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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-chip-ident.h>
  37 #include <media/v4l2-i2c-drv-legacy.h>
  38
  39 /* Addresses to scan */
  40 static unsigned short normal_i2c[] = {
  41         0x20 >> 1,
  42         0x22 >> 1,
  43         I2C_CLIENT_END,
  44 };
  45
  46 I2C_CLIENT_INSMOD;
  47
  48 /* insmod options */
  49 static unsigned int debug;
  50 static unsigned int xtal;
  51 static unsigned int rbds;
  52 static unsigned int plvl;
  53 static unsigned int bufblocks = 100;
  54
  55 module_param(debug, int, 0644);
  56 MODULE_PARM_DESC(debug, "enable debug messages");
  57 module_param(xtal, int, 0);
  58 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
  59 module_param(rbds, int, 0);
  60 MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
  61 module_param(plvl, int, 0);
  62 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
  63 module_param(bufblocks, int, 0);
  64 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
  65
  66 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
  67 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
  68
  69 MODULE_LICENSE("GPL");
  70
  71 /* ---------------------------------------------------------------------- */
  72
  73 #define UNSET       (-1U)
  74 #define PREFIX      "saa6588: "
  75 #define dprintk     if (debug) printk
  76
  77 struct saa6588 {
  78         struct v4l2_subdev sd;
  79         struct work_struct work;
  80         struct timer_list timer;
  81         spinlock_t lock;
  82         unsigned char *buffer;
  83         unsigned int buf_size;
  84         unsigned int rd_index;
  85         unsigned int wr_index;
  86         unsigned int block_count;
  87         unsigned char last_blocknum;
  88         wait_queue_head_t read_queue;
  89         int data_available_for_read;
  90 };
  91
  92 static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
  93 {
  94         return container_of(sd, struct saa6588, sd);
  95 }
  96
  97 /* ---------------------------------------------------------------------- */
  98
  99 /*
 100  * SAA6588 defines
 101  */
 102
 103 /* Initialization and mode control byte (0w) */
 104
 105 /* bit 0+1 (DAC0/DAC1) */
 106 #define cModeStandard           0x00
 107 #define cModeFastPI             0x01
 108 #define cModeReducedRequest     0x02
 109 #define cModeInvalid            0x03
 110
 111 /* bit 2 (RBDS) */
 112 #define cProcessingModeRDS      0x00
 113 #define cProcessingModeRBDS     0x04
 114
 115 /* bit 3+4 (SYM0/SYM1) */
 116 #define cErrCorrectionNone      0x00
 117 #define cErrCorrection2Bits     0x08
 118 #define cErrCorrection5Bits     0x10
 119 #define cErrCorrectionNoneRBDS  0x18
 120
 121 /* bit 5 (NWSY) */
 122 #define cSyncNormal             0x00
 123 #define cSyncRestart            0x20
 124
 125 /* bit 6 (TSQD) */
 126 #define cSigQualityDetectOFF    0x00
 127 #define cSigQualityDetectON     0x40
 128
 129 /* bit 7 (SQCM) */
 130 #define cSigQualityTriggered    0x00
 131 #define cSigQualityContinous    0x80
 132
 133 /* Pause level and flywheel control byte (1w) */
 134
 135 /* bits 0..5 (FEB0..FEB5) */
 136 #define cFlywheelMaxBlocksMask  0x3F
 137 #define cFlywheelDefault        0x20
 138
 139 /* bits 6+7 (PL0/PL1) */
 140 #define cPauseLevel_11mV        0x00
 141 #define cPauseLevel_17mV        0x40
 142 #define cPauseLevel_27mV        0x80
 143 #define cPauseLevel_43mV        0xC0
 144
 145 /* Pause time/oscillator frequency/quality detector control byte (1w) */
 146
 147 /* bits 0..4 (SQS0..SQS4) */
 148 #define cQualityDetectSensMask  0x1F
 149 #define cQualityDetectDefault   0x0F
 150
 151 /* bit 5 (SOSC) */
 152 #define cSelectOscFreqOFF       0x00
 153 #define cSelectOscFreqON        0x20
 154
 155 /* bit 6+7 (PTF0/PTF1) */
 156 #define cOscFreq_4332kHz        0x00
 157 #define cOscFreq_8664kHz        0x40
 158 #define cOscFreq_12996kHz       0x80
 159 #define cOscFreq_17328kHz       0xC0
 160
 161 /* ---------------------------------------------------------------------- */
 162
 163 static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
 164 {
 165         int i;
 166
 167         if (s->rd_index == s->wr_index) {
 168                 if (debug > 2)
 169                         dprintk(PREFIX "Read: buffer empty.\n");
