drivers/media/radio/si470x/radio-si470x-i2c.c

   1 /*
   2  * drivers/media/radio/si470x/radio-si470x-i2c.c
   3  *
   4  * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers
   5  *
   6  * Copyright (c) 2009 Samsung Electronics Co.Ltd
   7  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24
  25 /* driver definitions */
  26 #define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>";
  27 #define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 1)
  28 #define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
  29 #define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
  30 #define DRIVER_VERSION "1.0.1"
  31
  32 /* kernel includes */
  33 #include <linux/i2c.h>
  34 #include <linux/delay.h>
  35 #include <linux/interrupt.h>
  36
  37 #include "radio-si470x.h"
  38
  39
  40 /* I2C Device ID List */
  41 static const struct i2c_device_id si470x_i2c_id[] = {
  42         /* Generic Entry */
  43         { "si470x", 0 },
  44         /* Terminating entry */
  45         { }
  46 };
  47 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
  48
  49
  50
  51 /**************************************************************************
  52  * Module Parameters
  53  **************************************************************************/
  54
  55 /* Radio Nr */
  56 static int radio_nr = -1;
  57 module_param(radio_nr, int, 0444);
  58 MODULE_PARM_DESC(radio_nr, "Radio Nr");
  59
  60 /* RDS buffer blocks */
  61 static unsigned int rds_buf = 100;
  62 module_param(rds_buf, uint, 0444);
  63 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
  64
  65 /* RDS maximum block errors */
  66 static unsigned short max_rds_errors = 1;
  67 /* 0 means   0  errors requiring correction */
  68 /* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
  69 /* 2 means 3-5  errors requiring correction */
  70 /* 3 means   6+ errors or errors in checkword, correction not possible */
  71 module_param(max_rds_errors, ushort, 0644);
  72 MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
  73
  74
  75
  76 /**************************************************************************
  77  * I2C Definitions
  78  **************************************************************************/
  79
  80 /* Write starts with the upper byte of register 0x02 */
  81 #define WRITE_REG_NUM           8
  82 #define WRITE_INDEX(i)          (i + 0x02)
  83
  84 /* Read starts with the upper byte of register 0x0a */
  85 #define READ_REG_NUM            RADIO_REGISTER_NUM
  86 #define READ_INDEX(i)           ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
  87
  88
  89
  90 /**************************************************************************
  91  * General Driver Functions - REGISTERs
  92  **************************************************************************/
  93
  94 /*
  95  * si470x_get_register - read register
  96  */
  97 int si470x_get_register(struct si470x_device *radio, int regnr)
  98 {
  99         u16 buf[READ_REG_NUM];
 100         struct i2c_msg msgs[1] = {
 101                 { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
 102                         (void *)buf },
 103         };
 104
 105         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 106                 return -EIO;
 107
 108         radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
 109
 110         return 0;
 111 }
 112
 113
 114 /*
 115  * si470x_set_register - write register
 116  */
 117 int si470x_set_register(struct si470x_device *radio, int regnr)
 118 {
 119         int i;
 120         u16 buf[WRITE_REG_NUM];
 121         struct i2c_msg msgs[1] = {
 122                 { radio->client->addr, 0, sizeof(u16) * WRITE_REG_NUM,
 123                         (void *)buf },
 124         };
 125
 126         for (i = 0; i < WRITE_REG_NUM; i++)
 127                 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
 128
 129         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 130                 return -EIO;
 131
 132         return 0;
 133 }
 134
 135
 136
 137 /**************************************************************************
 138  * General Driver Functions - ENTIRE REGISTERS
 139  **************************************************************************/
 140
 141 /*
 142  * si470x_get_all_registers - read entire registers
 143  */
 144 static int si470x_get_all_registers(struct si470x_device *radio)
 145 {
 146         int i;
 147         u16 buf[READ_REG_NUM];
 148         struct i2c_msg msgs[1] = {
 149                 { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
 150                         (void *)buf },
 151         };
 152
 153         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 154                 return -EIO;
 155
 156         for (i = 0; i < READ_REG_NUM; i++)
