LXR linux/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/*
  26 * ToDo:
  27 * - RDS support
  28 */
  29
  30
  31/* driver definitions */
  32#define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>";
  33#define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 0)
  34#define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
  35#define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
  36#define DRIVER_VERSION "1.0.0"
  37
  38/* kernel includes */
  39#include <linux/i2c.h>
  40#include <linux/delay.h>
  41
  42#include "radio-si470x.h"
  43
  44
  45/* I2C Device ID List */
  46static const struct i2c_device_id si470x_i2c_id[] = {
  47        /* Generic Entry */
  48        { "si470x", 0 },
  49        /* Terminating entry */
  50        { }
  51};
  52MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
  53
  54
  55
  56/**************************************************************************
  57 * Module Parameters
  58 **************************************************************************/
  59
  60/* Radio Nr */
  61static int radio_nr = -1;
  62module_param(radio_nr, int, 0444);
  63MODULE_PARM_DESC(radio_nr, "Radio Nr");
  64
  65
  66
  67/**************************************************************************
  68 * I2C Definitions
  69 **************************************************************************/
  70
  71/* Write starts with the upper byte of register 0x02 */
  72#define WRITE_REG_NUM           8
  73#define WRITE_INDEX(i)          (i + 0x02)
  74
  75/* Read starts with the upper byte of register 0x0a */
  76#define READ_REG_NUM            RADIO_REGISTER_NUM
  77#define READ_INDEX(i)           ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
  78
  79
  80
  81/**************************************************************************
  82 * General Driver Functions - REGISTERs
  83 **************************************************************************/
  84
  85/*
  86 * si470x_get_register - read register
  87 */
  88int si470x_get_register(struct si470x_device *radio, int regnr)
  89{
  90        u16 buf[READ_REG_NUM];
  91        struct i2c_msg msgs[1] = {
  92                { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
  93                        (void *)buf },
  94        };
  95
  96        if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
  97                return -EIO;
  98
  99        radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
 100
 101        return 0;
 102}
 103
 104
 105/*
 106 * si470x_set_register - write register
 107 */
 108int si470x_set_register(struct si470x_device *radio, int regnr)
 109{
 110        int i;
 111        u16 buf[WRITE_REG_NUM];
 112        struct i2c_msg msgs[1] = {
 113                { radio->client->addr, 0, sizeof(u16) * WRITE_REG_NUM,
 114                        (void *)buf },
 115        };
 116
 117        for (i = 0; i < WRITE_REG_NUM; i++)
 118                buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
 119
 120        if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 121                return -EIO;
 122
 123        return 0;
 124}
 125
 126
 127
 128/**************************************************************************
 129 * General Driver Functions - ENTIRE REGISTERS
 130 **************************************************************************/
 131
 132/*
 133 * si470x_get_all_registers - read entire registers
 134 */
 135static int si470x_get_all_registers(struct si470x_device *radio)
 136{
 137        int i;
 138        u16 buf[READ_REG_NUM];
 139        struct i2c_msg msgs[1] = {
 140                { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
 141                        (void *)buf },
 142        };
 143
 144        if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
 145                return -EIO;
 146
 147        for (i = 0; i < READ_REG_NUM; i++)
 148                radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
 149
 150        return 0;
 151}
 152
 153
 154
 155/**************************************************************************
 156 * General Driver Functions - DISCONNECT_CHECK
 157 **************************************************************************/
 158
 159/*
 160 * si470x_disconnect_check - check whether radio disconnects
 161 */
 162int si470x_disconnect_check(struct si470x_device *radio)
 163{
 164        return 0;
 165}
 166
 167
 168
 169/**************************************************************************
 170 * File Operations Interface
 171 **************************************************************************/
 172
 173/*
 174 * si470x_fops_open - file open
 175 */
 176static int si470x_fops_open(struct file *file)
 177{
 178        struct si470x_device *radio = video_drvdata(file);
 179        int retval = 0;
 180
 181        mutex_lock(&radio->lock);
 182        radio->users++;
 183
 184        if (radio->users == 1)
 185                /* start radio */
 186                retval = si470x_start(radio);
 187
 188        mutex_unlock(&radio->lock);
 189
 190        return retval;
 191}
 192
 193
 194/*
 195 * si470x_fops_release - file release
 196 */
 197static int si470x_fops_release(struct file *file)
 198{
 199        struct si470x_device *radio = video_drvdata(file);
 200        int retval = 0;
 201
 202        /* safety check */
 203        if (!radio)
 204                return -ENODEV;
 205
 206        mutex_lock(&radio->lock);
 207        radio->users--;
 208        if (radio->users == 0)
 209                /* stop radio */
 210                retval = si470x_stop(radio);
 211
 212        mutex_unlock(&radio->lock);
 213
 214        return retval;
 215}
 216
 217
 218/*
 219 * si470x_fops - file operations interface
 220 */
 221const struct v4l2_file_operations si470x_fops = {
 222        .owner          = THIS_MODULE,
 223        .ioctl          = video_ioctl2,
