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/slab.h>
  31 #include <linux/utsname.h>
  32 #include <linux/init.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/ioport.h>
  35 #include <linux/errno.h>
  36 #include <linux/usb.h>
  37 #include <linux/i2c.h>
  38 #include "usbvision.h"
  39
  40 #define DBG_I2C         1<<0
  41
  42 static int i2c_debug;
  43
  44 module_param (i2c_debug, int, 0644);                    // debug_i2c_usb mode of the device driver
  45 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  46
  47 #define PDEBUG(level, fmt, args...) { \
  48                 if (i2c_debug & (level)) \
  49                         printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
  50                                 __func__, __LINE__ , ## args); \
  51         }
  52
  53 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  54                             short len);
  55 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  56                            short len);
  57
  58 static inline int try_write_address(struct i2c_adapter *i2c_adap,
  59                                     unsigned char addr, int retries)
  60 {
  61         struct usb_usbvision *usbvision;
  62         int i, ret = -1;
  63         char buf[4];
  64
  65         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  66         buf[0] = 0x00;
  67         for (i = 0; i <= retries; i++) {
  68                 ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
  69                 if (ret == 1)
  70                         break;  /* success! */
  71                 udelay(5);
  72                 if (i == retries)       /* no success */
  73                         break;
  74                 udelay(10);
  75         }
  76         if (i) {
  77                 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
  78                 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
  79         }
  80         return ret;
  81 }
  82
  83 static inline int try_read_address(struct i2c_adapter *i2c_adap,
  84                                    unsigned char addr, int retries)
  85 {
  86         struct usb_usbvision *usbvision;
  87         int i, ret = -1;
  88         char buf[4];
  89
  90         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  91         for (i = 0; i <= retries; i++) {
  92                 ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
  93                 if (ret == 1)
  94                         break;  /* success! */
  95                 udelay(5);
  96                 if (i == retries)       /* no success */
  97                         break;
  98                 udelay(10);
  99         }
 100         if (i) {
 101                 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
 102                 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
 103         }
 104         return ret;
 105 }
 106
 107 static inline int usb_find_address(struct i2c_adapter *i2c_adap,
 108                                    struct i2c_msg *msg, int retries,
 109                                    unsigned char *add)
 110 {
 111         unsigned short flags = msg->flags;
 112
 113         unsigned char addr;
 114         int ret;
 115         if ((flags & I2C_M_TEN)) {
 116                 /* a ten bit address */
 117                 addr = 0xf0 | ((msg->addr >> 7) & 0x03);
 118                 /* try extended address code... */
 119                 ret = try_write_address(i2c_adap, addr, retries);
 120                 if (ret != 1) {
 121                         dev_err(&i2c_adap->dev,
 122                                 "died at extended address code, while writing\n");
 123                         return -EREMOTEIO;
 124                 }
 125                 add[0] = addr;
 126                 if (flags & I2C_M_RD) {
 127                         /* okay, now switch into reading mode */
 128                         addr |= 0x01;
 129                         ret = try_read_address(i2c_adap, addr, retries);
 130                         if (ret != 1) {
 131                                 dev_err(&i2c_adap->dev,
 132                                         "died at extended address code, while reading\n");
 133                                 return -EREMOTEIO;
 134                         }
 135                 }
 136
 137         } else {                /* normal 7bit address  */
 138                 addr = (msg->addr << 1);
 139                 if (flags & I2C_M_RD)
 140                         addr |= 1;
 141
 142                 add[0] = addr;
 143                 if (flags & I2C_M_RD)
 144                         ret = try_read_address(i2c_adap, addr, retries);
 145                 else
 146                         ret = try_write_address(i2c_adap, addr, retries);
 147
 148                 if (ret != 1) {
 149                         return -EREMOTEIO;
 150                 }
 151         }
 152         return 0;
 153 }
 154
 155 static int
 156 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 157 {
 158         struct i2c_msg *pmsg;
 159         struct usb_usbvision *usbvision;
 160         int i, ret;
 161         unsigned char addr = 0;
 162
 163         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
 164
 165         for (i = 0; i < num; i++) {
 166                 pmsg = &msgs[i];
 167                 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
 168                 if (ret != 0) {
 169                         PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
 170                         return (ret < 0) ? ret : -EREMOTEIO;
 171                 }
 172
 173                 if (pmsg->flags & I2C_M_RD) {
 174                         /* read bytes into buffer */