 157                 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
 158
 159         return 0;
 160 }
 161
 162
 163
 164 /**************************************************************************
 165  * General Driver Functions - DISCONNECT_CHECK
 166  **************************************************************************/
 167
 168 /*
 169  * si470x_disconnect_check - check whether radio disconnects
 170  */
 171 int si470x_disconnect_check(struct si470x_device *radio)
 172 {
 173         return 0;
 174 }
 175
 176
 177
 178 /**************************************************************************
 179  * File Operations Interface
 180  **************************************************************************/
 181
 182 /*
 183  * si470x_fops_open - file open
 184  */
 185 int si470x_fops_open(struct file *file)
 186 {
 187         struct si470x_device *radio = video_drvdata(file);
 188         int retval = 0;
 189
 190         mutex_lock(&radio->lock);
 191         radio->users++;
 192
 193         if (radio->users == 1) {
 194                 /* start radio */
 195                 retval = si470x_start(radio);
 196                 if (retval < 0)
 197                         goto done;
 198
 199                 /* enable RDS interrupt */
 200                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
 201                 radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
 202                 radio->registers[SYSCONFIG1] |= 0x1 << 2;
 203                 retval = si470x_set_register(radio, SYSCONFIG1);
 204         }
 205
 206 done:
 207         mutex_unlock(&radio->lock);
 208         return retval;
 209 }
 210
 211
 212 /*
 213  * si470x_fops_release - file release
 214  */
 215 int si470x_fops_release(struct file *file)
 216 {
 217         struct si470x_device *radio = video_drvdata(file);
 218         int retval = 0;
 219
 220         /* safety check */
 221         if (!radio)
 222                 return -ENODEV;
 223
 224         mutex_lock(&radio->lock);
 225         radio->users--;
 226         if (radio->users == 0)
 227                 /* stop radio */
 228                 retval = si470x_stop(radio);
 229
 230         mutex_unlock(&radio->lock);
 231
 232         return retval;
 233 }
 234
 235
 236
 237 /**************************************************************************
 238  * Video4Linux Interface
 239  **************************************************************************/
 240
 241 /*
 242  * si470x_vidioc_querycap - query device capabilities
 243  */
 244 int si470x_vidioc_querycap(struct file *file, void *priv,
 245                 struct v4l2_capability *capability)
 246 {
 247         strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
 248         strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
 249         capability->version = DRIVER_KERNEL_VERSION;
 250         capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
 251                 V4L2_CAP_TUNER | V4L2_CAP_RADIO;
 252
 253         return 0;
 254 }
 255
 256
 257
 258 /**************************************************************************
 259  * I2C Interface
 260  **************************************************************************/
 261
 262 /*
 263  * si470x_i2c_interrupt_work - rds processing function
 264  */
 265 static void si470x_i2c_interrupt_work(struct work_struct *work)
 266 {
 267         struct si470x_device *radio = container_of(work,
 268                         struct si470x_device, radio_work);
 269         unsigned char regnr;
 270         unsigned char blocknum;
 271         unsigned short bler; /* rds block errors */
 272         unsigned short rds;
 273         unsigned char tmpbuf[3];
 274         int retval = 0;
 275
 276         /* safety checks */
 277         if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
 278                 return;
 279
 280         /* Update RDS registers */
 281         for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++) {
 282                 retval = si470x_get_register(radio, STATUSRSSI + regnr);
 283                 if (retval < 0)
 284                         return;
 285         }
 286
 287         /* get rds blocks */
 288         if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
 289                 /* No RDS group ready, better luck next time */
 290                 return;
 291
 292         for (blocknum = 0; blocknum < 4; blocknum++) {
 293                 switch (blocknum) {
 294                 default:
 295                         bler = (radio->registers[STATUSRSSI] &
 296                                         STATUSRSSI_BLERA) >> 9;
 297                         rds = radio->registers[RDSA];
 298                         break;
 299                 case 1:
 300                         bler = (radio->registers[READCHAN] &
