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/init.h>
  32 #include <asm/uaccess.h>
  33 #include <linux/ioport.h>
  34 #include <linux/errno.h>
  35 #include <linux/usb.h>
  36 #include <linux/i2c.h>
  37 #include "usbvision.h"
  38
  39 #define DBG_I2C         1<<0
  40
  41 static int i2c_debug;
  42
  43 module_param (i2c_debug, int, 0644);                    // debug_i2c_usb mode of the device driver
  44 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  45
  46 #define PDEBUG(level, fmt, args...) { \
  47                 if (i2c_debug & (level)) \
  48                         printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
  49                                 __func__, __LINE__ , ## args); \
  50         }
  51
  52 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  53                             short len);
  54 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  55                            short len);
  56
  57 static inline int try_write_address(struct i2c_adapter *i2c_adap,
  58                                     unsigned char addr, int retries)
  59 {
  60         struct usb_usbvision *usbvision;
  61         int i, ret = -1;
  62         char buf[4];
  63
  64         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  65         buf[0] = 0x00;
  66         for (i = 0; i <= retries; i++) {
  67                 ret = (usbvision_i2c_write(usbvision, addr, buf, 1));
  68                 if (ret == 1)
  69                         break;  /* success! */
  70                 udelay(5);
  71                 if (i == retries)       /* no success */
  72                         break;
  73                 udelay(10);
  74         }
  75         if (i) {
  76                 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
  77                 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
  78         }
  79         return ret;
  80 }
  81
  82 static inline int try_read_address(struct i2c_adapter *i2c_adap,
  83                                    unsigned char addr, int retries)
  84 {
  85         struct usb_usbvision *usbvision;
  86         int i, ret = -1;
  87         char buf[4];
  88
  89         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
  90         for (i = 0; i <= retries; i++) {
  91                 ret = (usbvision_i2c_read(usbvision, addr, buf, 1));
  92                 if (ret == 1)
  93                         break;  /* success! */
  94                 udelay(5);
  95                 if (i == retries)       /* no success */
  96                         break;
  97                 udelay(10);
  98         }
  99         if (i) {
 100                 PDEBUG(DBG_I2C,"Needed %d retries for address %#2x", i, addr);
 101                 PDEBUG(DBG_I2C,"Maybe there's no device at this address");
 102         }
 103         return ret;
 104 }
 105
 106 static inline int usb_find_address(struct i2c_adapter *i2c_adap,
 107                                    struct i2c_msg *msg, int retries,
 108                                    unsigned char *add)
 109 {
 110         unsigned short flags = msg->flags;
 111
 112         unsigned char addr;
 113         int ret;
 114         if ((flags & I2C_M_TEN)) {
 115                 /* a ten bit address */
 116                 addr = 0xf0 | ((msg->addr >> 7) & 0x03);
 117                 /* try extended address code... */
 118                 ret = try_write_address(i2c_adap, addr, retries);
 119                 if (ret != 1) {
 120                         dev_err(&i2c_adap->dev,
 121                                 "died at extended address code, while writing\n");
 122                         return -EREMOTEIO;
 123                 }
 124                 add[0] = addr;
 125                 if (flags & I2C_M_RD) {
 126                         /* okay, now switch into reading mode */
 127                         addr |= 0x01;
 128                         ret = try_read_address(i2c_adap, addr, retries);
 129                         if (ret != 1) {
 130                                 dev_err(&i2c_adap->dev,
 131                                         "died at extended address code, while reading\n");
 132                                 return -EREMOTEIO;
 133                         }
 134                 }
 135
 136         } else {                /* normal 7bit address  */
 137                 addr = (msg->addr << 1);
 138                 if (flags & I2C_M_RD)
 139                         addr |= 1;
 140
 141                 add[0] = addr;
 142                 if (flags & I2C_M_RD)
 143                         ret = try_read_address(i2c_adap, addr, retries);
 144                 else
 145                         ret = try_write_address(i2c_adap, addr, retries);
 146
 147                 if (ret != 1) {
 148                         return -EREMOTEIO;
 149                 }
 150         }
 151         return 0;
 152 }
 153
 154 static int
 155 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 156 {
 157         struct i2c_msg *pmsg;
 158         struct usb_usbvision *usbvision;
 159         int i, ret;
 160         unsigned char addr = 0;
 161
 162         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
 163
 164         for (i = 0; i < num; i++) {
 165                 pmsg = &msgs[i];
 166                 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
 167                 if (ret != 0) {
 168                         PDEBUG(DBG_I2C,"got NAK from device, message #%d", i);
 169                         return (ret < 0) ? ret : -EREMOTEIO;
 170                 }
 171
 172                 if (pmsg->flags & I2C_M_RD) {
 173                         /* read bytes into buffer */
 174                         ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
