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   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/videodev.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-i2c-drv-legacy.h>
  37
  38 /* Addresses to scan */
  39 static unsigned short normal_i2c[] = {
  40         0x20 >> 1,
  41         0x22 >> 1,
  42         I2C_CLIENT_END,
  43 };
  44
  45 I2C_CLIENT_INSMOD;
  46
  47 /* insmod options */
  48 static unsigned int debug;
  49 static unsigned int xtal;
  50 static unsigned int rbds;
  51 static unsigned int plvl;
  52 static unsigned int bufblocks = 100;
  53
  54 module_param(debug, int, 0644);
  55 MODULE_PARM_DESC(debug, "enable debug messages");
  56 module_param(xtal, int, 0);
  57 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
  58 module_param(rbds, int, 0);
  59 MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
  60 module_param(plvl, int, 0);
  61 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
  62 module_param(bufblocks, int, 0);
  63 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
  64
  65 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
  66 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
  67
  68 MODULE_LICENSE("GPL");
  69
  70 /* ---------------------------------------------------------------------- */
  71
  72 #define UNSET       (-1U)
  73 #define PREFIX      "saa6588: "
  74 #define dprintk     if (debug) printk
  75
  76 struct saa6588 {
  77         struct v4l2_subdev sd;
  78         struct work_struct work;
  79         struct timer_list timer;
  80         spinlock_t lock;
  81         unsigned char *buffer;
  82         unsigned int buf_size;
  83         unsigned int rd_index;
  84         unsigned int wr_index;
  85         unsigned int block_count;
  86         unsigned char last_blocknum;
  87         wait_queue_head_t read_queue;
  88         int data_available_for_read;
  89 };
  90
  91 static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
  92 {
  93         return container_of(sd, struct saa6588, sd);
  94 }
  95
  96 /* ---------------------------------------------------------------------- */
  97
  98 /*
  99  * SAA6588 defines
 100  */
 101
 102 /* Initialization and mode control byte (0w) */
 103
 104 /* bit 0+1 (DAC0/DAC1) */
 105 #define cModeStandard           0x00
 106 #define cModeFastPI             0x01
 107 #define cModeReducedRequest     0x02
 108 #define cModeInvalid            0x03
 109
 110 /* bit 2 (RBDS) */
 111 #define cProcessingModeRDS      0x00
 112 #define cProcessingModeRBDS     0x04
 113
 114 /* bit 3+4 (SYM0/SYM1) */
 115 #define cErrCorrectionNone      0x00
 116 #define cErrCorrection2Bits     0x08
 117 #define cErrCorrection5Bits     0x10
 118 #define cErrCorrectionNoneRBDS  0x18
 119
 120 /* bit 5 (NWSY) */
 121 #define cSyncNormal             0x00
 122 #define cSyncRestart            0x20
 123
 124 /* bit 6 (TSQD) */
 125 #define cSigQualityDetectOFF    0x00
 126 #define cSigQualityDetectON     0x40
 127
 128 /* bit 7 (SQCM) */
 129 #define cSigQualityTriggered    0x00
 130 #define cSigQualityContinous    0x80
 131
 132 /* Pause level and flywheel control byte (1w) */
 133
 134 /* bits 0..5 (FEB0..FEB5) */
 135 #define cFlywheelMaxBlocksMask  0x3F
 136 #define cFlywheelDefault        0x20
 137
 138 /* bits 6+7 (PL0/PL1) */
 139 #define cPauseLevel_11mV        0x00
 140 #define cPauseLevel_17mV        0x40
 141 #define cPauseLevel_27mV        0x80
 142 #define cPauseLevel_43mV        0xC0
 143
 144 /* Pause time/oscillator frequency/quality detector control byte (1w) */
 145
 146 /* bits 0..4 (SQS0..SQS4) */
 147 #define cQualityDetectSensMask  0x1F
 148 #define cQualityDetectDefault   0x0F
 149
 150 /* bit 5 (SOSC) */
 151 #define cSelectOscFreqOFF       0x00
 152 #define cSelectOscFreqON        0x20
 153
 154 /* bit 6+7 (PTF0/PTF1) */
 155 #define cOscFreq_4332kHz        0x00
