)
 520 {
 521         int i;
 522
 523         if (ivtv_getscl(itv) != 0) {
 524                 IVTV_DEBUG_HI_I2C("SCL not low when stopping\n");
 525                 ivtv_setscl(itv, 0);
 526                 if (!ivtv_waitscl(itv, 0)) {
 527                         IVTV_DEBUG_I2C("SCL could not be set low\n");
 528                 }
 529         }
 530         ivtv_setsda(itv, 0);
 531         ivtv_scldelay(itv);
 532         ivtv_setscl(itv, 1);
 533         if (!ivtv_waitscl(itv, 1)) {
 534                 IVTV_DEBUG_I2C("SCL could not be set high\n");
 535                 return -EREMOTEIO;
 536         }
 537         ivtv_scldelay(itv);
 538         ivtv_setsda(itv, 1);
 539         if (!ivtv_waitsda(itv, 1)) {
 540                 IVTV_DEBUG_I2C("resetting I2C\n");
 541                 for (i = 0; i < 16; ++i) {
 542                         ivtv_setscl(itv, 0);
 543                         ivtv_scldelay(itv);
 544                         ivtv_setscl(itv, 1);
 545                         ivtv_scldelay(itv);
 546                         ivtv_setsda(itv, 1);
 547                 }
 548                 ivtv_waitsda(itv, 1);
 549                 return -EREMOTEIO;
 550         }
 551         return 0;
 552 }
 553
 554 /* Write a message to the given i2c slave.  do_stop may be 0 to prevent
 555    issuing the i2c stop condition (when following with a read) */
 556 static int ivtv_write(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len, int do_stop)
 557 {
 558         int retry, ret = -EREMOTEIO;
 559         u32 i;
 560
 561         for (retry = 0; ret != 0 && retry < 8; ++retry) {
 562                 ret = ivtv_start(itv);
 563
 564                 if (ret == 0) {
 565                         ret = ivtv_sendbyte(itv, addr<<1);
 566                         for (i = 0; ret == 0 && i < len; ++i)
 567                                 ret = ivtv_sendbyte(itv, data[i]);
 568                 }
 569                 if (ret != 0 || do_stop) {
 570                         ivtv_stop(itv);
 571                 }
 572         }
 573         if (ret)
 574                 IVTV_DEBUG_I2C("i2c write to %x failed\n", addr);
 575         return ret;
 576 }
 577
 578 /* Read data from the given i2c slave.  A stop condition is always issued. */
 579 static int ivtv_read(struct ivtv *itv, unsigned char addr, unsigned char *data, u32 len)
 580 {
 581         int retry, ret = -EREMOTEIO;
 582         u32 i;
 583
 584         for (retry = 0; ret != 0 && retry < 8; ++retry) {
 585                 ret = ivtv_start(itv);
 586                 if (ret == 0)
 587                         ret = ivtv_sendbyte(itv, (addr << 1) | 1);
 588                 for (i = 0; ret == 0 && i < len; ++i) {
 589                         ret = ivtv_readbyte(itv, &data[i], i == len - 1);
 590                 }
 591                 ivtv_stop(itv);
 592         }
 593         if (ret)
 594                 IVTV_DEBUG_I2C("i2c read from %x failed\n", addr);
 595         return ret;
 596 }
 597
 598 /* Kernel i2c transfer implementation.  Takes a number of messages to be read
 599    or written.  If a read follows a write, this will occur without an
 600    intervening stop condition */
 601 static int ivtv_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
 602 {
 603         struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
 604         struct ivtv *itv = to_ivtv(v4l2_dev);
 605         int retval;
 606         int i;
 607
 608         mutex_lock(&itv->i2c_bus_lock);
 609         for (i = retval = 0; retval == 0 && i < num; i++) {
 610                 if (msgs[i].flags & I2C_M_RD)
 611                         retval = ivtv_read(itv, msgs[i].addr, msgs[i].buf, msgs[i].len);
 612                 else {
 613                         /* if followed by a read, don't stop */
 614                         int stop = !(i + 1 < num && msgs[i + 1].flags == I2C_M_RD);
 615
 616                         retval = ivtv_write(itv, msgs[i].addr, msgs[i].buf, msgs[i].len, stop);
 617                 }
 618         }
 619         mutex_unlock(&itv->i2c_bus_lock);
 620         return retval ? retval : num;
 621 }
 622
 623 /* Kernel i2c capabilities */
 624 static u32 ivtv_functionality(struct i2c_adapter *adap)
 625 {
 626         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 627 }
 628
 629 static struct i2c_algorithm ivtv_algo = {
 630         .master_xfer   = ivtv_xfer,
 631         .functionality = ivtv_functionality,
 632 };
 633
 634 /* template for our-bit banger */