 170                 return 0;
 171         }
 172
 173         if (debug > 2) {
 174                 dprintk(PREFIX "Read: ");
 175                 for (i = s->rd_index; i < s->rd_index + 3; i++)
 176                         dprintk("0x%02x ", s->buffer[i]);
 177         }
 178
 179         if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
 180                 return -EFAULT;
 181
 182         s->rd_index += 3;
 183         if (s->rd_index >= s->buf_size)
 184                 s->rd_index = 0;
 185         s->block_count--;
 186
 187         if (debug > 2)
 188                 dprintk("%d blocks total.\n", s->block_count);
 189
 190         return 1;
 191 }
 192
 193 static void read_from_buf(struct saa6588 *s, struct rds_command *a)
 194 {
 195         unsigned long flags;
 196
 197         unsigned char __user *buf_ptr = a->buffer;
 198         unsigned int i;
 199         unsigned int rd_blocks;
 200
 201         a->result = 0;
 202         if (!a->buffer)
 203                 return;
 204
 205         while (!s->data_available_for_read) {
 206                 int ret = wait_event_interruptible(s->read_queue,
 207                                              s->data_available_for_read);
 208                 if (ret == -ERESTARTSYS) {
 209                         a->result = -EINTR;
 210                         return;
 211                 }
 212         }
 213
 214         spin_lock_irqsave(&s->lock, flags);
 215         rd_blocks = a->block_count;
 216         if (rd_blocks > s->block_count)
 217                 rd_blocks = s->block_count;
 218
 219         if (!rd_blocks) {
 220                 spin_unlock_irqrestore(&s->lock, flags);
 221                 return;
 222         }
 223
 224         for (i = 0; i < rd_blocks; i++) {
 225                 if (block_to_user_buf(s, buf_ptr)) {
 226                         buf_ptr += 3;
 227                         a->result++;
 228                 } else
 229                         break;
 230         }
 231         a->result *= 3;
 232         s->data_available_for_read = (s->block_count > 0);
 233         spin_unlock_irqrestore(&s->lock, flags);
 234 }
 235
 236 static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
 237 {
 238         unsigned int i;
 239
 240         if (debug > 3)
 241                 dprintk(PREFIX "New block: ");
 242
 243         for (i = 0; i < 3; ++i) {
 244                 if (debug > 3)
 245                         dprintk("0x%02x ", blockbuf[i]);
 246                 s->buffer[s->wr_index] = blockbuf[i];
 247                 s->wr_index++;
 248         }
 249
 250         if (s->wr_index >= s->buf_size)
 251                 s->wr_index = 0;
 252
 253         if (s->wr_index == s->rd_index) {
 254                 s->rd_index += 3;
 255                 if (s->rd_index >= s->buf_size)
 256                         s->rd_index = 0;
 257         } else
 258                 s->block_count++;
 259
 260         if (debug > 3)
 261                 dprintk("%d blocks total.\n", s->block_count);
 262 }
 263
 264 static void saa6588_i2c_poll(struct saa6588 *s)
 265 {
 266         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 267         unsigned long flags;
 268         unsigned char tmpbuf[6];
 269         unsigned char blocknum;
 270         unsigned char tmp;
 271
 272         /* Although we only need 3 bytes, we have to read at least 6.
 273            SAA6588 returns garbage otherwise */
 274         if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
 275                 if (debug > 1)
 276                         dprintk(PREFIX "read error!\n");
 277                 return;
 278         }
 279
 280         blocknum = tmpbuf[0] >> 5;
 281         if (blocknum == s->last_blocknum) {
 282                 if (debug > 3)
 283                         dprintk("Saw block %d again.\n", blocknum);
 284                 return;
 285         }
 286
 287         s->last_blocknum = blocknum;
 288
 289         /*
 290            Byte order according to v4l2 specification:
 291
 292            Byte 0: Least Significant Byte of RDS Block
 293            Byte 1: Most Significant Byte of RDS Block
 294            Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
 295            occurred during reception of this block.
