/*
 * Copyright (C) 2016 MediaTek, Inc.
 *
 * Author: Chen Zhong <chen.zhong@mediatek.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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/input.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/kernel.h>
#include <linux/mfd/mt6323/registers.h>
#include <linux/mfd/mt6392/registers.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/mfd/mt6397/registers.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#define PMIC_RG_PWRKEY_RST_EN_MASK 0x1
#define PMIC_RG_PWRKEY_RST_EN_SHIFT 6
#define PMIC_RG_HOMEKEY_RST_EN_MASK 0x1
#define PMIC_RG_HOMEKEY_RST_EN_SHIFT 5
#define PMIC_RG_RST_DU_MASK 0x3
#define PMIC_RG_RST_DU_SHIFT 8

struct wakeup_source *pwrkey_lock;
#define PWRKEY_INITIAL_STATE (0)

struct pmic_keys_regs {
	u32 deb_reg;
	u32 deb_mask;
	u32 intsel_reg;
	u32 intsel_mask;
};

#define PMIC_KEYS_REGS(_deb_reg, _deb_mask, _intsel_reg, _intsel_mask)         \
	{                                                                      \
		.deb_reg = _deb_reg, .deb_mask = _deb_mask,                    \
		.intsel_reg = _intsel_reg, .intsel_mask = _intsel_mask,        \
	}

struct pmic_regs {
	const struct pmic_keys_regs pwrkey_regs;
	const struct pmic_keys_regs homekey_regs;
	u32 pmic_rst_reg;
	u8 indie_release_irq_mask;
};

static const struct pmic_regs mt6397_regs = {
	.pwrkey_regs =
		PMIC_KEYS_REGS(MT6397_CHRSTATUS, 0x8, MT6397_INT_RSV, 0x10),
	.homekey_regs =
		PMIC_KEYS_REGS(MT6397_OCSTATUS2, 0x10, MT6397_INT_RSV, 0x8),
	.pmic_rst_reg = MT6397_TOP_RST_MISC,
	.indie_release_irq_mask = 0,
};

static const struct pmic_regs mt6323_regs = {
	.pwrkey_regs = PMIC_KEYS_REGS(MT6323_CHRSTATUS, 0x2,
				      MT6323_INT_MISC_CON, 0x10),
	.homekey_regs =
		PMIC_KEYS_REGS(MT6323_CHRSTATUS, 0x4, MT6323_INT_MISC_CON, 0x8),
	.pmic_rst_reg = MT6323_TOP_RST_MISC,
	.indie_release_irq_mask = 0,
};

static const struct pmic_regs mt6392_regs = {
	.pwrkey_regs = PMIC_KEYS_REGS(MT6392_CHRSTATUS, 0x2,
				      MT6392_INT_MISC_CON, 0x10),
	.homekey_regs =
		PMIC_KEYS_REGS(MT6392_CHRSTATUS, 0x4, MT6392_INT_MISC_CON, 0x8),
	.pmic_rst_reg = MT6392_TOP_RST_MISC,
	.indie_release_irq_mask = 1,
};

struct pmic_keys_info {
	struct mtk_pmic_keys *keys;
	const struct pmic_keys_regs *regs;
	int keycode;
	int irq;
	u32 hw_irq;
};

struct mtk_pmic_keys {
	struct input_dev *input_dev;
	struct device *dev;
	struct regmap *regmap;
	struct irq_domain *irq_domain;
	struct pmic_keys_info pwrkey, homekey, pwr_release, home_release;
	u8 indie_release_irq_mask;
};

enum long_press_mode {
	LP_DISABLE,
	LP_ONEKEY,
	LP_TWOKEY,
};

static void mtk_pmic_long_press_reset_setup(struct mtk_pmic_keys *keys,
					    u32 pmic_rst_reg)
{
	int ret;
	u32 long_press_mode, long_press_duration;

	ret = of_property_read_u32(keys->dev->of_node,
				   "mediatek,long-press-duration",
				   &long_press_duration);
	if (ret)
		long_press_duration = 0;

	regmap_update_bits(keys->regmap, pmic_rst_reg,
			   PMIC_RG_RST_DU_MASK << PMIC_RG_RST_DU_SHIFT,
			   long_press_duration << PMIC_RG_RST_DU_SHIFT);
	regmap_update_bits(
		keys->regmap, pmic_rst_reg,
		PMIC_RG_PWRKEY_RST_EN_MASK << PMIC_RG_PWRKEY_RST_EN_SHIFT,
		PMIC_RG_PWRKEY_RST_EN_MASK << PMIC_RG_PWRKEY_RST_EN_SHIFT);

