// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2022 Rockchip Co.,Ltd.
 * Author: Wang Jie <dave.wang@rock-chips.com>
 *
 * Etek ET7303 Type-C Chip Driver
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/gpio/consumer.h>
#include <linux/usb/tcpm.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include "tcpci.h"

#define ET7303_VID		0x6DCF
#define ET7303_PID		0x1711
#define ET7303_RTCTRL8		0x9B
/* Autoidle timeout = (tout * 2 + 1) * 6.4ms */
#define ET7303_RTCTRL8_SET(ck300, ship_off, auto_idle, tout) \
			    (((ck300) << 7) | ((ship_off) << 5) | \
			    ((auto_idle) << 3) | ((tout) & 0x07))
#define ET7303_RTCTRL13	0xA0
#define ET7303_RTCTRL14	0xA1
#define ET7303_RTCTRL15	0xA2
#define ET7303_RTCTRL16	0xA3

struct et7303_chip {
	struct tcpci_data data;
	struct tcpci *tcpci;
	struct device *dev;
	struct regulator *vbus;
	bool vbus_on;
};

static int et7303_read16(struct et7303_chip *chip, unsigned int reg, u16 *val)
{
	return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u16));
}

static int et7303_write16(struct et7303_chip *chip, unsigned int reg, u16 val)
{
	return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u16));
}

static int et7303_read8(struct et7303_chip *chip, unsigned int reg, u8 *val)
{
	return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u8));
}

static int et7303_write8(struct et7303_chip *chip, unsigned int reg, u8 val)
{
	return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u8));
}

static const struct regmap_config et7303_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = 0xFF, /* 0x80 .. 0xFF are vendor defined */
};

static struct et7303_chip *tdata_to_et7303(struct tcpci_data *tdata)
{
	return container_of(tdata, struct et7303_chip, data);
}

static int et7303_init(struct tcpci *tcpci, struct tcpci_data *tdata)
{
	int ret;
	struct et7303_chip *chip = tdata_to_et7303(tdata);

	/* CK 300K from 320K, shipping off, auto_idle enable, tout = 32ms */
	ret = et7303_write8(chip, ET7303_RTCTRL8,
			     ET7303_RTCTRL8_SET(0, 1, 1, 2));
	/* tTCPCfilter : (26.7 * val) us */
	ret |= et7303_write8(chip, ET7303_RTCTRL14, 0x0F);
	/*  tDRP : (51.2 + 6.4 * val) ms */
	ret |= et7303_write8(chip, ET7303_RTCTRL15, 0x04);
	/* dcSRC.DRP : 33% */
	ret |= et7303_write16(chip, ET7303_RTCTRL16, 330);

	if (ret < 0)
		dev_err(chip->dev, "fail to init registers(%d)\n", ret);

	return ret;
}

static int et7303_set_vbus(struct tcpci *tcpci, struct tcpci_data *tdata,
			    bool on, bool charge)
{
	struct et7303_chip *chip = tdata_to_et7303(tdata);
	int ret = 0;

	if (chip->vbus_on == on) {
		dev_dbg(chip->dev, "vbus is already %s", on ? "On" : "Off");
		goto done;
	}

	if (on)
		ret = regulator_enable(chip->vbus);
	else
		ret = regulator_disable(chip->vbus);
	if (ret < 0) {
		dev_err(chip->dev, "cannot %s vbus regulator, ret=%d",
			on ? "enable" : "disable", ret);
		goto done;
	}

	chip->vbus_on = on;

done:
	return ret;
}

static int et7303_set_vconn(struct tcpci *tcpci, struct tcpci_data *tdata,
			    bool enable)
{
	struct et7303_chip *chip = tdata_to_et7303(tdata);

	return et7303_write8(chip, ET7303_RTCTRL8,
			      ET7303_RTCTRL8_SET(0, 1, !enable, 2));
}

static int et7303_start_drp_toggling(struct tcpci *tcpci,
				     struct tcpci_data *tdata,
				     enum typec_cc_status cc)
{
	struct et7303_chip *chip = tdata_to_et7303(tdata);
	int ret;
	unsigned int reg = 0;

	switch (cc) {
	default:
	case TYPEC_CC_RP_DEF:
		reg |= (TCPC_ROLE_CTRL_RP_VAL_DEF <<
			TCPC_ROLE_CTRL_RP_VAL_SHIFT);
		break;
	case TYPEC_CC_RP_1_5:
		reg |= (TCPC_ROLE_CTRL_RP_VAL_1_5 <<
			TCPC_ROLE_CTRL_RP_VAL_SHIFT);
		break;
	case TYPEC_CC_RP_3_0:
		reg |= (TCPC_ROLE_CTRL_RP_VAL_3_0 <<
			TCPC_ROLE_CTRL_RP_VAL_SHIFT);
		break;
	}

	if (cc == TYPEC_CC_RD)
		reg |= (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC1_SHIFT) |
			   (TCPC_ROLE_CTRL_CC_RD << TCPC_ROLE_CTRL_CC2_SHIFT);
	else
		reg |= (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC1_SHIFT) |
			   (TCPC_ROLE_CTRL_CC_RP << TCPC_ROLE_CTRL_CC2_SHIFT);

