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_CARD "Silicon Labs Si470x FM Radio Receiver"
  28 #define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
  29 #define DRIVER_VERSION "1.0.2"
  30
  31 /* kernel includes */
  32 #include <linux/i2c.h>
  33 #include <linux/slab.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 / STC interrupt */
 200                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
 201                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
 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->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 - interrupt handler
 264  */
 265 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
 266 {
 267         struct si470x_device *radio = dev_id;
 268         unsigned char regnr;
 269         unsigned char blocknum;
 270         unsigned short bler; /* rds block errors */
 271         unsigned short rds;
 272         unsigned char tmpbuf[3];
 273         int retval = 0;
 274
 275         /* check Seek/Tune Complete */
 276         retval = si470x_get_register(radio, STATUSRSSI);
 277         if (retval < 0)
 278                 goto end;
 279
 280         if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
 281                 complete(&radio->completion);
 282
 283         /* safety checks */
 284         if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
 285                 goto end;
 286
 287         /* Update RDS registers */
 288         for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
 289                 retval = si470x_get_register(radio, STATUSRSSI + regnr);
 290                 if (retval < 0)
 291                         goto end;
 292         }
 293
 294         /* get rds blocks */
 295         if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
 296                 /* No RDS group ready, better luck next time */
 297                 goto end;
 298
 299         for (blocknum = 0; blocknum < 4; blocknum++) {
 300                 switch (blocknum) {
 301                 default:
 302                         bler = (radio->registers[STATUSRSSI] &
 303                                         STATUSRSSI_BLERA) >> 9;
 304                         rds = radio->registers[RDSA];
 305                         break;
 306                 case 1:
 307                         bler = (radio->registers[READCHAN] &
 308                                         READCHAN_BLERB) >> 14;
 309                         rds = radio->registers[RDSB];
 310                         break;
 311                 case 2:
 312                         bler = (radio->registers[READCHAN] &
 313                                         READCHAN_BLERC) >> 12;
 314                         rds = radio->registers[RDSC];
 315                         break;
 316                 case 3:
 317                         bler = (radio->registers[READCHAN] &
 318                                         READCHAN_BLERD) >> 10;
 319                         rds = radio->registers[RDSD];
 320                         break;
 321                 };
 322
 323                 /* Fill the V4L2 RDS buffer */
 324                 put_unaligned_le16(rds, &tmpbuf);
 325                 tmpbuf[2] = blocknum;           /* offset name */
 326                 tmpbuf[2] |= blocknum << 3;     /* received offset */
 327                 if (bler > max_rds_errors)
 328                         tmpbuf[2] |= 0x80;      /* uncorrectable errors */
 329                 else if (bler > 0)
 330                         tmpbuf[2] |= 0x40;      /* corrected error(s) */
 331
 332                 /* copy RDS block to internal buffer */
 333                 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
 334                 radio->wr_index += 3;
 335
 336                 /* wrap write pointer */
 337                 if (radio->wr_index >= radio->buf_size)
 338                         radio->wr_index = 0;
 339
 340                 /* check for overflow */
 341                 if (radio->wr_index == radio->rd_index) {
 342                         /* increment and wrap read pointer */
 343                         radio->rd_index += 3;
 344                         if (radio->rd_index >= radio->buf_size)
 345                                 radio->rd_index = 0;
 346                 }
 347         }
 348
 349         if (radio->wr_index != radio->rd_index)
 350                 wake_up_interruptible(&radio->read_queue);
 351
 352 end:
 353         return IRQ_HANDLED;
 354 }
 355
 356
 357 /*
 358  * si470x_i2c_probe - probe for the device
 359  */
 360 static int __devinit si470x_i2c_probe(struct i2c_client *client,
 361                 const struct i2c_device_id *id)
 362 {
 363         struct si470x_device *radio;
 364         int retval = 0;
 365         unsigned char version_warning = 0;
 366
 367         /* private data allocation and initialization */
 368         radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 369         if (!radio) {
 370                 retval = -ENOMEM;
 371                 goto err_initial;
 372         }
 373
 374         radio->users = 0;
 375         radio->client = client;
 376         mutex_init(&radio->lock);
 377
 378         /* video device allocation and initialization */
 379         radio->videodev = video_device_alloc();
 380         if (!radio->videodev) {
 381                 retval = -ENOMEM;
 382                 goto err_radio;
 383         }
 384         memcpy(radio->videodev, &si470x_viddev_template,
 385                         sizeof(si470x_viddev_template));
 386         video_set_drvdata(radio->videodev, radio);
 387
 388         /* power up : need 110ms */
 389         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 390         if (si470x_set_register(radio, POWERCFG) < 0) {
 391                 retval = -EIO;
 392                 goto err_video;
 393         }
