/*
 * extcon-arizona.c - Extcon driver Wolfson Arizona devices
 *
 *  Copyright (C) 2012 Wolfson Microelectronics plc
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/extcon.h>

#include <linux/mfd/arizona/core.h>
#include <linux/mfd/arizona/pdata.h>
#include <linux/mfd/arizona/registers.h>

#define ARIZONA_NUM_BUTTONS 6

struct arizona_extcon_info {
	struct device *dev;
	struct arizona *arizona;
	struct mutex lock;
	struct regulator *micvdd;
	struct input_dev *input;

	int micd_mode;
	const struct arizona_micd_config *micd_modes;
	int micd_num_modes;

	bool micd_reva;

	bool mic;
	bool detecting;
	int jack_flips;

	struct extcon_dev edev;
};

static const struct arizona_micd_config micd_default_modes[] = {
	{ ARIZONA_ACCDET_SRC, 1 << ARIZONA_MICD_BIAS_SRC_SHIFT, 0 },
	{ 0,                  2 << ARIZONA_MICD_BIAS_SRC_SHIFT, 1 },
};

static struct {
	u16 status;
	int report;
} arizona_lvl_to_key[ARIZONA_NUM_BUTTONS] = {
	{  0x1, BTN_0 },
	{  0x2, BTN_1 },
	{  0x4, BTN_2 },
	{  0x8, BTN_3 },
	{ 0x10, BTN_4 },
	{ 0x20, BTN_5 },
};

#define ARIZONA_CABLE_MECHANICAL 0
#define ARIZONA_CABLE_MICROPHONE 1
#define ARIZONA_CABLE_HEADPHONE  2

static const char *arizona_cable[] = {
	"Mechanical",
	"Microphone",
	"Headphone",
	NULL,
};

static void arizona_extcon_set_mode(struct arizona_extcon_info *info, int mode)
{
	struct arizona *arizona = info->arizona;

	gpio_set_value_cansleep(arizona->pdata.micd_pol_gpio,
				info->micd_modes[mode].gpio);
	regmap_update_bits(arizona->regmap, ARIZONA_MIC_DETECT_1,
			   ARIZONA_MICD_BIAS_SRC_MASK,
			   info->micd_modes[mode].bias);
	regmap_update_bits(arizona->regmap, ARIZONA_ACCESSORY_DETECT_MODE_1,
			   ARIZONA_ACCDET_SRC, info->micd_modes[mode].src);

	info->micd_mode = mode;

	dev_dbg(arizona->dev, "Set jack polarity to %d\n", mode);
}

static void arizona_start_mic(struct arizona_extcon_info *info)
{
	struct arizona *arizona = info->arizona;
	bool change;
	int ret;

	info->detecting = true;
	info->mic = false;
	info->jack_flips = 0;

	/* Microphone detection can't use idle mode */
	pm_runtime_get(info->dev);

	ret = regulator_enable(info->micvdd);
	if (ret != 0) {
		dev_err(arizona->dev, "Failed to enable MICVDD: %d\n",
			ret);
	}

	if (info->micd_reva) {
		regmap_write(arizona->regmap, 0x80, 0x3);
		regmap_write(arizona->regmap, 0x294, 0);
		regmap_write(arizona->regmap, 0x80, 0x0);
	}

	regmap_update_bits_check(arizona->regmap, ARIZONA_MIC_DETECT_1,
				 ARIZONA_MICD_ENA, ARIZONA_MICD_ENA,
				 &change);
	if (!change) {
		regulator_disable(info->micvdd);
		pm_runtime_put_autosuspend(info->dev);
	}
}

static void arizona_stop_mic(struct arizona_extcon_info *info)
{
	struct arizona *arizona = info->arizona;
	bool change;

	regmap_update_bits_check(arizona->regmap, ARIZONA_MIC_DETECT_1,
				 ARIZONA_MICD_ENA, 0,
				 &change);

	if (info->micd_reva) {
		regmap_write(arizona->regmap, 0x80, 0x3);
		regmap_write(arizona->regmap, 0x294, 2);
		regmap_write(arizona->regmap, 0x80, 0x0);
	}

	if (change) {
		regulator_disable(info->micvdd);
		pm_runtime_mark_last_busy(info->dev);
		pm_runtime_put_autosuspend(info->dev);
	}
}

static irqreturn_t arizona_micdet(int irq, void *data)
{
	struct arizona_extcon_info *info = data;
	struct arizona *arizona = info->arizona;
	unsigned int val, lvl;
	int ret, i;

	mutex_lock(&info->lock);

	ret = regmap_read(arizona->regmap, ARIZONA_MIC_DETECT_3, &val);
	if (ret != 0) {
		dev_err(arizona->dev, "Failed to read MICDET: %d\n", ret);
		return IRQ_NONE;
	}

	dev_dbg(arizona->dev, "MICDET: %x\n", val);

	if (!(val & ARIZONA_MICD_VALID)) {
		dev_warn(arizona->dev, "Microphone detection state invalid\n");
		mutex_unlock(&info->lock);
		return IRQ_NONE;
	}

