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
  20
  21 /* driver definitions */
  22 #define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>";
  23 #define DRIVER_CARD "Silicon Labs Si470x FM Radio"
  24 #define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
  25 #define DRIVER_VERSION "1.0.2"
  26
  27 /* kernel includes */
  28 #include <linux/i2c.h>
  29 #include <linux/slab.h>
  30 #include <linux/delay.h>
  31 #include <linux/interrupt.h>
  32
  33 #include "radio-si470x.h"
  34
  35
  36 /* I2C Device ID List */
  37 static const struct i2c_device_id si470x_i2c_id[] = {
  38         /* Generic Entry */
  39         { "si470x", 0 },
  40         /* Terminating entry */
  41         { }
  42 };
  43 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
  44
  45
  46 /**************************************************************************
  47  * Module Parameters
  48  **************************************************************************/
  49
  50 /* Radio Nr */
  51 static int radio_nr = -1;
  52 module_param(radio_nr, int, 0444);
  53 MODULE_PARM_DESC(radio_nr, "Radio Nr");
  54
  55 /* RDS buffer blocks */
  56 static unsigned int rds_buf = 100;
  57 module_param(rds_buf, uint, 0444);
  58 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
  59
  60 /* RDS maximum block errors */
  61 static unsigned short max_rds_errors = 1;
  62 /* 0 means   0  errors requiring correction */
  63 /* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
  64 /* 2 means 3-5  errors requiring correction */
  65 /* 3 means   6+ errors or errors in checkword, correction not possible */
  66 module_param(max_rds_errors, ushort, 0644);
  67 MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
  68
  69
  70
  71 /**************************************************************************
  72  * I2C Definitions
  73  **************************************************************************/
  74
  75 /* Write starts with the upper byte of register 0x02 */
  76 #define WRITE_REG_NUM           8
  77 #define WRITE_INDEX(i)          (i + 0x02)
  78
  79 /* Read starts with the upper byte of register 0x0a */
  80 #define READ_REG_NUM            RADIO_REGISTER_NUM
  81 #define READ_INDEX(i)           ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
  82
  83
  84
  85 /**************************************************************************
  86  * General Driver Functions - REGISTERs
  87  **************************************************************************/
  88
  89 /*
  90  * si470x_get_register - read register
  91  */
  92 static int si470x_get_register(struct si470x_device *radio, int regnr)
  93 {
  94         __be16 buf[READ_REG_NUM];
  95         struct i2c_msg msgs[1] = {
  96                 {
  97                         .addr = radio->client->addr,
  98                         .flags = I2C_M_RD,
  99                         .len = sizeof(u16) * READ_REG_NUM,
 100                         .buf = (void *)buf
 101                 },
 102         };
 103
 104         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 105                 return -EIO;
 106
 107         radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
 108
 109         return 0;
 110 }
 111
 112
 113 /*
 114  * si470x_set_register - write register
 115  */
 116 static int si470x_set_register(struct si470x_device *radio, int regnr)
 117 {
 118         int i;
 119         __be16 buf[WRITE_REG_NUM];
 120         struct i2c_msg msgs[1] = {
 121                 {
 122                         .addr = radio->client->addr,
 123                         .len = sizeof(u16) * WRITE_REG_NUM,
 124                         .buf = (void *)buf
 125                 },
 126         };
 127
 128         for (i = 0; i < WRITE_REG_NUM; i++)
 129                 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
 130
 131         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 132                 return -EIO;
 133
 134         return 0;
 135 }
 136
 137
 138
 139 /**************************************************************************
 140  * General Driver Functions - ENTIRE REGISTERS
 141  **************************************************************************/
 142
 143 /*
 144  * si470x_get_all_registers - read entire registers
 145  */
 146 static int si470x_get_all_registers(struct si470x_device *radio)
 147 {
 148         int i;
 149         __be16 buf[READ_REG_NUM];
 150         struct i2c_msg msgs[1] = {
 151                 {
 152                         .addr = radio->client->addr,
 153                         .flags = I2C_M_RD,
 154                         .len = sizeof(u16) * READ_REG_NUM,