 394         msleep(110);
 395
 396         /* get device and chip versions */
 397         if (si470x_get_all_registers(radio) < 0) {
 398                 retval = -EIO;
 399                 goto err_video;
 400         }
 401         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 402                         radio->registers[DEVICEID], radio->registers[CHIPID]);
 403         if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 404                 dev_warn(&client->dev,
 405                         "This driver is known to work with "
 406                         "firmware version %hu,\n", RADIO_FW_VERSION);
 407                 dev_warn(&client->dev,
 408                         "but the device has firmware version %hu.\n",
 409                         radio->registers[CHIPID] & CHIPID_FIRMWARE);
 410                 version_warning = 1;
 411         }
 412
 413         /* give out version warning */
 414         if (version_warning == 1) {
 415                 dev_warn(&client->dev,
 416                         "If you have some trouble using this driver,\n");
 417                 dev_warn(&client->dev,
 418                         "please report to V4L ML at "
 419                         "linux-media@vger.kernel.org\n");
 420         }
 421
 422         /* set initial frequency */
 423         si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 424
 425         /* rds buffer allocation */
 426         radio->buf_size = rds_buf * 3;
 427         radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
 428         if (!radio->buffer) {
 429                 retval = -EIO;
 430                 goto err_video;
 431         }
 432
 433         /* rds buffer configuration */
 434         radio->wr_index = 0;
 435         radio->rd_index = 0;
 436         init_waitqueue_head(&radio->read_queue);
 437
 438         /* mark Seek/Tune Complete Interrupt enabled */
 439         radio->stci_enabled = true;
 440         init_completion(&radio->completion);
 441
 442         retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt,
 443                         IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
 444         if (retval) {
 445                 dev_err(&client->dev, "Failed to register interrupt\n");
 446                 goto err_rds;
 447         }
 448
 449         /* register video device */
 450         retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
 451                         radio_nr);
 452         if (retval) {
 453                 dev_warn(&client->dev, "Could not register video device\n");
 454                 goto err_all;
 455         }
 456         i2c_set_clientdata(client, radio);
 457
 458         return 0;
 459 err_all:
 460         free_irq(client->irq, radio);
 461 err_rds:
 462         kfree(radio->buffer);
 463 err_video:
 464         video_device_release(radio->videodev);
 465 err_radio:
 466         kfree(radio);
 467 err_initial:
 468         return retval;
 469 }
 470
 471
 472 /*
 473  * si470x_i2c_remove - remove the device
 474  */
 475 static __devexit int si470x_i2c_remove(struct i2c_client *client)
 476 {
 477         struct si470x_device *radio = i2c_get_clientdata(client);
 478
 479         free_irq(client->irq, radio);
 480         video_unregister_device(radio->videodev);
 481         kfree(radio);
 482
 483         return 0;
 484 }
 485
 486
 487 #ifdef CONFIG_PM
 488 /*
 489  * si470x_i2c_suspend - suspend the device
 490  */
 491 static int si470x_i2c_suspend(struct device *dev)
 492 {
 493         struct i2c_client *client = to_i2c_client(dev);
 494         struct si470x_device *radio = i2c_get_clientdata(client);
 495
 496         /* power down */
 497         radio->registers[POWERCFG] |= POWERCFG_DISABLE;
 498         if (si470x_set_register(radio, POWERCFG) < 0)
 499                 return -EIO;
 500
 501         return 0;
 502 }
 503
 504
 505 /*
 506  * si470x_i2c_resume - resume the device
 507  */
 508 static int si470x_i2c_resume(struct device *dev)
 509 {
 510         struct i2c_client *client = to_i2c_client(dev);
 511         struct si470x_device *radio = i2c_get_clientdata(client);
 512
 513         /* power up : need 110ms */
 514         radio->registers[POWERCFG] |= POWERCFG_ENABLE;
 515         if (si470x_set_register(radio, POWERCFG) < 0)
 516                 return -EIO;
 517         msleep(110);
 518
 519         return 0;
 520 }
 521
 522 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 523 #endif
 524
 525
 526 /*
 527  * si470x_i2c_driver - i2c driver interface
 528  */
 529 static struct i2c_driver si470x_i2c_driver = {
 530         .driver = {
 531                 .name           = "si470x",
 532                 .owner          = THIS_MODULE,
 533 #ifdef CONFIG_PM
 534                 .pm             = &si470x_i2c_pm,
 535 #endif
 536         },
 537         .probe                  = si470x_i2c_probe,
 538         .remove                 = __devexit_p(si470x_i2c_remove),
 539         .id_table               = si470x_i2c_id,
 540 };
 541
 542
 543
 544 /**************************************************************************
 545  * Module Interface
 546  **************************************************************************/
 547
 548 /*
 549  * si470x_i2c_init - module init
 550  */
 551 static int __init si470x_i2c_init(void)
 552 {
 553         printk(KERN_INFO DRIVER_DESC ", Version " DRIVER_VERSION "\n");
 554         return i2c_add_driver(&si470x_i2c_driver);
 555 }
 556
 557
 558 /*
 559  * si470x_i2c_exit - module exit
 560  */
 561 static void __exit si470x_i2c_exit(void)
 562 {
 563         i2c_del_driver(&si470x_i2c_driver);
 564 }
 565
 566
 567 module_init(si470x_i2c_init);
 568 module_exit(si470x_i2c_exit);
 569
 570 MODULE_LICENSE("GPL");
 571 MODULE_AUTHOR(DRIVER_AUTHOR);
 572 MODULE_DESCRIPTION(DRIVER_DESC);
 573 MODULE_VERSION(DRIVER_VERSION);