// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2011 Jana Rapava <fermata7@gmail.com>
 * Copyright (C) 2011 CompuLab, Ltd. <www.compulab.co.il>
 *
 * Authors: Jana Rapava <fermata7@gmail.com>
 *          Igor Grinberg <grinberg@compulab.co.il>
 *
 * Based on:
 * linux/drivers/usb/otg/ulpi.c
 * Generic ULPI USB transceiver support
 *
 * Original Copyright follow:
 * Copyright (C) 2009 Daniel Mack <daniel@caiaq.de>
 *
 * Based on sources from
 *
 *   Sascha Hauer <s.hauer@pengutronix.de>
 *   Freescale Semiconductors
 */

#include <common.h>
#include <exports.h>
#include <log.h>
#include <linux/delay.h>
#include <usb/ulpi.h>

#define ULPI_ID_REGS_COUNT      4
#define ULPI_TEST_VALUE         0x55    /* 0x55 == 0b01010101 */

static struct ulpi_regs *ulpi = (struct ulpi_regs *)0;

static int ulpi_integrity_check(struct ulpi_viewport *ulpi_vp)
{
        u32 val, tval = ULPI_TEST_VALUE;
        int err, i;

        /* Use the 'special' test value to check all bits */
        for (i = 0; i < 2; i++, tval <<= 1) {
                err = ulpi_write(ulpi_vp, &ulpi->scratch, tval);
                if (err)
                        return err;

                val = ulpi_read(ulpi_vp, &ulpi->scratch);
                if (val != tval) {
                        printf("ULPI integrity check failed\n");
                        return val;
                }
        }

        return 0;
}

int ulpi_init(struct ulpi_viewport *ulpi_vp)
{
        u32 val, id = 0;
        u8 *reg = &ulpi->product_id_high;
        int i;

        /* Assemble ID from four ULPI ID registers (8 bits each). */
        for (i = 0; i < ULPI_ID_REGS_COUNT; i++) {
                val = ulpi_read(ulpi_vp, reg - i);
                if (val == ULPI_ERROR)
                        return val;

                id = (id << 8) | val;
        }

        /* Split ID into vendor and product ID. */
        debug("ULPI transceiver ID 0x%04x:0x%04x\n", id >> 16, id & 0xffff);

        return ulpi_integrity_check(ulpi_vp);
}

int ulpi_select_transceiver(struct ulpi_viewport *ulpi_vp, unsigned speed)
{
        u32 tspeed = ULPI_FC_FULL_SPEED;
        u32 val;

        switch (speed) {
        case ULPI_FC_HIGH_SPEED:
        case ULPI_FC_FULL_SPEED:
        case ULPI_FC_LOW_SPEED:
        case ULPI_FC_FS4LS:
                tspeed = speed;
                break;
        default:
                printf("ULPI: %s: wrong transceiver speed specified: %u, "
                        "falling back to full speed\n", __func__, speed);
        }

        val = ulpi_read(ulpi_vp, &ulpi->function_ctrl);
        if (val == ULPI_ERROR)
                return val;

        /* clear the previous speed setting */
        val = (val & ~ULPI_FC_XCVRSEL_MASK) | tspeed;

        return ulpi_write(ulpi_vp, &ulpi->function_ctrl, val);
}

int ulpi_set_vbus(struct ulpi_viewport *ulpi_vp, int on, int ext_power)
{
        u32 flags = ULPI_OTG_DRVVBUS;
        u8 *reg = on ? &ulpi->otg_ctrl_set : &ulpi->otg_ctrl_clear;

        if (ext_power)
                flags |= ULPI_OTG_DRVVBUS_EXT;

        return ulpi_write(ulpi_vp, reg, flags);
}

int ulpi_set_vbus_indicator(struct ulpi_viewport *ulpi_vp, int external,
                        int passthu, int complement)
{
        u32 flags, val;
        u8 *reg;

        reg = external ? &ulpi->otg_ctrl_set : &ulpi->otg_ctrl_clear;
        val = ulpi_write(ulpi_vp, reg, ULPI_OTG_EXTVBUSIND);
        if (val)
                return val;

        flags = passthu ? ULPI_IFACE_PASSTHRU : 0;
        flags |= complement ? ULPI_IFACE_EXTVBUS_COMPLEMENT : 0;

