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