 155                         .buf = (void *)buf
 156                 },
 157         };
 158
 159         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 160                 return -EIO;
 161
 162         for (i = 0; i < READ_REG_NUM; i++)
 163                 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
 164
 165         return 0;
 166 }
 167
 168
 169
 170 /**************************************************************************
 171  * File Operations Interface
 172  **************************************************************************/
 173
 174 /*
 175  * si470x_fops_open - file open
 176  */
 177 static int si470x_fops_open(struct file *file)
 178 {
 179         struct si470x_device *radio = video_drvdata(file);
 180         int retval = v4l2_fh_open(file);
 181
 182         if (retval)
 183                 return retval;
 184
 185         if (v4l2_fh_is_singular_file(file)) {
 186                 /* start radio */
 187                 retval = si470x_start(radio);
 188                 if (retval < 0)
 189                         goto done;
 190
 191                 /* enable RDS / STC interrupt */
 192                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
 193                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
 194                 radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
 195                 radio->registers[SYSCONFIG1] |= 0x1 << 2;
 196                 retval = si470x_set_register(radio, SYSCONFIG1);
 197         }
 198
 199 done:
 200         if (retval)
 201                 v4l2_fh_release(file);
 202         return retval;
 203 }
 204
 205
 206 /*
 207  * si470x_fops_release - file release
 208  */
 209 static int si470x_fops_release(struct file *file)
 210 {
 211         struct si470x_device *radio = video_drvdata(file);
 212
 213         if (v4l2_fh_is_singular_file(file))
 214                 /* stop radio */
 215                 si470x_stop(radio);
 216
 217         return v4l2_fh_release(file);
 218 }
 219
 220
 221
 222 /**************************************************************************
 223  * Video4Linux Interface
 224  **************************************************************************/
 225
 226 /*
 227  * si470x_vidioc_querycap - query device capabilities
 228  */
 229 static int si470x_vidioc_querycap(struct file *file, void *priv,
 230                                   struct v4l2_capability *capability)
 231 {
 232         strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
 233         strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
 234         capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
 235                 V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
 236         capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
 237
 238         return 0;
 239 }
 240
 241
 242
 243 /**************************************************************************
 244  * I2C Interface
 245  **************************************************************************/
 246
 247 /*
 248  * si470x_i2c_interrupt - interrupt handler
 249  */
 250 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
 251 {
 252         struct si470x_device *radio = dev_id;
 253         unsigned char regnr;
 254         unsigned char blocknum;
 255         unsigned short bler; /* rds block errors */
 256         unsigned short rds;
 257         unsigned char tmpbuf[3];
 258         int retval = 0;
 259
 260         /* check Seek/Tune Complete */
 261         retval = si470x_get_register(radio, STATUSRSSI);
 262         if (retval < 0)
 263                 goto end;
 264
 265         if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
 266                 complete(&radio->completion);
 267
 268         /* safety checks */
 269         if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
 270                 goto end;
 271
 272         /* Update RDS registers */
 273         for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
 274                 retval = si470x_get_register(radio, STATUSRSSI + regnr);
 275                 if (retval < 0)
 276                         goto end;
 277         }
 278
 279         /* get rds blocks */
 280         if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
 281                 /* No RDS group ready, better luck next time */
 282                 goto end;
 283
 284         for (blocknum = 0; blocknum < 4; blocknum++) {
 285                 switch (blocknum) {
 286                 default:
 287                         bler = (radio->registers[STATUSRSSI] &
 288                                         STATUSRSSI_BLERA) >> 9;
 289                         rds = radio->registers[RDSA];
