// SPDX-License-Identifier: GPL-2.0
/*
 * NXP ISP1301 USB transceiver driver
 *
 * Copyright (C) 2012 Roland Stigge
 *
 * Author: Roland Stigge <stigge@antcom.de>
 */

#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/i2c.h>
#include <linux/usb/phy.h>
#include <linux/usb/isp1301.h>

#define DRV_NAME                "isp1301"

struct isp1301 {
        struct usb_phy          phy;
        struct mutex            mutex;

        struct i2c_client       *client;
};

#define phy_to_isp(p)           (container_of((p), struct isp1301, phy))

static const struct i2c_device_id isp1301_id[] = {
        { "isp1301" },
        { }
};
MODULE_DEVICE_TABLE(i2c, isp1301_id);

static const struct of_device_id isp1301_of_match[] = {
        {.compatible = "nxp,isp1301" },
        { },
};
MODULE_DEVICE_TABLE(of, isp1301_of_match);

static struct i2c_client *isp1301_i2c_client;

static int __isp1301_write(struct isp1301 *isp, u8 reg, u8 value, u8 clear)
{
        return i2c_smbus_write_byte_data(isp->client, reg | clear, value);
}

static int isp1301_write(struct isp1301 *isp, u8 reg, u8 value)
{
        return __isp1301_write(isp, reg, value, 0);
}

static int isp1301_clear(struct isp1301 *isp, u8 reg, u8 value)
{
        return __isp1301_write(isp, reg, value, ISP1301_I2C_REG_CLEAR_ADDR);
}

static int isp1301_phy_init(struct usb_phy *phy)
{
        struct isp1301 *isp = phy_to_isp(phy);

        /* Disable transparent UART mode first */
        isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_UART_EN);
        isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_1, ~MC1_SPEED_REG);
        isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_SPEED_REG);
        isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_2, ~0);
        isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_2, (MC2_BI_DI | MC2_PSW_EN
                                | MC2_SPD_SUSP_CTRL));

        isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, ~0);
        isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_DAT_SE0);
        isp1301_write(isp, ISP1301_I2C_OTG_CONTROL_1, (OTG1_DM_PULLDOWN
                                | OTG1_DP_PULLDOWN));
        isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, (OTG1_DM_PULLUP
                                | OTG1_DP_PULLUP));

        /* mask all interrupts */
        isp1301_clear(isp, ISP1301_I2C_INTERRUPT_LATCH, ~0);
        isp1301_clear(isp, ISP1301_I2C_INTERRUPT_FALLING, ~0);
        isp1301_clear(isp, ISP1301_I2C_INTERRUPT_RISING, ~0);

        return 0;
}

static int isp1301_phy_set_vbus(struct usb_phy *phy, int on)
{
        struct isp1301 *isp = phy_to_isp(phy);

        if (on)
                isp1301_write(isp, ISP1301_I2C_OTG_CONTROL_1, OTG1_VBUS_DRV);
        else
                isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, OTG1_VBUS_DRV);

        return 0;
}

static int isp1301_probe(struct i2c_client *client)
{
        struct isp1301 *isp;
        struct usb_phy *phy;

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

        isp->client = client;
        mutex_init(&isp->mutex);

        phy = &isp->phy;
        phy->dev = &client->dev;
        phy->label = DRV_NAME;
        phy->init = isp1301_phy_init;
        phy->set_vbus = isp1301_phy_set_vbus;
        phy->type = USB_PHY_TYPE_USB2;

        i2c_set_clientdata(client, isp);
        usb_add_phy_dev(phy);

        isp1301_i2c_client = client;

        return 0;
}

static void isp1301_remove(struct i2c_client *client)
{
        struct isp1301 *isp = i2c_get_clientdata(client);

        usb_remove_phy(&isp->phy);
        isp1301_i2c_client = NULL;
}

static struct i2c_driver isp1301_driver = {
        .driver = {
                .name = DRV_NAME,
                .of_match_table = isp1301_of_match,
        },
        .probe = isp1301_probe,
        .remove = isp1301_remove,
        .id_table = isp1301_id,
};

module_i2c_driver(isp1301_driver);

struct i2c_client *isp1301_get_client(struct device_node *node)
{
        struct i2c_client *client;

        /* reference of ISP1301 I2C node via DT */
        client = of_find_i2c_device_by_node(node);
        if (client)
                return client;

        /* non-DT: only one ISP1301 chip supported */
        if (isp1301_i2c_client) {
                get_device(&isp1301_i2c_client->dev);
                return isp1301_i2c_client;
        }

        return NULL;
}
EXPORT_SYMBOL_GPL(isp1301_get_client);

MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
MODULE_DESCRIPTION("NXP ISP1301 USB transceiver driver");
MODULE_LICENSE("GPL");