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                 {
 102                         .addr = radio->client->addr,
 103                         .flags = I2C_M_RD,
 104                         .len = sizeof(u16) * READ_REG_NUM,
 105                         .buf = (void *)buf
 106                 },
 107         };
 108
 109         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 110                 return -EIO;
 111
 112         radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
 113
 114         return 0;
 115 }
 116
 117
 118 /*
 119  * si470x_set_register - write register
 120  */
 121 int si470x_set_register(struct si470x_device *radio, int regnr)
 122 {
 123         int i;
 124         u16 buf[WRITE_REG_NUM];
 125         struct i2c_msg msgs[1] = {
 126                 {
 127                         .addr = radio->client->addr,
 128                         .len = sizeof(u16) * WRITE_REG_NUM,
 129                         .buf = (void *)buf
 130                 },
 131         };
 132
 133         for (i = 0; i < WRITE_REG_NUM; i++)
 134                 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
 135
 136         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 137                 return -EIO;
 138
 139         return 0;
 140 }
 141
 142
 143
 144 /**************************************************************************
 145  * General Driver Functions - ENTIRE REGISTERS
 146  **************************************************************************/
 147
 148 /*
 149  * si470x_get_all_registers - read entire registers
 150  */
 151 static int si470x_get_all_registers(struct si470x_device *radio)
 152 {
 153         int i;
 154         u16 buf[READ_REG_NUM];
 155         struct i2c_msg msgs[1] = {
 156                 {
 157                         .addr = radio->client->addr,
 158                         .flags = I2C_M_RD,
 159                         .len = sizeof(u16) * READ_REG_NUM,
 160                         .buf = (void *)buf
 161                 },
 162         };
 163
 164         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 165                 return -EIO;
 166
 167         for (i = 0; i < READ_REG_NUM; i++)
 168                 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
 169
 170         return 0;
 171 }
 172
 173
 174
 175 /**************************************************************************
 176  * File Operations Interface
 177  **************************************************************************/
 178
 179 /*
 180  * si470x_fops_open - file open
 181  */
 182 int si470x_fops_open(struct file *file)
 183 {
 184         struct si470x_device *radio = video_drvdata(file);
 185         int retval = v4l2_fh_open(file);
 186
 187         if (retval)
 188                 return retval;
 189
 190         if (v4l2_fh_is_singular_file(file)) {
 191                 /* start radio */
 192                 retval = si470x_start(radio);
 193                 if (retval < 0)
 194                         goto done;
 195
 196                 /* enable RDS / STC interrupt */
 197                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
 198                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
 199                 radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
 200                 radio->registers[SYSCONFIG1] |= 0x1 << 2;
 201                 retval = si470x_set_register(radio, SYSCONFIG1);
 202         }
 203
 204 done:
 205         if (retval)
 206                 v4l2_fh_release(file);
 207         return retval;
 208 }
 209
 210
 211 /*
 212  * si470x_fops_release - file release
 213  */
 214 int si470x_fops_release(struct file *file)
 215 {
 216         struct si470x_device *radio = video_drvdata(file);
 217
 218         if (v4l2_fh_is_singular_file(file))
 219                 /* stop radio */
 220                 si470x_stop(radio);
 221
 222         return v4l2_fh_release(file);
 223 }
 224
 225
 226
 227 /**************************************************************************
 228  * Video4Linux Interface
 229  **************************************************************************/
 230
 231 /*
 232  * si470x_vidioc_querycap - query device capabilities
 233  */
 234 int si470x_vidioc_querycap(struct file *file, void *priv,
 235                 struct v4l2_capability *capability)
 236 {
 237         strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
 238         strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
 239         capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
 240                 V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
 241         capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
 242
 243         return 0;
 244 }
 245
 246
 247
 248 /**************************************************************************
 249  * I2C Interface
 250  **************************************************************************/
 251
 252 /*
 253  * si470x_i2c_interrupt - interrupt handler
