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 Receiver"
  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 /**************************************************************************
  48  * Module Parameters
  49  **************************************************************************/
  50
  51 /* Radio Nr */
  52 static int radio_nr = -1;
  53 module_param(radio_nr, int, 0444);
  54 MODULE_PARM_DESC(radio_nr, "Radio Nr");
  55
  56 /* RDS buffer blocks */
  57 static unsigned int rds_buf = 100;
  58 module_param(rds_buf, uint, 0444);
  59 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
  60
  61 /* RDS maximum block errors */
  62 static unsigned short max_rds_errors = 1;
  63 /* 0 means   0  errors requiring correction */
  64 /* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
  65 /* 2 means 3-5  errors requiring correction */
  66 /* 3 means   6+ errors or errors in checkword, correction not possible */
  67 module_param(max_rds_errors, ushort, 0644);
  68 MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
  69
  70
  71
  72 /**************************************************************************
  73  * I2C Definitions
  74  **************************************************************************/
  75
  76 /* Write starts with the upper byte of register 0x02 */
  77 #define WRITE_REG_NUM           8
  78 #define WRITE_INDEX(i)          (i + 0x02)
  79
  80 /* Read starts with the upper byte of register 0x0a */
  81 #define READ_REG_NUM            RADIO_REGISTER_NUM
  82 #define READ_INDEX(i)           ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
  83
  84
  85
  86 /**************************************************************************
  87  * General Driver Functions - REGISTERs
  88  **************************************************************************/
  89
  90 /*
  91  * si470x_get_register - read register
  92  */
  93 int si470x_get_register(struct si470x_device *radio, int regnr)
  94 {
  95         u16 buf[READ_REG_NUM];
  96         struct i2c_msg msgs[1] = {
  97                 {
  98                         .addr = radio->client->addr,
  99                         .flags = I2C_M_RD,
 100                         .len = sizeof(u16) * READ_REG_NUM,
 101                         .buf = (void *)buf
 102                 },
 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                 {
 123                         .addr = radio->client->addr,
 124                         .len = sizeof(u16) * WRITE_REG_NUM,
 125                         .buf = (void *)buf
 126                 },
 127         };
 128
 129         for (i = 0; i < WRITE_REG_NUM; i++)
 130                 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
 131
 132         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 133                 return -EIO;
 134
 135         return 0;
 136 }
 137
 138
 139
 140 /**************************************************************************
 141  * General Driver Functions - ENTIRE REGISTERS
 142  **************************************************************************/
 143
 144 /*
 145  * si470x_get_all_registers - read entire registers
 146  */
 147 static int si470x_get_all_registers(struct si470x_device *radio)
 148 {
 149         int i;
 150         u16 buf[READ_REG_NUM];
 151         struct i2c_msg msgs[1] = {
 152                 {
 153                         .addr = radio->client->addr,
 154                         .flags = I2C_M_RD,
 155                         .len = sizeof(u16) * READ_REG_NUM,
 156                         .buf = (void *)buf
 157                 },
 158         };
 159
 160         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 161                 return -EIO;
 162
 163         for (i = 0; i < READ_REG_NUM; i++)
 164                 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
 165
 166         return 0;
 167 }
 168
 169
 170
 171 /**************************************************************************
 172  * File Operations Interface
 173  **************************************************************************/
 174
 175 /*
 176  * si470x_fops_open - file open
 177  */
 178 int si470x_fops_open(struct file *file)
 179 {
 180         struct si470x_device *radio = video_drvdata(file);
 181         int retval = v4l2_fh_open(file);
 182
 183         if (retval)
 184                 return retval;
 185
 186         if (v4l2_fh_is_singular_file(file)) {
 187                 /* start radio */
 188                 retval = si470x_start(radio);
 189                 if (retval < 0)
 190                         goto done;
 191
 192                 /* enable RDS / STC interrupt */
 193                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
 194                 radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
 195                 radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
 196                 radio->registers[SYSCONFIG1] |= 0x1 << 2;
 197                 retval = si470x_set_register(radio, SYSCONFIG1);
 198         }
 199
 200 done:
 201         if (retval)
 202                 v4l2_fh_release(file);
 203         return retval;
 204 }
 205
 206
 207 /*
 208  * si470x_fops_release - file release
 209  */
 210 int si470x_fops_release(struct file *file)
 211 {
 212         struct si470x_device *radio = video_drvdata(file);
 213
 214         if (v4l2_fh_is_singular_file(file))
 215                 /* stop radio */
 216                 si470x_stop(radio);
 217
 218         return v4l2_fh_release(file);
