drivers/media/video/usbvision/usbvision-i2c.c

   1 /*
   2  * usbvision_i2c.c
   3  *  i2c algorithm for USB-I2C Bridges
   4  *
   5  * Copyright (c) 1999-2007 Joerg Heckenbach <joerg@heckenbach-aw.de>
   6  *                         Dwaine Garden <dwainegarden@rogers.com>
   7  *
   8  * This module is part of usbvision driver project.
   9  * Updates to driver completed by Dwaine P. Garden
  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  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <asm/uaccess.h>
  32 #include <linux/ioport.h>
  33 #include <linux/errno.h>
  34 #include <linux/usb.h>
  35 #include <linux/i2c.h>
  36 #include "usbvision.h"
  37
  38 #define DBG_I2C         1<<0
  39
  40 static int i2c_debug;
  41
  42 module_param (i2c_debug, int, 0644);                    // debug_i2c_usb mode of the device driver
  43 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  44
  45 #define PDEBUG(level, fmt, args...) { \
  46                 if (i2c_debug & (level)) \
  47                         printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
  48                                 __func__, __LINE__ , ## args); \
  49         }
  50
  51 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  52                             short len);
  53 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  54                            short len);
  55
  56 static inline int try_write_address(struct i2c_adapter *i2c_adap,
  57                                     unsigned char addr, int retries)
  58 {
  59         struct usb_usbvision *usbvision;
  60         int i, ret = -1;
  61         char buf[4];
  62
  63         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  64         buf[0] = 0x00;
  65         for (i = 0; i <= retries; i++) {
  66                 ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
  67                 if (ret == 1)
  68                         break;  /* success! */
  69                 udelay(5);
  70                 if (i == retries)       /* no success */
  71                         break;
  72                 udelay(10);
  73         }
  74         if (i) {
  75                 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
  76                 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
  77         }
  78         return ret;
  79 }
  80
  81 static inline int try_read_address(struct i2c_adapter *i2c_adap,
  82                                    unsigned char addr, int retries)
  83 {
  84         struct usb_usbvision *usbvision;
  85         int i, ret = -1;
  86         char buf[4];
  87
  88         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  89         for (i = 0; i <= retries; i++) {
  90                 ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
  91                 if (ret == 1)
  92                         break;  /* success! */
  93                 udelay(5);
  94                 if (i == retries)       /* no success */
  95                         break;
  96                 udelay(10);
  97         }
  98         if (i) {
  99                 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
 100                 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
 101         }
 102         return ret;
 103 }
 104
 105 static inline int usb_find_address(struct i2c_adapter *i2c_adap,
 106                                    struct i2c_msg *msg, int retries,
 107                                    unsigned char *add)
 108 {
 109         unsigned short flags = msg->flags;
 110
 111         unsigned char addr;
 112         int ret;
 113         if ((flags & I2C_M_TEN)) {
 114                 /* a ten bit address */
 115                 addr = 0xf0 | ((msg->addr >> 7) & 0x03);
 116                 /* try extended address code... */
 117                 ret = try_write_address(i2c_adap, addr, retries);
 118                 if (ret != 1) {
 119                         dev_err(&i2c_adap->dev,
 120                                 "died at extended address code, while writing\n");
 121                         return -EREMOTEIO;
 122                 }
 123                 add[0] = addr;
 124                 if (flags & I2C_M_RD) {
 125                         /* okay, now switch into reading mode */
 126                         addr |= 0x01;
 127                         ret = try_read_address(i2c_adap, addr, retries);
 128                         if (ret != 1) {
 129                                 dev_err(&i2c_adap->dev,
 130                                         "died at extended address code, while reading\n");
 131                                 return -EREMOTEIO;
 132                         }
 133                 }
 134
 135         } else {                /* normal 7bit address  */
 136                 addr = (msg->addr << 1);
 137                 if (flags & I2C_M_RD)
 138                         addr |= 1;
 139
 140                 add[0] = addr;
 141                 if (flags & I2C_M_RD)
 142                         ret = try_read_address(i2c_adap, addr, retries);
 143                 else
 144                         ret = try_write_address(i2c_adap, addr, retries);
 145
 146                 if (ret != 1) {
 147                         return -EREMOTEIO;
 148                 }
 149         }
 150         return 0;
 151 }
 152
 153 static int
 154 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 155 {
 156         struct i2c_msg *pmsg;
 157         struct usb_usbvision *usbvision;
 158         int i, ret;
 159         unsigned char addr = 0;
 160
 161         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
 162
 163         for (i = 0; i < num; i++) {
 164                 pmsg = &msgs[i];
 165                 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
 166                 if (ret != 0) {
 167                         PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
 168                         return (ret < 0) ? ret : -EREMOTEIO;
 169                 }
 170
 171                 if (pmsg->flags & I2C_M_RD) {