	ret = of_property_read_u32(keys->dev->of_node,
				   "mediatek,long-press-mode",
				   &long_press_mode);

	if (!ret && long_press_mode == LP_ONEKEY) {
		regmap_update_bits(keys->regmap, pmic_rst_reg,
				   PMIC_RG_HOMEKEY_RST_EN_MASK
					   << PMIC_RG_HOMEKEY_RST_EN_SHIFT,
				   0);
	} else if (!ret && long_press_mode == LP_TWOKEY) {
		regmap_update_bits(keys->regmap, pmic_rst_reg,
				   PMIC_RG_HOMEKEY_RST_EN_MASK
					   << PMIC_RG_HOMEKEY_RST_EN_SHIFT,
				   PMIC_RG_HOMEKEY_RST_EN_MASK
					   << PMIC_RG_HOMEKEY_RST_EN_SHIFT);
	} else {
		regmap_update_bits(keys->regmap, pmic_rst_reg,
				   PMIC_RG_PWRKEY_RST_EN_MASK
					   << PMIC_RG_PWRKEY_RST_EN_SHIFT,
				   0);
		regmap_update_bits(keys->regmap, pmic_rst_reg,
				   PMIC_RG_HOMEKEY_RST_EN_MASK
					   << PMIC_RG_HOMEKEY_RST_EN_SHIFT,
				   0);
	}
}

static irqreturn_t mtk_pmic_keys_irq_handler_thread(int irq, void *data)
{
	struct pmic_keys_info *info = data;
	u32 key_deb, pressed;

	regmap_read(info->keys->regmap, info->regs->deb_reg, &key_deb);

	key_deb &= info->regs->deb_mask;

	pressed = !key_deb;

	input_report_key(info->keys->input_dev, info->keycode, pressed);
	input_sync(info->keys->input_dev);
	if (pressed)
		__pm_stay_awake(pwrkey_lock);
	else
		__pm_wakeup_event(pwrkey_lock, HZ/2);

	dev_info(info->keys->dev, "[PMICKEYS] (%s) key =%d using PMIC\n",
		 pressed ? "pressed" : "released", info->keycode);

	return IRQ_HANDLED;
}

static int mtk_pmic_key_setup(struct mtk_pmic_keys *keys, const char *propname,
			      struct pmic_keys_info *info, bool wakeup)
{
	int ret;

	ret = of_property_read_u32(keys->dev->of_node, propname,
				   &info->keycode);
	if (ret)
		return 0;

	if (!info->keycode)
		return 0;

	info->keys = keys;

	if (keys->indie_release_irq_mask == 1) {
		ret = regmap_update_bits(keys->regmap, info->regs->intsel_reg,
					 info->regs->intsel_mask, 0);
		if (ret < 0)
			return ret;
	} else {
		ret = regmap_update_bits(keys->regmap, info->regs->intsel_reg,
					 info->regs->intsel_mask,
					 info->regs->intsel_mask);
		if (ret < 0)
			return ret;
	}

	info->irq = irq_create_mapping(keys->irq_domain, info->hw_irq);
	if (info->irq <= 0)
		return -EINVAL;

	ret = devm_request_threaded_irq(
		keys->dev, info->irq, NULL, mtk_pmic_keys_irq_handler_thread,
		IRQF_ONESHOT | IRQF_TRIGGER_HIGH, "mtk-pmic-keys", info);
	if (ret) {
		dev_info(keys->dev, "Failed to request IRQ: %d: %d\n",
		info->irq, ret);
		return ret;
	}

	if (wakeup)
		irq_set_irq_wake(info->irq, 1);

	__set_bit(info->keycode, keys->input_dev->keybit);

	return 0;
}

static void mtk_pmic_keys_dispose_irq(struct mtk_pmic_keys *keys)
{
	if (keys->pwrkey.irq)
		irq_dispose_mapping(keys->pwrkey.irq);

	if (keys->homekey.irq)
		irq_dispose_mapping(keys->homekey.irq);
}

static const struct of_device_id of_pmic_keys_match_tbl[] = {
	{
		.compatible = "mediatek,mt6397-keys", .data = &mt6397_regs,
	},
	{
		.compatible = "mediatek,mt6323-keys", .data = &mt6323_regs,
	},
	{
		.compatible = "mediatek,mt6392-keys", .data = &mt6392_regs,
	},
	{
		/* sentinel */
	} };
MODULE_DEVICE_TABLE(of, of_pmic_keys_match_tbl);