	/* Due to jack detect this should never happen */
	if (!(val & ARIZONA_MICD_STS)) {
		dev_warn(arizona->dev, "Detected open circuit\n");
		info->detecting = false;
		goto handled;
	}

	/* If we got a high impedence we should have a headset, report it. */
	if (info->detecting && (val & 0x400)) {
		ret = extcon_update_state(&info->edev,
					  1 << ARIZONA_CABLE_MICROPHONE |
					  1 << ARIZONA_CABLE_HEADPHONE,
					  1 << ARIZONA_CABLE_MICROPHONE |
					  1 << ARIZONA_CABLE_HEADPHONE);

		if (ret != 0)
			dev_err(arizona->dev, "Headset report failed: %d\n",
				ret);

		info->mic = true;
		info->detecting = false;
		goto handled;
	}

	/* If we detected a lower impedence during initial startup
	 * then we probably have the wrong polarity, flip it.  Don't
	 * do this for the lowest impedences to speed up detection of
	 * plain headphones.  If both polarities report a low
	 * impedence then give up and report headphones.
	 */
	if (info->detecting && (val & 0x3f8)) {
		info->jack_flips++;

		if (info->jack_flips >= info->micd_num_modes) {
			dev_dbg(arizona->dev, "Detected headphone\n");
			info->detecting = false;
			arizona_stop_mic(info);

			ret = extcon_set_cable_state_(&info->edev,
						      ARIZONA_CABLE_HEADPHONE,
						      true);
			if (ret != 0)
				dev_err(arizona->dev,
					"Headphone report failed: %d\n",
				ret);
		} else {
			info->micd_mode++;
			if (info->micd_mode == info->micd_num_modes)
				info->micd_mode = 0;
			arizona_extcon_set_mode(info, info->micd_mode);

			info->jack_flips++;
		}

		goto handled;
	}

	/*
	 * If we're still detecting and we detect a short then we've
	 * got a headphone.  Otherwise it's a button press.
	 */
	if (val & 0x3fc) {
		if (info->mic) {
			dev_dbg(arizona->dev, "Mic button detected\n");

			lvl = val & ARIZONA_MICD_LVL_MASK;
			lvl >>= ARIZONA_MICD_LVL_SHIFT;

			for (i = 0; i < ARIZONA_NUM_BUTTONS; i++)
				if (lvl & arizona_lvl_to_key[i].status)
					input_report_key(info->input,
							 arizona_lvl_to_key[i].report,
							 1);
			input_sync(info->input);

		} else if (info->detecting) {
			dev_dbg(arizona->dev, "Headphone detected\n");
			info->detecting = false;
			arizona_stop_mic(info);

			ret = extcon_set_cable_state_(&info->edev,
						      ARIZONA_CABLE_HEADPHONE,
						      true);
			if (ret != 0)
				dev_err(arizona->dev,
					"Headphone report failed: %d\n",
				ret);
		} else {
			dev_warn(arizona->dev, "Button with no mic: %x\n",
				 val);
		}
	} else {
		dev_dbg(arizona->dev, "Mic button released\n");
		for (i = 0; i < ARIZONA_NUM_BUTTONS; i++)
			input_report_key(info->input,
					 arizona_lvl_to_key[i].report, 0);
		input_sync(info->input);
	}

handled:
	pm_runtime_mark_last_busy(info->dev);
	mutex_unlock(&info->lock);

	return IRQ_HANDLED;
}

static irqreturn_t arizona_jackdet(int irq, void *data)
{
	struct arizona_extcon_info *info = data;
	struct arizona *arizona = info->arizona;
	unsigned int val;
	int ret, i;

	pm_runtime_get_sync(info->dev);

	mutex_lock(&info->lock);

	ret = regmap_read(arizona->regmap, ARIZONA_AOD_IRQ_RAW_STATUS, &val);
	if (ret != 0) {
		dev_err(arizona->dev, "Failed to read jackdet status: %d\n",
			ret);
		mutex_unlock(&info->lock);
		pm_runtime_put_autosuspend(info->dev);
		return IRQ_NONE;
	}

