drivers/media/video/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 <asm/uaccess.h>
  33
  34 #include <media/rds.h>
  35 #include <media/v4l2-device.h>
  36 #include <media/v4l2-chip-ident.h>
  37 #include <media/v4l2-i2c-drv.h>
  38
  39
  40 /* insmod options */
  41 static unsigned int debug;
  42 static unsigned int xtal;
  43 static unsigned int mmbs;
  44 static unsigned int plvl;
  45 static unsigned int bufblocks = 100;
  46
  47 module_param(debug, int, 0644);
  48 MODULE_PARM_DESC(debug, "enable debug messages");
  49 module_param(xtal, int, 0);
  50 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
  51 module_param(mmbs, int, 0);
  52 MODULE_PARM_DESC(mmbs, "enable MMBS mode: 0=off (default), 1=on");
  53 module_param(plvl, int, 0);
  54 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
  55 module_param(bufblocks, int, 0);
  56 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
  57
  58 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
  59 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
  60
  61 MODULE_LICENSE("GPL");
  62
  63 /* ---------------------------------------------------------------------- */
  64
  65 #define UNSET       (-1U)
  66 #define PREFIX      "saa6588: "
  67 #define dprintk     if (debug) printk
  68
  69 struct saa6588 {
  70         struct v4l2_subdev sd;
  71         struct delayed_work work;
  72         spinlock_t lock;
  73         unsigned char *buffer;
  74         unsigned int buf_size;
  75         unsigned int rd_index;
  76         unsigned int wr_index;
  77         unsigned int block_count;
  78         unsigned char last_blocknum;
  79         wait_queue_head_t read_queue;
  80         int data_available_for_read;
  81         u8 sync;
  82 };
  83
  84 static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
  85 {
  86         return container_of(sd, struct saa6588, sd);
  87 }
  88
  89 /* ---------------------------------------------------------------------- */
  90
  91 /*
  92  * SAA6588 defines
  93  */
  94
  95 /* Initialization and mode control byte (0w) */
  96
  97 /* bit 0+1 (DAC0/DAC1) */
  98 #define cModeStandard           0x00
  99 #define cModeFastPI             0x01
 100 #define cModeReducedRequest     0x02
 101 #define cModeInvalid            0x03
 102
 103 /* bit 2 (RBDS) */
 104 #define cProcessingModeRDS      0x00
 105 #define cProcessingModeRBDS     0x04
 106
 107 /* bit 3+4 (SYM0/SYM1) */
 108 #define cErrCorrectionNone      0x00
 109 #define cErrCorrection2Bits     0x08
 110 #define cErrCorrection5Bits     0x10
 111 #define cErrCorrectionNoneRBDS  0x18
 112
 113 /* bit 5 (NWSY) */
 114 #define cSyncNormal             0x00
 115 #define cSyncRestart            0x20
 116
 117 /* bit 6 (TSQD) */
 118 #define cSigQualityDetectOFF    0x00
 119 #define cSigQualityDetectON     0x40
 120
 121 /* bit 7 (SQCM) */
 122 #define cSigQualityTriggered    0x00
 123 #define cSigQualityContinous    0x80
 124
 125 /* Pause level and flywheel control byte (1w) */
 126
 127 /* bits 0..5 (FEB0..FEB5) */
 128 #define cFlywheelMaxBlocksMask  0x3F
 129 #define cFlywheelDefault        0x20
 130
 131 /* bits 6+7 (PL0/PL1) */
 132 #define cPauseLevel_11mV        0x00
 133 #define cPauseLevel_17mV        0x40
 134 #define cPauseLevel_27mV        0x80
 135 #define cPauseLevel_43mV        0xC0
 136
 137 /* Pause time/oscillator frequency/quality detector control byte (1w) */
 138
 139 /* bits 0..4 (SQS0..SQS4) */
 140 #define cQualityDetectSensMask  0x1F
 141 #define cQualityDetectDefault   0x0F
 142
 143 /* bit 5 (SOSC) */
 144 #define cSelectOscFreqOFF       0x00
 145 #define cSelectOscFreqON        0x20
 146
 147 /* bit 6+7 (PTF0/PTF1) */
 148 #define cOscFreq_4332kHz        0x00
 149 #define cOscFreq_8664kHz        0x40
 150 #define cOscFreq_12996kHz       0x80
 151 #define cOscFreq_17328kHz       0xC0
 152
 153 /* ---------------------------------------------------------------------- */
 154
 155 static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
 156 {
 157         int i;
 158
 159         if (s->rd_index == s->wr_index) {
 160                 if (debug > 2)
 161                         dprintk(PREFIX "Read: buffer empty.\n");
 162                 return 0;
 163         }
 164
 165         if (debug > 2) {
