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 <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
  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         return 0;
 150 }
 151
 152 static int
 153 usbvision_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
 154 {
 155         struct i2c_msg *pmsg;
 156         struct usb_usbvision *usbvision;
 157         int i, ret;
 158         unsigned char addr = 0;
 159
 160         usbvision = (struct usb_usbvision *)i2c_get_adapdata(i2c_adap);
 161
 162         for (i = 0; i < num; i++) {
 163                 pmsg = &msgs[i];
 164                 ret = usb_find_address(i2c_adap, pmsg, i2c_adap->retries, &addr);
 165                 if (ret != 0) {
 166                         PDEBUG(DBG_I2C, "got NAK from device, message #%d", i);
 167                         return (ret < 0) ? ret : -EREMOTEIO;
 168                 }
 169
 170                 if (pmsg->flags & I2C_M_RD) {
 171                         /* read bytes into buffer */
 172                         ret = (usbvision_i2c_read(usbvision, addr, pmsg->buf, pmsg->len));
 173                         if (ret < pmsg->len)
 174                                 return (ret < 0) ? ret : -EREMOTEIO;
 175                 } else {
 176                         /* write bytes from buffer */
 177                         ret = (usbvision_i2c_write(usbvision, addr, pmsg->buf, pmsg->len));
 178                         if (ret < pmsg->len)
 179                                 return (ret < 0) ? ret : -EREMOTEIO;
 180                 }
 181         }
 182         return num;
 183 }
 184
 185 static u32 functionality(struct i2c_adapter *adap)
 186 {
 187         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
 188 }
 189
 190 /* -----exported algorithm data: -------------------------------------  */
 191
 192 static struct i2c_algorithm usbvision_algo = {
 193         .master_xfer   = usbvision_i2c_xfer,
 194         .smbus_xfer    = NULL,
 195         .functionality = functionality,
 196 };
 197
 198
 199 /* ----------------------------------------------------------------------- */
 200 /* usbvision specific I2C functions                                        */
 201 /* ----------------------------------------------------------------------- */
 202 static struct i2c_adapter i2c_adap_template;
 203
 204 int usbvision_i2c_register(struct usb_usbvision *usbvision)
 205 {
 206         static unsigned short saa711x_addrs[] = {
 207                 0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
 208                 0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
 209                 I2C_CLIENT_END };
 210
 211         if (usbvision->registered_i2c)
 212                 return 0;
 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_i2c_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->dev_model].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,
 252                                 "saa7115_auto", 0, saa711x_addrs);
 253                 break;
 254         }
 255         if (usbvision_device_data[usbvision->dev_model].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,
 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,
 269                                 "tuner", 0, v4l2_i2c_tuner_addrs(type));
 270
 271                 if (sd == NULL)
 272                         return -ENODEV;
 273                 if (usbvision->tuner_type != -1) {
 274                         tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 275                         tun_setup.type = usbvision->tuner_type;
 276                         tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 277                         call_all(usbvision, tuner, s_type_addr, &tun_setup);
 278                 }
 279         }
 280         usbvision->registered_i2c = 1;
 281
 282         return 0;
 283 }
 284
 285 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 286 {
 287         if (!usbvision->registered_i2c)
 288                 return 0;
 289
 290         i2c_del_adapter(&(usbvision->i2c_adap));
 291         usbvision->registered_i2c = 0;
 292
 293         PDEBUG(DBG_I2C, "i2c bus for %s unregistered", usbvision->i2c_adap.name);
 294
 295         return 0;
 296 }
 297
 298 static int
 299 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 300                      char *buf, short len)
 301 {
 302         int rc, retries;
 303
 304         for (retries = 5;;) {
 305                 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 306                 if (rc < 0)
 307                         return rc;
 308
 309                 /* Initiate byte read cycle                    */
 310                 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 311                 /*                    d3 0=Wr 1=Rd             */
 312                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 313                                       (len & 0x07) | 0x18);
 314                 if (rc < 0)
 315                         return rc;
 316
 317                 /* Test for Busy and ACK */
 318                 do {
 319                         /* USBVISION_SER_CONT -> d4 == 0 busy */
 320                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 321                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 322                 if (rc < 0)
 323                         return rc;
 324
