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