drivers/media/i2c/cs3308.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Cirrus Logic cs3308 8-Channel Analog Volume Control
   4  *
   5  * Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>
   6  * Copyright (C) 2012 Steven Toth <stoth@kernellabs.com>
   7  *
   8  * Derived from cs5345.c Copyright (C) 2007 Hans Verkuil
   9  */
  10
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/i2c.h>
  15 #include <linux/slab.h>
  16 #include <linux/videodev2.h>
  17 #include <media/v4l2-device.h>
  18
  19 MODULE_DESCRIPTION("i2c device driver for cs3308 8-channel volume control");
  20 MODULE_AUTHOR("Devin Heitmueller");
  21 MODULE_LICENSE("GPL");
  22
  23 static inline int cs3308_write(struct v4l2_subdev *sd, u8 reg, u8 value)
  24 {
  25         struct i2c_client *client = v4l2_get_subdevdata(sd);
  26
  27         return i2c_smbus_write_byte_data(client, reg, value);
  28 }
  29
  30 static inline int cs3308_read(struct v4l2_subdev *sd, u8 reg)
  31 {
  32         struct i2c_client *client = v4l2_get_subdevdata(sd);
  33
  34         return i2c_smbus_read_byte_data(client, reg);
  35 }
  36
  37 #ifdef CONFIG_VIDEO_ADV_DEBUG
  38 static int cs3308_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
  39 {
  40         reg->val = cs3308_read(sd, reg->reg & 0xffff);
  41         reg->size = 1;
  42         return 0;
  43 }
  44
  45 static int cs3308_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
  46 {
  47         cs3308_write(sd, reg->reg & 0xffff, reg->val & 0xff);
  48         return 0;
  49 }
  50 #endif
  51
  52 /* ----------------------------------------------------------------------- */
  53
  54 static const struct v4l2_subdev_core_ops cs3308_core_ops = {
  55 #ifdef CONFIG_VIDEO_ADV_DEBUG
  56         .g_register = cs3308_g_register,
  57         .s_register = cs3308_s_register,
  58 #endif
  59 };
  60
  61 static const struct v4l2_subdev_ops cs3308_ops = {
  62         .core = &cs3308_core_ops,
  63 };
  64
  65 /* ----------------------------------------------------------------------- */
  66
  67 static int cs3308_probe(struct i2c_client *client,
  68                         const struct i2c_device_id *id)
  69 {
  70         struct v4l2_subdev *sd;
  71         unsigned i;
  72
  73         /* Check if the adapter supports the needed features */
  74         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  75                 return -EIO;
  76
  77         if ((i2c_smbus_read_byte_data(client, 0x1c) & 0xf0) != 0xe0)
  78                 return -ENODEV;
  79
  80         v4l_info(client, "chip found @ 0x%x (%s)\n",
  81                  client->addr << 1, client->adapter->name);
  82
  83         sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
  84         if (sd == NULL)
  85                 return -ENOMEM;
  86
  87         v4l2_i2c_subdev_init(sd, client, &cs3308_ops);
  88
  89         /* Set some reasonable defaults */
  90         cs3308_write(sd, 0x0d, 0x00); /* Power up all channels */
  91         cs3308_write(sd, 0x0e, 0x00); /* Master Power */
  92         cs3308_write(sd, 0x0b, 0x00); /* Device Configuration */
  93         /* Set volume for each channel */
  94         for (i = 1; i <= 8; i++)
  95                 cs3308_write(sd, i, 0xd2);
  96         cs3308_write(sd, 0x0a, 0x00); /* Unmute all channels */
  97         return 0;
  98 }
  99
 100 /* ----------------------------------------------------------------------- */
 101
 102 static int cs3308_remove(struct i2c_client *client)
 103 {
 104         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 105
 106         v4l2_device_unregister_subdev(sd);
 107         kfree(sd);
 108         return 0;
 109 }
 110
 111 /* ----------------------------------------------------------------------- */
 112
 113 static const struct i2c_device_id cs3308_id[] = {
 114         { "cs3308", 0 },
 115         { }
 116 };
 117 MODULE_DEVICE_TABLE(i2c, cs3308_id);
 118
 119 static struct i2c_driver cs3308_driver = {
 120         .driver = {
 121                 .name   = "cs3308",
 122         },
 123         .probe          = cs3308_probe,
 124         .remove         = cs3308_remove,
 125         .id_table       = cs3308_id,
 126 };
 127
 128 module_i2c_driver(cs3308_driver);