/*
 * wm8728.c  --  WM8728 ALSA SoC Audio driver
 *
 * Copyright 2008 Wolfson Microelectronics plc
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.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.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/soc-dapm.h>
#include <sound/initval.h>
#include <sound/tlv.h>

#include "wm8728.h"

struct snd_soc_codec_device soc_codec_dev_wm8728;

/*
 * We can't read the WM8728 register space so we cache them instead.
 * Note that the defaults here aren't the physical defaults, we latch
 * the volume update bits, mute the output and enable infinite zero
 * detect.
 */
static const u16 wm8728_reg_defaults[] = {
	0x1ff,
	0x1ff,
	0x001,
	0x100,
};

static inline unsigned int wm8728_read_reg_cache(struct snd_soc_codec *codec,
	unsigned int reg)
{
	u16 *cache = codec->reg_cache;
	BUG_ON(reg > ARRAY_SIZE(wm8728_reg_defaults));
	return cache[reg];
}

static inline void wm8728_write_reg_cache(struct snd_soc_codec *codec,
	u16 reg, unsigned int value)
{
	u16 *cache = codec->reg_cache;
	BUG_ON(reg > ARRAY_SIZE(wm8728_reg_defaults));
	cache[reg] = value;
}

/*
 * write to the WM8728 register space
 */
static int wm8728_write(struct snd_soc_codec *codec, unsigned int reg,
	unsigned int value)
{
	u8 data[2];

	/* data is
	 *   D15..D9 WM8728 register offset
	 *   D8...D0 register data
	 */
	data[0] = (reg << 1) | ((value >> 8) & 0x0001);
	data[1] = value & 0x00ff;

	wm8728_write_reg_cache(codec, reg, value);

	if (codec->hw_write(codec->control_data, data, 2) == 2)
		return 0;
	else
		return -EIO;
}

static const DECLARE_TLV_DB_SCALE(wm8728_tlv, -12750, 50, 1);

static const struct snd_kcontrol_new wm8728_snd_controls[] = {

SOC_DOUBLE_R_TLV("Digital Playback Volume", WM8728_DACLVOL, WM8728_DACRVOL,
		 0, 255, 0, wm8728_tlv),

SOC_SINGLE("Deemphasis", WM8728_DACCTL, 1, 1, 0),
};

static int wm8728_add_controls(struct snd_soc_codec *codec)
{
	int err, i;

	for (i = 0; i < ARRAY_SIZE(wm8728_snd_controls); i++) {
		err = snd_ctl_add(codec->card,
				  snd_soc_cnew(&wm8728_snd_controls[i],
						codec, NULL));
		if (err < 0)
			return err;
	}

	return 0;
}

/*
 * DAPM controls.
 */
static const struct snd_soc_dapm_widget wm8728_dapm_widgets[] = {
SND_SOC_DAPM_DAC("DAC", "HiFi Playback", SND_SOC_NOPM, 0, 0),
SND_SOC_DAPM_OUTPUT("VOUTL"),
SND_SOC_DAPM_OUTPUT("VOUTR"),
};

static const struct snd_soc_dapm_route intercon[] = {
	{"VOUTL", NULL, "DAC"},
	{"VOUTR", NULL, "DAC"},
};

static int wm8728_add_widgets(struct snd_soc_codec *codec)
{
	snd_soc_dapm_new_controls(codec, wm8728_dapm_widgets,
				  ARRAY_SIZE(wm8728_dapm_widgets));

	snd_soc_dapm_add_routes(codec, intercon, ARRAY_SIZE(intercon));

	snd_soc_dapm_new_widgets(codec);

	return 0;
}

static int wm8728_mute(struct snd_soc_dai *dai, int mute)
{
	struct snd_soc_codec *codec = dai->codec;
	u16 mute_reg = wm8728_read_reg_cache(codec, WM8728_DACCTL);

	if (mute)
		wm8728_write(codec, WM8728_DACCTL, mute_reg | 1);
	else
		wm8728_write(codec, WM8728_DACCTL, mute_reg & ~1);

	return 0;
}

static int wm8728_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params,
	struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_soc_codec *codec = socdev->codec;
	u16 dac = wm8728_read_reg_cache(codec, WM8728_DACCTL);

	dac &= ~0x18;