 290                         break;
 291                 case 1:
 292                         bler = (radio->registers[READCHAN] &
 293                                         READCHAN_BLERB) >> 14;
 294                         rds = radio->registers[RDSB];
 295                         break;
 296                 case 2:
 297                         bler = (radio->registers[READCHAN] &
 298                                         READCHAN_BLERC) >> 12;
 299                         rds = radio->registers[RDSC];
 300                         break;
 301                 case 3:
 302                         bler = (radio->registers[READCHAN] &
 303                                         READCHAN_BLERD) >> 10;
 304                         rds = radio->registers[RDSD];
 305                         break;
 306                 }
 307
 308                 /* Fill the V4L2 RDS buffer */
 309                 put_unaligned_le16(rds, &tmpbuf);
 310                 tmpbuf[2] = blocknum;           /* offset name */
 311                 tmpbuf[2] |= blocknum << 3;     /* received offset */
 312                 if (bler > max_rds_errors)
 313                         tmpbuf[2] |= 0x80;      /* uncorrectable errors */
 314                 else if (bler > 0)
 315                         tmpbuf[2] |= 0x40;      /* corrected error(s) */
 316
 317                 /* copy RDS block to internal buffer */
 318                 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
 319                 radio->wr_index += 3;
 320
 321                 /* wrap write pointer */
 322                 if (radio->wr_index >= radio->buf_size)
 323                         radio->wr_index = 0;
 324
 325                 /* check for overflow */
 326                 if (radio->wr_index == radio->rd_index) {
 327                         /* increment and wrap read pointer */
 328                         radio->rd_index += 3;
 329                         if (radio->rd_index >= radio->buf_size)
 330                                 radio->rd_index = 0;
 331                 }
 332         }
 333
 334         if (radio->wr_index != radio->rd_index)
 335                 wake_up_interruptible(&radio->read_queue);
 336
 337 end:
 338         return IRQ_HANDLED;
 339 }
 340
 341
 342 /*
 343  * si470x_i2c_probe - probe for the device
 344  */
 345 static int si470x_i2c_probe(struct i2c_client *client,
 346                             const struct i2c_device_id *id)
 347 {
 348         struct si470x_device *radio;
 349         int retval = 0;
 350         unsigned char version_warning = 0;
 351
 352         /* private data allocation and initialization */
 353         radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 354         if (!radio) {
 355                 retval = -ENOMEM;
 356                 goto err_initial;
 357         }
 358
 359         radio->client = client;
 360         radio->band = 1; /* Default to 76 - 108 MHz */
 361         mutex_init(&radio->lock);
 362         init_completion(&radio->completion);
 363
 364         radio->get_register = si470x_get_register;
 365         radio->set_register = si470x_set_register;
 366         radio->fops_open = si470x_fops_open;
 367         radio->fops_release = si470x_fops_release;
 368         radio->vidioc_querycap = si470x_vidioc_querycap;
 369
 370         retval = v4l2_device_register(&client->dev, &radio->v4l2_dev);
 371         if (retval < 0) {
 372                 dev_err(&client->dev, "couldn't register v4l2_device\n");
 373                 goto err_radio;
 374         }
 375
 376         v4l2_ctrl_handler_init(&radio->hdl, 2);
 377         v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
 378                         V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
 379         v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
 380                         V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 15);
 381         if (radio->hdl.error) {
 382                 retval = radio->hdl.error;
 383                 dev_err(&client->dev, "couldn't register control\n");
 384                 goto err_all;
 385         }
 386
 387         /* video device initialization */
 388         radio->videodev = si470x_viddev_template;
 389         radio->videodev.ctrl_handler = &radio->hdl;
 390         radio->videodev.lock = &radio->lock;
 391         radio->videodev.v4l2_dev = &radio->v4l2_dev;
 392         radio->videodev.release = video_device_release_empty;
 393         video_set_drvdata(&radio->videodev, radio);
 394
 395         /* power up : need 110ms */
 396         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 397         if (si470x_set_register(radio, POWERCFG) < 0) {
 398                 retval = -EIO;