 172                         /* read bytes into buffer */
 173                         ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
 174                         if (ret < pmsg->len) {
 175                                 return (ret < 0) ? ret : -EREMOTEIO;
 176                         }
 177                 } else {
 178                         /* write bytes from buffer */
 179                         ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
 180                         if (ret < pmsg->len) {
 181                                 return (ret < 0) ? ret : -EREMOTEIO;
 182                         }
 183                 }
 184         }
 185         return num;
 186 }
 187
 188 static u32 functionality(struct i2c_adapter *adap)
 189 {
 190         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
 191 }
 192
 193 /* -----exported algorithm data: -------------------------------------  */
 194
 195 static struct i2c_algorithm usbvision_algo = {
 196         .master_xfer   = usbvision_i2c_xfer,
 197         .smbus_xfer    = NULL,
 198         .functionality = functionality,
 199 };
 200
 201
 202 /* ----------------------------------------------------------------------- */
 203 /* usbvision specific I2C functions                                        */
 204 /* ----------------------------------------------------------------------- */
 205 static struct i2c_adapter i2c_adap_template;
 206
 207 int usbvision_i2c_register(struct usb_usbvision *usbvision)
 208 {
 209         static unsigned short saa711x_addrs[] = {
 210                 0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
 211                 0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
 212                 I2C_CLIENT_END };
 213
 214         if (usbvision->registered_i2c)
 215                 return 0;
 216
 217         memcpy(&usbvision->i2c_adap, &i2c_adap_template,
 218                sizeof(struct i2c_adapter));
 219
 220         sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
 221                 usbvision->dev->bus->busnum, usbvision->dev->devpath);
 222         PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
 223         usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
 224
 225         i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
 226
 227         if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
 228                 printk(KERN_ERR "usbvision_register: can't write reg\n");
 229                 return -EBUSY;
 230         }
 231
 232         PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
 233         PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
 234
 235         /* register new adapter to i2c module... */
 236
 237         usbvision->i2c_adap.algo = &usbvision_algo;
 238
 239         usbvision->i2c_adap.timeout = 100;      /* default values, should       */
 240         usbvision->i2c_adap.retries = 3;        /* be replaced by defines       */
 241
 242         i2c_add_adapter(&usbvision->i2c_adap);
 243
 244         PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
 245
 246         /* Request the load of the i2c modules we need */
 247         switch (usbvision_device_data[usbvision->DevModel].Codec) {
 248         case CODEC_SAA7113:
 249         case CODEC_SAA7111:
 250                 /* Without this delay the detection of the saa711x is
 251                    hit-and-miss. */
 252                 mdelay(10);
 253                 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 254                                 &usbvision->i2c_adap, NULL,
 255                                 "saa7115_auto", 0, saa711x_addrs);
 256                 break;
 257         }
 258         if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
 259                 struct v4l2_subdev *sd;
 260                 enum v4l2_i2c_tuner_type type;
 261                 struct tuner_setup tun_setup;
 262
 263                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 264                                 &usbvision->i2c_adap, NULL,
 265                                 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 266                 /* depending on whether we found a demod or not, select
 267                    the tuner type. */
 268                 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 269
 270                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 271                                 &usbvision->i2c_adap, NULL,
 272                                 "tuner", 0, v4l2_i2c_tuner_addrs(type));
 273
 274                 if (sd == NULL)
 275                         return -ENODEV;
 276                 if (usbvision->tuner_type != -1) {
 277                         tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 278                         tun_setup.type = usbvision->tuner_type;
 279                         tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 280                         call_all(usbvision, tuner, s_type_addr, &tun_setup);
 281                 }
 282         }
 283         usbvision->registered_i2c = 1;
 284
 285         return 0;
 286 }
 287
 288 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 289 {
 290         if (!usbvision->registered_i2c)
 291                 return 0;
 292
 293         i2c_del_adapter(&(usbvision->i2c_adap));
 294         usbvision->registered_i2c = 0;
 295
 296         PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
 297
 298         return 0;
 299 }
 300
 301 static int
 302 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 303                      char *buf, short len)
 304 {
 305         int rc, retries;
 306
 307         for (retries = 5;;) {
 308                 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 309                 if (rc < 0)
 310                         return rc;
 311
 312                 /* Initiate byte read cycle                    */
 313                 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 314                 /*                    d3 0=Wr 1=Rd             */