 175                         if (ret < pmsg->len) {
 176                                 return (ret < 0) ? ret : -EREMOTEIO;
 177                         }
 178                 } else {
 179                         /* write bytes from buffer */
 180                         ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
 181                         if (ret < pmsg->len) {
 182                                 return (ret < 0) ? ret : -EREMOTEIO;
 183                         }
 184                 }
 185         }
 186         return num;
 187 }
 188
 189 static u32 functionality(struct i2c_adapter *adap)
 190 {
 191         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
 192 }
 193
 194 /* -----exported algorithm data: -------------------------------------  */
 195
 196 static struct i2c_algorithm usbvision_algo = {
 197         .master_xfer   = usbvision_i2c_xfer,
 198         .smbus_xfer    = NULL,
 199         .functionality = functionality,
 200 };
 201
 202
 203 /* ----------------------------------------------------------------------- */
 204 /* usbvision specific I2C functions                                        */
 205 /* ----------------------------------------------------------------------- */
 206 static struct i2c_adapter i2c_adap_template;
 207
 208 int usbvision_i2c_register(struct usb_usbvision *usbvision)
 209 {
 210         static unsigned short saa711x_addrs[] = {
 211                 0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
 212                 0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
 213                 I2C_CLIENT_END };
 214
 215         memcpy(&usbvision->i2c_adap, &i2c_adap_template,
 216                sizeof(struct i2c_adapter));
 217
 218         sprintf(usbvision->i2c_adap.name + strlen(usbvision->i2c_adap.name),
 219                 " #%d", usbvision->vdev->num);
 220         PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
 221         usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
 222
 223         i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
 224
 225         if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
 226                 printk(KERN_ERR "usbvision_register: can't write reg\n");
 227                 return -EBUSY;
 228         }
 229
 230         PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
 231         PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
 232
 233         /* register new adapter to i2c module... */
 234
 235         usbvision->i2c_adap.algo = &usbvision_algo;
 236
 237         usbvision->i2c_adap.timeout = 100;      /* default values, should       */
 238         usbvision->i2c_adap.retries = 3;        /* be replaced by defines       */
 239
 240         i2c_add_adapter(&usbvision->i2c_adap);
 241
 242         PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
 243
 244         /* Request the load of the i2c modules we need */
 245         switch (usbvision_device_data[usbvision->DevModel].Codec) {
 246         case CODEC_SAA7113:
 247         case CODEC_SAA7111:
 248                 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 249                                 &usbvision->i2c_adap, "saa7115",
 250                                 "saa7115_auto", 0, saa711x_addrs);
 251                 break;
 252         }
 253         if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
 254                 struct v4l2_subdev *sd;
 255                 enum v4l2_i2c_tuner_type type;
 256                 struct tuner_setup tun_setup;
 257
 258                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 259                                 &usbvision->i2c_adap, "tuner",
 260                                 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 261                 /* depending on whether we found a demod or not, select
 262                    the tuner type. */
 263                 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 264
 265                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 266                                 &usbvision->i2c_adap, "tuner",
 267                                 "tuner", 0, v4l2_i2c_tuner_addrs(type));
 268
 269                 if (usbvision->tuner_type != -1) {
 270                         tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 271                         tun_setup.type = usbvision->tuner_type;
 272                         tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 273                         call_all(usbvision, tuner, s_type_addr, &tun_setup);
 274                 }
 275         }
 276
 277         return 0;
 278 }
 279
 280 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 281 {
 282
 283         i2c_del_adapter(&(usbvision->i2c_adap));
 284
 285         PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
 286
 287         return 0;
 288 }
 289
 290 static int
 291 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 292                      char *buf, short len)
 293 {
 294         int rc, retries;
 295
 296         for (retries = 5;;) {
 297                 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 298                 if (rc < 0)
 299                         return rc;
 300
 301                 /* Initiate byte read cycle                    */
 302                 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 303                 /*                    d3 0=Wr 1=Rd             */
 304                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 305                                       (len & 0x07) | 0x18);
 306                 if (rc < 0)
 307                         return rc;
 308
 309                 /* Test for Busy and ACK */
 310                 do {
