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
 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
 130 static int
 131 usbvision_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
 163 static u32 functionality(struct i2c_adapter *adap)
 164 {
 165         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 166 }
 167
 168 /* -----exported algorithm data: -------------------------------------  */
 169
 170 static 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 /* ----------------------------------------------------------------------- */
 180 static struct i2c_adapter i2c_adap_template;
 181
 182 int 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         memcpy(&usbvision->i2c_adap, &i2c_adap_template,
 193                sizeof(struct i2c_adapter));
 194
 195         sprintf(usbvision->i2c_adap.name, "%s-%d-%s", i2c_adap_template.name,
 196                 usbvision->dev->bus->busnum, usbvision->dev->devpath);
 197         PDEBUG(DBG_I2C, "Adaptername: %s", usbvision->i2c_adap.name);
 198         usbvision->i2c_adap.dev.parent = &usbvision->dev->dev;
 199
 200         i2c_set_adapdata(&usbvision->i2c_adap, &usbvision->v4l2_dev);
 201
 202         if (usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_IIC_LRNACK) < 0) {
 203                 printk(KERN_ERR "usbvision_i2c_register: can't write reg\n");
 204                 return -EBUSY;
 205         }
 206
 207         PDEBUG(DBG_I2C, "I2C   debugging is enabled [i2c]");
 208         PDEBUG(DBG_I2C, "ALGO   debugging is enabled [i2c]");
 209
 210         /* register new adapter to i2c module... */
 211
 212         usbvision->i2c_adap.algo = &usbvision_algo;
 213
 214         usbvision->i2c_adap.timeout = 100;      /* default values, should       */
 215         usbvision->i2c_adap.retries = 3;        /* be replaced by defines       */
 216
 217         i2c_add_adapter(&usbvision->i2c_adap);
 218
 219         PDEBUG(DBG_I2C, "i2c bus for %s registered", usbvision->i2c_adap.name);
 220
 221         /* Request the load of the i2c modules we need */
 222         switch (usbvision_device_data[usbvision->dev_model].codec) {
 223         case CODEC_SAA7113:
 224         case CODEC_SAA7111:
 225                 /* Without this delay the detection of the saa711x is
 226                    hit-and-miss. */
 227                 mdelay(10);
 228                 v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 229                                 &usbvision->i2c_adap,
 230                                 "saa7115_auto", 0, saa711x_addrs);
 231                 break;
 232         }
 233         if (usbvision_device_data[usbvision->dev_model].tuner == 1) {
 234                 struct v4l2_subdev *sd;
 235                 enum v4l2_i2c_tuner_type type;
 236                 struct tuner_setup tun_setup;
 237
 238                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 239                                 &usbvision->i2c_adap,
 240                                 "tuner", 0, v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
 241                 /* depending on whether we found a demod or not, select
 242                    the tuner type. */
 243                 type = sd ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 244
 245                 sd = v4l2_i2c_new_subdev(&usbvision->v4l2_dev,
 246                                 &usbvision->i2c_adap,
 247                                 "tuner", 0, v4l2_i2c_tuner_addrs(type));
 248
 249                 if (sd == NULL)
 250                         return -ENODEV;
 251                 if (usbvision->tuner_type != -1) {
 252                         tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
 253                         tun_setup.type = usbvision->tuner_type;
 254                         tun_setup.addr = v4l2_i2c_subdev_addr(sd);
 255                         call_all(usbvision, tuner, s_type_addr, &tun_setup);
 256                 }
 257         }
 258         usbvision->registered_i2c = 1;
 259
 260         return 0;
 261 }
 262
 263 int usbvision_i2c_unregister(struct usb_usbvision *usbvision)
 264 {
 265         if (!usbvision->registered_i2c)
 266                 return 0;
 267
 268         i2c_del_adapter(&(usbvision->i2c_adap));
 269         usbvision->registered_i2c = 0;
 270
 271         PDEBUG(DBG_I2C, "i2c bus for %s unregistered", usbvision->i2c_adap.name);
 272
 273         return 0;
 274 }
 275
 276 static int
 277 usbvision_i2c_read_max4(struct usb_usbvision *usbvision, unsigned char addr,
 278                      char *buf, short len)
 279 {
 280         int rc, retries;
 281
 282         for (retries = 5;;) {
 283                 rc = usbvision_write_reg(usbvision, USBVISION_SER_ADRS, addr);
 284                 if (rc < 0)
 285                         return rc;
 286
 287                 /* Initiate byte read cycle                    */
 288                 /* USBVISION_SER_CONT <- d0-d2 n. of bytes to r/w */
 289                 /*                    d3 0=Wr 1=Rd             */
 290                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 291                                       (len & 0x07) | 0x18);
 292                 if (rc < 0)
 293                         return rc;
 294
 295                 /* Test for Busy and ACK */
 296                 do {
 297                         /* USBVISION_SER_CONT -> d4 == 0 busy */
 298                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 299                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 300                 if (rc < 0)
 301                         return rc;
 302
