SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 it
  10  *  under  the terms of  the GNU General  Public License as published by the
  11  *  Free Software Foundation;  either version 2 of the  License, or (at your
  12  *  option) any later version.
  13  *
  14  *
  15  * TODO:
  16  * - RDS support
  17  *
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/i2c.h>
  23 #include <linux/delay.h>
  24
  25 #include "radio-si470x.h"
  26
  27 #define DRIVER_KERNEL_VERSION   KERNEL_VERSION(1, 0, 0)
  28 #define DRIVER_CARD             "Silicon Labs Si470x FM Radio Receiver"
  29 #define DRIVER_VERSION          "1.0.0"
  30
  31 /* starting with the upper byte of register 0x0a */
  32 #define READ_REG_NUM            RADIO_REGISTER_NUM
  33 #define READ_INDEX(i)           ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
  34
  35 static int si470x_get_all_registers(struct si470x_device *radio)
  36 {
  37         int i;
  38         u16 buf[READ_REG_NUM];
  39         struct i2c_msg msgs[1] = {
  40                 { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
  41                         (void *)buf },
  42         };
  43
  44         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
  45                 return -EIO;
  46
  47         for (i = 0; i < READ_REG_NUM; i++)
  48                 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
  49
  50         return 0;
  51 }
  52
  53 int si470x_get_register(struct si470x_device *radio, int regnr)
  54 {
  55         u16 buf[READ_REG_NUM];
  56         struct i2c_msg msgs[1] = {
  57                 { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
  58                         (void *)buf },
  59         };
  60
  61         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
  62                 return -EIO;
  63
  64         radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
  65
  66         return 0;
  67 }
  68
  69 /* starting with the upper byte of register 0x02h */
  70 #define WRITE_REG_NUM           8
  71 #define WRITE_INDEX(i)          (i + 0x02)
  72
  73 int si470x_set_register(struct si470x_device *radio, int regnr)
  74 {
  75         int i;
  76         u16 buf[WRITE_REG_NUM];
  77         struct i2c_msg msgs[1] = {
  78                 { radio->client->addr, 0, sizeof(u16) * WRITE_REG_NUM,
  79                         (void *)buf },
  80         };
  81
  82         for (i = 0; i < WRITE_REG_NUM; i++)
  83                 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
  84
  85         if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
  86                 return -EIO;
  87
  88         return 0;
  89 }
  90
  91 int si470x_disconnect_check(struct si470x_device *radio)
  92 {
  93         return 0;
  94 }
  95
  96 static int si470x_fops_open(struct file *file)
  97 {
  98         struct si470x_device *radio = video_drvdata(file);
  99         int retval = 0;
 100
 101         mutex_lock(&radio->lock);
 102         radio->users++;
 103
 104         if (radio->users == 1)
 105                 /* start radio */
 106                 retval = si470x_start(radio);
 107         mutex_unlock(&radio->lock);
 108
 109         return retval;
 110 }
 111
 112 static int si470x_fops_release(struct file *file)
 113 {
 114         struct si470x_device *radio = video_drvdata(file);
 115         int retval = 0;
 116
 117         /* safety check */
 118         if (!radio)
 119                 return -ENODEV;
 120
 121         mutex_lock(&radio->lock);
 122         radio->users--;
 123         if (radio->users == 0)
 124                 /* stop radio */
 125                 retval = si470x_stop(radio);
 126         mutex_unlock(&radio->lock);
 127
 128         return retval;
 129 }
 130
 131 const struct v4l2_file_operations si470x_fops = {
 132         .owner          = THIS_MODULE,
 133         .ioctl          = video_ioctl2,
 134         .open           = si470x_fops_open,
 135         .release        = si470x_fops_release,
 136 };
 137
 138 int si470x_vidioc_querycap(struct file *file, void *priv,
 139                 struct v4l2_capability *capability)
 140 {
 141         strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
 142         strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
 143         capability->version = DRIVER_KERNEL_VERSION;
 144         capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
 145                 V4L2_CAP_TUNER | V4L2_CAP_RADIO;
 146
 147         return 0;
 148 }
 149
 150 static int __devinit si470x_i2c_probe(struct i2c_client *client,
 151                 const struct i2c_device_id *id)
 152 {
 153         struct si470x_device *radio;
 154         int retval = 0;
 155
 156         /* private data allocation and initialization */
 157         radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
 158         if (!radio) {
 159                 retval = -ENOMEM;
 160                 goto err_initial;
 161         }
 162         radio->client = client;
 163         radio->users = 0;
 164         mutex_init(&radio->lock);
 165
 166         /* video device allocation and initialization */
 167         radio->videodev = video_device_alloc();
 168         if (!radio->videodev) {
 169                 retval = -ENOMEM;
 170                 goto err_radio;
 171         }
 172         memcpy(radio->videodev, &si470x_viddev_template,
 173                         sizeof(si470x_viddev_template));
 174         video_set_drvdata(radio->videodev, radio);
 175
 176         /* power up : need 110ms */
 177         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 178         if (si470x_set_register(radio, POWERCFG) < 0) {
 179                 retval = -EIO;
 180                 goto err_all;
 181         }
 182         msleep(110);
 183
 184         /* show some infos about the specific si470x device */
 185         if (si470x_get_all_registers(radio) < 0) {
 186                 retval = -EIO;
 187                 goto err_radio;
 188         }
 189         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 190                         radio->registers[DEVICEID], radio->registers[CHIPID]);
 191
 192         /* set initial frequency */
 193         si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 194
 195         /* register video device */
 196         retval = video_register_device(radio->videodev, VFL_TYPE_RADIO, -1);
 197         if (retval) {
 198                 dev_warn(&client->dev, "Could not register video device\n");
 199                 goto err_all;
 200         }
 201
 202         i2c_set_clientdata(client, radio);
 203
 204         return 0;
 205 err_all:
 206         video_device_release(radio->videodev);
 207 err_radio:
 208         kfree(radio);
 209 err_initial:
 210         return retval;
 211 }
 212
 213 static __devexit int si470x_i2c_remove(struct i2c_client *client)
 214 {
 215         struct si470x_device *radio = i2c_get_clientdata(client);
 216
 217         video_unregister_device(radio->videodev);
 218         kfree(radio);
 219         i2c_set_clientdata(client, NULL);
 220
 221         return 0;
 222 }
 223
 224 static const struct i2c_device_id si470x_i2c_id[] = {
 225         { "si470x", 0 },
 226         { }
 227 };
 228 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
 229
 230 static struct i2c_driver si470x_i2c_driver = {
 231         .driver = {
 232                 .name = "si470x",
 233                 .owner = THIS_MODULE,
 234         },
 235         .probe = si470x_i2c_probe,
 236         .remove = __devexit_p(si470x_i2c_remove),
 237         .id_table = si470x_i2c_id,
 238 };
 239
 240 static int __init si470x_i2c_init(void)
 241 {
 242         return i2c_add_driver(&si470x_i2c_driver);
 243 }
 244 module_init(si470x_i2c_init);
 245
 246 static void __exit si470x_i2c_exit(void)
 247 {
 248         i2c_del_driver(&si470x_i2c_driver);
 249 }
 250 module_exit(si470x_i2c_exit);
 251
 252 MODULE_DESCRIPTION("i2c radio driver for si470x fm radio receivers");
 253 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
 254 MODULE_LICENSE("GPL");