static int mtk_pmic_keys_probe(struct platform_device *pdev)
{
	int ret;
	struct resource *res;
	struct mt6397_chip *pmic_chip = dev_get_drvdata(pdev->dev.parent);
	struct mtk_pmic_keys *keys;
	const struct pmic_regs *pmic_regs;
	struct input_dev *input_dev;
	const struct of_device_id *of_id =
		of_match_device(of_pmic_keys_match_tbl, &pdev->dev);

	keys = devm_kzalloc(&pdev->dev, sizeof(struct mtk_pmic_keys),
			    GFP_KERNEL);
	if (!keys)
		return -ENOMEM;

	keys->dev = &pdev->dev;
	keys->regmap = pmic_chip->regmap;
	keys->irq_domain = pmic_chip->irq_domain;

	pmic_regs = of_id->data;
	keys->pwrkey.regs = &pmic_regs->pwrkey_regs;
	keys->homekey.regs = &pmic_regs->homekey_regs;
	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!res) {
		dev_info(&pdev->dev, "no IRQ resource\n");
		return -ENODEV;
	}

	keys->indie_release_irq_mask = pmic_regs->indie_release_irq_mask;
	keys->pwrkey.hw_irq = res->start;
	if (keys->indie_release_irq_mask == 1) {
		keys->pwr_release.regs = &pmic_regs->pwrkey_regs;
		keys->home_release.regs = &pmic_regs->homekey_regs;
		keys->homekey.hw_irq = res->end - 2;
		keys->pwr_release.hw_irq = res->end - 1;
		keys->home_release.hw_irq = res->end;
	} else {
		keys->homekey.hw_irq = res->end;
	}

	pwrkey_lock = wakeup_source_register(NULL, "pwrkey wakelock");

	keys->input_dev = input_dev = devm_input_allocate_device(keys->dev);
	if (!input_dev) {
		dev_info(&pdev->dev, "[PMICKEYS] input allocate device fail.\n");
		return -ENOMEM;
	}

	input_dev->name = "mtk-pmic-keys";
	input_dev->id.bustype = BUS_HOST;
	input_dev->id.vendor = 0x0001;
	input_dev->id.product = 0x0001;
	input_dev->id.version = 0x0001;
	input_dev->dev.parent = &pdev->dev;

	__set_bit(EV_KEY, input_dev->evbit);

	ret = mtk_pmic_key_setup(keys, "mediatek,pwrkey-code", &keys->pwrkey,
				 true);
	if (ret)
		goto out_dispose_irq;

	ret = mtk_pmic_key_setup(keys, "mediatek,homekey-code", &keys->homekey,
				 false);
	if (ret)
		goto out_dispose_irq;

	if (keys->indie_release_irq_mask == 1) {
		ret = mtk_pmic_key_setup(keys, "mediatek,pwrkey-code",
					 &keys->pwr_release, true);
		if (ret)
			goto out_dispose_irq;

		ret = mtk_pmic_key_setup(keys, "mediatek,homekey-code",
					 &keys->home_release, false);
		if (ret)
			goto out_dispose_irq;
	}

	ret = input_register_device(input_dev);
	if (ret) {
		dev_info(&pdev->dev,
			"[PMICKEYS] register input device failed (%d)\n", ret);
		input_free_device(input_dev);
		return ret;
	}

	input_set_drvdata(input_dev, keys);

	mtk_pmic_long_press_reset_setup(keys, pmic_regs->pmic_rst_reg);

	return 0;

out_dispose_irq:
	mtk_pmic_keys_dispose_irq(keys);
	return ret;
}

static int mtk_pmic_keys_remove(struct platform_device *pdev)
{
	struct mtk_pmic_keys *keys = platform_get_drvdata(pdev);

	mtk_pmic_keys_dispose_irq(keys);

	input_unregister_device(keys->input_dev);

	return 0;
}

static struct platform_driver pmic_keys_pdrv = {
	.probe = mtk_pmic_keys_probe,
	.remove = mtk_pmic_keys_remove,
	.driver = {

			.name = "mtk-pmic-keys",
			.owner = THIS_MODULE,
			.of_match_table = of_pmic_keys_match_tbl,
		},
};

module_platform_driver(pmic_keys_pdrv);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Chen Zhong <chen.zhong@mediatek.com>");
MODULE_DESCRIPTION("MTK pmic-keys driver v0.1");
MODULE_ALIAS("keypad:pmic");