 315                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 316                                       (len & 0x07) | 0x18);
 317                 if (rc < 0)
 318                         return rc;
 319
 320                 /* Test for Busy and ACK */
 321                 do {
 322                         /* USBVISION_SER_CONT -> d4 == 0 busy */
 323                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 324                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 325                 if (rc < 0)
 326                         return rc;
 327
 328                 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 329                 if ((rc & 0x20) == 0)   /* Ack? */
 330                         break;
 331
 332                 /* I2C abort */
 333                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 334                 if (rc < 0)
 335                         return rc;
 336
 337                 if (--retries < 0)
 338                         return -1;
 339         }
 340
 341         switch (len) {
 342         case 4:
 343                 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 344         case 3:
 345                 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 346         case 2:
 347                 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 348         case 1:
 349                 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 350                 break;
 351         default:
 352                 printk(KERN_ERR
 353                        "usbvision_i2c_read_max4: buffer length > 4\n");
 354         }
 355
 356         if (i2c_debug & DBG_I2C) {
 357                 int idx;
 358                 for (idx = 0; idx < len; idx++) {
 359                         PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
 360                 }
 361         }
 362         return len;
 363 }
 364
 365
 366 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 367                                  unsigned char addr, const char *buf,
 368                                  short len)
 369 {
 370         int rc, retries;
 371         int i;
 372         unsigned char value[6];
 373         unsigned char ser_cont;
 374
 375         ser_cont = (len & 0x07) | 0x10;
 376
 377         value[0] = addr;
 378         value[1] = ser_cont;
 379         for (i = 0; i < len; i++)
 380                 value[i + 2] = buf[i];
 381
 382         for (retries = 5;;) {
 383                 rc = usb_control_msg(usbvision->dev,
 384                                      usb_sndctrlpipe(usbvision->dev, 1),
 385                                      USBVISION_OP_CODE,
 386                                      USB_DIR_OUT | USB_TYPE_VENDOR |
 387                                      USB_RECIP_ENDPOINT, 0,
 388                                      (__u16) USBVISION_SER_ADRS, value,
 389                                      len + 2, HZ);
 390
 391                 if (rc < 0)
 392                         return rc;
 393
 394                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 395                                       (len & 0x07) | 0x10);
 396                 if (rc < 0)
 397                         return rc;
 398
 399                 /* Test for Busy and ACK */
 400                 do {
 401                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 402                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 403                 if (rc < 0)
 404                         return rc;
 405
 406                 if ((rc & 0x20) == 0)   /* Ack? */
 407                         break;
 408
 409                 /* I2C abort */
 410                 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 411
 412                 if (--retries < 0)
 413                         return -1;
 414
 415         }
 416
 417         if (i2c_debug & DBG_I2C) {
 418                 int idx;
 419                 for (idx = 0; idx < len; idx++) {
 420                         PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
 421                 }
 422         }
 423         return len;
 424 }
 425
 426 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 427                             short len)
 428 {
 429         char *bufPtr = buf;
 430         int retval;
 431         int wrcount = 0;
 432         int count;
 433         int maxLen = 4;
 434
 435         while (len > 0) {
 436                 count = (len > maxLen) ? maxLen : len;
 437                 retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
 438                 if (retval > 0) {
 439                         len -= count;
 440                         bufPtr += count;
 441                         wrcount += count;
 442                 } else
 443                         return (retval < 0) ? retval : -EFAULT;
 444         }
 445         return wrcount;
 446 }
 447
 448 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 449                            short len)
 450 {
 451         char temp[4];
 452         int retval, i;
 453         int rdcount = 0;
 454         int count;
 455
 456         while (len > 0) {
 457                 count = (len > 3) ? 4 : len;
 458                 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 459                 if (retval > 0) {
 460                         for (i = 0; i < len; i++)
 461                                 buf[rdcount + i] = temp[i];
 462                         len -= count;
 463                         rdcount += count;
 464                 } else
 465                         return (retval < 0) ? retval : -EFAULT;
 466         }
 467         return rdcount;
 468 }
 469
 470 static struct i2c_adapter i2c_adap_template = {
 471         .owner = THIS_MODULE,
 472         .name              = "usbvision",
 473 };
 474
 475 /*
 476  * Overrides for Emacs so that we follow Linus's tabbing style.
 477  * ---------------------------------------------------------------------------
 478  * Local variables:
 479  * c-basic-offset: 8
 480  * End:
 481  */