 219 }
 220
 221
 222
 223 /**************************************************************************
 224  * Video4Linux Interface
 225  **************************************************************************/
 226
 227 /*
 228  * si470x_vidioc_querycap - query device capabilities
 229  */
 230 int si470x_vidioc_querycap(struct file *file, void *priv,
 231                 struct v4l2_capability *capability)
 232 {
 233         strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
 234         strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
 235         capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
 236                 V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
 237         capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
 238
 239         return 0;
 240 }
 241
 242
 243
 244 /**************************************************************************
 245  * I2C Interface
 246  **************************************************************************/
 247
 248 /*
 249  * si470x_i2c_interrupt - interrupt handler
 250  */
 251 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
 252 {
 253         struct si470x_device *radio = dev_id;
 254         unsigned char regnr;
 255         unsigned char blocknum;
 256         unsigned short bler; /* rds block errors */
 257         unsigned short rds;
 258         unsigned char tmpbuf[3];
 259         int retval = 0;
 260
 261         /* check Seek/Tune Complete */
 262         retval = si470x_get_register(radio, STATUSRSSI);
 263         if (retval < 0)
 264                 goto end;
 265
 266         if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
 267                 complete(&radio->completion);
 268
 269         /* safety checks */
 270         if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
 271                 goto end;
 272
 273         /* Update RDS registers */
 274         for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
 275                 retval = si470x_get_register(radio, STATUSRSSI + regnr);
 276                 if (retval < 0)
 277                         goto end;
 278         }
 279
 280         /* get rds blocks */
 281         if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
 282                 /* No RDS group ready, better luck next time */
 283                 goto end;
 284
 285         for (blocknum = 0; blocknum < 4; blocknum++) {
 286                 switch (blocknum) {
 287                 default:
 288                         bler = (radio->registers[STATUSRSSI] &
 289                                         STATUSRSSI_BLERA) >> 9;
 290                         rds = radio->registers[RDSA];
 291                         break;
 292                 case 1:
 293                         bler = (radio->registers[READCHAN] &
 294                                         READCHAN_BLERB) >> 14;
 295                         rds = radio->registers[RDSB];
 296                         break;
 297                 case 2:
 298                         bler = (radio->registers[READCHAN] &
 299                                         READCHAN_BLERC) >> 12;
 300                         rds = radio->registers[RDSC];
 301                         break;
 302                 case 3:
 303                         bler = (radio->registers[READCHAN] &
 304                                         READCHAN_BLERD) >> 10;
 305                         rds = radio->registers[RDSD];
 306                         break;
 307                 }
 308
 309                 /* Fill the V4L2 RDS buffer */
 310                 put_unaligned_le16(rds, &tmpbuf);
 311                 tmpbuf[2] = blocknum;           /* offset name */
 312                 tmpbuf[2] |= blocknum << 3;     /* received offset */
 313                 if (bler > max_rds_errors)
 314                         tmpbuf[2] |= 0x80;      /* uncorrectable errors */
 315                 else if (bler > 0)
 316                         tmpbuf[2] |= 0x40;      /* corrected error(s) */
 317
 318                 /* copy RDS block to internal buffer */
 319                 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
 320                 radio->wr_index += 3;
 321
 322                 /* wrap write pointer */
 323                 if (radio->wr_index >= radio->buf_size)
 324                         radio->wr_index = 0;
 325
 326                 /* check for overflow */
 327                 if (radio->wr_index == radio->rd_index) {
 328                         /* increment and wrap read pointer */
 329                         radio->rd_index += 3;
 330                         if (radio->rd_index >= radio->buf_size)
 331                                 radio->rd_index = 0;
 332                 }
 333         }
 334
 335         if (radio->wr_index != radio->rd_index)
 336                 wake_up_interruptible(&radio->read_queue);
 337
 338 end:
 339         return IRQ_HANDLED;
 340 }
 341
 342
 343 /*
 344  * si470x_i2c_probe - probe for the device
 345  */
 346 static int si470x_i2c_probe(struct i2c_client *client,
 347                             const struct i2c_device_id *id)
 348 {
 349         struct si470x_device *radio;
 350         int retval = 0;
 351         unsigned char version_warning = 0;
 352
 353         /* private data allocation and initialization */
 354         radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 355         if (!radio) {
 356                 retval = -ENOMEM;
 357                 goto err_initial;
 358         }
 359
