linux/drivers/media/i2c/cs3308.c
Hans Verkuil fc279cc288 [media] cs3308: add new 8-channel volume control driver
Add simple support for this 8 channel volume control driver.
Currently all it does is to unmute all 8 channels.

Based upon Devin's initial patch made for an older kernel which I
cleaned up and rebased. Thanks to Kernel Labs for that work.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-12-18 13:35:51 -02:00

139 lines
3.7 KiB
C

/*
* Cirrus Logic cs3308 8-Channel Analog Volume Control
*
* Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>
* Copyright (C) 2012 Steven Toth <stoth@kernellabs.com>
*
* Derived from cs5345.c Copyright (C) 2007 Hans Verkuil
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
MODULE_DESCRIPTION("i2c device driver for cs3308 8-channel volume control");
MODULE_AUTHOR("Devin Heitmueller");
MODULE_LICENSE("GPL");
static inline int cs3308_write(struct v4l2_subdev *sd, u8 reg, u8 value)
{
struct i2c_client *client = v4l2_get_subdevdata(sd);
return i2c_smbus_write_byte_data(client, reg, value);
}
static inline int cs3308_read(struct v4l2_subdev *sd, u8 reg)
{
struct i2c_client *client = v4l2_get_subdevdata(sd);
return i2c_smbus_read_byte_data(client, reg);
}
#ifdef CONFIG_VIDEO_ADV_DEBUG
static int cs3308_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
{
reg->val = cs3308_read(sd, reg->reg & 0xffff);
reg->size = 1;
return 0;
}
static int cs3308_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
{
cs3308_write(sd, reg->reg & 0xffff, reg->val & 0xff);
return 0;
}
#endif
/* ----------------------------------------------------------------------- */
static const struct v4l2_subdev_core_ops cs3308_core_ops = {
#ifdef CONFIG_VIDEO_ADV_DEBUG
.g_register = cs3308_g_register,
.s_register = cs3308_s_register,
#endif
};
static const struct v4l2_subdev_ops cs3308_ops = {
.core = &cs3308_core_ops,
};
/* ----------------------------------------------------------------------- */
static int cs3308_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct v4l2_subdev *sd;
unsigned i;
/* Check if the adapter supports the needed features */
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -EIO;
if ((i2c_smbus_read_byte_data(client, 0x1c) & 0xf0) != 0xe0)
return -ENODEV;
v4l_info(client, "chip found @ 0x%x (%s)\n",
client->addr << 1, client->adapter->name);
sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
if (sd == NULL)
return -ENOMEM;
v4l2_i2c_subdev_init(sd, client, &cs3308_ops);
/* Set some reasonable defaults */
cs3308_write(sd, 0x0d, 0x00); /* Power up all channels */
cs3308_write(sd, 0x0e, 0x00); /* Master Power */
cs3308_write(sd, 0x0b, 0x00); /* Device Configuration */
/* Set volume for each channel */
for (i = 1; i <= 8; i++)
cs3308_write(sd, i, 0xd2);
cs3308_write(sd, 0x0a, 0x00); /* Unmute all channels */
return 0;
}
/* ----------------------------------------------------------------------- */
static int cs3308_remove(struct i2c_client *client)
{
struct v4l2_subdev *sd = i2c_get_clientdata(client);
v4l2_device_unregister_subdev(sd);
kfree(sd);
return 0;
}
/* ----------------------------------------------------------------------- */
static const struct i2c_device_id cs3308_id[] = {
{ "cs3308", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, cs3308_id);
static struct i2c_driver cs3308_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "cs3308",
},
.probe = cs3308_probe,
.remove = cs3308_remove,
.id_table = cs3308_id,
};
module_i2c_driver(cs3308_driver);