 156 #define cOscFreq_8664kHz        0x40
 157 #define cOscFreq_12996kHz       0x80
 158 #define cOscFreq_17328kHz       0xC0
 159
 160 /* ---------------------------------------------------------------------- */
 161
 162 static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
 163 {
 164         int i;
 165
 166         if (s->rd_index == s->wr_index) {
 167                 if (debug > 2)
 168                         dprintk(PREFIX "Read: buffer empty.\n");
 169                 return 0;
 170         }
 171
 172         if (debug > 2) {
 173                 dprintk(PREFIX "Read: ");
 174                 for (i = s->rd_index; i < s->rd_index + 3; i++)
 175                         dprintk("0x%02x ", s->buffer[i]);
 176         }
 177
 178         if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
 179                 return -EFAULT;
 180
 181         s->rd_index += 3;
 182         if (s->rd_index >= s->buf_size)
 183                 s->rd_index = 0;
 184         s->block_count--;
 185
 186         if (debug > 2)
 187                 dprintk("%d blocks total.\n", s->block_count);
 188
 189         return 1;
 190 }
 191
 192 static void read_from_buf(struct saa6588 *s, struct rds_command *a)
 193 {
 194         unsigned long flags;
 195
 196         unsigned char __user *buf_ptr = a->buffer;
 197         unsigned int i;
 198         unsigned int rd_blocks;
 199
 200         a->result = 0;
 201         if (!a->buffer)
 202                 return;
 203
 204         while (!s->data_available_for_read) {
 205                 int ret = wait_event_interruptible(s->read_queue,
 206                                              s->data_available_for_read);
 207                 if (ret == -ERESTARTSYS) {
 208                         a->result = -EINTR;
 209                         return;
 210                 }
 211         }
 212
 213         spin_lock_irqsave(&s->lock, flags);
 214         rd_blocks = a->block_count;
 215         if (rd_blocks > s->block_count)
 216                 rd_blocks = s->block_count;
 217
 218         if (!rd_blocks) {
 219                 spin_unlock_irqrestore(&s->lock, flags);
 220                 return;
 221         }
 222
 223         for (i = 0; i < rd_blocks; i++) {
 224                 if (block_to_user_buf(s, buf_ptr)) {
 225                         buf_ptr += 3;
 226                         a->result++;
 227                 } else
 228                         break;
 229         }
 230         a->result *= 3;
 231         s->data_available_for_read = (s->block_count > 0);
 232         spin_unlock_irqrestore(&s->lock, flags);
 233 }
 234
 235 static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
 236 {
 237         unsigned int i;
 238
 239         if (debug > 3)
 240                 dprintk(PREFIX "New block: ");
 241
 242         for (i = 0; i < 3; ++i) {
 243                 if (debug > 3)
 244                         dprintk("0x%02x ", blockbuf[i]);
 245                 s->buffer[s->wr_index] = blockbuf[i];
 246                 s->wr_index++;
 247         }
 248
 249         if (s->wr_index >= s->buf_size)
 250                 s->wr_index = 0;
 251
 252         if (s->wr_index == s->rd_index) {
 253                 s->rd_index += 3;
 254                 if (s->rd_index >= s->buf_size)
 255                         s->rd_index = 0;
 256         } else
 257                 s->block_count++;
 258
 259         if (debug > 3)
 260                 dprintk("%d blocks total.\n", s->block_count);
 261 }
 262
 263 static void saa6588_i2c_poll(struct saa6588 *s)
 264 {
 265         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 266         unsigned long flags;
 267         unsigned char tmpbuf[6];
 268         unsigned char blocknum;
 269         unsigned char tmp;
 270
 271         /* Although we only need 3 bytes, we have to read at least 6.
