drivers/media/i2c/cs3308.c

   1 /*
   2  * Cirrus Logic cs3308 8-Channel Analog Volume Control
   3  *
   4  * Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>
   5  * Copyright (C) 2012 Steven Toth <stoth@kernellabs.com>
   6  *
   7  * Derived from cs5345.c Copyright (C) 2007 Hans Verkuil
   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 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/i2c.h>
  24 #include <linux/slab.h>
  25 #include <linux/videodev2.h>
  26 #include <media/v4l2-device.h>
  27
  28 MODULE_DESCRIPTION("i2c device driver for cs3308 8-channel volume control");
  29 MODULE_AUTHOR("Devin Heitmueller");
  30 MODULE_LICENSE("GPL");
  31
  32 static inline int cs3308_write(struct v4l2_subdev *sd, u8 reg, u8 value)
  33 {
  34         struct i2c_client *client = v4l2_get_subdevdata(sd);
  35
  36         return i2c_smbus_write_byte_data(client, reg, value);
  37 }
  38
  39 static inline int cs3308_read(struct v4l2_subdev *sd, u8 reg)
  40 {
  41         struct i2c_client *client = v4l2_get_subdevdata(sd);
  42
  43         return i2c_smbus_read_byte_data(client, reg);
  44 }
  45
  46 #ifdef CONFIG_VIDEO_ADV_DEBUG
  47 static int cs3308_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
  48 {
  49         reg->val = cs3308_read(sd, reg->reg & 0xffff);
  50         reg->size = 1;
  51         return 0;
  52 }
  53
  54 static int cs3308_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
  55 {
  56         cs3308_write(sd, reg->reg & 0xffff, reg->val & 0xff);
  57         return 0;
  58 }
  59 #endif
  60
  61 /* ----------------------------------------------------------------------- */
  62
  63 static const struct v4l2_subdev_core_ops cs3308_core_ops = {
  64 #ifdef CONFIG_VIDEO_ADV_DEBUG
  65         .g_register = cs3308_g_register,
  66         .s_register = cs3308_s_register,
  67 #endif
  68 };
  69
  70 static const struct v4l2_subdev_ops cs3308_ops = {
  71         .core = &cs3308_core_ops,
  72 };
  73
  74 /* ----------------------------------------------------------------------- */
  75
  76 static int cs3308_probe(struct i2c_client *client,
  77                         const struct i2c_device_id *id)
  78 {
  79         struct v4l2_subdev *sd;
  80         unsigned i;
  81
  82         /* Check if the adapter supports the needed features */
  83         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  84                 return -EIO;
  85
  86         if ((i2c_smbus_read_byte_data(client, 0x1c) & 0xf0) != 0xe0)
  87                 return -ENODEV;
  88
  89         v4l_info(client, "chip found @ 0x%x (%s)\n",
  90                  client->addr << 1, client->adapter->name);
  91
  92         sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
  93         if (sd == NULL)
  94                 return -ENOMEM;
  95
  96         v4l2_i2c_subdev_init(sd, client, &cs3308_ops);
  97
  98         /* Set some reasonable defaults */
  99         cs3308_write(sd, 0x0d, 0x00); /* Power up all channels */
 100         cs3308_write(sd, 0x0e, 0x00); /* Master Power */
 101         cs3308_write(sd, 0x0b, 0x00); /* Device Configuration */
 102         /* Set volume for each channel */
 103         for (i = 1; i <= 8; i++)
 104                 cs3308_write(sd, i, 0xd2);
 105         cs3308_write(sd, 0x0a, 0x00); /* Unmute all channels */
 106         return 0;
 107 }
 108
 109 /* ----------------------------------------------------------------------- */
 110
 111 static int cs3308_remove(struct i2c_client *client)
 112 {
 113         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 114
 115         v4l2_device_unregister_subdev(sd);
 116         kfree(sd);
 117         return 0;
 118 }
 119
 120 /* ----------------------------------------------------------------------- */
 121
 122 static const struct i2c_device_id cs3308_id[] = {
 123         { "cs3308", 0 },
 124         { }
 125 };
 126 MODULE_DEVICE_TABLE(i2c, cs3308_id);
 127
 128 static struct i2c_driver cs3308_driver = {
 129         .driver = {
 130                 .owner  = THIS_MODULE,
 131                 .name   = "cs3308",
 132         },
 133         .probe          = cs3308_probe,
 134         .remove         = cs3308_remove,
 135         .id_table       = cs3308_id,
 136 };
 137
 138 module_i2c_driver(cs3308_driver);