// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020 BayLibre, SAS.
 * Author: Fabien Parent <fparent@baylibre.com>
 */

#include <linux/interrupt.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/usb/usb_phy_generic.h>
#include <linux/usb/role.h>
#include <linux/usb/typec.h>

#define TYPEC_CTRL		0x06
#define     PORT_SUPPORT_ROLE_SINK	0
#define     PORT_SUPPORT_ROLE_SOURCE	1
#define     PORT_SUPPORT_ROLE_DRP	2
#define     PORT_SUPPORT_ROLE_MASK	3
#define TYPEC_CC_SW_CTRL	0x0a
#define     STATE_ENTER_DISABLED	BIT(0)
#define     STATE_ENTER_UNATTACHED_SRC	BIT(1)
#define     STATE_ENTER_UNATTACHED_SINK	BIT(2)
#define TYPEC_INTR_EN_0		0x30
#define TYPEC_INTR_EN_2		0x34
#define TYPEC_INTR_0		0x38
#define     INTR_ENTER_ATTACHED_SRC	BIT(0)
#define     INTR_ENTER_ATTACHED_SINK	BIT(1)
#define     INTR_ENTER_UNATTACHED_SRC	BIT(4)
#define     INTR_ENTER_ATTACH_WAIT_SINK	BIT(7)
#define TYPEC_INTR_2		0x3c
#define TYPEC_CC_STATUS		0x40
#define TYPEC_PWR_STATUS	0x42

struct mt6392_typec {
	struct device			*dev;
	struct regmap			*regmap;
	struct usb_role_switch		*role_sw;
	struct typec_port		*port;
	struct typec_capability		cap;
	u32				base_addr;
	int				irq;
};

static int typec_write(struct mt6392_typec *typec, u32 reg, u16 val)
{
	return regmap_write(typec->regmap, typec->base_addr + reg, val);
}

static u16 typec_read(struct mt6392_typec *typec, u32 reg)
{
	unsigned int val;

	regmap_read(typec->regmap, typec->base_addr + reg, &val);

	return val;
}

static irqreturn_t mtk_typec_irq_handler_thread(int irq, void *data)
{
	uint16_t intr0;
	struct mt6392_typec *typec = data;

	intr0 = typec_read(typec, TYPEC_INTR_0);
	typec_write(typec, TYPEC_INTR_0, intr0);

	if (!intr0)
		return IRQ_NONE;

	if (intr0 & INTR_ENTER_ATTACHED_SRC) {
		usb_role_switch_set_role(typec->role_sw, USB_ROLE_HOST);
		typec_set_data_role(typec->port, TYPEC_HOST);
	} else if (intr0 & INTR_ENTER_ATTACH_WAIT_SINK) {
		usb_role_switch_set_role(typec->role_sw, USB_ROLE_DEVICE);
		typec_set_data_role(typec->port, TYPEC_DEVICE);
	} else if (intr0 & INTR_ENTER_UNATTACHED_SRC) {
		usb_role_switch_set_role(typec->role_sw, USB_ROLE_NONE);
	} else {
		dev_err(typec->dev, "unexpected IRQ: %d\n", intr0);
		return IRQ_NONE;
	}

	return IRQ_HANDLED;
}

static void mt6392_enable_irq(struct mt6392_typec *typec)
{
	regmap_write(typec->regmap, typec->base_addr + TYPEC_INTR_EN_0,
		INTR_ENTER_ATTACHED_SRC | INTR_ENTER_UNATTACHED_SRC |
		INTR_ENTER_ATTACH_WAIT_SINK);
}

static void mt6392_disable_irq(struct mt6392_typec *typec)
{
	regmap_write(typec->regmap, typec->base_addr + TYPEC_INTR_EN_0, 0);
	regmap_write(typec->regmap, typec->base_addr + TYPEC_INTR_EN_2, 0);
}

static int mt6392_typec_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
	struct mt6392_typec *typec;
	int ret;

	typec = devm_kzalloc(&pdev->dev, sizeof(*typec), GFP_KERNEL);
	if (!typec)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	typec->base_addr = res->start;

	typec->irq = platform_get_irq(pdev, 0);
	if (typec->irq < 0)
		return typec->irq;

	typec->regmap = mt6397_chip->regmap;
	typec->dev = &pdev->dev;

	platform_set_drvdata(pdev, typec);

	typec->role_sw = usb_role_switch_get(&pdev->dev);
	if (IS_ERR(typec->role_sw))
		return PTR_ERR(typec->role_sw);

	typec->cap.prefer_role = TYPEC_NO_PREFERRED_ROLE;
	typec->cap.type = TYPEC_PORT_DRP;
	typec->cap.data = TYPEC_PORT_DRD;
	typec->cap.revision = USB_TYPEC_REV_1_1;

	typec->port = typec_register_port(typec->dev, &typec->cap);
	if (IS_ERR(typec->port)) {
		ret = PTR_ERR(typec->port);
		goto out_role_switch_put;
	}

	mt6392_disable_irq(typec);

	regmap_update_bits(typec->regmap, typec->base_addr + TYPEC_CTRL,
		PORT_SUPPORT_ROLE_MASK, PORT_SUPPORT_ROLE_DRP);
	regmap_update_bits(typec->regmap, typec->base_addr + TYPEC_CC_SW_CTRL,
		STATE_ENTER_UNATTACHED_SINK, STATE_ENTER_UNATTACHED_SINK);

	ret = devm_request_threaded_irq(typec->dev, typec->irq, NULL,
				   mtk_typec_irq_handler_thread,
				   IRQF_ONESHOT | IRQF_TRIGGER_LOW,
				   "mt6392-typec", typec);
	if (ret) {
		dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n",
			typec->irq, ret);
		goto out_typec_unregister_port;
	}

	mt6392_enable_irq(typec);

	return 0;

out_typec_unregister_port:
	typec_unregister_port(typec->port);
out_role_switch_put:
	usb_role_switch_put(typec->role_sw);

	return ret;
}

static int mt6392_typec_remove(struct platform_device *pdev)
{
	struct mt6392_typec *typec = platform_get_drvdata(pdev);

	disable_irq(typec->irq);
	typec_unregister_port(typec->port);
	usb_role_switch_put(typec->role_sw);

	return 0;
}

static int __maybe_unused mt6392_typec_suspend(struct device *dev)
{
	struct mt6392_typec *typec = dev_get_drvdata(dev);

	disable_irq(typec->irq);

	return 0;
}

static int __maybe_unused mt6392_typec_resume(struct device *dev)
{
	struct mt6392_typec *typec = dev_get_drvdata(dev);

	enable_irq(typec->irq);

	return 0;
}

static SIMPLE_DEV_PM_OPS(mt6392_typec_pm_ops, mt6392_typec_suspend,
			mt6392_typec_resume);

static const struct of_device_id mt6392_typec_of_match[] = {
	{ .compatible = "mediatek,mt6392-typec" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mt6392_typec_of_match);

static struct platform_driver mt6392_typec_driver = {
	.probe = mt6392_typec_probe,
	.remove = mt6392_typec_remove,
	.driver = {
		.name  = "mt6392-typec",
		.of_match_table = of_match_ptr(mt6392_typec_of_match),
		.pm = &mt6392_typec_pm_ops,
	},
};

module_platform_driver(mt6392_typec_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Fabien Parent <fparent@baylibre.com>");
MODULE_DESCRIPTION("MediaTek MT6392 Type-C Controller Driver");