 325                 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 326                 if ((rc & 0x20) == 0)   /* Ack? */
 327                         break;
 328
 329                 /* I2C abort */
 330                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 331                 if (rc < 0)
 332                         return rc;
 333
 334                 if (--retries < 0)
 335                         return -1;
 336         }
 337
 338         switch (len) {
 339         case 4:
 340                 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 341         case 3:
 342                 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 343         case 2:
 344                 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 345         case 1:
 346                 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 347                 break;
 348         default:
 349                 printk(KERN_ERR
 350                        "usbvision_i2c_read_max4: buffer length > 4\n");
 351         }
 352
 353         if (i2c_debug & DBG_I2C) {
 354                 int idx;
 355
 356                 for (idx = 0; idx < len; idx++)
 357                         PDEBUG(DBG_I2C, "read %x from address %x", (unsigned char)buf[idx], addr);
 358         }
 359         return len;
 360 }
 361
 362
 363 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 364                                  unsigned char addr, const char *buf,
 365                                  short len)
 366 {
 367         int rc, retries;
 368         int i;
 369         unsigned char value[6];
 370         unsigned char ser_cont;
 371
 372         ser_cont = (len & 0x07) | 0x10;
 373
 374         value[0] = addr;
 375         value[1] = ser_cont;
 376         for (i = 0; i < len; i++)
 377                 value[i + 2] = buf[i];
 378
 379         for (retries = 5;;) {
 380                 rc = usb_control_msg(usbvision->dev,
 381                                      usb_sndctrlpipe(usbvision->dev, 1),
 382                                      USBVISION_OP_CODE,
 383                                      USB_DIR_OUT | USB_TYPE_VENDOR |
 384                                      USB_RECIP_ENDPOINT, 0,
 385                                      (__u16) USBVISION_SER_ADRS, value,
 386                                      len + 2, HZ);
 387
 388                 if (rc < 0)
 389                         return rc;
 390
 391                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 392                                       (len & 0x07) | 0x10);
 393                 if (rc < 0)
 394                         return rc;
 395
 396                 /* Test for Busy and ACK */
 397                 do {
 398                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 399                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 400                 if (rc < 0)
 401                         return rc;
 402
 403                 if ((rc & 0x20) == 0)   /* Ack? */
 404                         break;
 405
 406                 /* I2C abort */
 407                 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 408
 409                 if (--retries < 0)
 410                         return -1;
 411
 412         }
 413
 414         if (i2c_debug & DBG_I2C) {
 415                 int idx;
 416
 417                 for (idx = 0; idx < len; idx++)
 418                         PDEBUG(DBG_I2C, "wrote %x at address %x", (unsigned char)buf[idx], addr);
 419         }
 420         return len;
 421 }
 422
 423 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 424                             short len)
 425 {
 426         char *buf_ptr = buf;
 427         int retval;
 428         int wrcount = 0;
 429         int count;
 430         int max_len = 4;
 431
 432         while (len > 0) {
 433                 count = (len > max_len) ? max_len : len;
 434                 retval = usbvision_i2c_write_max4(usbvision, addr, buf_ptr, count);
 435                 if (retval > 0) {
 436                         len -= count;
 437                         buf_ptr += count;
 438                         wrcount += count;
 439                 } else
 440                         return (retval < 0) ? retval : -EFAULT;
 441         }
 442         return wrcount;
 443 }
 444
 445 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 446                            short len)
 447 {
 448         char temp[4];
 449         int retval, i;
 450         int rdcount = 0;
 451         int count;
 452
 453         while (len > 0) {
 454                 count = (len > 3) ? 4 : len;
 455                 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 456                 if (retval > 0) {
 457                         for (i = 0; i < len; i++)
 458                                 buf[rdcount + i] = temp[i];
 459                         len -= count;
 460                         rdcount += count;
 461                 } else
 462                         return (retval < 0) ? retval : -EFAULT;
 463         }
 464         return rdcount;
 465 }
 466
 467 static struct i2c_adapter i2c_adap_template = {
 468         .owner = THIS_MODULE,
 469         .name              = "usbvision",
 470 };
 471
 472 /*
 473  * Overrides for Emacs so that we follow Linus's tabbing style.
 474  * ---------------------------------------------------------------------------
 475  * Local variables:
 476  * c-basic-offset: 8
 477  * End:
 478  */