/*
 * ALSA SoC Texas Instruments TPA6130A2 headset stereo amplifier driver
 *
 * Copyright (C) Nokia Corporation
 *
 * Author: Peter Ujfalusi <peter.ujfalusi@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <sound/tpa6130a2-plat.h>
#include <sound/soc.h>
#include <sound/soc-dapm.h>
#include <sound/tlv.h>

#include "tpa6130a2.h"

static struct i2c_client *tpa6130a2_client;

/* This struct is used to save the context */
struct tpa6130a2_data {
	struct mutex mutex;
	unsigned char regs[TPA6130A2_CACHEREGNUM];
	int power_gpio;
	unsigned char power_state;
};

static int tpa6130a2_i2c_read(int reg)
{
	struct tpa6130a2_data *data;
	int val;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	/* If powered off, return the cached value */
	if (data->power_state) {
		val = i2c_smbus_read_byte_data(tpa6130a2_client, reg);
		if (val < 0)
			dev_err(&tpa6130a2_client->dev, "Read failed\n");
		else
			data->regs[reg] = val;
	} else {
		val = data->regs[reg];
	}

	return val;
}

static int tpa6130a2_i2c_write(int reg, u8 value)
{
	struct tpa6130a2_data *data;
	int val = 0;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	if (data->power_state) {
		val = i2c_smbus_write_byte_data(tpa6130a2_client, reg, value);
		if (val < 0)
			dev_err(&tpa6130a2_client->dev, "Write failed\n");
	}

	/* Either powered on or off, we save the context */
	data->regs[reg] = value;

	return val;
}

static u8 tpa6130a2_read(int reg)
{
	struct tpa6130a2_data *data;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	return data->regs[reg];
}

static void tpa6130a2_initialize(void)
{
	struct tpa6130a2_data *data;
	int i;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	for (i = 1; i < TPA6130A2_REG_VERSION; i++)
		tpa6130a2_i2c_write(i, data->regs[i]);
}

static void tpa6130a2_power(int power)
{
	struct	tpa6130a2_data *data;
	u8	val;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	mutex_lock(&data->mutex);
	if (power) {
		/* Power on */
		if (data->power_gpio >= 0) {
			gpio_set_value(data->power_gpio, 1);
			data->power_state = 1;
			tpa6130a2_initialize();
		}
		/* Clear SWS */
		val = tpa6130a2_read(TPA6130A2_REG_CONTROL);
		val &= ~TPA6130A2_SWS;
		tpa6130a2_i2c_write(TPA6130A2_REG_CONTROL, val);
	} else {
		/* set SWS */
		val = tpa6130a2_read(TPA6130A2_REG_CONTROL);
		val |= TPA6130A2_SWS;
		tpa6130a2_i2c_write(TPA6130A2_REG_CONTROL, val);
		/* Power off */
		if (data->power_gpio >= 0) {
			gpio_set_value(data->power_gpio, 0);
			data->power_state = 0;
		}
	}
	mutex_unlock(&data->mutex);
}

static int tpa6130a2_get_reg(struct snd_kcontrol *kcontrol,
		struct snd_ctl_elem_value *ucontrol)
{
	struct soc_mixer_control *mc =
		(struct soc_mixer_control *)kcontrol->private_value;
	struct tpa6130a2_data *data;
	unsigned int reg = mc->reg;
	unsigned int shift = mc->shift;
	unsigned int mask = mc->max;
	unsigned int invert = mc->invert;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	mutex_lock(&data->mutex);

	ucontrol->value.integer.value[0] =
		(tpa6130a2_read(reg) >> shift) & mask;

	if (invert)
		ucontrol->value.integer.value[0] =
			mask - ucontrol->value.integer.value[0];

	mutex_unlock(&data->mutex);
	return 0;
}

static int tpa6130a2_set_reg(struct snd_kcontrol *kcontrol,
		struct snd_ctl_elem_value *ucontrol)
{
	struct soc_mixer_control *mc =
		(struct soc_mixer_control *)kcontrol->private_value;
	struct tpa6130a2_data *data;
	unsigned int reg = mc->reg;
	unsigned int shift = mc->shift;
	unsigned int mask = mc->max;
	unsigned int invert = mc->invert;
	unsigned int val = (ucontrol->value.integer.value[0] & mask);
	unsigned int val_reg;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	if (invert)
		val = mask - val;

	mutex_lock(&data->mutex);

	val_reg = tpa6130a2_read(reg);
	if (((val_reg >> shift) & mask) == val) {
		mutex_unlock(&data->mutex);
		return 0;
	}

	val_reg &= ~(mask << shift);
	val_reg |= val << shift;
	tpa6130a2_i2c_write(reg, val_reg);

	mutex_unlock(&data->mutex);

