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 / STC interrupt */
 201                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
 202                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
 203                 radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
 204                 radio->registers[SYSCONFIG1] |= 0x1 << 2;
 205                 retval = si470x_set_register(radio, SYSCONFIG1);
 206         }
 207
 208 done:
 209         mutex_unlock(&radio->lock);
 210         return retval;
 211 }
 212
 213
 214 /*
 215  * si470x_fops_release - file release
 216  */
 217 int si470x_fops_release(struct file *file)
 218 {
 219         struct si470x_device *radio = video_drvdata(file);
 220         int retval = 0;
 221
 222         /* safety check */
 223         if (!radio)
 224                 return -ENODEV;
 225
 226         mutex_lock(&radio->lock);
 227         radio->users--;
 228         if (radio->users == 0)
 229                 /* stop radio */
 230                 retval = si470x_stop(radio);
 231
 232         mutex_unlock(&radio->lock);
 233
 234         return retval;
 235 }
 236
 237
 238
 239 /**************************************************************************
 240  * Video4Linux Interface
 241  **************************************************************************/
 242
 243 /*
 244  * si470x_vidioc_querycap - query device capabilities
 245  */
 246 int si470x_vidioc_querycap(struct file *file, void *priv,
 247                 struct v4l2_capability *capability)
 248 {
 249         strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
 250         strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
 251         capability->version = DRIVER_KERNEL_VERSION;
 252         capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
 253                 V4L2_CAP_TUNER | V4L2_CAP_RADIO;
 254
 255         return 0;
 256 }
 257
 258
 259
 260 /**************************************************************************
 261  * I2C Interface
 262  **************************************************************************/
 263
 264 /*
 265  * si470x_i2c_interrupt - interrupt handler
 266  */
 267 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
 268 {
 269         struct si470x_device *radio = dev_id;
 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         /* check Seek/Tune Complete */
 278         retval = si470x_get_register(radio, STATUSRSSI);
 279         if (retval < 0)
 280                 goto end;
 281
 282         if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
 283                 complete(&radio->completion);
 284
 285         /* safety checks */
 286         if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
 287                 goto end;
 288
 289         /* Update RDS registers */
 290         for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
 291                 retval = si470x_get_register(radio, STATUSRSSI + regnr);
 292                 if (retval < 0)
 293                         goto end;
 294         }
 295
 296         /* get rds blocks */
 297         if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
 298                 /* No RDS group ready, better luck next time */
 299                 goto end;
 300
 301         for (blocknum = 0; blocknum < 4; blocknum++) {
 302                 switch (blocknum) {
 303                 default:
 304                         bler = (radio->registers[STATUSRSSI] &
 305                                         STATUSRSSI_BLERA) >> 9;
 306                         rds = radio->registers[RDSA];
 307                         break;
 308                 case 1:
 309                         bler = (radio->registers[READCHAN] &
 310                                         READCHAN_BLERB) >> 14;
 311                         rds = radio->registers[RDSB];
 312                         break;
 313                 case 2:
 314                         bler = (radio->registers[READCHAN] &
 315                                         READCHAN_BLERC) >> 12;
 316                         rds = radio->registers[RDSC];
 317                         break;
 318                 case 3:
 319                         bler = (radio->registers[READCHAN] &
 320                                         READCHAN_BLERD) >> 10;
 321                         rds = radio->registers[RDSD];
 322                         break;
 323                 };
 324
 325                 /* Fill the V4L2 RDS buffer */
 326                 put_unaligned_le16(rds, &tmpbuf);
 327                 tmpbuf[2] = blocknum;           /* offset name */
 328                 tmpbuf[2] |= blocknum << 3;     /* received offset */
 329                 if (bler > max_rds_errors)
 330                         tmpbuf[2] |= 0x80;      /* uncorrectable errors */
 331                 else if (bler > 0)
 332                         tmpbuf[2] |= 0x40;      /* corrected error(s) */
 333
 334                 /* copy RDS block to internal buffer */
 335                 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
 336                 radio->wr_index += 3;
 337
