drivers/media/i2c/saa6588.c

   1 /*
   2     Driver for SAA6588 RDS decoder
   3
   4     (c) 2005 Hans J. Koch
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/kernel.h>
  24 #include <linux/i2c.h>
  25 #include <linux/types.h>
  26 #include <linux/videodev2.h>
  27 #include <linux/init.h>
  28 #include <linux/errno.h>
  29 #include <linux/slab.h>
  30 #include <linux/poll.h>
  31 #include <linux/wait.h>
  32 #include <linux/uaccess.h>
  33
  34 #include <media/i2c/saa6588.h>
  35 #include <media/v4l2-device.h>
  36
  37
  38 /* insmod options */
  39 static unsigned int debug;
  40 static unsigned int xtal;
  41 static unsigned int mmbs;
  42 static unsigned int plvl;
  43 static unsigned int bufblocks = 100;
  44
  45 module_param(debug, int, 0644);
  46 MODULE_PARM_DESC(debug, "enable debug messages");
  47 module_param(xtal, int, 0);
  48 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
  49 module_param(mmbs, int, 0);
  50 MODULE_PARM_DESC(mmbs, "enable MMBS mode: 0=off (default), 1=on");
  51 module_param(plvl, int, 0);
  52 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
  53 module_param(bufblocks, int, 0);
  54 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
  55
  56 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
  57 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
  58
  59 MODULE_LICENSE("GPL");
  60
  61 /* ---------------------------------------------------------------------- */
  62
  63 #define UNSET       (-1U)
  64 #define PREFIX      "saa6588: "
  65 #define dprintk     if (debug) printk
  66
  67 struct saa6588 {
  68         struct v4l2_subdev sd;
  69         struct delayed_work work;
  70         spinlock_t lock;
  71         unsigned char *buffer;
  72         unsigned int buf_size;
  73         unsigned int rd_index;
  74         unsigned int wr_index;
  75         unsigned int block_count;
  76         unsigned char last_blocknum;
  77         wait_queue_head_t read_queue;
  78         int data_available_for_read;
  79         u8 sync;
  80 };
  81
  82 static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
  83 {
  84         return container_of(sd, struct saa6588, sd);
  85 }
  86
  87 /* ---------------------------------------------------------------------- */
  88
  89 /*
  90  * SAA6588 defines
  91  */
  92
  93 /* Initialization and mode control byte (0w) */
  94
  95 /* bit 0+1 (DAC0/DAC1) */
  96 #define cModeStandard           0x00
  97 #define cModeFastPI             0x01
  98 #define cModeReducedRequest     0x02
  99 #define cModeInvalid            0x03
 100
 101 /* bit 2 (RBDS) */
 102 #define cProcessingModeRDS      0x00
 103 #define cProcessingModeRBDS     0x04
 104
 105 /* bit 3+4 (SYM0/SYM1) */
 106 #define cErrCorrectionNone      0x00
 107 #define cErrCorrection2Bits     0x08
 108 #define cErrCorrection5Bits     0x10
 109 #define cErrCorrectionNoneRBDS  0x18
 110
 111 /* bit 5 (NWSY) */
 112 #define cSyncNormal             0x00
 113 #define cSyncRestart            0x20
 114
 115 /* bit 6 (TSQD) */
 116 #define cSigQualityDetectOFF    0x00
 117 #define cSigQualityDetectON     0x40
 118
 119 /* bit 7 (SQCM) */
 120 #define cSigQualityTriggered    0x00
 121 #define cSigQualityContinous    0x80
 122
 123 /* Pause level and flywheel control byte (1w) */
 124
 125 /* bits 0..5 (FEB0..FEB5) */
 126 #define cFlywheelMaxBlocksMask  0x3F
 127 #define cFlywheelDefault        0x20
 128
 129 /* bits 6+7 (PL0/PL1) */
 130 #define cPauseLevel_11mV        0x00
 131 #define cPauseLevel_17mV        0x40
 132 #define cPauseLevel_27mV        0x80
 133 #define cPauseLevel_43mV        0xC0
 134
 135 /* Pause time/oscillator frequency/quality detector control byte (1w) */
 136
 137 /* bits 0..4 (SQS0..SQS4) */
 138 #define cQualityDetectSensMask  0x1F
 139 #define cQualityDetectDefault   0x0F
 140
 141 /* bit 5 (SOSC) */
 142 #define cSelectOscFreqOFF       0x00
 143 #define cSelectOscFreqON        0x20
 144
 145 /* bit 6+7 (PTF0/PTF1) */
 146 #define cOscFreq_4332kHz        0x00
 147 #define cOscFreq_8664kHz        0x40
 148 #define cOscFreq_12996kHz       0x80