 399                 goto err_ctrl;
 400         }
 401         msleep(110);
 402
 403         /* get device and chip versions */
 404         if (si470x_get_all_registers(radio) < 0) {
 405                 retval = -EIO;
 406                 goto err_ctrl;
 407         }
 408         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 409                         radio->registers[DEVICEID], radio->registers[SI_CHIPID]);
 410         if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 411                 dev_warn(&client->dev,
 412                         "This driver is known to work with firmware version %hu,\n",
 413                         RADIO_FW_VERSION);
 414                 dev_warn(&client->dev,
 415                         "but the device has firmware version %hu.\n",
 416                         radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE);
 417                 version_warning = 1;
 418         }
 419
 420         /* give out version warning */
 421         if (version_warning == 1) {
 422                 dev_warn(&client->dev,
 423                         "If you have some trouble using this driver,\n");
 424                 dev_warn(&client->dev,
 425                         "please report to V4L ML at 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_ctrl;
 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_threaded_irq(client->irq, NULL, si470x_i2c_interrupt,
 445                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT, DRIVER_NAME,
 446                         radio);
 447         if (retval) {
 448                 dev_err(&client->dev, "Failed to register interrupt\n");
 449                 goto err_rds;
 450         }
 451
 452         /* register video device */
 453         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
 454                         radio_nr);
 455         if (retval) {
 456                 dev_warn(&client->dev, "Could not register video device\n");
 457                 goto err_all;
 458         }
 459         i2c_set_clientdata(client, radio);
 460
 461         return 0;
 462 err_all:
 463         free_irq(client->irq, radio);
 464 err_rds:
 465         kfree(radio->buffer);
 466 err_ctrl:
 467         v4l2_ctrl_handler_free(&radio->hdl);
 468         v4l2_device_unregister(&radio->v4l2_dev);
 469 err_radio:
 470         kfree(radio);
 471 err_initial:
 472         return retval;
 473 }
 474
 475
 476 /*
 477  * si470x_i2c_remove - remove the device
 478  */
 479 static int si470x_i2c_remove(struct i2c_client *client)
 480 {
 481         struct si470x_device *radio = i2c_get_clientdata(client);
 482
 483         free_irq(client->irq, radio);
 484         video_unregister_device(&radio->videodev);
 485
 486         v4l2_ctrl_handler_free(&radio->hdl);
 487         v4l2_device_unregister(&radio->v4l2_dev);
 488         kfree(radio);
 489         return 0;
 490 }
 491
 492
 493 #ifdef CONFIG_PM_SLEEP
 494 /*
 495  * si470x_i2c_suspend - suspend the device
 496  */
 497 static int si470x_i2c_suspend(struct device *dev)
 498 {
 499         struct i2c_client *client = to_i2c_client(dev);
 500         struct si470x_device *radio = i2c_get_clientdata(client);
 501
 502         /* power down */
 503         radio->registers[POWERCFG] |= POWERCFG_DISABLE;
 504         if (si470x_set_register(radio, POWERCFG) < 0)
 505                 return -EIO;
 506
 507         return 0;
 508 }
 509
 510
 511 /*
 512  * si470x_i2c_resume - resume the device
 513  */
 514 static int si470x_i2c_resume(struct device *dev)
 515 {
 516         struct i2c_client *client = to_i2c_client(dev);
 517         struct si470x_device *radio = i2c_get_clientdata(client);
 518
 519         /* power up : need 110ms */
 520         radio->registers[POWERCFG] |= POWERCFG_ENABLE;
 521         if (si470x_set_register(radio, POWERCFG) < 0)
 522                 return -EIO;
 523         msleep(110);
 524
 525         return 0;
 526 }
 527
 528 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 529 #endif
 530
 531
 532 /*
 533  * si470x_i2c_driver - i2c driver interface
 534  */
 535 static struct i2c_driver si470x_i2c_driver = {
 536         .driver = {
 537                 .name           = "si470x",
 538 #ifdef CONFIG_PM_SLEEP
 539                 .pm             = &si470x_i2c_pm,
 540 #endif
 541         },
 542         .probe                  = si470x_i2c_probe,
 543         .remove                 = si470x_i2c_remove,
 544         .id_table               = si470x_i2c_id,
 545 };
 546
 547 module_i2c_driver(si470x_i2c_driver);
 548
 549 MODULE_LICENSE("GPL");
 550 MODULE_AUTHOR(DRIVER_AUTHOR);
 551 MODULE_DESCRIPTION(DRIVER_DESC);
 552 MODULE_VERSION(DRIVER_VERSION);