	if (val & ARIZONA_JD1_STS) {
		dev_dbg(arizona->dev, "Detected jack\n");
		ret = extcon_set_cable_state_(&info->edev,
					      ARIZONA_CABLE_MECHANICAL, true);

		if (ret != 0)
			dev_err(arizona->dev, "Mechanical report failed: %d\n",
				ret);

		arizona_start_mic(info);
	} else {
		dev_dbg(arizona->dev, "Detected jack removal\n");

		arizona_stop_mic(info);

		for (i = 0; i < ARIZONA_NUM_BUTTONS; i++)
			input_report_key(info->input,
					 arizona_lvl_to_key[i].report, 0);
		input_sync(info->input);

		ret = extcon_update_state(&info->edev, 0xffffffff, 0);
		if (ret != 0)
			dev_err(arizona->dev, "Removal report failed: %d\n",
				ret);
	}

	mutex_unlock(&info->lock);

	pm_runtime_mark_last_busy(info->dev);
	pm_runtime_put_autosuspend(info->dev);

	return IRQ_HANDLED;
}

static int arizona_extcon_probe(struct platform_device *pdev)
{
	struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
	struct arizona_pdata *pdata;
	struct arizona_extcon_info *info;
	int ret, mode, i;

	pdata = dev_get_platdata(arizona->dev);

	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	if (!info) {
		dev_err(&pdev->dev, "Failed to allocate memory\n");
		ret = -ENOMEM;
		goto err;
	}

	info->micvdd = devm_regulator_get(arizona->dev, "MICVDD");
	if (IS_ERR(info->micvdd)) {
		ret = PTR_ERR(info->micvdd);
		dev_err(arizona->dev, "Failed to get MICVDD: %d\n", ret);
		goto err;
	}

	mutex_init(&info->lock);
	info->arizona = arizona;
	info->dev = &pdev->dev;
	info->detecting = true;
	platform_set_drvdata(pdev, info);

	switch (arizona->type) {
	case WM5102:
		switch (arizona->rev) {
		case 0:
			info->micd_reva = true;
			break;
		default:
			break;
		}
		break;
	default:
		break;
	}

	info->edev.name = "Headset Jack";
	info->edev.supported_cable = arizona_cable;

	ret = extcon_dev_register(&info->edev, arizona->dev);
	if (ret < 0) {
		dev_err(arizona->dev, "extcon_dev_register() failed: %d\n",
			ret);
		goto err;
	}

	if (pdata->num_micd_configs) {
		info->micd_modes = pdata->micd_configs;
		info->micd_num_modes = pdata->num_micd_configs;
	} else {
		info->micd_modes = micd_default_modes;
		info->micd_num_modes = ARRAY_SIZE(micd_default_modes);
	}

	if (arizona->pdata.micd_pol_gpio > 0) {
		if (info->micd_modes[0].gpio)
			mode = GPIOF_OUT_INIT_HIGH;
		else
			mode = GPIOF_OUT_INIT_LOW;

		ret = devm_gpio_request_one(&pdev->dev,
					    arizona->pdata.micd_pol_gpio,
					    mode,
					    "MICD polarity");
		if (ret != 0) {
			dev_err(arizona->dev, "Failed to request GPIO%d: %d\n",
				arizona->pdata.micd_pol_gpio, ret);
			goto err_register;
		}
	}

	arizona_extcon_set_mode(info, 0);

	info->input = input_allocate_device();
	if (!info->input) {
		dev_err(arizona->dev, "Can't allocate input dev\n");
		ret = -ENOMEM;
		goto err_register;
	}

	for (i = 0; i < ARIZONA_NUM_BUTTONS; i++)
		input_set_capability(info->input, EV_KEY,
				     arizona_lvl_to_key[i].report);
	info->input->name = "Headset";
	info->input->phys = "arizona/extcon";
	info->input->dev.parent = &pdev->dev;

	pm_runtime_enable(&pdev->dev);
	pm_runtime_idle(&pdev->dev);
	pm_runtime_get_sync(&pdev->dev);

	ret = arizona_request_irq(arizona, ARIZONA_IRQ_JD_RISE,
				  "JACKDET rise", arizona_jackdet, info);
	if (ret != 0) {
		dev_err(&pdev->dev, "Failed to get JACKDET rise IRQ: %d\n",
			ret);
		goto err_input;
	}