 149 #define cOscFreq_17328kHz       0xC0
 150
 151 /* ---------------------------------------------------------------------- */
 152
 153 static bool block_from_buf(struct saa6588 *s, unsigned char *buf)
 154 {
 155         int i;
 156
 157         if (s->rd_index == s->wr_index) {
 158                 if (debug > 2)
 159                         dprintk(PREFIX "Read: buffer empty.\n");
 160                 return false;
 161         }
 162
 163         if (debug > 2) {
 164                 dprintk(PREFIX "Read: ");
 165                 for (i = s->rd_index; i < s->rd_index + 3; i++)
 166                         dprintk("0x%02x ", s->buffer[i]);
 167         }
 168
 169         memcpy(buf, &s->buffer[s->rd_index], 3);
 170
 171         s->rd_index += 3;
 172         if (s->rd_index >= s->buf_size)
 173                 s->rd_index = 0;
 174         s->block_count--;
 175
 176         if (debug > 2)
 177                 dprintk("%d blocks total.\n", s->block_count);
 178
 179         return true;
 180 }
 181
 182 static void read_from_buf(struct saa6588 *s, struct saa6588_command *a)
 183 {
 184         unsigned char __user *buf_ptr = a->buffer;
 185         unsigned char buf[3];
 186         unsigned long flags;
 187         unsigned int rd_blocks;
 188         unsigned int i;
 189
 190         a->result = 0;
 191         if (!a->buffer)
 192                 return;
 193
 194         while (!a->nonblocking && !s->data_available_for_read) {
 195                 int ret = wait_event_interruptible(s->read_queue,
 196                                              s->data_available_for_read);
 197                 if (ret == -ERESTARTSYS) {
 198                         a->result = -EINTR;
 199                         return;
 200                 }
 201         }
 202
 203         rd_blocks = a->block_count;
 204         spin_lock_irqsave(&s->lock, flags);
 205         if (rd_blocks > s->block_count)
 206                 rd_blocks = s->block_count;
 207         spin_unlock_irqrestore(&s->lock, flags);
 208
 209         if (!rd_blocks)
 210                 return;
 211
 212         for (i = 0; i < rd_blocks; i++) {
 213                 bool got_block;
 214
 215                 spin_lock_irqsave(&s->lock, flags);
 216                 got_block = block_from_buf(s, buf);
 217                 spin_unlock_irqrestore(&s->lock, flags);
 218                 if (!got_block)
 219                         break;
 220                 if (copy_to_user(buf_ptr, buf, 3)) {
 221                         a->result = -EFAULT;
 222                         return;
 223                 }
 224                 buf_ptr += 3;
 225                 a->result += 3;
 226         }
 227         spin_lock_irqsave(&s->lock, flags);
 228         s->data_available_for_read = (s->block_count > 0);
 229         spin_unlock_irqrestore(&s->lock, flags);
 230 }
 231
 232 static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
 233 {
 234         unsigned int i;
 235
 236         if (debug > 3)
 237                 dprintk(PREFIX "New block: ");
 238
 239         for (i = 0; i < 3; ++i) {
 240                 if (debug > 3)
 241                         dprintk("0x%02x ", blockbuf[i]);
 242                 s->buffer[s->wr_index] = blockbuf[i];
 243                 s->wr_index++;
 244         }
 245
 246         if (s->wr_index >= s->buf_size)
 247                 s->wr_index = 0;
 248
 249         if (s->wr_index == s->rd_index) {
 250                 s->rd_index += 3;
 251                 if (s->rd_index >= s->buf_size)
 252                         s->rd_index = 0;
 253         } else
 254                 s->block_count++;
 255
 256         if (debug > 3)
 257                 dprintk("%d blocks total.\n", s->block_count);
 258 }
 259
 260 static void saa6588_i2c_poll(struct saa6588 *s)
 261 {
 262         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 263         unsigned long flags;
 264         unsigned char tmpbuf[6];
 265         unsigned char blocknum;
 266         unsigned char tmp;
 267
 268         /* Although we only need 3 bytes, we have to read at least 6.
