linux/drivers/media/video/usbvision/usbvision-i2c.c
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   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
  40static int i2c_debug;
  41
  42module_param (i2c_debug, int, 0644);                    // debug_i2c_usb mode of the device driver
  43MODULE_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
  51static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  52                            short len);
  53static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
  54                           short len);
  55
  56static 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
  81static 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
 105static 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
 153static int
 154usbvision_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
 188static u32 functionality(struct i2c_adapter *adap)
 189{
 190        return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
 191}
 192
 193/* -----exported algorithm data: -------------------------------------  */
 194
 195static 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/* ----------------------------------------------------------------------- */
 205static struct i2c_adapter i2c_adap_template;
 206
 207int 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
 282int 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
 292static int
 293usbvision_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
 357static 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
 417static 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
 439static 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
 461static 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 */
 473