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