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                 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 248                                 &usbvision->i2c_adap, "saa7115",
 249                                 "saa7115_auto", 0, saa711x_addrs);
 250                 break;
 251         }
 252         if (usbvision_device_data[usbvision->DevModel].Tuner == 1) {
 253                 struct v4l2_subdev *sd;
 254                 enum v4l2_i2c_tuner_type type;
 255                 struct tuner_setup tun_setup;
 256
 257                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 258                                 &usbvision->i2c_adap, "tuner",
 259                                 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 260                 /* depending on whether we found a demod or not, select
 261                    the tuner type. */
 262                 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 263
 264                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 265                                 &usbvision->i2c_adap, "tuner",
 266                                 "tuner", 0, 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  */