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S16_LE:
		break;
	case SNDRV_PCM_FORMAT_S20_3LE:
		dac |= 0x10;
		break;
	case SNDRV_PCM_FORMAT_S24_LE:
		dac |= 0x08;
		break;
	default:
		return -EINVAL;
	}

	wm8728_write(codec, WM8728_DACCTL, dac);

	return 0;
}

static int wm8728_set_dai_fmt(struct snd_soc_dai *codec_dai,
		unsigned int fmt)
{
	struct snd_soc_codec *codec = codec_dai->codec;
	u16 iface = wm8728_read_reg_cache(codec, WM8728_IFCTL);

	/* Currently only I2S is supported by the driver, though the
	 * hardware is more flexible.
	 */
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
		iface |= 1;
		break;
	default:
		return -EINVAL;
	}

	/* The hardware only support full slave mode */
	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBS_CFS:
		break;
	default:
		return -EINVAL;
	}

	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
		iface &= ~0x22;
		break;
	case SND_SOC_DAIFMT_IB_NF:
		iface |=  0x20;
		iface &= ~0x02;
		break;
	case SND_SOC_DAIFMT_NB_IF:
		iface |= 0x02;
		iface &= ~0x20;
		break;
	case SND_SOC_DAIFMT_IB_IF:
		iface |= 0x22;
		break;
	default:
		return -EINVAL;
	}

	wm8728_write(codec, WM8728_IFCTL, iface);
	return 0;
}

static int wm8728_set_bias_level(struct snd_soc_codec *codec,
				 enum snd_soc_bias_level level)
{
	u16 reg;
	int i;

	switch (level) {
	case SND_SOC_BIAS_ON:
	case SND_SOC_BIAS_PREPARE:
	case SND_SOC_BIAS_STANDBY:
		if (codec->bias_level == SND_SOC_BIAS_OFF) {
			/* Power everything up... */
			reg = wm8728_read_reg_cache(codec, WM8728_DACCTL);
			wm8728_write(codec, WM8728_DACCTL, reg & ~0x4);

			/* ..then sync in the register cache. */
			for (i = 0; i < ARRAY_SIZE(wm8728_reg_defaults); i++)
				wm8728_write(codec, i,
					     wm8728_read_reg_cache(codec, i));
		}
		break;

	case SND_SOC_BIAS_OFF:
		reg = wm8728_read_reg_cache(codec, WM8728_DACCTL);
		wm8728_write(codec, WM8728_DACCTL, reg | 0x4);
		break;
	}
	codec->bias_level = level;
	return 0;
}

#define WM8728_RATES (SNDRV_PCM_RATE_8000_192000)

#define WM8728_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE |\
	SNDRV_PCM_FMTBIT_S24_LE)

struct snd_soc_dai wm8728_dai = {
	.name = "WM8728",
	.playback = {
		.stream_name = "Playback",
		.channels_min = 2,
		.channels_max = 2,
		.rates = WM8728_RATES,
		.formats = WM8728_FORMATS,
	},
	.ops = {
		 .hw_params = wm8728_hw_params,
		 .digital_mute = wm8728_mute,
		 .set_fmt = wm8728_set_dai_fmt,
	}
};
EXPORT_SYMBOL_GPL(wm8728_dai);

static int wm8728_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
	struct snd_soc_codec *codec = socdev->codec;

	wm8728_set_bias_level(codec, SND_SOC_BIAS_OFF);

	return 0;
}

static int wm8728_resume(struct platform_device *pdev)
{
	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
	struct snd_soc_codec *codec = socdev->codec;

	wm8728_set_bias_level(codec, codec->suspend_bias_level);

