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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
  35 #include <media/rds.h>
  36
  37 /* Addresses to scan */
  38 static unsigned short normal_i2c[] = {
  39         0x20 >> 1,
  40         0x22 >> 1,
  41         I2C_CLIENT_END,
  42 };
  43
  44 I2C_CLIENT_INSMOD;
  45
  46 /* insmod options */
  47 static unsigned int debug = 0;
  48 static unsigned int xtal = 0;
  49 static unsigned int rbds = 0;
  50 static unsigned int plvl = 0;
  51 static unsigned int bufblocks = 100;
  52
  53 module_param(debug, int, 0644);
  54 MODULE_PARM_DESC(debug, "enable debug messages");
  55 module_param(xtal, int, 0);
  56 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
  57 module_param(rbds, int, 0);
  58 MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
  59 module_param(plvl, int, 0);
  60 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
  61 module_param(bufblocks, int, 0);
  62 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
  63
  64 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
  65 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
  66
  67 MODULE_LICENSE("GPL");
  68
  69 /* ---------------------------------------------------------------------- */
  70
  71 #define UNSET       (-1U)
  72 #define PREFIX      "saa6588: "
  73 #define dprintk     if (debug) printk
  74
  75 struct saa6588 {
  76         struct i2c_client client;
  77         struct work_struct work;
  78         struct timer_list timer;
  79         spinlock_t lock;
  80         unsigned char *buffer;
  81         unsigned int buf_size;
  82         unsigned int rd_index;
  83         unsigned int wr_index;
  84         unsigned int block_count;
  85         unsigned char last_blocknum;
  86         wait_queue_head_t read_queue;
  87         int data_available_for_read;
  88 };
  89
  90 static struct i2c_driver driver;
  91 static struct i2c_client client_template;
  92
  93 /* ---------------------------------------------------------------------- */
  94
  95 /*
  96  * SAA6588 defines
  97  */
  98
  99 /* Initialization and mode control byte (0w) */
 100
 101 /* bit 0+1 (DAC0/DAC1) */
 102 #define cModeStandard           0x00
 103 #define cModeFastPI             0x01
 104 #define cModeReducedRequest     0x02
 105 #define cModeInvalid            0x03
 106
 107 /* bit 2 (RBDS) */
 108 #define cProcessingModeRDS      0x00
 109 #define cProcessingModeRBDS     0x04
 110
 111 /* bit 3+4 (SYM0/SYM1) */
 112 #define cErrCorrectionNone      0x00
 113 #define cErrCorrection2Bits     0x08
 114 #define cErrCorrection5Bits     0x10
 115 #define cErrCorrectionNoneRBDS  0x18
 116
 117 /* bit 5 (NWSY) */
 118 #define cSyncNormal             0x00
 119 #define cSyncRestart            0x20
 120
 121 /* bit 6 (TSQD) */
 122 #define cSigQualityDetectOFF    0x00
 123 #define cSigQualityDetectON     0x40
 124
 125 /* bit 7 (SQCM) */
 126 #define cSigQualityTriggered    0x00
 127 #define cSigQualityContinous    0x80
 128
 129 /* Pause level and flywheel control byte (1w) */
 130
 131 /* bits 0..5 (FEB0..FEB5) */
 132 #define cFlywheelMaxBlocksMask  0x3F
 133 #define cFlywheelDefault        0x20
 134
 135 /* bits 6+7 (PL0/PL1) */
 136 #define cPauseLevel_11mV        0x00
 137 #define cPauseLevel_17mV        0x40
 138 #define cPauseLevel_27mV        0x80
 139 #define cPauseLevel_43mV        0xC0
 140
 141 /* Pause time/oscillator frequency/quality detector control byte (1w) */
 142
 143 /* bits 0..4 (SQS0..SQS4) */
 144 #define cQualityDetectSensMask  0x1F
 145 #define cQualityDetectDefault   0x0F
 146
 147 /* bit 5 (SOSC) */
 148 #define cSelectOscFreqOFF       0x00
 149 #define cSelectOscFreqON        0x20
 150
 151 /* bit 6+7 (PTF0/PTF1) */
 152 #define cOscFreq_4332kHz        0x00
 153 #define cOscFreq_8664kHz        0x40
 154 #define cOscFreq_12996kHz       0x80
 155 #define cOscFreq_17328kHz       0xC0
 156
 157 /* ---------------------------------------------------------------------- */
 158
 159 static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
 160 {
 161         int i;
 162
 163         if (s->rd_index == s->wr_index) {
 164                 if (debug > 2)
 165                         dprintk(PREFIX "Read: buffer empty.\n");
 166                 return 0;
 167         }
 168
 169         if (debug > 2) {
 170                 dprintk(PREFIX "Read: ");
 171                 for (i = s->rd_index; i < s->rd_index + 3; i++)
 172                         dprintk("0x%02x ", s->buffer[i]);
 173         }
 174
 175         if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
 176                 return -EFAULT;
 177
 178         s->rd_index += 3;
 179         if (s->rd_index >= s->buf_size)
 180                 s->rd_index = 0;
 181         s->block_count--;
 182
 183         if (debug > 2)