 272            SAA6588 returns garbage otherwise */
 273         if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
 274                 if (debug > 1)
 275                         dprintk(PREFIX "read error!\n");
 276                 return;
 277         }
 278
 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: Received Offset. Indicates the offset received
 298            by the sync system.
 299            Bits 2-0: Offset Name. Indicates the offset applied to this data.
 300
 301            SAA6588 byte order is Status-MSB-LSB, so we have to swap the
 302            first and the last of the 3 bytes block.
 303          */
 304
 305         tmp = tmpbuf[2];
 306         tmpbuf[2] = tmpbuf[0];
 307         tmpbuf[0] = tmp;
 308
 309         tmp = blocknum;
 310         tmp |= blocknum << 3;   /* Received offset == Offset Name (OK ?) */
 311         if ((tmpbuf[2] & 0x03) == 0x03)
 312                 tmp |= 0x80;    /* uncorrectable error */
 313         else if ((tmpbuf[2] & 0x03) != 0x00)
 314                 tmp |= 0x40;    /* corrected error */
 315         tmpbuf[2] = tmp;        /* Is this enough ? Should we also check other bits ? */
 316
 317         spin_lock_irqsave(&s->lock, flags);
 318         block_to_buf(s, tmpbuf);
 319         spin_unlock_irqrestore(&s->lock, flags);
 320         s->data_available_for_read = 1;
 321         wake_up_interruptible(&s->read_queue);
 322 }
 323
 324 static void saa6588_timer(unsigned long data)
 325 {
 326         struct saa6588 *s = (struct saa6588 *)data;
 327
 328         schedule_work(&s->work);
 329 }
 330
 331 static void saa6588_work(struct work_struct *work)
 332 {
 333         struct saa6588 *s = container_of(work, struct saa6588, work);
 334
 335         saa6588_i2c_poll(s);
 336         mod_timer(&s->timer, jiffies + msecs_to_jiffies(20));
 337 }
 338
 339 static int saa6588_configure(struct saa6588 *s)
 340 {
 341         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 342         unsigned char buf[3];
 343         int rc;
 344
 345         buf[0] = cSyncRestart;
 346         if (rbds)
 347                 buf[0] |= cProcessingModeRBDS;
 348
 349         buf[1] = cFlywheelDefault;
 350         switch (plvl) {
 351         case 0:
 352                 buf[1] |= cPauseLevel_11mV;
 353                 break;
 354         case 1:
 355                 buf[1] |= cPauseLevel_17mV;
 356                 break;
 357         case 2:
 358                 buf[1] |= cPauseLevel_27mV;
 359                 break;
 360         case 3:
 361                 buf[1] |= cPauseLevel_43mV;
 362                 break;
 363         default:                /* nothing */
 364                 break;
 365         }
 366
 367         buf[2] = cQualityDetectDefault | cSelectOscFreqON;
 368
 369         switch (xtal) {
 370         case 0:
 371                 buf[2] |= cOscFreq_4332kHz;
 372                 break;
 373         case 1:
 374                 buf[2] |= cOscFreq_8664kHz;
 375                 break;
 376         case 2:
 377                 buf[2] |= cOscFreq_12996kHz;
 378                 break;
 379         case 3:
 380                 buf[2] |= cOscFreq_17328kHz;
 381                 break;
 382         default:                /* nothing */
 383                 break;
 384         }
 385
 386         dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
 387                 buf[0], buf[1], buf[2]);
 388
 389         rc = i2c_master_send(client, buf, 3);
 390         if (rc != 3)
 391                 printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
 392
 393         return 0;
 394 }
 395
 396 /* ---------------------------------------------------------------------- */
 397
 398 static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
 399 {
 400         struct saa6588 *s = to_saa6588(sd);
 401         struct rds_command *a = arg;
 402
 403         switch (cmd) {
 404                 /* --- open() for /dev/radio --- */
 405         case RDS_CMD_OPEN:
 406                 a->result = 0;  /* return error if chip doesn't work ??? */
 407                 break;
 408                 /* --- close() for /dev/radio --- */
 409         case RDS_CMD_CLOSE:
 410                 s->data_available_for_read = 1;
 411                 wake_up_interruptible(&s->read_queue);
 412                 a->result = 0;
 413                 break;
 414                 /* --- read() for /dev/radio --- */
 415         case RDS_CMD_READ:
 416                 read_from_buf(s, a);
 417                 break;
 418                 /* --- poll() for /dev/radio --- */
 419         case RDS_CMD_POLL:
 420                 a->result = 0;
 421                 if (s->data_available_for_read) {
 422                         a->result |= POLLIN | POLLRDNORM;
 423                 }
 424                 poll_wait(a->instance, &s->read_queue, a->event_list);
 425                 break;
 426
 427         default:
 428                 /* nothing */
 429                 return -ENOIOCTLCMD;
 430         }
 431         return 0;
 432 }
 433
 434 static int saa6588_command(struct i2c_client *client, unsigned cmd, void *arg)
 435 {
 436         return v4l2_subdev_command(i2c_get_clientdata(client), cmd, arg);
 437 }
 438
 439 /* ----------------------------------------------------------------------- */
 440
 441 static const struct v4l2_subdev_core_ops saa6588_core_ops = {
 442         .ioctl = saa6588_ioctl,
 443 };
 444
 445 static const struct v4l2_subdev_ops saa6588_ops = {
 446         .core = &saa6588_core_ops,
 447 };
 448
 449 /* ---------------------------------------------------------------------- */
 450
 451 static int saa6588_probe(struct i2c_client *client,
 452                          const struct i2c_device_id *id)
 453 {
 454         struct saa6588 *s;
 455         struct v4l2_subdev *sd;
 456
 457         v4l_info(client, "saa6588 found @ 0x%x (%s)\n",
 458                         client->addr << 1, client->adapter->name);
 459
 460         s = kzalloc(sizeof(*s), GFP_KERNEL);
 461         if (s == NULL)
 462                 return -ENOMEM;
 463
 464         s->buf_size = bufblocks * 3;
 465
 466         s->buffer = kmalloc(s->buf_size, GFP_KERNEL);
 467         if (s->buffer == NULL) {
 468                 kfree(s);
 469                 return -ENOMEM;
 470         }
 471         sd = &s->sd;
 472         v4l2_i2c_subdev_init(sd, client, &saa6588_ops);
 473         spin_lock_init(&s->lock);
 474         s->block_count = 0;
 475         s->wr_index = 0;
 476         s->rd_index = 0;
 477         s->last_blocknum = 0xff;
 478         init_waitqueue_head(&s->read_queue);
 479         s->data_available_for_read = 0;
 480
 481         saa6588_configure(s);
 482
 483         /* start polling via eventd */
 484         INIT_WORK(&s->work, saa6588_work);
 485         init_timer(&s->timer);
 486         s->timer.function = saa6588_timer;
 487         s->timer.data = (unsigned long)s;
 488         schedule_work(&s->work);
 489         return 0;
 490 }
 491
 492 static int saa6588_remove(struct i2c_client *client)
 493 {
 494         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 495         struct saa6588 *s = to_saa6588(sd);
 496
 497         v4l2_device_unregister_subdev(sd);
 498
 499         del_timer_sync(&s->timer);
 500         flush_scheduled_work();
 501
 502         kfree(s->buffer);
 503         kfree(s);
 504         return 0;
 505 }
 506
 507 /* ----------------------------------------------------------------------- */
 508
 509 static const struct i2c_device_id saa6588_id[] = {
 510         { "saa6588", 0 },
 511         { }
 512 };
 513 MODULE_DEVICE_TABLE(i2c, saa6588_id);
 514
 515 static struct v4l2_i2c_driver_data v4l2_i2c_data = {
 516         .name = "saa6588",
 517         .command = saa6588_command,
 518         .probe = saa6588_probe,
 519         .remove = saa6588_remove,
 520         .legacy_class = I2C_CLASS_TV_ANALOG,
 521         .id_table = saa6588_id,
 522 };