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