 184                 dprintk("%d blocks total.\n", s->block_count);
 185
 186         return 1;
 187 }
 188
 189 static void read_from_buf(struct saa6588 *s, struct rds_command *a)
 190 {
 191         unsigned long flags;
 192
 193         unsigned char __user *buf_ptr = a->buffer;
 194         unsigned int i;
 195         unsigned int rd_blocks;
 196
 197         a->result = 0;
 198         if (!a->buffer)
 199                 return;
 200
 201         while (!s->data_available_for_read) {
 202                 int ret = wait_event_interruptible(s->read_queue,
 203                                              s->data_available_for_read);
 204                 if (ret == -ERESTARTSYS) {
 205                         a->result = -EINTR;
 206                         return;
 207                 }
 208         }
 209
 210         spin_lock_irqsave(&s->lock, flags);
 211         rd_blocks = a->block_count;
 212         if (rd_blocks > s->block_count)
 213                 rd_blocks = s->block_count;
 214
 215         if (!rd_blocks) {
 216                 spin_unlock_irqrestore(&s->lock, flags);
 217                 return;
 218         }
 219
 220         for (i = 0; i < rd_blocks; i++) {
 221                 if (block_to_user_buf(s, buf_ptr)) {
 222                         buf_ptr += 3;
 223                         a->result++;
 224                 } else
 225                         break;
 226         }
 227         a->result *= 3;
 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         unsigned long flags;
 263         unsigned char tmpbuf[6];
 264         unsigned char blocknum;
 265         unsigned char tmp;
 266
 267         /* Although we only need 3 bytes, we have to read at least 6.
 268            SAA6588 returns garbage otherwise */
 269         if (6 != i2c_master_recv(&s->client, &tmpbuf[0], 6)) {
 270                 if (debug > 1)
 271                         dprintk(PREFIX "read error!\n");
 272                 return;
 273         }
 274
 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: Received Offset. Indicates the offset received
 294            by the sync system.
 295            Bits 2-0: Offset Name. Indicates the offset applied to this data.
 296
 297            SAA6588 byte order is Status-MSB-LSB, so we have to swap the
 298            first and the last of the 3 bytes block.
 299          */
 300
 301         tmp = tmpbuf[2];
 302         tmpbuf[2] = tmpbuf[0];
 303         tmpbuf[0] = tmp;
 304
 305         tmp = blocknum;
 306         tmp |= blocknum << 3;   /* Received offset == Offset Name (OK ?) */
 307         if ((tmpbuf[2] & 0x03) == 0x03)
 308                 tmp |= 0x80;    /* uncorrectable error */
 309         else if ((tmpbuf[2] & 0x03) != 0x00)
 310                 tmp |= 0x40;    /* corrected error */
 311         tmpbuf[2] = tmp;        /* Is this enough ? Should we also check other bits ? */
 312
 313         spin_lock_irqsave(&s->lock, flags);
 314         block_to_buf(s, tmpbuf);
 315         spin_unlock_irqrestore(&s->lock, flags);
 316         s->data_available_for_read = 1;
 317         wake_up_interruptible(&s->read_queue);
 318 }
 319
 320 static void saa6588_timer(unsigned long data)
 321 {
 322         struct saa6588 *s = (struct saa6588 *)data;
 323
 324         schedule_work(&s->work);
 325 }
 326
 327 static void saa6588_work(struct work_struct *work)
 328 {
 329         struct saa6588 *s = container_of(work, struct saa6588, work);
 330
 331         saa6588_i2c_poll(s);
 332         mod_timer(&s->timer, jiffies + msecs_to_jiffies(20));
 333 }
 334
 335 static int saa6588_configure(struct saa6588 *s)
 336 {
 337         unsigned char buf[3];
 338         int rc;
 339
 340         buf[0] = cSyncRestart;
 341         if (rbds)
 342                 buf[0] |= cProcessingModeRBDS;
 343
 344         buf[1] = cFlywheelDefault;
 345         switch (plvl) {
 346         case 0:
 347                 buf[1] |= cPauseLevel_11mV;
 348                 break;
 349         case 1:
 350                 buf[1] |= cPauseLevel_17mV;
 351                 break;
 352         case 2:
 353                 buf[1] |= cPauseLevel_27mV;
 354                 break;
 355         case 3:
 356                 buf[1] |= cPauseLevel_43mV;
 357                 break;
 358         default:                /* nothing */
 359                 break;
 360         }
 361
 362         buf[2] = cQualityDetectDefault | cSelectOscFreqON;
 363
 364         switch (xtal) {
 365         case 0:
 366                 buf[2] |= cOscFreq_4332kHz;
 367                 break;
 368         case 1:
 369                 buf[2] |= cOscFreq_8664kHz;
 370                 break;
 371         case 2:
 372                 buf[2] |= cOscFreq_12996kHz;
 373                 break;
 374         case 3:
 375                 buf[2] |= cOscFreq_17328kHz;
 376                 break;