        val = ulpi_read(ulpi_vp, &ulpi->iface_ctrl);
        if (val == ULPI_ERROR)
                return val;

        val = val & ~(ULPI_IFACE_PASSTHRU & ULPI_IFACE_EXTVBUS_COMPLEMENT);
        val |= flags;
        val = ulpi_write(ulpi_vp, &ulpi->iface_ctrl, val);
        if (val)
                return val;

        return 0;
}

int ulpi_set_pd(struct ulpi_viewport *ulpi_vp, int enable)
{
        u32 val = ULPI_OTG_DP_PULLDOWN | ULPI_OTG_DM_PULLDOWN;
        u8 *reg = enable ? &ulpi->otg_ctrl_set : &ulpi->otg_ctrl_clear;

        return ulpi_write(ulpi_vp, reg, val);
}

int ulpi_opmode_sel(struct ulpi_viewport *ulpi_vp, unsigned opmode)
{
        u32 topmode = ULPI_FC_OPMODE_NORMAL;
        u32 val;

        switch (opmode) {
        case ULPI_FC_OPMODE_NORMAL:
        case ULPI_FC_OPMODE_NONDRIVING:
        case ULPI_FC_OPMODE_DISABLE_NRZI:
        case ULPI_FC_OPMODE_NOSYNC_NOEOP:
                topmode = opmode;
                break;
        default:
                printf("ULPI: %s: wrong OpMode specified: %u, "
                        "falling back to OpMode Normal\n", __func__, opmode);
        }

        val = ulpi_read(ulpi_vp, &ulpi->function_ctrl);
        if (val == ULPI_ERROR)
                return val;

        /* clear the previous opmode setting */
        val = (val & ~ULPI_FC_OPMODE_MASK) | topmode;

        return ulpi_write(ulpi_vp, &ulpi->function_ctrl, val);
}

int ulpi_serial_mode_enable(struct ulpi_viewport *ulpi_vp, unsigned smode)
{
        switch (smode) {
        case ULPI_IFACE_6_PIN_SERIAL_MODE:
        case ULPI_IFACE_3_PIN_SERIAL_MODE:
                break;
        default:
                printf("ULPI: %s: unrecognized Serial Mode specified: %u\n",
                        __func__, smode);
                return ULPI_ERROR;
        }

        return ulpi_write(ulpi_vp, &ulpi->iface_ctrl_set, smode);
}

int ulpi_suspend(struct ulpi_viewport *ulpi_vp)
{
        int err;

        err = ulpi_write(ulpi_vp, &ulpi->function_ctrl_clear,
                        ULPI_FC_SUSPENDM);
        if (err)
                printf("ULPI: %s: failed writing the suspend bit\n", __func__);

        return err;
}

/*
 * Wait for ULPI PHY reset to complete.
 * Actual wait for reset must be done in a view port specific way,
 * because it involves checking the DIR line.
 */
static int __ulpi_reset_wait(struct ulpi_viewport *ulpi_vp)
{
        u32 val;
        int timeout = CONFIG_USB_ULPI_TIMEOUT;

        /* Wait for the RESET bit to become zero */
        while (--timeout) {
                /*
                 * This function is generic and suppose to work
                 * with any viewport, so we cheat here and don't check
                 * for the error of ulpi_read(), if there is one, then
                 * there will be a timeout.
                 */
                val = ulpi_read(ulpi_vp, &ulpi->function_ctrl);
                if (!(val & ULPI_FC_RESET))
                        return 0;

                udelay(1);
        }

        printf("ULPI: %s: reset timed out\n", __func__);

        return ULPI_ERROR;
}
int ulpi_reset_wait(struct ulpi_viewport *ulpi_vp)
        __attribute__((weak, alias("__ulpi_reset_wait")));

int ulpi_reset(struct ulpi_viewport *ulpi_vp)
{
        int err;

        err = ulpi_write(ulpi_vp,
                        &ulpi->function_ctrl_set, ULPI_FC_RESET);
        if (err) {
                printf("ULPI: %s: failed writing reset bit\n", __func__);
                return err;
        }

        return ulpi_reset_wait(ulpi_vp);
}