1. 根目录:
2. drivers
3. media
4. i2c
5. cs5345.c

/*
 * cs5345 Cirrus Logic 24-bit, 192 kHz Stereo Audio ADC
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/videodev2.h>
#include <linux/slab.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>

MODULE_DESCRIPTION("i2c device driver for cs5345 Audio ADC");
MODULE_AUTHOR("Hans Verkuil");
MODULE_LICENSE("GPL");

static bool debug;

module_param(debug, bool, 0644);

MODULE_PARM_DESC(debug, "Debugging messages, 0=Off (default), 1=On");

struct cs5345_state {
	struct v4l2_subdev sd;
	struct v4l2_ctrl_handler hdl;
};

static inline struct cs5345_state *to_state(struct v4l2_subdev *sd)
{
	return container_of(sd, struct cs5345_state, sd);
}

static inline struct v4l2_subdev *to_sd(struct v4l2_ctrl *ctrl)
{
	return &container_of(ctrl->handler, struct cs5345_state, hdl)->sd;
}

/* ----------------------------------------------------------------------- */

static inline int cs5345_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 cs5345_read(struct v4l2_subdev *sd, u8 reg)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	return i2c_smbus_read_byte_data(client, reg);
}

static int cs5345_s_routing(struct v4l2_subdev *sd,
			    u32 input, u32 output, u32 config)
{
	if ((input & 0xf) > 6) {
		v4l2_err(sd, "Invalid input %d.\n", input);
		return -EINVAL;
	}
	cs5345_write(sd, 0x09, input & 0xf);
	cs5345_write(sd, 0x05, input & 0xf0);
	return 0;
}

static int cs5345_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct v4l2_subdev *sd = to_sd(ctrl);

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
		cs5345_write(sd, 0x04, ctrl->val ? 0x80 : 0);
		return 0;
	case V4L2_CID_AUDIO_VOLUME:
		cs5345_write(sd, 0x07, ((u8)ctrl->val) & 0x3f);
		cs5345_write(sd, 0x08, ((u8)ctrl->val) & 0x3f);
		return 0;
	}
	return -EINVAL;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int cs5345_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
{
	reg->size = 1;
	reg->val = cs5345_read(sd, reg->reg & 0x1f);
	return 0;
}

static int cs5345_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg)
{
	cs5345_write(sd, reg->reg & 0x1f, reg->val & 0xff);
	return 0;
}
#endif

static int cs5345_log_status(struct v4l2_subdev *sd)
{
	u8 v = cs5345_read(sd, 0x09) & 7;
	u8 m = cs5345_read(sd, 0x04);
	int vol = cs5345_read(sd, 0x08) & 0x3f;

	v4l2_info(sd, "Input:  %d%s\n", v,
			(m & 0x80) ? " (muted)" : "");
	if (vol >= 32)
		vol = vol - 64;
	v4l2_info(sd, "Volume: %d dB\n", vol);
	return 0;
}

/* ----------------------------------------------------------------------- */

static const struct v4l2_ctrl_ops cs5345_ctrl_ops = {
	.s_ctrl = cs5345_s_ctrl,
};

static const struct v4l2_subdev_core_ops cs5345_core_ops = {
	.log_status = cs5345_log_status,
	.g_ext_ctrls = v4l2_subdev_g_ext_ctrls,
	.try_ext_ctrls = v4l2_subdev_try_ext_ctrls,
	.s_ext_ctrls = v4l2_subdev_s_ext_ctrls,
	.g_ctrl = v4l2_subdev_g_ctrl,
	.s_ctrl = v4l2_subdev_s_ctrl,
	.queryctrl = v4l2_subdev_queryctrl,
	.querymenu = v4l2_subdev_querymenu,
#ifdef CONFIG_VIDEO_ADV_DEBUG
	.g_register = cs5345_g_register,
	.s_register = cs5345_s_register,
#endif
};

static const struct v4l2_subdev_audio_ops cs5345_audio_ops = {
	.s_routing = cs5345_s_routing,
};

static const struct v4l2_subdev_ops cs5345_ops = {
	.core = &cs5345_core_ops,
	.audio = &cs5345_audio_ops,
};

/* ----------------------------------------------------------------------- */

static int cs5345_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct cs5345_state *state;
	struct v4l2_subdev *sd;

	/* Check if the adapter supports the needed features */
	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -EIO;

	v4l_info(client, "chip found @ 0x%x (%s)\n",
			client->addr << 1, client->adapter->name);

	state = devm_kzalloc(&client->dev, sizeof(*state), GFP_KERNEL);
	if (state == NULL)
		return -ENOMEM;
	sd = &state->sd;
	v4l2_i2c_subdev_init(sd, client, &cs5345_ops);

	v4l2_ctrl_handler_init(&state->hdl, 2);
	v4l2_ctrl_new_std(&state->hdl, &cs5345_ctrl_ops,
			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 0);
	v4l2_ctrl_new_std(&state->hdl, &cs5345_ctrl_ops,
			V4L2_CID_AUDIO_VOLUME, -24, 24, 1, 0);
	sd->ctrl_handler = &state->hdl;
	if (state->hdl.error) {
		int err = state->hdl.error;

		v4l2_ctrl_handler_free(&state->hdl);
		return err;
	}
	/* set volume/mute */
	v4l2_ctrl_handler_setup(&state->hdl);

	cs5345_write(sd, 0x02, 0x00);
	cs5345_write(sd, 0x04, 0x01);
	cs5345_write(sd, 0x09, 0x01);
	return 0;
}

/* ----------------------------------------------------------------------- */

static int cs5345_remove(struct i2c_client *client)
{
	struct v4l2_subdev *sd = i2c_get_clientdata(client);
	struct cs5345_state *state = to_state(sd);

	v4l2_device_unregister_subdev(sd);
	v4l2_ctrl_handler_free(&state->hdl);
	return 0;
}

/* ----------------------------------------------------------------------- */

static const struct i2c_device_id cs5345_id[] = {
	{ "cs5345", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, cs5345_id);

static struct i2c_driver cs5345_driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= "cs5345",
	},
	.probe		= cs5345_probe,
	.remove		= cs5345_remove,
	.id_table	= cs5345_id,
};

module_i2c_driver(cs5345_driver);