	return 1;
}

/*
 * TPA6130 volume. From -59.5 to 4 dB with increasing step size when going
 * down in gain.
 */
static const unsigned int tpa6130_tlv[] = {
	TLV_DB_RANGE_HEAD(10),
	0, 1, TLV_DB_SCALE_ITEM(-5950, 600, 0),
	2, 3, TLV_DB_SCALE_ITEM(-5000, 250, 0),
	4, 5, TLV_DB_SCALE_ITEM(-4550, 160, 0),
	6, 7, TLV_DB_SCALE_ITEM(-4140, 190, 0),
	8, 9, TLV_DB_SCALE_ITEM(-3650, 120, 0),
	10, 11, TLV_DB_SCALE_ITEM(-3330, 160, 0),
	12, 13, TLV_DB_SCALE_ITEM(-3040, 180, 0),
	14, 20, TLV_DB_SCALE_ITEM(-2710, 110, 0),
	21, 37, TLV_DB_SCALE_ITEM(-1960, 74, 0),
	38, 63, TLV_DB_SCALE_ITEM(-720, 45, 0),
};

static const struct snd_kcontrol_new tpa6130a2_controls[] = {
	SOC_SINGLE_EXT_TLV("TPA6130A2 Headphone Playback Volume",
		       TPA6130A2_REG_VOL_MUTE, 0, 0x3f, 0,
		       tpa6130a2_get_reg, tpa6130a2_set_reg,
		       tpa6130_tlv),
};

/*
 * Enable or disable channel (left or right)
 * The bit number for mute and amplifier are the same per channel:
 * bit 6: Right channel
 * bit 7: Left channel
 * in both registers.
 */
static void tpa6130a2_channel_enable(u8 channel, int enable)
{
	struct	tpa6130a2_data *data;
	u8	val;

	BUG_ON(tpa6130a2_client == NULL);
	data = i2c_get_clientdata(tpa6130a2_client);

	if (enable) {
		/* Enable channel */
		/* Enable amplifier */
		val = tpa6130a2_read(TPA6130A2_REG_CONTROL);
		val |= channel;
		tpa6130a2_i2c_write(TPA6130A2_REG_CONTROL, val);

		/* Unmute channel */
		val = tpa6130a2_read(TPA6130A2_REG_VOL_MUTE);
		val &= ~channel;
		tpa6130a2_i2c_write(TPA6130A2_REG_VOL_MUTE, val);
	} else {
		/* Disable channel */
		/* Mute channel */
		val = tpa6130a2_read(TPA6130A2_REG_VOL_MUTE);
		val |= channel;
		tpa6130a2_i2c_write(TPA6130A2_REG_VOL_MUTE, val);

		/* Disable amplifier */
		val = tpa6130a2_read(TPA6130A2_REG_CONTROL);
		val &= ~channel;
		tpa6130a2_i2c_write(TPA6130A2_REG_CONTROL, val);
	}
}

static int tpa6130a2_left_event(struct snd_soc_dapm_widget *w,
		struct snd_kcontrol *kcontrol, int event)
{
	switch (event) {
	case SND_SOC_DAPM_POST_PMU:
		tpa6130a2_channel_enable(TPA6130A2_HP_EN_L, 1);
		break;
	case SND_SOC_DAPM_POST_PMD:
		tpa6130a2_channel_enable(TPA6130A2_HP_EN_L, 0);
		break;
	}
	return 0;
}

static int tpa6130a2_right_event(struct snd_soc_dapm_widget *w,
		struct snd_kcontrol *kcontrol, int event)
{
	switch (event) {
	case SND_SOC_DAPM_POST_PMU:
		tpa6130a2_channel_enable(TPA6130A2_HP_EN_R, 1);
		break;
	case SND_SOC_DAPM_POST_PMD:
		tpa6130a2_channel_enable(TPA6130A2_HP_EN_R, 0);
		break;
	}
	return 0;
}

static int tpa6130a2_supply_event(struct snd_soc_dapm_widget *w,
		struct snd_kcontrol *kcontrol, int event)
{
	switch (event) {
	case SND_SOC_DAPM_POST_PMU:
		tpa6130a2_power(1);
		break;
	case SND_SOC_DAPM_POST_PMD:
		tpa6130a2_power(0);
		break;
	}
	return 0;
}

static const struct snd_soc_dapm_widget tpa6130a2_dapm_widgets[] = {
	SND_SOC_DAPM_PGA_E("TPA6130A2 Left", SND_SOC_NOPM,
			0, 0, NULL, 0, tpa6130a2_left_event,
			SND_SOC_DAPM_POST_PMU|SND_SOC_DAPM_POST_PMD),
	SND_SOC_DAPM_PGA_E("TPA6130A2 Right", SND_SOC_NOPM,
			0, 0, NULL, 0, tpa6130a2_right_event,
			SND_SOC_DAPM_POST_PMU|SND_SOC_DAPM_POST_PMD),
	SND_SOC_DAPM_SUPPLY("TPA6130A2 Enable", SND_SOC_NOPM,
			0, 0, tpa6130a2_supply_event,
			SND_SOC_DAPM_POST_PMU|SND_SOC_DAPM_POST_PMD),
	/* Outputs */
	SND_SOC_DAPM_HP("TPA6130A2 Headphone Left", NULL),
	SND_SOC_DAPM_HP("TPA6130A2 Headphone Right", NULL),
};