 224        .open           = si470x_fops_open,
 225        .release        = si470x_fops_release,
 226};
 227
 228
 229
 230/**************************************************************************
 231 * Video4Linux Interface
 232 **************************************************************************/
 233
 234/*
 235 * si470x_vidioc_querycap - query device capabilities
 236 */
 237int si470x_vidioc_querycap(struct file *file, void *priv,
 238                struct v4l2_capability *capability)
 239{
 240        strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
 241        strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
 242        capability->version = DRIVER_KERNEL_VERSION;
 243        capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
 244                V4L2_CAP_TUNER | V4L2_CAP_RADIO;
 245
 246        return 0;
 247}
 248
 249
 250
 251/**************************************************************************
 252 * I2C Interface
 253 **************************************************************************/
 254
 255/*
 256 * si470x_i2c_probe - probe for the device
 257 */
 258static int __devinit si470x_i2c_probe(struct i2c_client *client,
 259                const struct i2c_device_id *id)
 260{
 261        struct si470x_device *radio;
 262        int retval = 0;
 263        unsigned char version_warning = 0;
 264
 265        /* private data allocation and initialization */
 266        radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 267        if (!radio) {
 268                retval = -ENOMEM;
 269                goto err_initial;
 270        }
 271        radio->users = 0;
 272        radio->client = client;
 273        mutex_init(&radio->lock);
 274
 275        /* video device allocation and initialization */
 276        radio->videodev = video_device_alloc();
 277        if (!radio->videodev) {
 278                retval = -ENOMEM;
 279                goto err_radio;
 280        }
 281        memcpy(radio->videodev, &si470x_viddev_template,
 282                        sizeof(si470x_viddev_template));
 283        video_set_drvdata(radio->videodev, radio);
 284
 285        /* power up : need 110ms */
 286        radio->registers[POWERCFG] = POWERCFG_ENABLE;
 287        if (si470x_set_register(radio, POWERCFG) < 0) {
 288                retval = -EIO;
 289                goto err_all;
 290        }
 291        msleep(110);
 292
 293        /* get device and chip versions */
 294        if (si470x_get_all_registers(radio) < 0) {
 295                retval = -EIO;
 296                goto err_video;
 297        }
 298        dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 299                        radio->registers[DEVICEID], radio->registers[CHIPID]);
 300        if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 301                dev_warn(&client->dev,
 302                        "This driver is known to work with "
 303                        "firmware version %hu,\n", RADIO_FW_VERSION);
 304                dev_warn(&client->dev,
 305                        "but the device has firmware version %hu.\n",
 306                        radio->registers[CHIPID] & CHIPID_FIRMWARE);
 307                version_warning = 1;
 308        }
 309
 310        /* give out version warning */
 311        if (version_warning == 1) {
 312                dev_warn(&client->dev,
 313                        "If you have some trouble using this driver,\n");
 314                dev_warn(&client->dev,
 315                        "please report to V4L ML at "
 316                        "linux-media@vger.kernel.org\n");
 317        }
 318
 319        /* set initial frequency */
 320        si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 321
 322        /* register video device */
 323        retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
 324                        radio_nr);
 325        if (retval) {
 326                dev_warn(&client->dev, "Could not register video device\n");
 327                goto err_all;
 328        }
 329        i2c_set_clientdata(client, radio);
 330
 331        return 0;
 332err_all:
 333err_video:
 334        video_device_release(radio->videodev);
 335err_radio:
 336        kfree(radio);
 337err_initial:
 338        return retval;
 339}
 340
 341
 342/*
 343 * si470x_i2c_remove - remove the device
 344 */
 345static __devexit int si470x_i2c_remove(struct i2c_client *client)
 346{
 347        struct si470x_device *radio = i2c_get_clientdata(client);
 348
 349        video_unregister_device(radio->videodev);
 350        kfree(radio);
 351        i2c_set_clientdata(client, NULL);
 352
 353        return 0;
 354}
 355
 356
 357/*
 358 * si470x_i2c_driver - i2c driver interface
 359 */
 360static struct i2c_driver si470x_i2c_driver = {
 361        .driver = {
 362                .name           = "si470x",
 363                .owner          = THIS_MODULE,
 364        },
 365        .probe                  = si470x_i2c_probe,
 366        .remove                 = __devexit_p(si470x_i2c_remove),
 367        .id_table               = si470x_i2c_id,
 368};
 369
 370
 371
 372/**************************************************************************
 373 * Module Interface
 374 **************************************************************************/
 375
 376/*
 377 * si470x_i2c_init - module init
 378 */
 379static int __init si470x_i2c_init(void)
 380{
 381        printk(KERN_INFO DRIVER_DESC ", Version " DRIVER_VERSION "\n");
 382        return i2c_add_driver(&si470x_i2c_driver);
 383}
 384
 385
 386/*
 387 * si470x_i2c_exit - module exit
 388 */
 389static void __exit si470x_i2c_exit(void)
 390{
 391        i2c_del_driver(&si470x_i2c_driver);
 392}
 393
 394
 395module_init(si470x_i2c_init);
 396module_exit(si470x_i2c_exit);
 397
 398MODULE_LICENSE("GPL");
 399MODULE_AUTHOR(DRIVER_AUTHOR);
 400MODULE_DESCRIPTION(DRIVER_DESC);
 401MODULE_VERSION(DRIVER_VERSION);
 402