 296            Bit 6: Corrected bit. Indicates that an error was
 297            corrected for this data block.
 298            Bits 5-3: Received Offset. Indicates the offset received
 299            by the sync system.
 300            Bits 2-0: Offset Name. Indicates the offset applied to this data.
 301
 302            SAA6588 byte order is Status-MSB-LSB, so we have to swap the
 303            first and the last of the 3 bytes block.
 304          */
 305
 306         tmp = tmpbuf[2];
 307         tmpbuf[2] = tmpbuf[0];
 308         tmpbuf[0] = tmp;
 309
 310         tmp = blocknum;
 311         tmp |= blocknum << 3;   /* Received offset == Offset Name (OK ?) */
 312         if ((tmpbuf[2] & 0x03) == 0x03)
 313                 tmp |= 0x80;    /* uncorrectable error */
 314         else if ((tmpbuf[2] & 0x03) != 0x00)
 315                 tmp |= 0x40;    /* corrected error */
 316         tmpbuf[2] = tmp;        /* Is this enough ? Should we also check other bits ? */
 317
 318         spin_lock_irqsave(&s->lock, flags);
 319         block_to_buf(s, tmpbuf);
 320         spin_unlock_irqrestore(&s->lock, flags);
 321         s->data_available_for_read = 1;
 322         wake_up_interruptible(&s->read_queue);
 323 }
 324
 325 static void saa6588_timer(unsigned long data)
 326 {
 327         struct saa6588 *s = (struct saa6588 *)data;
 328
 329         schedule_work(&s->work);
 330 }
 331
 332 static void saa6588_work(struct work_struct *work)
 333 {
 334         struct saa6588 *s = container_of(work, struct saa6588, work);
 335
 336         saa6588_i2c_poll(s);
 337         mod_timer(&s->timer, jiffies + msecs_to_jiffies(20));
 338 }
 339
 340 static int saa6588_configure(struct saa6588 *s)
 341 {
 342         struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 343         unsigned char buf[3];
 344         int rc;
 345
 346         buf[0] = cSyncRestart;
 347         if (rbds)
 348                 buf[0] |= cProcessingModeRBDS;
 349
 350         buf[1] = cFlywheelDefault;
 351         switch (plvl) {
 352         case 0:
 353                 buf[1] |= cPauseLevel_11mV;
 354                 break;
 355         case 1:
 356                 buf[1] |= cPauseLevel_17mV;
 357                 break;
 358         case 2:
 359                 buf[1] |= cPauseLevel_27mV;
 360                 break;
 361         case 3:
 362                 buf[1] |= cPauseLevel_43mV;
 363                 break;
 364         default:                /* nothing */
 365                 break;
 366         }
 367
 368         buf[2] = cQualityDetectDefault | cSelectOscFreqON;
 369
 370         switch (xtal) {
 371         case 0:
 372                 buf[2] |= cOscFreq_4332kHz;
 373                 break;
 374         case 1:
 375                 buf[2] |= cOscFreq_8664kHz;
 376                 break;
 377         case 2:
 378                 buf[2] |= cOscFreq_12996kHz;
 379                 break;
 380         case 3:
 381                 buf[2] |= cOscFreq_17328kHz;
 382                 break;
 383         default:                /* nothing */
 384                 break;
 385         }
 386
 387         dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
 388                 buf[0], buf[1], buf[2]);
 389
 390         rc = i2c_master_send(client, buf, 3);
 391         if (rc != 3)
 392                 printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
 393
 394         return 0;
 395 }
 396
 397 /* ---------------------------------------------------------------------- */
 398
 399 static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
 400 {
 401         struct saa6588 *s = to_saa6588(sd);
 402         struct rds_command *a = arg;
 403
 404         switch (cmd) {
 405                 /* --- open() for /dev/radio --- */
 406         case RDS_CMD_OPEN:
 407                 a->result = 0;  /* return error if chip doesn't work ??? */
 408                 break;
 409                 /* --- close() for /dev/radio --- */
 410         case RDS_CMD_CLOSE:
 411                 s->data_available_for_read = 1;
 412                 wake_up_interruptible(&s->read_queue);
 413                 a->result = 0;
 414                 break;
 415                 /* --- read() for /dev/radio --- */
 416         case RDS_CMD_READ:
 417                 read_from_buf(s, a);
 418                 break;
 419                 /* --- poll() for /dev/radio --- */
 420         case RDS_CMD_POLL:
 421                 a->result = 0;
 422                 if (s->data_available_for_read) {
 423                         a->result |= POLLIN | POLLRDNORM;
 424                 }
 425                 poll_wait(a->instance, &s->read_queue, a->event_list);
 426                 break;
 427
 428         default:
 429                 /* nothing */
 430                 return -ENOIOCTLCMD;
 431         }
 432         return 0;
 433 }
 434
 435 static int saa6588_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
 436 {
 437         struct i2c_client *client = v4l2_get_subdevdata(sd);
 438
 439         return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_SAA6588, 0);
 440 }
 441
 442 static int saa6588_command(struct i2c_client *client, unsigned cmd, void *arg)
 443 {
 444         return v4l2_subdev_command(i2c_get_clientdata(client), cmd, arg);
 445 }
 446
 447 /* ----------------------------------------------------------------------- */
 448
 449 static const struct v4l2_subdev_core_ops saa6588_core_ops = {
 450         .g_chip_ident = saa6588_g_chip_ident,
 451         .ioctl = saa6588_ioctl,
 452 };
 453
 454 static const struct v4l2_subdev_ops saa6588_ops = {
 455         .core = &saa6588_core_ops,
 456 };
 457
 458 /* ---------------------------------------------------------------------- */
 459
 460 static int saa6588_probe(struct i2c_client *client,
 461                          const struct i2c_device_id *id)
 462 {
 463         struct saa6588 *s;
 464         struct v4l2_subdev *sd;
 465
 466         v4l_info(client, "saa6588 found @ 0x%x (%s)\n",
 467                         client->addr << 1, client->adapter->name);
 468
 469         s = kzalloc(sizeof(*s), GFP_KERNEL);
 470         if (s == NULL)
 471                 return -ENOMEM;
 472
 473         s->buf_size = bufblocks * 3;
 474
 475         s->buffer = kmalloc(s->buf_size, GFP_KERNEL);
 476         if (s->buffer == NULL) {
 477                 kfree(s);
 478                 return -ENOMEM;
 479         }
 480         sd = &s->sd;
 481         v4l2_i2c_subdev_init(sd, client, &saa6588_ops);
 482         spin_lock_init(&s->lock);
 483         s->block_count = 0;
 484         s->wr_index = 0;
 485         s->rd_index = 0;
 486         s->last_blocknum = 0xff;
 487         init_waitqueue_head(&s->read_queue);
 488         s->data_available_for_read = 0;
 489
 490         saa6588_configure(s);
 491
 492         /* start polling via eventd */
 493         INIT_WORK(&s->work, saa6588_work);
 494         init_timer(&s->timer);
 495         s->timer.function = saa6588_timer;
 496         s->timer.data = (unsigned long)s;
 497         schedule_work(&s->work);
 498         return 0;
 499 }
 500
 501 static int saa6588_remove(struct i2c_client *client)
 502 {
 503         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 504         struct saa6588 *s = to_saa6588(sd);
 505
 506         v4l2_device_unregister_subdev(sd);
 507
 508         del_timer_sync(&s->timer);
 509         flush_scheduled_work();
 510
 511         kfree(s->buffer);
 512         kfree(s);
 513         return 0;
 514 }
 515
 516 /* ----------------------------------------------------------------------- */
 517
 518 static const struct i2c_device_id saa6588_id[] = {
 519         { "saa6588", 0 },
 520         { }
 521 };
 522 MODULE_DEVICE_TABLE(i2c, saa6588_id);
 523
 524 static struct v4l2_i2c_driver_data v4l2_i2c_data = {
 525         .name = "saa6588",
 526         .command = saa6588_command,
 527         .probe = saa6588_probe,
 528         .remove = saa6588_remove,
 529         .id_table = saa6588_id,
 530 };