linux/drivers/media/usb/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 <linux/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
 114        addr = (msg->addr << 1);
 115        if (flags & I2C_M_RD)
 116                addr |= 1;
 117
 118        add[0] = addr;
 119        if (flags & I2C_M_RD)
 120                ret = try_read_address(i2c_adap, addr, retries);
 121        else
 122                ret = try_write_address(i2c_adap, addr, retries);
 123
 124        if (ret != 1)
 125                return -EREMOTEIO;
 126
 127        return 0;
 128}
 129
 130static int
 131usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 132{
 133        struct i2c_msg *pmsg;
 134        struct usb_usbvision *usbvision;
 135        int i, ret;
 136        unsigned char addr = 0;
 137
 138        usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
 139
 140        for (i = 0; i < num; i++) {
 141                pmsg = &msgs[i];
 142                ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
 143                if (ret != 0) {
 144                        PDEBUG(DBG_I2C, "got NAK from device, message #%d", i);
 145                        return (ret < 0) ? ret : -EREMOTEIO;
 146                }
 147
 148                if (pmsg->flags & I2C_M_RD) {
 149                        /* read bytes into buffer */
 150                        ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
 151                        if (ret < pmsg->len)
 152                                return (ret < 0) ? ret : -EREMOTEIO;
 153                } else {
 154                        /* write bytes from buffer */
 155                        ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
 156                        if (ret < pmsg->len)
 157                                return (ret < 0) ? ret : -EREMOTEIO;
 158                }
 159        }
 160        return num;
 161}
 162
 163static u32 functionality(struct i2c_adapter *adap)
 164{
 165        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 166}
 167
 168/* -----exported algorithm data: -------------------------------------  */
 169
 170static struct i2c_algorithm usbvision_algo = {
 171        .master_xfer   = usbvision_i2c_xfer,
 172        .smbus_xfer    = NULL,
 173        .functionality = functionality,
 174};
 175
 176
 177/* ----------------------------------------------------------------------- */
 178/* usbvision specific I2C functions                                        */
 179/* ----------------------------------------------------------------------- */
 180static struct i2c_adapter i2c_adap_template;
 181
 182int usbvision_i2c_register(struct usb_usbvision *usbvision)
 183{
 184        static unsigned short saa711x_addrs[] = {
 185                0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
 186                0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
 187                I2C_CLIENT_END };
 188
 189        if (usbvision->registered_i2c)
 190                return 0;
 191
 192        usbvision->i2c_adap = i2c_adap_template;
 193
 194        sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
 195                usbvision->dev->bus->busnum, usbvision->dev->devpath);
 196        PDEBUG(DBG_I2C, "Adaptername: %s", usbvision->i2c_adap.name);
 197        usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
 198
 199        i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
 200
 201        if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
 202                printk(KERN_ERR "usbvision_i2c_register: can't write reg\n");
 203                return -EBUSY;
 204        }
 205
 206        PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
 207        PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
 208
 209        /* register new adapter to i2c module... */
 210
 211        usbvision->i2c_adap.algo = &usbvision_algo;
 212
 213        usbvision->i2c_adap.timeout = 100;      /* default values, should       */
 214        usbvision->i2c_adap.retries = 3;        /* be replaced by defines       */
 215
 216        i2c_add_adapter(&usbvision->i2c_adap);
 217
 218        PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
 219
 220        /* Request the load of the i2c modules we need */
 221        switch (usbvision_device_data[usbvision->dev_model].codec) {
 222        case CODEC_SAA7113:
 223        case CODEC_SAA7111:
 224                /* Without this delay the detection of the saa711x is
 225                   hit-and-miss. */
 226                mdelay(10);
 227                v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 228                                &usbvision->i2c_adap,
 229                                "saa7115_auto", 0, saa711x_addrs);
 230                break;
 231        }
 232        if (usbvision_device_data[usbvision->dev_model].tuner == 1) {
 233                struct v4l2_subdev *sd;
 234                enum v4l2_i2c_tuner_type type;
 235                struct tuner_setup tun_setup;
 236
 237                sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 238                                &usbvision->i2c_adap,
 239                                "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 240                /* depending on whether we found a demod or not, select
 241                   the tuner type. */
 242                type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 243
 244                sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 245                                &usbvision->i2c_adap,
 246                                "tuner", 0, v4l2_i2c_tuner_addrs(type));
 247
 248                if (sd == NULL)
 249                        return -ENODEV;
 250                if (usbvision->tuner_type != -1) {
 251                        tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 252                        tun_setup.type = usbvision->tuner_type;
 253                        tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 254                        call_all(usbvision, tuner, s_type_addr, &tun_setup);
 255                }
 256        }
 257        usbvision->registered_i2c = 1;
 258
 259        return 0;
 260}
 261
 262int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 263{
 264        if (!usbvision->registered_i2c)
 265                return 0;
 266
 267        i2c_del_adapter(&(usbvision->i2c_adap));
 268        usbvision->registered_i2c = 0;
 269