static const struct snd_soc_dapm_route audio_map[] = {
	{"TPA6130A2 Headphone Left", NULL, "TPA6130A2 Left"},
	{"TPA6130A2 Headphone Right", NULL, "TPA6130A2 Right"},

	{"TPA6130A2 Headphone Left", NULL, "TPA6130A2 Enable"},
	{"TPA6130A2 Headphone Right", NULL, "TPA6130A2 Enable"},
};

int tpa6130a2_add_controls(struct snd_soc_codec *codec)
{
	snd_soc_dapm_new_controls(codec, tpa6130a2_dapm_widgets,
				ARRAY_SIZE(tpa6130a2_dapm_widgets));

	snd_soc_dapm_add_routes(codec, audio_map, ARRAY_SIZE(audio_map));

	return snd_soc_add_controls(codec, tpa6130a2_controls,
				ARRAY_SIZE(tpa6130a2_controls));

}
EXPORT_SYMBOL_GPL(tpa6130a2_add_controls);

static int tpa6130a2_probe(struct i2c_client *client,
			   const struct i2c_device_id *id)
{
	struct device *dev;
	struct tpa6130a2_data *data;
	struct tpa6130a2_platform_data *pdata;
	int ret;

	dev = &client->dev;

	if (client->dev.platform_data == NULL) {
		dev_err(dev, "Platform data not set\n");
		dump_stack();
		return -ENODEV;
	}

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (data == NULL) {
		dev_err(dev, "Can not allocate memory\n");
		return -ENOMEM;
	}

	tpa6130a2_client = client;

	i2c_set_clientdata(tpa6130a2_client, data);

	pdata = client->dev.platform_data;
	data->power_gpio = pdata->power_gpio;

	mutex_init(&data->mutex);

	/* Set default register values */
	data->regs[TPA6130A2_REG_CONTROL] =	TPA6130A2_SWS;
	data->regs[TPA6130A2_REG_VOL_MUTE] =	TPA6130A2_MUTE_R |
						TPA6130A2_MUTE_L;

	if (data->power_gpio >= 0) {
		ret = gpio_request(data->power_gpio, "tpa6130a2 enable");
		if (ret < 0) {
			dev_err(dev, "Failed to request power GPIO (%d)\n",
				data->power_gpio);
			goto fail;
		}
		gpio_direction_output(data->power_gpio, 0);
	} else {
		data->power_state = 1;
		tpa6130a2_initialize();
	}

	tpa6130a2_power(1);

	/* Read version */
	ret = tpa6130a2_i2c_read(TPA6130A2_REG_VERSION) &
				 TPA6130A2_VERSION_MASK;
	if ((ret != 1) && (ret != 2))
		dev_warn(dev, "UNTESTED version detected (%d)\n", ret);

	/* Disable the chip */
	tpa6130a2_power(0);

	return 0;
fail:
	kfree(data);
	i2c_set_clientdata(tpa6130a2_client, NULL);
	tpa6130a2_client = NULL;

	return ret;
}

static int tpa6130a2_remove(struct i2c_client *client)
{
	struct tpa6130a2_data *data = i2c_get_clientdata(client);

	tpa6130a2_power(0);

	if (data->power_gpio >= 0)
		gpio_free(data->power_gpio);
	kfree(data);
	tpa6130a2_client = NULL;

	return 0;
}

static const struct i2c_device_id tpa6130a2_id[] = {
	{ "tpa6130a2", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, tpa6130a2_id);

static struct i2c_driver tpa6130a2_i2c_driver = {
	.driver = {
		.name = "tpa6130a2",
		.owner = THIS_MODULE,
	},
	.probe = tpa6130a2_probe,
	.remove = __devexit_p(tpa6130a2_remove),
	.id_table = tpa6130a2_id,
};

static int __init tpa6130a2_init(void)
{
	return i2c_add_driver(&tpa6130a2_i2c_driver);
}

static void __exit tpa6130a2_exit(void)
{
	i2c_del_driver(&tpa6130a2_i2c_driver);
}

MODULE_AUTHOR("Peter Ujfalusi");
MODULE_DESCRIPTION("TPA6130A2 Headphone amplifier driver");
MODULE_LICENSE("GPL");

module_init(tpa6130a2_init);
module_exit(tpa6130a2_exit);