 360         radio->client = client;
 361         radio->band = 1; /* Default to 76 - 108 MHz */
 362         mutex_init(&radio->lock);
 363         init_completion(&radio->completion);
 364
 365         /* video device initialization */
 366         radio->videodev = si470x_viddev_template;
 367         video_set_drvdata(&radio->videodev, radio);
 368
 369         /* power up : need 110ms */
 370         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 371         if (si470x_set_register(radio, POWERCFG) < 0) {
 372                 retval = -EIO;
 373                 goto err_radio;
 374         }
 375         msleep(110);
 376
 377         /* get device and chip versions */
 378         if (si470x_get_all_registers(radio) < 0) {
 379                 retval = -EIO;
 380                 goto err_radio;
 381         }
 382         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 383                         radio->registers[DEVICEID], radio->registers[SI_CHIPID]);
 384         if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 385                 dev_warn(&client->dev,
 386                         "This driver is known to work with firmware version %hu,\n",
 387                         RADIO_FW_VERSION);
 388                 dev_warn(&client->dev,
 389                         "but the device has firmware version %hu.\n",
 390                         radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE);
 391                 version_warning = 1;
 392         }
 393
 394         /* give out version warning */
 395         if (version_warning == 1) {
 396                 dev_warn(&client->dev,
 397                         "If you have some trouble using this driver,\n");
 398                 dev_warn(&client->dev,
 399                         "please report to V4L ML at linux-media@vger.kernel.org\n");
 400         }
 401
 402         /* set initial frequency */
 403         si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 404
 405         /* rds buffer allocation */
 406         radio->buf_size = rds_buf * 3;
 407         radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
 408         if (!radio->buffer) {
 409                 retval = -EIO;
 410                 goto err_radio;
 411         }
 412
 413         /* rds buffer configuration */
 414         radio->wr_index = 0;
 415         radio->rd_index = 0;
 416         init_waitqueue_head(&radio->read_queue);
 417
 418         retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt,
 419                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT, DRIVER_NAME,
 420                         radio);
 421         if (retval) {
 422                 dev_err(&client->dev, "Failed to register interrupt\n");
 423                 goto err_rds;
 424         }
 425
 426         /* register video device */
 427         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
 428                         radio_nr);
 429         if (retval) {
 430                 dev_warn(&client->dev, "Could not register video device\n");
 431                 goto err_all;
 432         }
 433         i2c_set_clientdata(client, radio);
 434
 435         return 0;
 436 err_all:
 437         free_irq(client->irq, radio);
 438 err_rds:
 439         kfree(radio->buffer);
 440 err_radio:
 441         kfree(radio);
 442 err_initial:
 443         return retval;
 444 }
 445
 446
 447 /*
 448  * si470x_i2c_remove - remove the device
 449  */
 450 static int si470x_i2c_remove(struct i2c_client *client)
 451 {
 452         struct si470x_device *radio = i2c_get_clientdata(client);
 453
 454         free_irq(client->irq, radio);
 455         video_unregister_device(&radio->videodev);
 456         kfree(radio);
 457
 458         return 0;
 459 }
 460
 461
 462 #ifdef CONFIG_PM_SLEEP
 463 /*
 464  * si470x_i2c_suspend - suspend the device
 465  */
 466 static int si470x_i2c_suspend(struct device *dev)
 467 {
 468         struct i2c_client *client = to_i2c_client(dev);
 469         struct si470x_device *radio = i2c_get_clientdata(client);
 470
 471         /* power down */
 472         radio->registers[POWERCFG] |= POWERCFG_DISABLE;
 473         if (si470x_set_register(radio, POWERCFG) < 0)
 474                 return -EIO;
 475
 476         return 0;
 477 }
 478
 479
 480 /*
 481  * si470x_i2c_resume - resume the device
 482  */
 483 static int si470x_i2c_resume(struct device *dev)
 484 {
 485         struct i2c_client *client = to_i2c_client(dev);
 486         struct si470x_device *radio = i2c_get_clientdata(client);
 487
 488         /* power up : need 110ms */
 489         radio->registers[POWERCFG] |= POWERCFG_ENABLE;
 490         if (si470x_set_register(radio, POWERCFG) < 0)
 491                 return -EIO;
 492         msleep(110);
 493
 494         return 0;
 495 }
 496
 497 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 498 #endif
 499
 500
 501 /*
 502  * si470x_i2c_driver - i2c driver interface
 503  */
 504 static struct i2c_driver si470x_i2c_driver = {
 505         .driver = {
 506                 .name           = "si470x",
 507 #ifdef CONFIG_PM_SLEEP
 508                 .pm             = &si470x_i2c_pm,
 509 #endif
 510         },
 511         .probe                  = si470x_i2c_probe,
 512         .remove                 = si470x_i2c_remove,
 513         .id_table               = si470x_i2c_id,
 514 };
 515
 516 module_i2c_driver(si470x_i2c_driver);
 517
 518 MODULE_LICENSE("GPL");
 519 MODULE_AUTHOR(DRIVER_AUTHOR);
 520 MODULE_DESCRIPTION(DRIVER_DESC);
 521 MODULE_VERSION(DRIVER_VERSION);