 175                         ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
 176                         if (ret < pmsg->len) {
 177                                 return (ret < 0) ? ret : -EREMOTEIO;
 178                         }
 179                 } else {
 180                         /* write bytes from buffer */
 181                         ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
 182                         if (ret < pmsg->len) {
 183                                 return (ret < 0) ? ret : -EREMOTEIO;
 184                         }
 185                 }
 186         }
 187         return num;
 188 }
 189
 190 static u32 functionality(struct i2c_adapter *adap)
 191 {
 192         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
 193 }
 194
 195 /* -----exported algorithm data: -------------------------------------  */
 196
 197 static struct i2c_algorithm usbvision_algo = {
 198         .master_xfer   = usbvision_i2c_xfer,
 199         .smbus_xfer    = NULL,
 200         .functionality = functionality,
 201 };
 202
 203
 204 /* ----------------------------------------------------------------------- */
 205 /* usbvision specific I2C functions                                        */
 206 /* ----------------------------------------------------------------------- */
 207 static struct i2c_adapter i2c_adap_template;
 208
 209 int usbvision_i2c_register(struct usb_usbvision *usbvision)
 210 {
 211         static unsigned short saa711x_addrs[] = {
 212                 0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
 213                 0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
 214                 I2C_CLIENT_END };
 215
 216         memcpy(&usbvision->i2c_adap, &i2c_adap_template,
 217                sizeof(struct i2c_adapter));
 218
 219         sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
 220                 " #%d", usbvision->vdev->num);
 221         PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
 222         usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
 223
 224         i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
 225
 226         if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
 227                 printk(KERN_ERR "usbvision_register: can't write reg\n");
 228                 return -EBUSY;
 229         }
 230
 231         PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
 232         PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
 233
 234         /* register new adapter to i2c module... */
 235
 236         usbvision->i2c_adap.algo = &usbvision_algo;
 237
 238         usbvision->i2c_adap.timeout = 100;      /* default values, should       */
 239         usbvision->i2c_adap.retries = 3;        /* be replaced by defines       */
 240
 241         i2c_add_adapter(&usbvision->i2c_adap);
 242
 243         PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
 244
 245         /* Request the load of the i2c modules we need */
 246         switch (usbvision_device_data[usbvision->DevModel].Codec) {
 247         case CODEC_SAA7113:
 248         case CODEC_SAA7111:
 249                 v4l2_i2c_new_probed_subdev(&usbvision->v4l2_dev,
 250                                 &usbvision->i2c_adap, "saa7115",
 251                                 "saa7115_auto", saa711x_addrs);
 252                 break;
 253         }
 254         if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
 255                 struct v4l2_subdev *sd;
 256                 enum v4l2_i2c_tuner_type type;
 257                 struct tuner_setup tun_setup;
 258
 259                 sd = v4l2_i2c_new_probed_subdev(&usbvision->v4l2_dev,
 260                                 &usbvision->i2c_adap, "tuner",
 261                                 "tuner", v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 262                 /* depending on whether we found a demod or not, select
 263                    the tuner type. */
 264                 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 265
 266                 sd = v4l2_i2c_new_probed_subdev(&usbvision->v4l2_dev,
 267                                 &usbvision->i2c_adap, "tuner",
 268                                 "tuner", v4l2_i2c_tuner_addrs(type));
 269
 270                 if (usbvision->tuner_type != -1) {
 271                         tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 272                         tun_setup.type = usbvision->tuner_type;
 273                         tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 274                         call_all(usbvision, tuner, s_type_addr, &tun_setup);
 275                 }
 276         }
 277
 278         return 0;
 279 }
 280
 281 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 282 {
 283
 284         i2c_del_adapter(&(usbvision->i2c_adap));
 285
 286         PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
 287
 288         return 0;
 289 }
 290
 291 static int
 292 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 293                      char *buf, short len)
 294 {
 295         int rc, retries;
 296
 297         for (retries = 5;;) {
 298                 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 299                 if (rc < 0)
 300                         return rc;
 301
 302                 /* Initiate byte read cycle                    */
 303                 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 304                 /*                    d3 0=Wr 1=Rd             */
 305                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 306                                       (len & 0x07) | 0x18);
 307                 if (rc < 0)
 308                         return rc;
 309
 310                 /* Test for Busy and ACK */
 311                 do {