 303                 /* USBVISION_SER_CONT -> d5 == 1 Not ack */
 304                 if ((rc & 0x20) == 0)   /* Ack? */
 305                         break;
 306
 307                 /* I2C abort */
 308                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 309                 if (rc < 0)
 310                         return rc;
 311
 312                 if (--retries < 0)
 313                         return -1;
 314         }
 315
 316         switch (len) {
 317         case 4:
 318                 buf[3] = usbvision_read_reg(usbvision, USBVISION_SER_DAT4);
 319         case 3:
 320                 buf[2] = usbvision_read_reg(usbvision, USBVISION_SER_DAT3);
 321         case 2:
 322                 buf[1] = usbvision_read_reg(usbvision, USBVISION_SER_DAT2);
 323         case 1:
 324                 buf[0] = usbvision_read_reg(usbvision, USBVISION_SER_DAT1);
 325                 break;
 326         default:
 327                 printk(KERN_ERR
 328                        "usbvision_i2c_read_max4: buffer length > 4\n");
 329         }
 330
 331         if (i2c_debug & DBG_I2C) {
 332                 int idx;
 333
 334                 for (idx = 0; idx < len; idx++)
 335                         PDEBUG(DBG_I2C, "read %x from address %x", (unsigned char)buf[idx], addr);
 336         }
 337         return len;
 338 }
 339
 340
 341 static int usbvision_i2c_write_max4(struct usb_usbvision *usbvision,
 342                                  unsigned char addr, const char *buf,
 343                                  short len)
 344 {
 345         int rc, retries;
 346         int i;
 347         unsigned char value[6];
 348         unsigned char ser_cont;
 349
 350         ser_cont = (len & 0x07) | 0x10;
 351
 352         value[0] = addr;
 353         value[1] = ser_cont;
 354         for (i = 0; i < len; i++)
 355                 value[i + 2] = buf[i];
 356
 357         for (retries = 5;;) {
 358                 rc = usb_control_msg(usbvision->dev,
 359                                      usb_sndctrlpipe(usbvision->dev, 1),
 360                                      USBVISION_OP_CODE,
 361                                      USB_DIR_OUT | USB_TYPE_VENDOR |
 362                                      USB_RECIP_ENDPOINT, 0,
 363                                      (__u16) USBVISION_SER_ADRS, value,
 364                                      len + 2, HZ);
 365
 366                 if (rc < 0)
 367                         return rc;
 368
 369                 rc = usbvision_write_reg(usbvision, USBVISION_SER_CONT,
 370                                       (len & 0x07) | 0x10);
 371                 if (rc < 0)
 372                         return rc;
 373
 374                 /* Test for Busy and ACK */
 375                 do {
 376                         rc = usbvision_read_reg(usbvision, USBVISION_SER_CONT);
 377                 } while (rc > 0 && ((rc & 0x10) != 0)); /* Retry while busy */
 378                 if (rc < 0)
 379                         return rc;
 380
 381                 if ((rc & 0x20) == 0)   /* Ack? */
 382                         break;
 383
 384                 /* I2C abort */
 385                 usbvision_write_reg(usbvision, USBVISION_SER_CONT, 0x00);
 386
 387                 if (--retries < 0)
 388                         return -1;
 389
 390         }
 391
 392         if (i2c_debug & DBG_I2C) {
 393                 int idx;
 394
 395                 for (idx = 0; idx < len; idx++)
 396                         PDEBUG(DBG_I2C, "wrote %x at address %x", (unsigned char)buf[idx], addr);
 397         }
 398         return len;
 399 }
 400
 401 static int usbvision_i2c_write(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 402                             short len)
 403 {
 404         char *buf_ptr = buf;
 405         int retval;
 406         int wrcount = 0;
 407         int count;
 408         int max_len = 4;
 409
 410         while (len > 0) {
 411                 count = (len > max_len) ? max_len : len;
 412                 retval = usbvision_i2c_write_max4(usbvision, addr, buf_ptr, count);
 413                 if (retval > 0) {
 414                         len -= count;
 415                         buf_ptr += count;
 416                         wrcount += count;
 417                 } else
 418                         return (retval < 0) ? retval : -EFAULT;
 419         }
 420         return wrcount;
 421 }
 422
 423 static int usbvision_i2c_read(struct usb_usbvision *usbvision, unsigned char addr, char *buf,
 424                            short len)
 425 {
 426         char temp[4];
 427         int retval, i;
 428         int rdcount = 0;
 429         int count;
 430
 431         while (len > 0) {
 432                 count = (len > 3) ? 4 : len;
 433                 retval = usbvision_i2c_read_max4(usbvision, addr, temp, count);
 434                 if (retval > 0) {
 435                         for (i = 0; i < len; i++)
 436                                 buf[rdcount + i] = temp[i];
 437                         len -= count;
 438                         rdcount += count;
 439                 } else
 440                         return (retval < 0) ? retval : -EFAULT;
 441         }
 442         return rdcount;
 443 }
 444
 445 static struct i2c_adapter i2c_adap_template = {
 446         .owner = THIS_MODULE,
 447         .name              = "usbvision",
 448 };
 449
 450 /*
 451  * Overrides for Emacs so that we follow Linus's tabbing style.
 452  * ---------------------------------------------------------------------------
 453  * Local variables:
 454  * c-basic-offset: 8
 455  * End:
 456  */