	return 0;
}

/*
 * initialise the WM8728 driver
 * register the mixer and dsp interfaces with the kernel
 */
static int wm8728_init(struct snd_soc_device *socdev)
{
	struct snd_soc_codec *codec = socdev->codec;
	int ret = 0;

	codec->name = "WM8728";
	codec->owner = THIS_MODULE;
	codec->read = wm8728_read_reg_cache;
	codec->write = wm8728_write;
	codec->set_bias_level = wm8728_set_bias_level;
	codec->dai = &wm8728_dai;
	codec->num_dai = 1;
	codec->bias_level = SND_SOC_BIAS_OFF;
	codec->reg_cache_size = ARRAY_SIZE(wm8728_reg_defaults);
	codec->reg_cache = kmemdup(wm8728_reg_defaults,
				   sizeof(wm8728_reg_defaults),
				   GFP_KERNEL);
	if (codec->reg_cache == NULL)
		return -ENOMEM;

	/* register pcms */
	ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
	if (ret < 0) {
		printk(KERN_ERR "wm8728: failed to create pcms\n");
		goto pcm_err;
	}

	/* power on device */
	wm8728_set_bias_level(codec, SND_SOC_BIAS_STANDBY);

	wm8728_add_controls(codec);
	wm8728_add_widgets(codec);
	ret = snd_soc_init_card(socdev);
	if (ret < 0) {
		printk(KERN_ERR "wm8728: failed to register card\n");
		goto card_err;
	}

	return ret;

card_err:
	snd_soc_free_pcms(socdev);
	snd_soc_dapm_free(socdev);
pcm_err:
	kfree(codec->reg_cache);
	return ret;
}

static struct snd_soc_device *wm8728_socdev;

#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)

/*
 * WM8728 2 wire address is determined by GPIO5
 * state during powerup.
 *    low  = 0x1a
 *    high = 0x1b
 */

static int wm8728_i2c_probe(struct i2c_client *i2c,
			    const struct i2c_device_id *id)
{
	struct snd_soc_device *socdev = wm8728_socdev;
	struct snd_soc_codec *codec = socdev->codec;
	int ret;

	i2c_set_clientdata(i2c, codec);
	codec->control_data = i2c;

	ret = wm8728_init(socdev);
	if (ret < 0)
		pr_err("failed to initialise WM8728\n");

	return ret;
}

static int wm8728_i2c_remove(struct i2c_client *client)
{
	struct snd_soc_codec *codec = i2c_get_clientdata(client);
	kfree(codec->reg_cache);
	return 0;
}

static const struct i2c_device_id wm8728_i2c_id[] = {
	{ "wm8728", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, wm8728_i2c_id);

static struct i2c_driver wm8728_i2c_driver = {
	.driver = {
		.name = "WM8728 I2C Codec",
		.owner = THIS_MODULE,
	},
	.probe =    wm8728_i2c_probe,
	.remove =   wm8728_i2c_remove,
	.id_table = wm8728_i2c_id,
};

static int wm8728_add_i2c_device(struct platform_device *pdev,
				 const struct wm8728_setup_data *setup)
{
	struct i2c_board_info info;
	struct i2c_adapter *adapter;
	struct i2c_client *client;
	int ret;

	ret = i2c_add_driver(&wm8728_i2c_driver);
	if (ret != 0) {
		dev_err(&pdev->dev, "can't add i2c driver\n");
		return ret;
	}

	memset(&info, 0, sizeof(struct i2c_board_info));
	info.addr = setup->i2c_address;
	strlcpy(info.type, "wm8728", I2C_NAME_SIZE);

	adapter = i2c_get_adapter(setup->i2c_bus);
	if (!adapter) {
		dev_err(&pdev->dev, "can't get i2c adapter %d\n",
			setup->i2c_bus);
		goto err_driver;
	}

	client = i2c_new_device(adapter, &info);
	i2c_put_adapter(adapter);
	if (!client) {
		dev_err(&pdev->dev, "can't add i2c device at 0x%x\n",
			(unsigned int)info.addr);
		goto err_driver;
	}

	return 0;

