// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2016 Linaro Ltd.
 */

#include <linux/device.h>
#include <linux/usb/chipidea.h>
#include <linux/ulpi/interface.h>

#include "ci.h"

#define ULPI_WAKEUP             BIT(31)
#define ULPI_RUN                BIT(30)
#define ULPI_WRITE              BIT(29)
#define ULPI_SYNC_STATE         BIT(27)
#define ULPI_ADDR(n)            ((n) << 16)
#define ULPI_DATA(n)            (n)

static int ci_ulpi_wait(struct ci_hdrc *ci, u32 mask)
{
        unsigned long usec = 10000;

        while (usec--) {
                if (!hw_read(ci, OP_ULPI_VIEWPORT, mask))
                        return 0;

                udelay(1);
        }

        return -ETIMEDOUT;
}

static int ci_ulpi_read(struct device *dev, u8 addr)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);
        int ret;

        hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_WRITE | ULPI_WAKEUP);
        ret = ci_ulpi_wait(ci, ULPI_WAKEUP);
        if (ret)
                return ret;

        hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_RUN | ULPI_ADDR(addr));
        ret = ci_ulpi_wait(ci, ULPI_RUN);
        if (ret)
                return ret;

        return hw_read(ci, OP_ULPI_VIEWPORT, GENMASK(15, 8)) >> 8;
}

static int ci_ulpi_write(struct device *dev, u8 addr, u8 val)
{
        struct ci_hdrc *ci = dev_get_drvdata(dev);
        int ret;

        hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_WRITE | ULPI_WAKEUP);
        ret = ci_ulpi_wait(ci, ULPI_WAKEUP);
        if (ret)
                return ret;

        hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff,
                 ULPI_RUN | ULPI_WRITE | ULPI_ADDR(addr) | val);
        return ci_ulpi_wait(ci, ULPI_RUN);
}

int ci_ulpi_init(struct ci_hdrc *ci)
{
        if (ci->platdata->phy_mode != USBPHY_INTERFACE_MODE_ULPI)
                return 0;

        /*
         * Set PORTSC correctly so we can read/write ULPI registers for
         * identification purposes
         */
        hw_phymode_configure(ci);

        ci->ulpi_ops.read = ci_ulpi_read;
        ci->ulpi_ops.write = ci_ulpi_write;
        ci->ulpi = ulpi_register_interface(ci->dev, &ci->ulpi_ops);
        if (IS_ERR(ci->ulpi))
                dev_err(ci->dev, "failed to register ULPI interface");

        return PTR_ERR_OR_ZERO(ci->ulpi);
}

void ci_ulpi_exit(struct ci_hdrc *ci)
{
        if (ci->ulpi) {
                ulpi_unregister_interface(ci->ulpi);
                ci->ulpi = NULL;
        }
}

int ci_ulpi_resume(struct ci_hdrc *ci)
{
        int cnt = 100000;

        if (ci->platdata->phy_mode != USBPHY_INTERFACE_MODE_ULPI)
                return 0;

        while (cnt-- > 0) {
                if (hw_read(ci, OP_ULPI_VIEWPORT, ULPI_SYNC_STATE))
                        return 0;
                udelay(1);
        }

        return -ETIMEDOUT;
}