1. 根目录:
2. drivers
3. media
4. i2c
5. wm8739.c

/*
 * wm8739
 *
 * Copyright (C) 2005 T. Adachi <tadachi@tadachi-net.com>
 *
 * Copyright (C) 2005 Hans Verkuil <hverkuil@xs4all.nl>
 * - Cleanup
 *
 * 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/types.h>
#include <linux/slab.h>
#include <linux/ioctl.h>
#include <asm/uaccess.h>
#include <linux/i2c.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>

MODULE_DESCRIPTION("wm8739 driver");
MODULE_AUTHOR("T. Adachi, Hans Verkuil");
MODULE_LICENSE("GPL");

static int debug;

module_param(debug, int, 0644);

MODULE_PARM_DESC(debug, "Debug level (0-1)");


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

enum {
	R0 = 0, R1,
	R5 = 5, R6, R7, R8, R9, R15 = 15,
	TOT_REGS
};

struct wm8739_state {
	struct v4l2_subdev sd;
	struct v4l2_ctrl_handler hdl;
	struct {
		/* audio cluster */
		struct v4l2_ctrl *volume;
		struct v4l2_ctrl *mute;
		struct v4l2_ctrl *balance;
	};
	u32 clock_freq;
};

static inline struct wm8739_state *to_state(struct v4l2_subdev *sd)
{
	return container_of(sd, struct wm8739_state, sd);
}

static inline struct v4l2_subdev *to_sd(struct v4l2_ctrl *ctrl)
{
	return &container_of(ctrl->handler, struct wm8739_state, hdl)->sd;
}

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

static int wm8739_write(struct v4l2_subdev *sd, int reg, u16 val)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	int i;

	if (reg < 0 || reg >= TOT_REGS) {
		v4l2_err(sd, "Invalid register R%d\n", reg);
		return -1;
	}

	v4l2_dbg(1, debug, sd, "write: %02x %02x\n", reg, val);

	for (i = 0; i < 3; i++)
		if (i2c_smbus_write_byte_data(client,
				(reg << 1) | (val >> 8), val & 0xff) == 0)
			return 0;
	v4l2_err(sd, "I2C: cannot write %03x to register R%d\n", val, reg);
	return -1;
}

static int wm8739_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct v4l2_subdev *sd = to_sd(ctrl);
	struct wm8739_state *state = to_state(sd);
	unsigned int work_l, work_r;
	u8 vol_l;	/* +12dB to -34.5dB 1.5dB step (5bit) def:0dB */
	u8 vol_r;	/* +12dB to -34.5dB 1.5dB step (5bit) def:0dB */
	u16 mute;

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_VOLUME:
		break;

	default:
		return -EINVAL;
	}

	/* normalize ( 65535 to 0 -> 31 to 0 (12dB to -34.5dB) ) */
	work_l = (min(65536 - state->balance->val, 32768) * state->volume->val) / 32768;
	work_r = (min(state->balance->val, 32768) * state->volume->val) / 32768;

	vol_l = (long)work_l * 31 / 65535;
	vol_r = (long)work_r * 31 / 65535;

	/* set audio volume etc. */
	mute = state->mute->val ? 0x80 : 0;

	/* Volume setting: bits 0-4, 0x1f = 12 dB, 0x00 = -34.5 dB
	 * Default setting: 0x17 = 0 dB
	 */
	wm8739_write(sd, R0, (vol_l & 0x1f) | mute);
	wm8739_write(sd, R1, (vol_r & 0x1f) | mute);
	return 0;
}

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

static int wm8739_s_clock_freq(struct v4l2_subdev *sd, u32 audiofreq)
{
	struct wm8739_state *state = to_state(sd);

	state->clock_freq = audiofreq;
	/* de-activate */
	wm8739_write(sd, R9, 0x000);
	switch (audiofreq) {
	case 44100:
		/* 256fps, fs=44.1k */
		wm8739_write(sd, R8, 0x020);
		break;
	case 48000:
		/* 256fps, fs=48k */
		wm8739_write(sd, R8, 0x000);
		break;
	case 32000:
		/* 256fps, fs=32k */
		wm8739_write(sd, R8, 0x018);
		break;
	default:
		break;
	}
	/* activate */
	wm8739_write(sd, R9, 0x001);
	return 0;
}

static int wm8739_log_status(struct v4l2_subdev *sd)
{
	struct wm8739_state *state = to_state(sd);

	v4l2_info(sd, "Frequency: %u Hz\n", state->clock_freq);
	v4l2_ctrl_handler_log_status(&state->hdl, sd->name);
	return 0;
}

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

static const struct v4l2_ctrl_ops wm8739_ctrl_ops = {
	.s_ctrl = wm8739_s_ctrl,
};

static const struct v4l2_subdev_core_ops wm8739_core_ops = {
	.log_status = wm8739_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,
};

static const struct v4l2_subdev_audio_ops wm8739_audio_ops = {
	.s_clock_freq = wm8739_s_clock_freq,
};

static const struct v4l2_subdev_ops wm8739_ops = {
	.core = &wm8739_core_ops,
	.audio = &wm8739_audio_ops,
};

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

/* i2c implementation */

static int wm8739_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct wm8739_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, &wm8739_ops);
	v4l2_ctrl_handler_init(&state->hdl, 2);
	state->volume = v4l2_ctrl_new_std(&state->hdl, &wm8739_ctrl_ops,
			V4L2_CID_AUDIO_VOLUME, 0, 65535, 65535 / 100, 50736);
	state->mute = v4l2_ctrl_new_std(&state->hdl, &wm8739_ctrl_ops,
			V4L2_CID_AUDIO_MUTE, 0, 1, 1, 0);
	state->balance = v4l2_ctrl_new_std(&state->hdl, &wm8739_ctrl_ops,
			V4L2_CID_AUDIO_BALANCE, 0, 65535, 65535 / 100, 32768);
	sd->ctrl_handler = &state->hdl;
	if (state->hdl.error) {
		int err = state->hdl.error;

		v4l2_ctrl_handler_free(&state->hdl);
		return err;
	}
	v4l2_ctrl_cluster(3, &state->volume);

	state->clock_freq = 48000;

	/* Initialize wm8739 */

	/* reset */
	wm8739_write(sd, R15, 0x00);
	/* filter setting, high path, offet clear */
	wm8739_write(sd, R5, 0x000);
	/* ADC, OSC, Power Off mode Disable */
	wm8739_write(sd, R6, 0x000);
	/* Digital Audio interface format:
	   Enable Master mode, 24 bit, MSB first/left justified */
	wm8739_write(sd, R7, 0x049);
	/* sampling control: normal, 256fs, 48KHz sampling rate */
	wm8739_write(sd, R8, 0x000);
	/* activate */
	wm8739_write(sd, R9, 0x001);
	/* set volume/mute */
	v4l2_ctrl_handler_setup(&state->hdl);
	return 0;
}

static int wm8739_remove(struct i2c_client *client)
{
	struct v4l2_subdev *sd = i2c_get_clientdata(client);
	struct wm8739_state *state = to_state(sd);

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

static const struct i2c_device_id wm8739_id[] = {
	{ "wm8739", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, wm8739_id);

static struct i2c_driver wm8739_driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= "wm8739",
	},
	.probe		= wm8739_probe,
	.remove		= wm8739_remove,
	.id_table	= wm8739_id,
};

module_i2c_driver(wm8739_driver);