linux/drivers/media/radio/si470x/radio-si470x-i2c.c
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   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 */
  41static const struct i2c_device_id si470x_i2c_id[] = {
  42        /* Generic Entry */
  43        { "si470x", 0 },
  44        /* Terminating entry */
  45        { }
  46};
  47MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
  48
  49
  50
  51/**************************************************************************
  52 * Module Parameters
  53 **************************************************************************/
  54
  55/* Radio Nr */
  56static int radio_nr = -1;
  57module_param(radio_nr, int, 0444);
  58MODULE_PARM_DESC(radio_nr, "Radio Nr");
  59
  60/* RDS buffer blocks */
  61static unsigned int rds_buf = 100;
  62module_param(rds_buf, uint, 0444);
  63MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
  64
  65/* RDS maximum block errors */
  66static 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 */
  71module_param(max_rds_errors, ushort, 0644);
  72MODULE_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 */
  97int 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 */
 121int 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 */
 151static 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 */
 182int 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
 204done:
 205        if (retval)
 206                v4l2_fh_release(file);
 207        return retval;
 208}
 209
 210
 211/*
 212 * si470x_fops_release - file release
 213 */
 214int 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 */
 234int 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 */
 255static 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
 342end:
 343        return IRQ_HANDLED;
 344}
 345
 346
 347/*
 348 * si470x_i2c_probe - probe for the device
 349 */
 350static 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[CHIPID]);
 388        if ((radio->registers[CHIPID] & 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[CHIPID] & 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, DRIVER_NAME, radio);
 425        if (retval) {
 426                dev_err(&client->dev, "Failed to register interrupt\n");
 427                goto err_rds;
 428        }
 429
 430        /* register video device */
 431        retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
 432                        radio_nr);
 433        if (retval) {
 434                dev_warn(&client->dev, "Could not register video device\n");
 435                goto err_all;
 436        }
 437        i2c_set_clientdata(client, radio);
 438
 439        return 0;
 440err_all:
 441        free_irq(client->irq, radio);
 442err_rds:
 443        kfree(radio->buffer);
 444err_radio:
 445        kfree(radio);
 446err_initial:
 447        return retval;
 448}
 449
 450
 451/*
 452 * si470x_i2c_remove - remove the device
 453 */
 454static int si470x_i2c_remove(struct i2c_client *client)
 455{
 456        struct si470x_device *radio = i2c_get_clientdata(client);
 457
 458        free_irq(client->irq, radio);
 459        video_unregister_device(&radio->videodev);
 460        kfree(radio);
 461
 462        return 0;
 463}
 464
 465
 466#ifdef CONFIG_PM_SLEEP
 467/*
 468 * si470x_i2c_suspend - suspend the device
 469 */
 470static int si470x_i2c_suspend(struct device *dev)
 471{
 472        struct i2c_client *client = to_i2c_client(dev);
 473        struct si470x_device *radio = i2c_get_clientdata(client);
 474
 475        /* power down */
 476        radio->registers[POWERCFG] |= POWERCFG_DISABLE;
 477        if (si470x_set_register(radio, POWERCFG) < 0)
 478                return -EIO;
 479
 480        return 0;
 481}
 482
 483
 484/*
 485 * si470x_i2c_resume - resume the device
 486 */
 487static int si470x_i2c_resume(struct device *dev)
 488{
 489        struct i2c_client *client = to_i2c_client(dev);
 490        struct si470x_device *radio = i2c_get_clientdata(client);
 491
 492        /* power up : need 110ms */
 493        radio->registers[POWERCFG] |= POWERCFG_ENABLE;
 494        if (si470x_set_register(radio, POWERCFG) < 0)
 495                return -EIO;
 496        msleep(110);
 497
 498        return 0;
 499}
 500
 501static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 502#endif
 503
 504
 505/*
 506 * si470x_i2c_driver - i2c driver interface
 507 */
 508static struct i2c_driver si470x_i2c_driver = {
 509        .driver = {
 510                .name           = "si470x",
 511                .owner          = THIS_MODULE,
 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
 521module_i2c_driver(si470x_i2c_driver);
 522
 523MODULE_LICENSE("GPL");
 524MODULE_AUTHOR(DRIVER_AUTHOR);
 525MODULE_DESCRIPTION(DRIVER_DESC);
 526MODULE_VERSION(DRIVER_VERSION);
 527