	ret = et7303_write8(chip, TCPC_ROLE_CTRL, reg);
	if (ret < 0)
		return ret;
	usleep_range(500, 1000);

	return 0;
}

static irqreturn_t et7303_irq(int irq, void *dev_id)
{
	int ret;
	u16 alert;
	u8 status;
	struct et7303_chip *chip = dev_id;

	ret = et7303_read16(chip, TCPC_ALERT, &alert);
	if (ret < 0)
		goto out;

	if (alert & TCPC_ALERT_CC_STATUS) {
		ret = et7303_read8(chip, TCPC_CC_STATUS, &status);
		if (ret < 0)
			goto out;
		/* Clear cc change event triggered by starting toggling */
		if (status & TCPC_CC_STATUS_TOGGLING)
			et7303_write8(chip, TCPC_ALERT, TCPC_ALERT_CC_STATUS);
	}

out:
	return tcpci_irq(chip->tcpci);
}

static int et7303_sw_reset(struct et7303_chip *chip)
{
	int ret;

	ret = et7303_write8(chip, ET7303_RTCTRL13, 0x01);
	if (ret < 0)
		return ret;

	usleep_range(1000, 2000);
	return 0;
}

static int et7303_check_revision(struct i2c_client *i2c)
{
	int ret;

	ret = i2c_smbus_read_word_data(i2c, TCPC_VENDOR_ID);
	if (ret < 0) {
		dev_err(&i2c->dev, "fail to read Vendor id(%d)\n", ret);
		return ret;
	}

	if (ret != ET7303_VID) {
		dev_err(&i2c->dev, "vid is not correct, 0x%04x\n", ret);
		return -ENODEV;
	}

	ret = i2c_smbus_read_word_data(i2c, TCPC_PRODUCT_ID);
	if (ret < 0) {
		dev_err(&i2c->dev, "fail to read Product id(%d)\n", ret);
		return ret;
	}

	if (ret != ET7303_PID) {
		dev_err(&i2c->dev, "pid is not correct, 0x%04x\n", ret);
		return -ENODEV;
	}

	return 0;
}

static int et7303_probe(struct i2c_client *client,
			const struct i2c_device_id *i2c_id)
{
	int ret;
	struct et7303_chip *chip;

	ret = et7303_check_revision(client);
	if (ret < 0) {
		dev_err(&client->dev, "check vid/pid fail(%d)\n", ret);
		return ret;
	}

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

	chip->data.regmap = devm_regmap_init_i2c(client,
						 &et7303_regmap_config);
	if (IS_ERR(chip->data.regmap))
		return PTR_ERR(chip->data.regmap);

	chip->dev = &client->dev;
	i2c_set_clientdata(client, chip);

	chip->vbus = devm_regulator_get_optional(chip->dev, "vbus");
	if (IS_ERR(chip->vbus)) {
		ret = PTR_ERR(chip->vbus);
		chip->vbus = NULL;
		if (ret != -ENODEV)
			return ret;
	}

	ret = et7303_sw_reset(chip);
	if (ret < 0)
		return ret;

	/* Disable chip interrupts before requesting irq */
	ret = et7303_write16(chip, TCPC_ALERT_MASK, 0);
	if (ret < 0)
		return ret;

	if (chip->vbus)
		chip->data.set_vbus = et7303_set_vbus;
	chip->data.init = et7303_init;
	chip->data.set_vconn = et7303_set_vconn;
	chip->data.start_drp_toggling = et7303_start_drp_toggling;
	chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
	if (IS_ERR(chip->tcpci))
		return PTR_ERR(chip->tcpci);

	ret = devm_request_threaded_irq(chip->dev, client->irq, NULL,
					et7303_irq,
					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
					client->name, chip);
	if (ret < 0)
		return ret;
	enable_irq_wake(client->irq);

	return 0;
}

static int et7303_remove(struct i2c_client *client)
{
	struct et7303_chip *chip = i2c_get_clientdata(client);

	tcpci_unregister_port(chip->tcpci);
	return 0;
}

static const struct i2c_device_id et7303_id[] = {
	{ "et7303", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, et7303_id);

#ifdef CONFIG_OF
static const struct of_device_id et7303_of_match[] = {
	{ .compatible = "etek,et7303", },
	{},
};
MODULE_DEVICE_TABLE(of, et7303_of_match);
#endif

static struct i2c_driver et7303_i2c_driver = {
	.driver = {
		.name = "et7303",
		.of_match_table = of_match_ptr(et7303_of_match),
	},
	.probe = et7303_probe,
	.remove = et7303_remove,
	.id_table = et7303_id,
};
module_i2c_driver(et7303_i2c_driver);

MODULE_AUTHOR("Wang Jie <dave.wang@rock-chips.com>");
MODULE_DESCRIPTION("ET7303 USB Type-C Port Controller Interface Driver");
MODULE_LICENSE("GPL");