err_driver:
	i2c_del_driver(&wm8728_i2c_driver);
	return -ENODEV;
}
#endif

#if defined(CONFIG_SPI_MASTER)
static int __devinit wm8728_spi_probe(struct spi_device *spi)
{
	struct snd_soc_device *socdev = wm8728_socdev;
	struct snd_soc_codec *codec = socdev->codec;
	int ret;

	codec->control_data = spi;

	ret = wm8728_init(socdev);
	if (ret < 0)
		dev_err(&spi->dev, "failed to initialise WM8728\n");

	return ret;
}

static int __devexit wm8728_spi_remove(struct spi_device *spi)
{
	return 0;
}

static struct spi_driver wm8728_spi_driver = {
	.driver = {
		.name	= "wm8728",
		.bus	= &spi_bus_type,
		.owner	= THIS_MODULE,
	},
	.probe		= wm8728_spi_probe,
	.remove		= __devexit_p(wm8728_spi_remove),
};

static int wm8728_spi_write(struct spi_device *spi, const char *data, int len)
{
	struct spi_transfer t;
	struct spi_message m;
	u8 msg[2];

	if (len <= 0)
		return 0;

	msg[0] = data[0];
	msg[1] = data[1];

	spi_message_init(&m);
	memset(&t, 0, (sizeof t));

	t.tx_buf = &msg[0];
	t.len = len;

	spi_message_add_tail(&t, &m);
	spi_sync(spi, &m);

	return len;
}
#endif /* CONFIG_SPI_MASTER */

static int wm8728_probe(struct platform_device *pdev)
{
	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
	struct wm8728_setup_data *setup;
	struct snd_soc_codec *codec;
	int ret = 0;

	setup = socdev->codec_data;
	codec = kzalloc(sizeof(struct snd_soc_codec), GFP_KERNEL);
	if (codec == NULL)
		return -ENOMEM;

	socdev->codec = codec;
	mutex_init(&codec->mutex);
	INIT_LIST_HEAD(&codec->dapm_widgets);
	INIT_LIST_HEAD(&codec->dapm_paths);

	wm8728_socdev = socdev;
	ret = -ENODEV;

#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
	if (setup->i2c_address) {
		codec->hw_write = (hw_write_t)i2c_master_send;
		ret = wm8728_add_i2c_device(pdev, setup);
	}
#endif
#if defined(CONFIG_SPI_MASTER)
	if (setup->spi) {
		codec->hw_write = (hw_write_t)wm8728_spi_write;
		ret = spi_register_driver(&wm8728_spi_driver);
		if (ret != 0)
			printk(KERN_ERR "can't add spi driver");
	}
#endif

	if (ret != 0)
		kfree(codec);

	return ret;
}

/* power down chip */
static int wm8728_remove(struct platform_device *pdev)
{
	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
	struct snd_soc_codec *codec = socdev->codec;

	if (codec->control_data)
		wm8728_set_bias_level(codec, SND_SOC_BIAS_OFF);

	snd_soc_free_pcms(socdev);
	snd_soc_dapm_free(socdev);
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
	i2c_unregister_device(codec->control_data);
	i2c_del_driver(&wm8728_i2c_driver);
#endif
#if defined(CONFIG_SPI_MASTER)
	spi_unregister_driver(&wm8728_spi_driver);
#endif
	kfree(codec);

	return 0;
}

struct snd_soc_codec_device soc_codec_dev_wm8728 = {
	.probe = 	wm8728_probe,
	.remove = 	wm8728_remove,
	.suspend = 	wm8728_suspend,
	.resume =	wm8728_resume,
};
EXPORT_SYMBOL_GPL(soc_codec_dev_wm8728);

static int __init wm8728_modinit(void)
{
	return snd_soc_register_dai(&wm8728_dai);
}
module_init(wm8728_modinit);

static void __exit wm8728_exit(void)
{
	snd_soc_unregister_dai(&wm8728_dai);
}
module_exit(wm8728_exit);

MODULE_DESCRIPTION("ASoC WM8728 driver");
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_LICENSE("GPL");