 254  */
 255 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
 256 {
 257         struct si470x_device *radio = dev_id;
 258         unsigned char regnr;
 259         unsigned char blocknum;
 260         unsigned short bler; /* rds block errors */
 261         unsigned short rds;
 262         unsigned char tmpbuf[3];
 263         int retval = 0;
 264
 265         /* check Seek/Tune Complete */
 266         retval = si470x_get_register(radio, STATUSRSSI);
 267         if (retval < 0)
 268                 goto end;
 269
 270         if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
 271                 complete(&radio->completion);
 272
 273         /* safety checks */
 274         if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
 275                 goto end;
 276
 277         /* Update RDS registers */
 278         for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
 279                 retval = si470x_get_register(radio, STATUSRSSI + regnr);
 280                 if (retval < 0)
 281                         goto end;
 282         }
 283
 284         /* get rds blocks */
 285         if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
 286                 /* No RDS group ready, better luck next time */
 287                 goto end;
 288
 289         for (blocknum = 0; blocknum < 4; blocknum++) {
 290                 switch (blocknum) {
 291                 default:
 292                         bler = (radio->registers[STATUSRSSI] &
 293                                         STATUSRSSI_BLERA) >> 9;
 294                         rds = radio->registers[RDSA];
 295                         break;
 296                 case 1:
 297                         bler = (radio->registers[READCHAN] &
 298                                         READCHAN_BLERB) >> 14;
 299                         rds = radio->registers[RDSB];
 300                         break;
 301                 case 2:
 302                         bler = (radio->registers[READCHAN] &
 303                                         READCHAN_BLERC) >> 12;
 304                         rds = radio->registers[RDSC];
 305                         break;
 306                 case 3:
 307                         bler = (radio->registers[READCHAN] &
 308                                         READCHAN_BLERD) >> 10;
 309                         rds = radio->registers[RDSD];
 310                         break;
 311                 }
 312
 313                 /* Fill the V4L2 RDS buffer */
 314                 put_unaligned_le16(rds, &tmpbuf);
 315                 tmpbuf[2] = blocknum;           /* offset name */
 316                 tmpbuf[2] |= blocknum << 3;     /* received offset */
 317                 if (bler > max_rds_errors)
 318                         tmpbuf[2] |= 0x80;      /* uncorrectable errors */
 319                 else if (bler > 0)
 320                         tmpbuf[2] |= 0x40;      /* corrected error(s) */
 321
 322                 /* copy RDS block to internal buffer */
 323                 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
 324                 radio->wr_index += 3;
 325
 326                 /* wrap write pointer */
 327                 if (radio->wr_index >= radio->buf_size)
 328                         radio->wr_index = 0;
 329
 330                 /* check for overflow */
 331                 if (radio->wr_index == radio->rd_index) {
 332                         /* increment and wrap read pointer */
 333                         radio->rd_index += 3;
 334                         if (radio->rd_index >= radio->buf_size)
 335                                 radio->rd_index = 0;
 336                 }
 337         }
 338
 339         if (radio->wr_index != radio->rd_index)
 340                 wake_up_interruptible(&radio->read_queue);
 341
 342 end:
 343         return IRQ_HANDLED;
 344 }
 345
 346
 347 /*
 348  * si470x_i2c_probe - probe for the device
 349  */
 350 static int si470x_i2c_probe(struct i2c_client *client,
 351                             const struct i2c_device_id *id)
 352 {
 353         struct si470x_device *radio;
 354         int retval = 0;
 355         unsigned char version_warning = 0;
 356
 357         /* private data allocation and initialization */
 358         radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 359         if (!radio) {
 360                 retval = -ENOMEM;
 361                 goto err_initial;
 362         }
 363
 364         radio->client = client;
 365         radio->band = 1; /* Default to 76 - 108 MHz */
 366         mutex_init(&radio->lock);
 367         init_completion(&radio->completion);
 368
 369         /* video device initialization */
 370         radio->videodev = si470x_viddev_template;
 371         video_set_drvdata(&radio->videodev, radio);
 372
 373         /* power up : need 110ms */
 374         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 375         if (si470x_set_register(radio, POWERCFG) < 0) {
 376                 retval = -EIO;