 635 static struct i2c_adapter ivtv_i2c_adap_hw_template = {
 636         .name = "ivtv i2c driver",
 637         .algo = &ivtv_algo,
 638         .algo_data = NULL,                      /* filled from template */
 639         .owner = THIS_MODULE,
 640 };
 641
 642 static void ivtv_setscl_old(void *data, int state)
 643 {
 644         struct ivtv *itv = (struct ivtv *)data;
 645
 646         if (state)
 647                 itv->i2c_state |= 0x01;
 648         else
 649                 itv->i2c_state &= ~0x01;
 650
 651         /* write them out */
 652         /* write bits are inverted */
 653         write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSCL_OFFSET);
 654 }
 655
 656 static void ivtv_setsda_old(void *data, int state)
 657 {
 658         struct ivtv *itv = (struct ivtv *)data;
 659
 660         if (state)
 661                 itv->i2c_state |= 0x01;
 662         else
 663                 itv->i2c_state &= ~0x01;
 664
 665         /* write them out */
 666         /* write bits are inverted */
 667         write_reg(~itv->i2c_state, IVTV_REG_I2C_SETSDA_OFFSET);
 668 }
 669
 670 static int ivtv_getscl_old(void *data)
 671 {
 672         struct ivtv *itv = (struct ivtv *)data;
 673
 674         return read_reg(IVTV_REG_I2C_GETSCL_OFFSET) & 1;
 675 }
 676
 677 static int ivtv_getsda_old(void *data)
 678 {
 679         struct ivtv *itv = (struct ivtv *)data;
 680
 681         return read_reg(IVTV_REG_I2C_GETSDA_OFFSET) & 1;
 682 }
 683
 684 /* template for i2c-bit-algo */
 685 static struct i2c_adapter ivtv_i2c_adap_template = {
 686         .name = "ivtv i2c driver",
 687         .algo = NULL,                   /* set by i2c-algo-bit */
 688         .algo_data = NULL,              /* filled from template */
 689         .owner = THIS_MODULE,
 690 };
 691
 692 #define IVTV_ALGO_BIT_TIMEOUT   (2)     /* seconds */
 693
 694 static const struct i2c_algo_bit_data ivtv_i2c_algo_template = {
 695         .setsda         = ivtv_setsda_old,
 696         .setscl         = ivtv_setscl_old,
 697         .getsda         = ivtv_getsda_old,
 698         .getscl         = ivtv_getscl_old,
 699         .udelay         = IVTV_DEFAULT_I2C_CLOCK_PERIOD / 2,  /* microseconds */
 700         .timeout        = IVTV_ALGO_BIT_TIMEOUT * HZ,         /* jiffies */
 701 };
 702
 703 static struct i2c_client ivtv_i2c_client_template = {
 704         .name = "ivtv internal",
 705 };
 706
 707 /* init + register i2c adapter */
 708 int init_ivtv_i2c(struct ivtv *itv)
 709 {
 710         int retval;
 711
 712         IVTV_DEBUG_I2C("i2c init\n");
 713
 714         /* Sanity checks for the I2C hardware arrays. They must be the
 715          * same size.
 716          */
 717         if (ARRAY_SIZE(hw_devicenames) != ARRAY_SIZE(hw_addrs)) {
 718                 IVTV_ERR("Mismatched I2C hardware arrays\n");
 719                 return -ENODEV;
 720         }
 721         if (itv->options.newi2c > 0) {
 722                 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_hw_template,
 723                        sizeof(struct i2c_adapter));
 724         } else {
 725                 memcpy(&itv->i2c_adap, &ivtv_i2c_adap_template,
 726                        sizeof(struct i2c_adapter));
 727                 memcpy(&itv->i2c_algo, &ivtv_i2c_algo_template,
 728                        sizeof(struct i2c_algo_bit_data));
 729         }
 730         itv->i2c_algo.udelay = itv->options.i2c_clock_period / 2;
 731         itv->i2c_algo.data = itv;
 732         itv->i2c_adap.algo_data = &itv->i2c_algo;
 733
 734         sprintf(itv->i2c_adap.name + strlen(itv->i2c_adap.name), " #%d",
 735                 itv->instance);
 736         i2c_set_adapdata(&itv->i2c_adap, &itv->v4l2_dev);
 737
 738         memcpy(&itv->i2c_client, &ivtv_i2c_client_template,
 739                sizeof(struct i2c_client));
 740         itv->i2c_client.adapter = &itv->i2c_adap;
 741         itv->i2c_adap.dev.parent = &itv->pdev->dev;
 742
 743         IVTV_DEBUG_I2C("setting scl and sda to 1\n");
 744         ivtv_setscl(itv, 1);
 745         ivtv_setsda(itv, 1);
 746
 747         if (itv->options.newi2c > 0)
 748                 retval = i2c_add_adapter(&itv->i2c_adap);
 749         else
 750                 retval = i2c_bit_add_bus(&itv->i2c_adap);
 751
 752         return retval;
 753 }
 754
 755 void exit_ivtv_i2c(struct ivtv *itv)
 756 {
 757         IVTV_DEBUG_I2C("i2c exit\n");
 758
 759         i2c_del_adapter(&itv->i2c_adap);
 760 }