 166                 dprintk(PREFIX "Read: ");
 167                 for (i = s->rd_index; i < s->rd_index + 3; i++)
 168                         dprintk("0x%02x ", s->buffer[i]);
 169         }
 170
 171         if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
 172                 return -EFAULT;
 173
 174         s->rd_index += 3;
 175         if (s->rd_index >= s->buf_size)
 176                 s->rd_index = 0;
 177         s->block_count--;
 178
 179         if (debug > 2)
 180                 dprintk("%d blocks total.\n", s->block_count);
 181
 182         return 1;
 183 }
 184
 185 static void read_from_buf(struct saa6588 *s, struct rds_command *a)
 186 {
 187         unsigned long flags;
 188
 189         unsigned char __user *buf_ptr = a->buffer;
 190         unsigned int i;
 191         unsigned int rd_blocks;
 192
 193         a->result = 0;
 194         if (!a->buffer)
 195                 return;
 196
 197         while (!s->data_available_for_read) {
 198                 int ret = wait_event_interruptible(s->read_queue,
 199                                              s->data_available_for_read);
 200                 if (ret == -ERESTARTSYS) {
 201                         a->result = -EINTR;
 202                         return;
 203                 }
 204         }
 205
 206         spin_lock_irqsave(&s->lock, flags);
 207         rd_blocks = a->block_count;
 208         if (rd_blocks > s->block_count)
 209                 rd_blocks = s->block_count;
 210
 211         if (!rd_blocks) {
 212                 spin_unlock_irqrestore(&s->lock, flags);
 213                 return;
 214         }
 215
 216         for (i = 0; i < rd_blocks; i++) {
 217                 if (block_to_user_buf(s, buf_ptr)) {
 218                         buf_ptr += 3;
 219                         a->result++;
 220                 } else
 221                         break;
 222         }
 223         a->result *= 3;
 224         s->data_available_for_read = (s->block_count > 0);
 225         spin_unlock_irqrestore(&s->lock, flags);
 226 }
 227
 228 static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
 229 {
 230         unsigned int i;
 231
 232         if (debug > 3)
 233                 dprintk(PREFIX "New block: ");
 234
 235         for (i = 0; i < 3; ++i) {
 236                 if (debug > 3)
 237                         dprintk("0x%02x ", blockbuf[i]);
 238                 s->buffer[s->wr_index] = blockbuf[i];
 239                 s->wr_index++;
 240         }
 241
 242         if (s->wr_index >= s->buf_size)
 243                 s->wr_index = 0;
 244
 245         if (s->wr_index == s->rd_index) {
 246                 s->rd_index += 3;
 247                 if (s->rd_index >= s->buf_size)
 248                         s->rd_index = 0;
 249         } else
 250                 s->block_count++;
 251
 252         if (debug > 3)
 253                 dprintk("%d blocks total.\n", s->block_count);
 254 }
 255
 256 static void saa6588_i2c_poll(struct saa6588 *s)
 257 {
 258         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 259         unsigned long flags;
 260         unsigned char tmpbuf[6];
 261         unsigned char blocknum;
 262         unsigned char tmp;
 263
 264         /* Although we only need 3 bytes, we have to read at least 6.
 265            SAA6588 returns garbage otherwise. */
 266         if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
 267                 if (debug > 1)
 268                         dprintk(PREFIX "read error!\n");
 269                 return;
 270         }
 271
 272         s->sync = tmpbuf[0] & 0x10;
 273         if (!s->sync)
 274                 return;
 275         blocknum = tmpbuf[0] >> 5;
 276         if (blocknum == s->last_blocknum) {
 277                 if (debug > 3)
 278                         dprintk("Saw block %d again.\n", blocknum);
 279                 return;
 280         }
 281
 282         s->last_blocknum = blocknum;
 283
 284         /*
 285            Byte order according to v4l2 specification:
 286
 287            Byte 0: Least Significant Byte of RDS Block
 288            Byte 1: Most Significant Byte of RDS Block
 289            Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
 290            occurred during reception of this block.