	ret = arizona_set_irq_wake(arizona, ARIZONA_IRQ_JD_RISE, 1);
	if (ret != 0) {
		dev_err(&pdev->dev, "Failed to set JD rise IRQ wake: %d\n",
			ret);
		goto err_rise;
	}

	ret = arizona_request_irq(arizona, ARIZONA_IRQ_JD_FALL,
				  "JACKDET fall", arizona_jackdet, info);
	if (ret != 0) {
		dev_err(&pdev->dev, "Failed to get JD fall IRQ: %d\n", ret);
		goto err_rise_wake;
	}

	ret = arizona_set_irq_wake(arizona, ARIZONA_IRQ_JD_FALL, 1);
	if (ret != 0) {
		dev_err(&pdev->dev, "Failed to set JD fall IRQ wake: %d\n",
			ret);
		goto err_fall;
	}

	ret = arizona_request_irq(arizona, ARIZONA_IRQ_MICDET,
				  "MICDET", arizona_micdet, info);
	if (ret != 0) {
		dev_err(&pdev->dev, "Failed to get MICDET IRQ: %d\n", ret);
		goto err_fall_wake;
	}

	regmap_update_bits(arizona->regmap, ARIZONA_MIC_DETECT_1,
			   ARIZONA_MICD_BIAS_STARTTIME_MASK |
			   ARIZONA_MICD_RATE_MASK,
			   7 << ARIZONA_MICD_BIAS_STARTTIME_SHIFT |
			   8 << ARIZONA_MICD_RATE_SHIFT);

	arizona_clk32k_enable(arizona);
	regmap_update_bits(arizona->regmap, ARIZONA_JACK_DETECT_DEBOUNCE,
			   ARIZONA_JD1_DB, ARIZONA_JD1_DB);
	regmap_update_bits(arizona->regmap, ARIZONA_JACK_DETECT_ANALOGUE,
			   ARIZONA_JD1_ENA, ARIZONA_JD1_ENA);

	ret = regulator_allow_bypass(info->micvdd, true);
	if (ret != 0)
		dev_warn(arizona->dev, "Failed to set MICVDD to bypass: %d\n",
			 ret);

	pm_runtime_put(&pdev->dev);

	ret = input_register_device(info->input);
	if (ret) {
		dev_err(&pdev->dev, "Can't register input device: %d\n", ret);
		goto err_micdet;
	}

	return 0;

err_micdet:
	arizona_free_irq(arizona, ARIZONA_IRQ_MICDET, info);
err_fall_wake:
	arizona_set_irq_wake(arizona, ARIZONA_IRQ_JD_FALL, 0);
err_fall:
	arizona_free_irq(arizona, ARIZONA_IRQ_JD_FALL, info);
err_rise_wake:
	arizona_set_irq_wake(arizona, ARIZONA_IRQ_JD_RISE, 0);
err_rise:
	arizona_free_irq(arizona, ARIZONA_IRQ_JD_RISE, info);
err_input:
	input_free_device(info->input);
err_register:
	pm_runtime_disable(&pdev->dev);
	extcon_dev_unregister(&info->edev);
err:
	return ret;
}

static int arizona_extcon_remove(struct platform_device *pdev)
{
	struct arizona_extcon_info *info = platform_get_drvdata(pdev);
	struct arizona *arizona = info->arizona;

	pm_runtime_disable(&pdev->dev);

	arizona_set_irq_wake(arizona, ARIZONA_IRQ_JD_RISE, 0);
	arizona_set_irq_wake(arizona, ARIZONA_IRQ_JD_FALL, 0);
	arizona_free_irq(arizona, ARIZONA_IRQ_MICDET, info);
	arizona_free_irq(arizona, ARIZONA_IRQ_JD_RISE, info);
	arizona_free_irq(arizona, ARIZONA_IRQ_JD_FALL, info);
	regmap_update_bits(arizona->regmap, ARIZONA_JACK_DETECT_ANALOGUE,
			   ARIZONA_JD1_ENA, 0);
	arizona_clk32k_disable(arizona);
	input_unregister_device(info->input);
	extcon_dev_unregister(&info->edev);

	return 0;
}

static struct platform_driver arizona_extcon_driver = {
	.driver		= {
		.name	= "arizona-extcon",
		.owner	= THIS_MODULE,
	},
	.probe		= arizona_extcon_probe,
	.remove		= arizona_extcon_remove,
};

module_platform_driver(arizona_extcon_driver);

MODULE_DESCRIPTION("Arizona Extcon driver");
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:extcon-arizona");