 377         default:                /* nothing */
 378                 break;
 379         }
 380
 381         dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
 382                 buf[0], buf[1], buf[2]);
 383
 384         if (3 != (rc = i2c_master_send(&s->client, buf, 3)))
 385                 printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
 386
 387         return 0;
 388 }
 389
 390 /* ---------------------------------------------------------------------- */
 391
 392 static int saa6588_attach(struct i2c_adapter *adap, int addr, int kind)
 393 {
 394         struct saa6588 *s;
 395         client_template.adapter = adap;
 396         client_template.addr = addr;
 397
 398         printk(PREFIX "chip found @ 0x%x\n", addr << 1);
 399
 400         if (NULL == (s = kmalloc(sizeof(*s), GFP_KERNEL)))
 401                 return -ENOMEM;
 402
 403         s->buf_size = bufblocks * 3;
 404
 405         if (NULL == (s->buffer = kmalloc(s->buf_size, GFP_KERNEL))) {
 406                 kfree(s);
 407                 return -ENOMEM;
 408         }
 409         s->client = client_template;
 410         s->block_count = 0;
 411         s->wr_index = 0;
 412         s->rd_index = 0;
 413         s->last_blocknum = 0xff;
 414         init_waitqueue_head(&s->read_queue);
 415         s->data_available_for_read = 0;
 416         i2c_set_clientdata(&s->client, s);
 417         i2c_attach_client(&s->client);
 418
 419         saa6588_configure(s);
 420
 421         /* start polling via eventd */
 422         INIT_WORK(&s->work, saa6588_work);
 423         init_timer(&s->timer);
 424         s->timer.function = saa6588_timer;
 425         s->timer.data = (unsigned long)s;
 426         schedule_work(&s->work);
 427         return 0;
 428 }
 429
 430 static int saa6588_probe(struct i2c_adapter *adap)
 431 {
 432         if (adap->class & I2C_CLASS_TV_ANALOG)
 433                 return i2c_probe(adap, &addr_data, saa6588_attach);
 434         return 0;
 435 }
 436
 437 static int saa6588_detach(struct i2c_client *client)
 438 {
 439         struct saa6588 *s = i2c_get_clientdata(client);
 440
 441         del_timer_sync(&s->timer);
 442         flush_scheduled_work();
 443
 444         i2c_detach_client(client);
 445         kfree(s->buffer);
 446         kfree(s);
 447         return 0;
 448 }
 449
 450 static int saa6588_command(struct i2c_client *client, unsigned int cmd,
 451                                                         void *arg)
 452 {
 453         struct saa6588 *s = i2c_get_clientdata(client);
 454         struct rds_command *a = (struct rds_command *)arg;
 455
 456         switch (cmd) {
 457                 /* --- open() for /dev/radio --- */
 458         case RDS_CMD_OPEN:
 459                 a->result = 0;  /* return error if chip doesn't work ??? */
 460                 break;
 461                 /* --- close() for /dev/radio --- */
 462         case RDS_CMD_CLOSE:
 463                 s->data_available_for_read = 1;
 464                 wake_up_interruptible(&s->read_queue);
 465                 a->result = 0;
 466                 break;
 467                 /* --- read() for /dev/radio --- */
 468         case RDS_CMD_READ:
 469                 read_from_buf(s, a);
 470                 break;
 471                 /* --- poll() for /dev/radio --- */
 472         case RDS_CMD_POLL:
 473                 a->result = 0;
 474                 if (s->data_available_for_read) {
 475                         a->result |= POLLIN | POLLRDNORM;
 476                 }
 477                 poll_wait(a->instance, &s->read_queue, a->event_list);
 478                 break;
 479
 480         default:
 481                 /* nothing */
 482                 break;
 483         }
 484         return 0;
 485 }
 486
 487 /* ----------------------------------------------------------------------- */
 488
 489 static struct i2c_driver driver = {
 490         .driver = {
 491                 .name = "saa6588",
 492         },
 493         .id = -1,               /* FIXME */
 494         .attach_adapter = saa6588_probe,
 495         .detach_client = saa6588_detach,
 496         .command = saa6588_command,
 497 };
 498
 499 static struct i2c_client client_template = {
 500         .name = "saa6588",
 501         .driver = &driver,
 502 };
 503
 504 static int __init saa6588_init_module(void)
 505 {
 506         return i2c_add_driver(&driver);
 507 }
 508
 509 static void __exit saa6588_cleanup_module(void)
 510 {
 511         i2c_del_driver(&driver);
 512 }
 513
 514 module_init(saa6588_init_module);
 515 module_exit(saa6588_cleanup_module);
 516
 517 /*
 518  * Overrides for Emacs so that we follow Linus's tabbing style.
 519  * ---------------------------------------------------------------------------
 520  * Local variables:
 521  * c-basic-offset: 8
 522  * End:
 523  */