 377                 goto err_radio;
 378         }
 379         msleep(110);
 380
 381         /* get device and chip versions */
 382         if (si470x_get_all_registers(radio) < 0) {
 383                 retval = -EIO;
 384                 goto err_radio;
 385         }
 386         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 387                         radio->registers[DEVICEID], radio->registers[SI_CHIPID]);
 388         if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 389                 dev_warn(&client->dev,
 390                         "This driver is known to work with "
 391                         "firmware version %hu,\n", RADIO_FW_VERSION);
 392                 dev_warn(&client->dev,
 393                         "but the device has firmware version %hu.\n",
 394                         radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE);
 395                 version_warning = 1;
 396         }
 397
 398         /* give out version warning */
 399         if (version_warning == 1) {
 400                 dev_warn(&client->dev,
 401                         "If you have some trouble using this driver,\n");
 402                 dev_warn(&client->dev,
 403                         "please report to V4L ML at "
 404                         "linux-media@vger.kernel.org\n");
 405         }
 406
 407         /* set initial frequency */
 408         si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 409
 410         /* rds buffer allocation */
 411         radio->buf_size = rds_buf * 3;
 412         radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
 413         if (!radio->buffer) {
 414                 retval = -EIO;
 415                 goto err_radio;
 416         }
 417
 418         /* rds buffer configuration */
 419         radio->wr_index = 0;
 420         radio->rd_index = 0;
 421         init_waitqueue_head(&radio->read_queue);
 422
 423         retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt,
 424                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT, DRIVER_NAME,
 425                         radio);
 426         if (retval) {
 427                 dev_err(&client->dev, "Failed to register interrupt\n");
 428                 goto err_rds;
 429         }
 430
 431         /* register video device */
 432         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
 433                         radio_nr);
 434         if (retval) {
 435                 dev_warn(&client->dev, "Could not register video device\n");
 436                 goto err_all;
 437         }
 438         i2c_set_clientdata(client, radio);
 439
 440         return 0;
 441 err_all:
 442         free_irq(client->irq, radio);
 443 err_rds:
 444         kfree(radio->buffer);
 445 err_radio:
 446         kfree(radio);
 447 err_initial:
 448         return retval;
 449 }
 450
 451
 452 /*
 453  * si470x_i2c_remove - remove the device
 454  */
 455 static int si470x_i2c_remove(struct i2c_client *client)
 456 {
 457         struct si470x_device *radio = i2c_get_clientdata(client);
 458
 459         free_irq(client->irq, radio);
 460         video_unregister_device(&radio->videodev);
 461         kfree(radio);
 462
 463         return 0;
 464 }
 465
 466
 467 #ifdef CONFIG_PM_SLEEP
 468 /*
 469  * si470x_i2c_suspend - suspend the device
 470  */
 471 static int si470x_i2c_suspend(struct device *dev)
 472 {
 473         struct i2c_client *client = to_i2c_client(dev);
 474         struct si470x_device *radio = i2c_get_clientdata(client);
 475
 476         /* power down */
 477         radio->registers[POWERCFG] |= POWERCFG_DISABLE;
 478         if (si470x_set_register(radio, POWERCFG) < 0)
 479                 return -EIO;
 480
 481         return 0;
 482 }
 483
 484
 485 /*
 486  * si470x_i2c_resume - resume the device
 487  */
 488 static int si470x_i2c_resume(struct device *dev)
 489 {
 490         struct i2c_client *client = to_i2c_client(dev);
 491         struct si470x_device *radio = i2c_get_clientdata(client);
 492
 493         /* power up : need 110ms */
 494         radio->registers[POWERCFG] |= POWERCFG_ENABLE;
 495         if (si470x_set_register(radio, POWERCFG) < 0)
 496                 return -EIO;
 497         msleep(110);
 498
 499         return 0;
 500 }
 501
 502 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 503 #endif
 504
 505
 506 /*
 507  * si470x_i2c_driver - i2c driver interface
 508  */
 509 static struct i2c_driver si470x_i2c_driver = {
 510         .driver = {
 511                 .name           = "si470x",
 512 #ifdef CONFIG_PM_SLEEP
 513                 .pm             = &si470x_i2c_pm,
 514 #endif
 515         },
 516         .probe                  = si470x_i2c_probe,
 517         .remove                 = si470x_i2c_remove,
 518         .id_table               = si470x_i2c_id,
 519 };
 520
 521 module_i2c_driver(si470x_i2c_driver);
 522
 523 MODULE_LICENSE("GPL");
 524 MODULE_AUTHOR(DRIVER_AUTHOR);
 525 MODULE_DESCRIPTION(DRIVER_DESC);
 526 MODULE_VERSION(DRIVER_VERSION);