 311                         /* USBVISION_SER_CONT -> d4 == 0 busy */
 312                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 313                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 314                 if (rc < 0)
 315                         return rc;
 316
 317                 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 318                 if ((rc & 0x20) == 0)   /* Ack? */
 319                         break;
 320
 321                 /* I2C abort */
 322                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 323                 if (rc < 0)
 324                         return rc;
 325
 326                 if (--retries < 0)
 327                         return -1;
 328         }
 329
 330         switch (len) {
 331         case 4:
 332                 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 333         case 3:
 334                 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 335         case 2:
 336                 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 337         case 1:
 338                 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 339                 break;
 340         default:
 341                 printk(KERN_ERR
 342                        "usbvision_i2c_read_max4: buffer length > 4\n");
 343         }
 344
 345         if (i2c_debug & DBG_I2C) {
 346                 int idx;
 347                 for (idx = 0; idx < len; idx++) {
 348                         PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
 349                 }
 350         }
 351         return len;
 352 }
 353
 354
 355 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 356                                  unsigned char addr, const char *buf,
 357                                  short len)
 358 {
 359         int rc, retries;
 360         int i;
 361         unsigned char value[6];
 362         unsigned char ser_cont;
 363
 364         ser_cont = (len & 0x07) | 0x10;
 365
 366         value[0] = addr;
 367         value[1] = ser_cont;
 368         for (i = 0; i < len; i++)
 369                 value[i + 2] = buf[i];
 370
 371         for (retries = 5;;) {
 372                 rc = usb_control_msg(usbvision->dev,
 373                                      usb_sndctrlpipe(usbvision->dev, 1),
 374                                      USBVISION_OP_CODE,
 375                                      USB_DIR_OUT | USB_TYPE_VENDOR |
 376                                      USB_RECIP_ENDPOINT, 0,
 377                                      (__u16) USBVISION_SER_ADRS, value,
 378                                      len + 2, HZ);
 379
 380                 if (rc < 0)
 381                         return rc;
 382
 383                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 384                                       (len & 0x07) | 0x10);
 385                 if (rc < 0)
 386                         return rc;
 387
 388                 /* Test for Busy and ACK */
 389                 do {
 390                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 391                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 392                 if (rc < 0)
 393                         return rc;
 394
 395                 if ((rc & 0x20) == 0)   /* Ack? */
 396                         break;
 397
 398                 /* I2C abort */
 399                 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 400
 401                 if (--retries < 0)
 402                         return -1;
 403
 404         }
 405
 406         if (i2c_debug & DBG_I2C) {
 407                 int idx;
 408                 for (idx = 0; idx < len; idx++) {
 409                         PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
 410                 }
 411         }
 412         return len;
 413 }
 414
 415 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 416                             short len)
 417 {
 418         char *bufPtr = buf;
 419         int retval;
 420         int wrcount = 0;
 421         int count;
 422         int maxLen = 4;
 423
 424         while (len > 0) {
 425                 count = (len > maxLen) ? maxLen : len;
 426                 retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
 427                 if (retval > 0) {
 428                         len -= count;
 429                         bufPtr += count;
 430                         wrcount += count;
 431                 } else
 432                         return (retval < 0) ? retval : -EFAULT;
 433         }
 434         return wrcount;
 435 }
 436
 437 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 438                            short len)
 439 {
 440         char temp[4];
 441         int retval, i;
 442         int rdcount = 0;
 443         int count;
 444
 445         while (len > 0) {
 446                 count = (len > 3) ? 4 : len;
 447                 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 448                 if (retval > 0) {
 449                         for (i = 0; i < len; i++)
 450                                 buf[rdcount + i] = temp[i];
 451                         len -= count;
 452                         rdcount += count;
 453                 } else
 454                         return (retval < 0) ? retval : -EFAULT;
 455         }
 456         return rdcount;
 457 }
 458
 459 static struct i2c_adapter i2c_adap_template = {
 460         .owner = THIS_MODULE,
 461         .name              = "usbvision",
 462 };
 463
 464 /*
 465  * Overrides for Emacs so that we follow Linus's tabbing style.
 466  * ---------------------------------------------------------------------------
 467  * Local variables:
 468  * c-basic-offset: 8
 469  * End:
 470  */