 312                         /* USBVISION_SER_CONT -> d4 == 0 busy */
 313                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 314                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 315                 if (rc < 0)
 316                         return rc;
 317
 318                 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 319                 if ((rc & 0x20) == 0)   /* Ack? */
 320                         break;
 321
 322                 /* I2C abort */
 323                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 324                 if (rc < 0)
 325                         return rc;
 326
 327                 if (--retries < 0)
 328                         return -1;
 329         }
 330
 331         switch (len) {
 332         case 4:
 333                 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 334         case 3:
 335                 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 336         case 2:
 337                 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 338         case 1:
 339                 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 340                 break;
 341         default:
 342                 printk(KERN_ERR
 343                        "usbvision_i2c_read_max4: buffer length > 4\n");
 344         }
 345
 346         if (i2c_debug & DBG_I2C) {
 347                 int idx;
 348                 for (idx = 0; idx < len; idx++) {
 349                         PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
 350                 }
 351         }
 352         return len;
 353 }
 354
 355
 356 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 357                                  unsigned char addr, const char *buf,
 358                                  short len)
 359 {
 360         int rc, retries;
 361         int i;
 362         unsigned char value[6];
 363         unsigned char ser_cont;
 364
 365         ser_cont = (len & 0x07) | 0x10;
 366
 367         value[0] = addr;
 368         value[1] = ser_cont;
 369         for (i = 0; i < len; i++)
 370                 value[i + 2] = buf[i];
 371
 372         for (retries = 5;;) {
 373                 rc = usb_control_msg(usbvision->dev,
 374                                      usb_sndctrlpipe(usbvision->dev, 1),
 375                                      USBVISION_OP_CODE,
 376                                      USB_DIR_OUT | USB_TYPE_VENDOR |
 377                                      USB_RECIP_ENDPOINT, 0,
 378                                      (__u16) USBVISION_SER_ADRS, value,
 379                                      len + 2, HZ);
 380
 381                 if (rc < 0)
 382                         return rc;
 383
 384                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 385                                       (len & 0x07) | 0x10);
 386                 if (rc < 0)
 387                         return rc;
 388
 389                 /* Test for Busy and ACK */
 390                 do {
 391                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 392                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 393                 if (rc < 0)
 394                         return rc;
 395
 396                 if ((rc & 0x20) == 0)   /* Ack? */
 397                         break;
 398
 399                 /* I2C abort */
 400                 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 401
 402                 if (--retries < 0)
 403                         return -1;
 404
 405         }
 406
 407         if (i2c_debug & DBG_I2C) {
 408                 int idx;
 409                 for (idx = 0; idx < len; idx++) {
 410                         PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
 411                 }
 412         }
 413         return len;
 414 }
 415
 416 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 417                             short len)
 418 {
 419         char *bufPtr = buf;
 420         int retval;
 421         int wrcount = 0;
 422         int count;
 423         int maxLen = 4;
 424
 425         while (len > 0) {
 426                 count = (len > maxLen) ? maxLen : len;
 427                 retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
 428                 if (retval > 0) {
 429                         len -= count;
 430                         bufPtr += count;
 431                         wrcount += count;
 432                 } else
 433                         return (retval < 0) ? retval : -EFAULT;
 434         }
 435         return wrcount;
 436 }
 437
 438 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 439                            short len)
 440 {
 441         char temp[4];
 442         int retval, i;
 443         int rdcount = 0;
 444         int count;
 445
 446         while (len > 0) {
 447                 count = (len > 3) ? 4 : len;
 448                 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 449                 if (retval > 0) {
 450                         for (i = 0; i < len; i++)
 451                                 buf[rdcount + i] = temp[i];
 452                         len -= count;
 453                         rdcount += count;
 454                 } else
 455                         return (retval < 0) ? retval : -EFAULT;
 456         }
 457         return rdcount;
 458 }
 459
 460 static struct i2c_adapter i2c_adap_template = {
 461         .owner = THIS_MODULE,
 462         .name              = "usbvision",
 463 };
 464
 465 /*
 466  * Overrides for Emacs so that we follow Linus's tabbing style.
 467  * ---------------------------------------------------------------------------
 468  * Local variables:
 469  * c-basic-offset: 8
 470  * End:
 471  */