 301                                         READCHAN_BLERB) >> 14;
 302                         rds = radio->registers[RDSB];
 303                         break;
 304                 case 2:
 305                         bler = (radio->registers[READCHAN] &
 306                                         READCHAN_BLERC) >> 12;
 307                         rds = radio->registers[RDSC];
 308                         break;
 309                 case 3:
 310                         bler = (radio->registers[READCHAN] &
 311                                         READCHAN_BLERD) >> 10;
 312                         rds = radio->registers[RDSD];
 313                         break;
 314                 };
 315
 316                 /* Fill the V4L2 RDS buffer */
 317                 put_unaligned_le16(rds, &tmpbuf);
 318                 tmpbuf[2] = blocknum;           /* offset name */
 319                 tmpbuf[2] |= blocknum << 3;     /* received offset */
 320                 if (bler > max_rds_errors)
 321                         tmpbuf[2] |= 0x80;      /* uncorrectable errors */
 322                 else if (bler > 0)
 323                         tmpbuf[2] |= 0x40;      /* corrected error(s) */
 324
 325                 /* copy RDS block to internal buffer */
 326                 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
 327                 radio->wr_index += 3;
 328
 329                 /* wrap write pointer */
 330                 if (radio->wr_index >= radio->buf_size)
 331                         radio->wr_index = 0;
 332
 333                 /* check for overflow */
 334                 if (radio->wr_index == radio->rd_index) {
 335                         /* increment and wrap read pointer */
 336                         radio->rd_index += 3;
 337                         if (radio->rd_index >= radio->buf_size)
 338                                 radio->rd_index = 0;
 339                 }
 340         }
 341
 342         if (radio->wr_index != radio->rd_index)
 343                 wake_up_interruptible(&radio->read_queue);
 344 }
 345
 346
 347 /*
 348  * si470x_i2c_interrupt - interrupt handler
 349  */
 350 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
 351 {
 352         struct si470x_device *radio = dev_id;
 353
 354         if (!work_pending(&radio->radio_work))
 355                 schedule_work(&radio->radio_work);
 356
 357         return IRQ_HANDLED;
 358 }
 359
 360
 361 /*
 362  * si470x_i2c_probe - probe for the device
 363  */
 364 static int __devinit si470x_i2c_probe(struct i2c_client *client,
 365                 const struct i2c_device_id *id)
 366 {
 367         struct si470x_device *radio;
 368         int retval = 0;
 369         unsigned char version_warning = 0;
 370
 371         /* private data allocation and initialization */
 372         radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 373         if (!radio) {
 374                 retval = -ENOMEM;
 375                 goto err_initial;
 376         }
 377
 378         INIT_WORK(&radio->radio_work, si470x_i2c_interrupt_work);
 379         radio->users = 0;
 380         radio->client = client;
 381         mutex_init(&radio->lock);
 382
 383         /* video device allocation and initialization */
 384         radio->videodev = video_device_alloc();
 385         if (!radio->videodev) {
 386                 retval = -ENOMEM;
 387                 goto err_radio;
 388         }
 389         memcpy(radio->videodev, &si470x_viddev_template,
 390                         sizeof(si470x_viddev_template));
 391         video_set_drvdata(radio->videodev, radio);
 392
 393         /* power up : need 110ms */
 394         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 395         if (si470x_set_register(radio, POWERCFG) < 0) {
 396                 retval = -EIO;
 397                 goto err_all;
 398         }
 399         msleep(110);
 400
 401         /* get device and chip versions */
 402         if (si470x_get_all_registers(radio) < 0) {
 403                 retval = -EIO;
 404                 goto err_video;
 405         }
 406         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 407                         radio->registers[DEVICEID], radio->registers[CHIPID]);
 408         if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 409                 dev_warn(&client->dev,
 410                         "This driver is known to work with "
 411                         "firmware version %hu,\n", RADIO_FW_VERSION);
 412                 dev_warn(&client->dev,
 413                         "but the device has firmware version %hu.\n",
 414                         radio->registers[CHIPID] & CHIPID_FIRMWARE);
 415                 version_warning = 1;
 416         }
 417
 418         /* give out version warning */
 419         if (version_warning == 1) {