 269            SAA6588 returns garbage otherwise. */
 270         if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
 271                 if (debug > 1)
 272                         dprintk(PREFIX "read error!\n");
 273                 return;
 274         }
 275
 276         s->sync = tmpbuf[0] & 0x10;
 277         if (!s->sync)
 278                 return;
 279         blocknum = tmpbuf[0] >> 5;
 280         if (blocknum == s->last_blocknum) {
 281                 if (debug > 3)
 282                         dprintk("Saw block %d again.\n", blocknum);
 283                 return;
 284         }
 285
 286         s->last_blocknum = blocknum;
 287
 288         /*
 289            Byte order according to v4l2 specification:
 290
 291            Byte 0: Least Significant Byte of RDS Block
 292            Byte 1: Most Significant Byte of RDS Block
 293            Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
 294            occurred during reception of this block.
 295            Bit 6: Corrected bit. Indicates that an error was
 296            corrected for this data block.
 297            Bits 5-3: Same as bits 0-2.
 298            Bits 2-0: Block number.
 299
 300            SAA6588 byte order is Status-MSB-LSB, so we have to swap the
 301            first and the last of the 3 bytes block.
 302          */
 303
 304         swap(tmpbuf[2], tmpbuf[0]);
 305
 306         /* Map 'Invalid block E' to 'Invalid Block' */
 307         if (blocknum == 6)
 308                 blocknum = V4L2_RDS_BLOCK_INVALID;
 309         /* And if are not in mmbs mode, then 'Block E' is also mapped
 310            to 'Invalid Block'. As far as I can tell MMBS is discontinued,
 311            and if there is ever a need to support E blocks, then please
 312            contact the linux-media mailinglist. */
 313         else if (!mmbs && blocknum == 5)
 314                 blocknum = V4L2_RDS_BLOCK_INVALID;
 315         tmp = blocknum;
 316         tmp |= blocknum << 3;   /* Received offset == Offset Name (OK ?) */
 317         if ((tmpbuf[2] & 0x03) == 0x03)
 318                 tmp |= V4L2_RDS_BLOCK_ERROR;     /* uncorrectable error */
 319         else if ((tmpbuf[2] & 0x03) != 0x00)
 320                 tmp |= V4L2_RDS_BLOCK_CORRECTED; /* corrected error */
 321         tmpbuf[2] = tmp;        /* Is this enough ? Should we also check other bits ? */
 322
 323         spin_lock_irqsave(&s->lock, flags);
 324         block_to_buf(s, tmpbuf);
 325         spin_unlock_irqrestore(&s->lock, flags);
 326         s->data_available_for_read = 1;
 327         wake_up_interruptible(&s->read_queue);
 328 }
 329
 330 static void saa6588_work(struct work_struct *work)
 331 {
 332         struct saa6588 *s = container_of(work, struct saa6588, work.work);
 333
 334         saa6588_i2c_poll(s);
 335         schedule_delayed_work(&s->work, msecs_to_jiffies(20));
 336 }
 337
 338 static void saa6588_configure(struct saa6588 *s)
 339 {
 340         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 341         unsigned char buf[3];
 342         int rc;
 343
 344         buf[0] = cSyncRestart;
 345         if (mmbs)
 346                 buf[0] |= cProcessingModeRBDS;
 347
 348         buf[1] = cFlywheelDefault;
 349         switch (plvl) {
 350         case 0:
 351                 buf[1] |= cPauseLevel_11mV;
 352                 break;
 353         case 1:
 354                 buf[1] |= cPauseLevel_17mV;
 355                 break;
 356         case 2:
 357                 buf[1] |= cPauseLevel_27mV;
 358                 break;
 359         case 3:
 360                 buf[1] |= cPauseLevel_43mV;
 361                 break;
 362         default:                /* nothing */
 363                 break;
 364         }
 365
 366         buf[2] = cQualityDetectDefault | cSelectOscFreqON;
 367
 368         switch (xtal) {
 369         case 0:
 370                 buf[2] |= cOscFreq_4332kHz;
 371                 break;
 372         case 1:
 373                 buf[2] |= cOscFreq_8664kHz;
 374                 break;
 375         case 2:
 376                 buf[2] |= cOscFreq_12996kHz;
 377                 break;
 378         case 3:
 379                 buf[2] |= cOscFreq_17328kHz;
 380                 break;
 381         default:                /* nothing */
 382                 break;
 383         }
 384
 385         dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
 386                 buf[0], buf[1], buf[2]);
 387
 388         rc = i2c_master_send(client, buf, 3);
 389         if (rc != 3)
 390                 printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
