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         memcpy(&usbvision->i2c_adap, &i2c_adap_template,
 215                sizeof(struct i2c_adapter));
 216
 217         sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
 218                 usbvision->dev->bus->busnum, usbvision->dev->devpath);
 219         PDEBUG(DBG_I2C,"Adaptername: %s", usbvision->i2c_adap.name);
 220         usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
 221
 222         i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
 223
 224         if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
 225                 printk(KERN_ERR "usbvision_register: can't write reg\n");
 226                 return -EBUSY;
 227         }
 228
 229         PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
 230         PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
 231
 232         /* register new adapter to i2c module... */
 233
 234         usbvision->i2c_adap.algo = &usbvision_algo;
 235
 236         usbvision->i2c_adap.timeout = 100;      /* default values, should       */
 237         usbvision->i2c_adap.retries = 3;        /* be replaced by defines       */
 238
 239         i2c_add_adapter(&usbvision->i2c_adap);
 240
 241         PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
 242
 243         /* Request the load of the i2c modules we need */
 244         switch (usbvision_device_data[usbvision->DevModel].Codec) {
 245         case CODEC_SAA7113:
 246         case CODEC_SAA7111:
 247                 /* Without this delay the detection of the saa711x is
 248                    hit-and-miss. */
 249                 mdelay(10);
 250                 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 251                                 &usbvision->i2c_adap, "saa7115",
 252                                 "saa7115_auto", 0, saa711x_addrs);
 253                 break;
 254         }
 255         if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
 256                 struct v4l2_subdev *sd;
 257                 enum v4l2_i2c_tuner_type type;
 258                 struct tuner_setup tun_setup;
 259
 260                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 261                                 &usbvision->i2c_adap, "tuner",
 262                                 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 263                 /* depending on whether we found a demod or not, select
 264                    the tuner type. */
 265                 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 266
 267                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 268                                 &usbvision->i2c_adap, "tuner",
 269                                 "tuner", 0, v4l2_i2c_tuner_addrs(type));
 270
 271                 if (usbvision->tuner_type != -1) {
 272                         tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 273                         tun_setup.type = usbvision->tuner_type;
 274                         tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 275                         call_all(usbvision, tuner, s_type_addr, &tun_setup);
 276                 }
 277         }
 278
 279         return 0;
 280 }
 281
 282 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 283 {
 284
 285         i2c_del_adapter(&(usbvision->i2c_adap));
 286
 287         PDEBUG(DBG_I2C,"i2c bus for %s unregistered", usbvision->i2c_adap.name);
 288
 289         return 0;
 290 }
 291
 292 static int
 293 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 294                      char *buf, short len)
 295 {
 296         int rc, retries;
 297
 298         for (retries = 5;;) {
 299                 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 300                 if (rc < 0)
 301                         return rc;
 302
 303                 /* Initiate byte read cycle                    */
 304                 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 305                 /*                    d3 0=Wr 1=Rd             */
 306                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 307                                       (len & 0x07) | 0x18);
 308                 if (rc < 0)
 309                         return rc;
 310
 311                 /* Test for Busy and ACK */
 312                 do {
 313                         /* USBVISION_SER_CONT -> d4 == 0 busy */
 314                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 315                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 316                 if (rc < 0)
 317                         return rc;
 318
 319                 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 320                 if ((rc & 0x20) == 0)   /* Ack? */
 321                         break;
 322
 323                 /* I2C abort */
 324                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 325                 if (rc < 0)
 326                         return rc;
 327
 328                 if (--retries < 0)
 329                         return -1;
 330         }
 331
 332         switch (len) {
 333         case 4:
 334                 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 335         case 3:
 336                 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 337         case 2:
 338                 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 339         case 1:
 340                 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 341                 break;
 342         default:
 343                 printk(KERN_ERR
 344                        "usbvision_i2c_read_max4: buffer length > 4\n");
 345         }
 346
 347         if (i2c_debug & DBG_I2C) {
 348                 int idx;
 349                 for (idx = 0; idx < len; idx++) {
 350                         PDEBUG(DBG_I2C,"read %x from address %x", (unsigned char)buf[idx], addr);
 351                 }
 352         }
 353         return len;
 354 }
 355
 356
 357 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 358                                  unsigned char addr, const char *buf,
 359                                  short len)
 360 {
 361         int rc, retries;
 362         int i;
 363         unsigned char value[6];
 364         unsigned char ser_cont;
 365
 366         ser_cont = (len & 0x07) | 0x10;
 367
 368         value[0] = addr;
 369         value[1] = ser_cont;
 370         for (i = 0; i < len; i++)
 371                 value[i + 2] = buf[i];
 372
 373         for (retries = 5;;) {
 374                 rc = usb_control_msg(usbvision->dev,
 375                                      usb_sndctrlpipe(usbvision->dev, 1),
 376                                      USBVISION_OP_CODE,
 377                                      USB_DIR_OUT | USB_TYPE_VENDOR |
 378                                      USB_RECIP_ENDPOINT, 0,
 379                                      (__u16) USBVISION_SER_ADRS, value,
 380                                      len + 2, HZ);
 381
 382                 if (rc < 0)
 383                         return rc;
 384
 385                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 386                                       (len & 0x07) | 0x10);
 387                 if (rc < 0)
 388                         return rc;
 389
 390                 /* Test for Busy and ACK */
 391                 do {
 392                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 393                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 394                 if (rc < 0)
 395                         return rc;
 396
 397                 if ((rc & 0x20) == 0)   /* Ack? */
 398                         break;
 399
 400                 /* I2C abort */
 401                 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 402
 403                 if (--retries < 0)
 404                         return -1;
 405
 406         }
 407
 408         if (i2c_debug & DBG_I2C) {
 409                 int idx;
 410                 for (idx = 0; idx < len; idx++) {
 411                         PDEBUG(DBG_I2C,"wrote %x at address %x", (unsigned char)buf[idx], addr);
 412                 }
 413         }
 414         return len;
 415 }
 416
 417 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 418                             short len)
 419 {
 420         char *bufPtr = buf;
 421         int retval;
 422         int wrcount = 0;
 423         int count;
 424         int maxLen = 4;
 425
 426         while (len > 0) {
 427                 count = (len > maxLen) ? maxLen : len;
 428                 retval = usbvision_i2c_write_max4(usbvision, addr, bufPtr, count);
 429                 if (retval > 0) {
 430                         len -= count;
 431                         bufPtr += count;
 432                         wrcount += count;
 433                 } else
 434                         return (retval < 0) ? retval : -EFAULT;
 435         }
 436         return wrcount;
 437 }
 438
 439 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 440                            short len)
 441 {
 442         char temp[4];
 443         int retval, i;
 444         int rdcount = 0;
 445         int count;
 446
 447         while (len > 0) {
 448                 count = (len > 3) ? 4 : len;
 449                 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 450                 if (retval > 0) {
 451                         for (i = 0; i < len; i++)
 452                                 buf[rdcount + i] = temp[i];
 453                         len -= count;
 454                         rdcount += count;
 455                 } else
 456                         return (retval < 0) ? retval : -EFAULT;
 457         }
 458         return rdcount;
 459 }
 460
 461 static struct i2c_adapter i2c_adap_template = {
 462         .owner = THIS_MODULE,
 463         .name              = "usbvision",
 464 };
 465
 466 /*
 467  * Overrides for Emacs so that we follow Linus's tabbing style.
 468  * ---------------------------------------------------------------------------
 469  * Local variables:
 470  * c-basic-offset: 8
 471  * End:
 472  */