 291            Bit 6: Corrected bit. Indicates that an error was
 292            corrected for this data block.
 293            Bits 5-3: Same as bits 0-2.
 294            Bits 2-0: Block number.
 295
 296            SAA6588 byte order is Status-MSB-LSB, so we have to swap the
 297            first and the last of the 3 bytes block.
 298          */
 299
 300         tmp = tmpbuf[2];
 301         tmpbuf[2] = tmpbuf[0];
 302         tmpbuf[0] = tmp;
 303
 304         /* Map 'Invalid block E' to 'Invalid Block' */
 305         if (blocknum == 6)
 306                 blocknum = V4L2_RDS_BLOCK_INVALID;
 307         /* And if are not in mmbs mode, then 'Block E' is also mapped
 308            to 'Invalid Block'. As far as I can tell MMBS is discontinued,
 309            and if there is ever a need to support E blocks, then please
 310            contact the linux-media mailinglist. */
 311         else if (!mmbs && blocknum == 5)
 312                 blocknum = V4L2_RDS_BLOCK_INVALID;
 313         tmp = blocknum;
 314         tmp |= blocknum << 3;   /* Received offset == Offset Name (OK ?) */
 315         if ((tmpbuf[2] & 0x03) == 0x03)
 316                 tmp |= V4L2_RDS_BLOCK_ERROR;     /* uncorrectable error */
 317         else if ((tmpbuf[2] & 0x03) != 0x00)
 318                 tmp |= V4L2_RDS_BLOCK_CORRECTED; /* corrected error */
 319         tmpbuf[2] = tmp;        /* Is this enough ? Should we also check other bits ? */
 320
 321         spin_lock_irqsave(&s->lock, flags);
 322         block_to_buf(s, tmpbuf);
 323         spin_unlock_irqrestore(&s->lock, flags);
 324         s->data_available_for_read = 1;
 325         wake_up_interruptible(&s->read_queue);
 326 }
 327
 328 static void saa6588_work(struct work_struct *work)
 329 {
 330         struct saa6588 *s = container_of(work, struct saa6588, work.work);
 331
 332         saa6588_i2c_poll(s);
 333         schedule_delayed_work(&s->work, msecs_to_jiffies(20));
 334 }
 335
 336 static void saa6588_configure(struct saa6588 *s)
 337 {
 338         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 339         unsigned char buf[3];
 340         int rc;
 341
 342         buf[0] = cSyncRestart;
 343         if (mmbs)
 344                 buf[0] |= cProcessingModeRBDS;
 345
 346         buf[1] = cFlywheelDefault;
 347         switch (plvl) {
 348         case 0:
 349                 buf[1] |= cPauseLevel_11mV;
 350                 break;
 351         case 1:
 352                 buf[1] |= cPauseLevel_17mV;
 353                 break;
 354         case 2:
 355                 buf[1] |= cPauseLevel_27mV;
 356                 break;
 357         case 3:
 358                 buf[1] |= cPauseLevel_43mV;
 359                 break;
 360         default:                /* nothing */
 361                 break;
 362         }
 363
 364         buf[2] = cQualityDetectDefault | cSelectOscFreqON;
 365
 366         switch (xtal) {
 367         case 0:
 368                 buf[2] |= cOscFreq_4332kHz;
 369                 break;
 370         case 1:
 371                 buf[2] |= cOscFreq_8664kHz;
 372                 break;
 373         case 2:
 374                 buf[2] |= cOscFreq_12996kHz;
 375                 break;
 376         case 3:
 377                 buf[2] |= cOscFreq_17328kHz;
 378                 break;
 379         default:                /* nothing */
 380                 break;
 381         }
 382
 383         dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
 384                 buf[0], buf[1], buf[2]);
 385
 386         rc = i2c_master_send(client, buf, 3);
 387         if (rc != 3)
 388                 printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
 389 }
 390
 391 /* ---------------------------------------------------------------------- */
 392
 393 static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
 394 {
 395         struct saa6588 *s = to_saa6588(sd);
 396         struct rds_command *a = arg;
 397
 398         switch (cmd) {
 399                 /* --- open() for /dev/radio --- */
 400         case RDS_CMD_OPEN:
 401                 a->result = 0;  /* return error if chip doesn't work ??? */
 402                 break;
 403                 /* --- close() for /dev/radio --- */
 404         case RDS_CMD_CLOSE:
 405                 s->data_available_for_read = 1;