 391 }
 392
 393 /* ---------------------------------------------------------------------- */
 394
 395 static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
 396 {
 397         struct saa6588 *s = to_saa6588(sd);
 398         struct saa6588_command *a = arg;
 399
 400         switch (cmd) {
 401                 /* --- close() for /dev/radio --- */
 402         case SAA6588_CMD_CLOSE:
 403                 s->data_available_for_read = 1;
 404                 wake_up_interruptible(&s->read_queue);
 405                 s->data_available_for_read = 0;
 406                 a->result = 0;
 407                 break;
 408                 /* --- read() for /dev/radio --- */
 409         case SAA6588_CMD_READ:
 410                 read_from_buf(s, a);
 411                 break;
 412                 /* --- poll() for /dev/radio --- */
 413         case SAA6588_CMD_POLL:
 414                 a->result = 0;
 415                 if (s->data_available_for_read)
 416                         a->result |= EPOLLIN | EPOLLRDNORM;
 417                 poll_wait(a->instance, &s->read_queue, a->event_list);
 418                 break;
 419
 420         default:
 421                 /* nothing */
 422                 return -ENOIOCTLCMD;
 423         }
 424         return 0;
 425 }
 426
 427 static int saa6588_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
 428 {
 429         struct saa6588 *s = to_saa6588(sd);
 430
 431         vt->capability |= V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO;
 432         if (s->sync)
 433                 vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
 434         return 0;
 435 }
 436
 437 static int saa6588_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *vt)
 438 {
 439         struct saa6588 *s = to_saa6588(sd);
 440
 441         saa6588_configure(s);
 442         return 0;
 443 }
 444
 445 /* ----------------------------------------------------------------------- */
 446
 447 static const struct v4l2_subdev_core_ops saa6588_core_ops = {
 448         .ioctl = saa6588_ioctl,
 449 };
 450
 451 static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = {
 452         .g_tuner = saa6588_g_tuner,
 453         .s_tuner = saa6588_s_tuner,
 454 };
 455
 456 static const struct v4l2_subdev_ops saa6588_ops = {
 457         .core = &saa6588_core_ops,
 458         .tuner = &saa6588_tuner_ops,
 459 };
 460
 461 /* ---------------------------------------------------------------------- */
 462
 463 static int saa6588_probe(struct i2c_client *client,
 464                          const struct i2c_device_id *id)
 465 {
 466         struct saa6588 *s;
 467         struct v4l2_subdev *sd;
 468
 469         v4l_info(client, "saa6588 found @ 0x%x (%s)\n",
 470                         client->addr << 1, client->adapter->name);
 471
 472         s = devm_kzalloc(&client->dev, sizeof(*s), GFP_KERNEL);
 473         if (s == NULL)
 474                 return -ENOMEM;
 475
 476         s->buf_size = bufblocks * 3;
 477
 478         s->buffer = devm_kzalloc(&client->dev, s->buf_size, GFP_KERNEL);
 479         if (s->buffer == NULL)
 480                 return -ENOMEM;
 481         sd = &s->sd;
 482         v4l2_i2c_subdev_init(sd, client, &saa6588_ops);
 483         spin_lock_init(&s->lock);
 484         s->block_count = 0;
 485         s->wr_index = 0;
 486         s->rd_index = 0;
 487         s->last_blocknum = 0xff;
 488         init_waitqueue_head(&s->read_queue);
 489         s->data_available_for_read = 0;
 490
 491         saa6588_configure(s);
 492
 493         /* start polling via eventd */
 494         INIT_DELAYED_WORK(&s->work, saa6588_work);
 495         schedule_delayed_work(&s->work, 0);
 496         return 0;
 497 }
 498
 499 static int saa6588_remove(struct i2c_client *client)
 500 {
 501         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 502         struct saa6588 *s = to_saa6588(sd);
 503
 504         v4l2_device_unregister_subdev(sd);
 505
 506         cancel_delayed_work_sync(&s->work);
 507
 508         return 0;
 509 }
 510
 511 /* ----------------------------------------------------------------------- */
 512
 513 static const struct i2c_device_id saa6588_id[] = {
 514         { "saa6588", 0 },
 515         { }
 516 };
 517 MODULE_DEVICE_TABLE(i2c, saa6588_id);
 518
 519 static struct i2c_driver saa6588_driver = {
 520         .driver = {
 521                 .name   = "saa6588",
 522         },
 523         .probe          = saa6588_probe,
 524         .remove         = saa6588_remove,
 525         .id_table       = saa6588_id,
 526 };
 527
 528 module_i2c_driver(saa6588_driver);