 338                 /* wrap write pointer */
 339                 if (radio->wr_index >= radio->buf_size)
 340                         radio->wr_index = 0;
 341
 342                 /* check for overflow */
 343                 if (radio->wr_index == radio->rd_index) {
 344                         /* increment and wrap read pointer */
 345                         radio->rd_index += 3;
 346                         if (radio->rd_index >= radio->buf_size)
 347                                 radio->rd_index = 0;
 348                 }
 349         }
 350
 351         if (radio->wr_index != radio->rd_index)
 352                 wake_up_interruptible(&radio->read_queue);
 353
 354 end:
 355         return IRQ_HANDLED;
 356 }
 357
 358
 359 /*
 360  * si470x_i2c_probe - probe for the device
 361  */
 362 static int __devinit si470x_i2c_probe(struct i2c_client *client,
 363                 const struct i2c_device_id *id)
 364 {
 365         struct si470x_device *radio;
 366         int retval = 0;
 367         unsigned char version_warning = 0;
 368
 369         /* private data allocation and initialization */
 370         radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 371         if (!radio) {
 372                 retval = -ENOMEM;
 373                 goto err_initial;
 374         }
 375
 376         radio->users = 0;
 377         radio->client = client;
 378         mutex_init(&radio->lock);
 379
 380         /* video device allocation and initialization */
 381         radio->videodev = video_device_alloc();
 382         if (!radio->videodev) {
 383                 retval = -ENOMEM;
 384                 goto err_radio;
 385         }
 386         memcpy(radio->videodev, &si470x_viddev_template,
 387                         sizeof(si470x_viddev_template));
 388         video_set_drvdata(radio->videodev, radio);
 389
 390         /* power up : need 110ms */
 391         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 392         if (si470x_set_register(radio, POWERCFG) < 0) {
 393                 retval = -EIO;
 394                 goto err_video;
 395         }
 396         msleep(110);
 397
 398         /* get device and chip versions */
 399         if (si470x_get_all_registers(radio) < 0) {
 400                 retval = -EIO;
 401                 goto err_video;
 402         }
 403         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 404                         radio->registers[DEVICEID], radio->registers[CHIPID]);
 405         if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 406                 dev_warn(&client->dev,
 407                         "This driver is known to work with "
 408                         "firmware version %hu,\n", RADIO_FW_VERSION);
 409                 dev_warn(&client->dev,
 410                         "but the device has firmware version %hu.\n",
 411                         radio->registers[CHIPID] & CHIPID_FIRMWARE);
 412                 version_warning = 1;
 413         }
 414
 415         /* give out version warning */
 416         if (version_warning == 1) {
 417                 dev_warn(&client->dev,
 418                         "If you have some trouble using this driver,\n");
 419                 dev_warn(&client->dev,
 420                         "please report to V4L ML at "
 421                         "linux-media@vger.kernel.org\n");
 422         }
 423
 424         /* set initial frequency */
 425         si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 426
 427         /* rds buffer allocation */
 428         radio->buf_size = rds_buf * 3;
 429         radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
 430         if (!radio->buffer) {
 431                 retval = -EIO;
 432                 goto err_video;
 433         }
 434
 435         /* rds buffer configuration */
 436         radio->wr_index = 0;
 437         radio->rd_index = 0;
 438         init_waitqueue_head(&radio->read_queue);
 439
 440         /* mark Seek/Tune Complete Interrupt enabled */
 441         radio->stci_enabled = true;
 442         init_completion(&radio->completion);
 443
 444         retval = request_threaded_irq(client->irq, NULL, 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         video_unregister_device(radio->videodev);
 483         kfree(radio);
 484
 485         return 0;
 486 }
 487
 488
 489 #ifdef CONFIG_PM
 490 /*
 491  * si470x_i2c_suspend - suspend the device
 492  */
 493 static int si470x_i2c_suspend(struct device *dev)
 494 {
 495         struct i2c_client *client = to_i2c_client(dev);
 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 device *dev)
 511 {
 512         struct i2c_client *client = to_i2c_client(dev);
 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
 524 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 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 #ifdef CONFIG_PM
 536                 .pm             = &si470x_i2c_pm,
 537 #endif
 538         },
 539         .probe                  = si470x_i2c_probe,
 540         .remove                 = __devexit_p(si470x_i2c_remove),
 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);