 420                 dev_warn(&client->dev,
 421                         "If you have some trouble using this driver,\n");
 422                 dev_warn(&client->dev,
 423                         "please report to V4L ML at "
 424                         "linux-media@vger.kernel.org\n");
 425         }
 426
 427         /* set initial frequency */
 428         si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 429
 430         /* rds buffer allocation */
 431         radio->buf_size = rds_buf * 3;
 432         radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
 433         if (!radio->buffer) {
 434                 retval = -EIO;
 435                 goto err_video;
 436         }
 437
 438         /* rds buffer configuration */
 439         radio->wr_index = 0;
 440         radio->rd_index = 0;
 441         init_waitqueue_head(&radio->read_queue);
 442
 443         retval = request_irq(client->irq, si470x_i2c_interrupt,
 444                         IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
 445         if (retval) {
 446                 dev_err(&client->dev, "Failed to register interrupt\n");
 447                 goto err_rds;
 448         }
 449
 450         /* register video device */
 451         retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
 452                         radio_nr);
 453         if (retval) {
 454                 dev_warn(&client->dev, "Could not register video device\n");
 455                 goto err_all;
 456         }
 457         i2c_set_clientdata(client, radio);
 458
 459         return 0;
 460 err_all:
 461         free_irq(client->irq, radio);
 462 err_rds:
 463         kfree(radio->buffer);
 464 err_video:
 465         video_device_release(radio->videodev);
 466 err_radio:
 467         kfree(radio);
 468 err_initial:
 469         return retval;
 470 }
 471
 472
 473 /*
 474  * si470x_i2c_remove - remove the device
 475  */
 476 static __devexit int si470x_i2c_remove(struct i2c_client *client)
 477 {
 478         struct si470x_device *radio = i2c_get_clientdata(client);
 479
 480         free_irq(client->irq, radio);
 481         cancel_work_sync(&radio->radio_work);
 482         video_unregister_device(radio->videodev);
 483         kfree(radio);
 484         i2c_set_clientdata(client, NULL);
 485
 486         return 0;
 487 }
 488
 489
 490 #ifdef CONFIG_PM
 491 /*
 492  * si470x_i2c_suspend - suspend the device
 493  */
 494 static int si470x_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
 495 {
 496         struct si470x_device *radio = i2c_get_clientdata(client);
 497
 498         /* power down */
 499         radio->registers[POWERCFG] |= POWERCFG_DISABLE;
 500         if (si470x_set_register(radio, POWERCFG) < 0)
 501                 return -EIO;
 502
 503         return 0;
 504 }
 505
 506
 507 /*
 508  * si470x_i2c_resume - resume the device
 509  */
 510 static int si470x_i2c_resume(struct i2c_client *client)
 511 {
 512         struct si470x_device *radio = i2c_get_clientdata(client);
 513
 514         /* power up : need 110ms */
 515         radio->registers[POWERCFG] |= POWERCFG_ENABLE;
 516         if (si470x_set_register(radio, POWERCFG) < 0)
 517                 return -EIO;
 518         msleep(110);
 519
 520         return 0;
 521 }
 522 #else
 523 #define si470x_i2c_suspend      NULL
 524 #define si470x_i2c_resume       NULL
 525 #endif
 526
 527
 528 /*
 529  * si470x_i2c_driver - i2c driver interface
 530  */
 531 static struct i2c_driver si470x_i2c_driver = {
 532         .driver = {
 533                 .name           = "si470x",
 534                 .owner          = THIS_MODULE,
 535         },
 536         .probe                  = si470x_i2c_probe,
 537         .remove                 = __devexit_p(si470x_i2c_remove),
 538         .suspend                = si470x_i2c_suspend,
 539         .resume                 = si470x_i2c_resume,
 540         .id_table               = si470x_i2c_id,
 541 };
 542
 543
 544
 545 /**************************************************************************
 546  * Module Interface
 547  **************************************************************************/
 548
 549 /*
 550  * si470x_i2c_init - module init
 551  */
 552 static int __init si470x_i2c_init(void)
 553 {
 554         printk(KERN_INFO DRIVER_DESC ", Version " DRIVER_VERSION "\n");
 555         return i2c_add_driver(&si470x_i2c_driver);
 556 }
 557
 558
 559 /*
 560  * si470x_i2c_exit - module exit
 561  */
 562 static void __exit si470x_i2c_exit(void)
 563 {
 564         i2c_del_driver(&si470x_i2c_driver);
 565 }
 566
 567
 568 module_init(si470x_i2c_init);
 569 module_exit(si470x_i2c_exit);
 570
 571 MODULE_LICENSE("GPL");
 572 MODULE_AUTHOR(DRIVER_AUTHOR);
 573 MODULE_DESCRIPTION(DRIVER_DESC);
 574 MODULE_VERSION(DRIVER_VERSION);