 270        PDEBUG(DBG_I2C, "i2c bus for %s unregistered", usbvision->i2c_adap.name);
 271
 272        return 0;
 273}
 274
 275static int
 276usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 277                     char *buf, short len)
 278{
 279        int rc, retries;
 280
 281        for (retries = 5;;) {
 282                rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 283                if (rc < 0)
 284                        return rc;
 285
 286                /* Initiate byte read cycle                    */
 287                /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 288                /*                    d3 0=Wr 1=Rd             */
 289                rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 290                                      (len & 0x07) | 0x18);
 291                if (rc < 0)
 292                        return rc;
 293
 294                /* Test for Busy and ACK */
 295                do {
 296                        /* USBVISION_SER_CONT -> d4 == 0 busy */
 297                        rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 298                } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 299                if (rc < 0)
 300                        return rc;
 301
 302                /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 303                if ((rc & 0x20) == 0)   /* Ack? */
 304                        break;
 305
 306                /* I2C abort */
 307                rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 308                if (rc < 0)
 309                        return rc;
 310
 311                if (--retries < 0)
 312                        return -1;
 313        }
 314
 315        switch (len) {
 316        case 4:
 317                buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 318        case 3:
 319                buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 320        case 2:
 321                buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 322        case 1:
 323                buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 324                break;
 325        default:
 326                printk(KERN_ERR
 327                       "usbvision_i2c_read_max4: buffer length > 4\n");
 328        }
 329
 330        if (i2c_debug & DBG_I2C) {
 331                int idx;
 332
 333                for (idx = 0; idx < len; idx++)
 334                        PDEBUG(DBG_I2C, "read %x from address %x", (unsigned char)buf[idx], addr);
 335        }
 336        return len;
 337}
 338
 339
 340static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 341                                 unsigned char addr, const char *buf,
 342                                 short len)
 343{
 344        int rc, retries;
 345        int i;
 346        unsigned char *value = usbvision->ctrl_urb_buffer;
 347        unsigned char ser_cont;
 348
 349        ser_cont = (len & 0x07) | 0x10;
 350
 351        value[0] = addr;
 352        value[1] = ser_cont;
 353        for (i = 0; i < len; i++)
 354                value[i + 2] = buf[i];
 355
 356        for (retries = 5;;) {
 357                rc = usb_control_msg(usbvision->dev,
 358                                     usb_sndctrlpipe(usbvision->dev, 1),
 359                                     USBVISION_OP_CODE,
 360                                     USB_DIR_OUT | USB_TYPE_VENDOR |
 361                                     USB_RECIP_ENDPOINT, 0,
 362                                     (__u16) USBVISION_SER_ADRS, value,
 363                                     len + 2, HZ);
 364
 365                if (rc < 0)
 366                        return rc;
 367
 368                rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 369                                      (len & 0x07) | 0x10);
 370                if (rc < 0)
 371                        return rc;
 372
 373                /* Test for Busy and ACK */
 374                do {
 375                        rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 376                } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 377                if (rc < 0)
 378                        return rc;
 379
 380                if ((rc & 0x20) == 0)   /* Ack? */
 381                        break;
 382
 383                /* I2C abort */
 384                usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 385
 386                if (--retries < 0)
 387                        return -1;
 388
 389        }
 390
 391        if (i2c_debug & DBG_I2C) {
 392                int idx;
 393
 394                for (idx = 0; idx < len; idx++)
 395                        PDEBUG(DBG_I2C, "wrote %x at address %x", (unsigned char)buf[idx], addr);
 396        }
 397        return len;
 398}
 399
 400static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 401                            short len)
 402{
 403        char *buf_ptr = buf;
 404        int retval;
 405        int wrcount = 0;
 406        int count;
 407        int max_len = 4;
 408
 409        while (len > 0) {
 410                count = (len > max_len) ? max_len : len;
 411                retval = usbvision_i2c_write_max4(usbvision, addr, buf_ptr, count);
 412                if (retval > 0) {
 413                        len -= count;
 414                        buf_ptr += count;
 415                        wrcount += count;
 416                } else
 417                        return (retval < 0) ? retval : -EFAULT;
 418        }
 419        return wrcount;
 420}
 421
 422static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 423                           short len)
 424{
 425        char temp[4];
 426        int retval, i;
 427        int rdcount = 0;
 428        int count;
 429
 430        while (len > 0) {
 431                count = (len > 3) ? 4 : len;
 432                retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 433                if (retval > 0) {
 434                        for (i = 0; i < len; i++)
 435                                buf[rdcount + i] = temp[i];
 436                        len -= count;
 437                        rdcount += count;
 438                } else
 439                        return (retval < 0) ? retval : -EFAULT;
 440        }
 441        return rdcount;
 442}
 443
 444static struct i2c_adapter i2c_adap_template = {
 445        .owner = THIS_MODULE,
 446        .name              = "usbvision",
 447};
 448