 406                 wake_up_interruptible(&s->read_queue);
 407                 a->result = 0;
 408                 break;
 409                 /* --- read() for /dev/radio --- */
 410         case RDS_CMD_READ:
 411                 read_from_buf(s, a);
 412                 break;
 413                 /* --- poll() for /dev/radio --- */
 414         case RDS_CMD_POLL:
 415                 a->result = 0;
 416                 if (s->data_available_for_read) {
 417                         a->result |= POLLIN | POLLRDNORM;
 418                 }
 419                 poll_wait(a->instance, &s->read_queue, a->event_list);
 420                 break;
 421
 422         default:
 423                 /* nothing */
 424                 return -ENOIOCTLCMD;
 425         }
 426         return 0;
 427 }
 428
 429 static int saa6588_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
 430 {
 431         struct saa6588 *s = to_saa6588(sd);
 432
 433         vt->capability |= V4L2_TUNER_CAP_RDS;
 434         if (s->sync)
 435                 vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
 436         return 0;
 437 }
 438
 439 static int saa6588_s_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
 440 {
 441         struct saa6588 *s = to_saa6588(sd);
 442
 443         saa6588_configure(s);
 444         return 0;
 445 }
 446
 447 static int saa6588_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
 448 {
 449         struct i2c_client *client = v4l2_get_subdevdata(sd);
 450
 451         return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_SAA6588, 0);
 452 }
 453
 454 /* ----------------------------------------------------------------------- */
 455
 456 static const struct v4l2_subdev_core_ops saa6588_core_ops = {
 457         .g_chip_ident = saa6588_g_chip_ident,
 458         .ioctl = saa6588_ioctl,
 459 };
 460
 461 static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = {
 462         .g_tuner = saa6588_g_tuner,
 463         .s_tuner = saa6588_s_tuner,
 464 };
 465
 466 static const struct v4l2_subdev_ops saa6588_ops = {
 467         .core = &saa6588_core_ops,
 468         .tuner = &saa6588_tuner_ops,
 469 };
 470
 471 /* ---------------------------------------------------------------------- */
 472
 473 static int saa6588_probe(struct i2c_client *client,
 474                          const struct i2c_device_id *id)
 475 {
 476         struct saa6588 *s;
 477         struct v4l2_subdev *sd;
 478
 479         v4l_info(client, "saa6588 found @ 0x%x (%s)\n",
 480                         client->addr << 1, client->adapter->name);
 481
 482         s = kzalloc(sizeof(*s), GFP_KERNEL);
 483         if (s == NULL)
 484                 return -ENOMEM;
 485
 486         s->buf_size = bufblocks * 3;
 487
 488         s->buffer = kmalloc(s->buf_size, GFP_KERNEL);
 489         if (s->buffer == NULL) {
 490                 kfree(s);
 491                 return -ENOMEM;
 492         }
 493         sd = &s->sd;
 494         v4l2_i2c_subdev_init(sd, client, &saa6588_ops);
 495         spin_lock_init(&s->lock);
 496         s->block_count = 0;
 497         s->wr_index = 0;
 498         s->rd_index = 0;
 499         s->last_blocknum = 0xff;
 500         init_waitqueue_head(&s->read_queue);
 501         s->data_available_for_read = 0;
 502
 503         saa6588_configure(s);
 504
 505         /* start polling via eventd */
 506         INIT_DELAYED_WORK(&s->work, saa6588_work);
 507         schedule_delayed_work(&s->work, 0);
 508         return 0;
 509 }
 510
 511 static int saa6588_remove(struct i2c_client *client)
 512 {
 513         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 514         struct saa6588 *s = to_saa6588(sd);
 515
 516         v4l2_device_unregister_subdev(sd);
 517
 518         cancel_delayed_work_sync(&s->work);
 519
 520         kfree(s->buffer);
 521         kfree(s);
 522         return 0;
 523 }
 524
 525 /* ----------------------------------------------------------------------- */
 526
 527 static const struct i2c_device_id saa6588_id[] = {
 528         { "saa6588", 0 },
 529         { }
 530 };
 531 MODULE_DEVICE_TABLE(i2c, saa6588_id);
 532
 533 static struct v4l2_i2c_driver_data v4l2_i2c_data = {
 534         .name = "saa6588",
 535         .probe = saa6588_probe,
 536         .remove = saa6588_remove,
 537         .id_table = saa6588_id,
 538 };