/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
/*
 * USBPHY driver for Freescale i.MX6 family of SoCs.
 */

#include "opt_bus.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/rman.h>

#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <machine/bus.h>

#include <arm/freescale/imx/imx_ccmvar.h>
#include <arm/freescale/imx/imx6_anatopreg.h>
#include <arm/freescale/imx/imx6_anatopvar.h>

/*
 * Hardware register defines.
 */
#define PWD_REG                         0x0000
#define CTRL_STATUS_REG                 0x0030
#define CTRL_SET_REG                    0x0034
#define CTRL_CLR_REG                    0x0038
#define CTRL_TOGGLE_REG                 0x003c
#define   CTRL_SFTRST                     (1U << 31)
#define   CTRL_CLKGATE                    (1 << 30)
#define   CTRL_ENUTMILEVEL3               (1 << 15)
#define   CTRL_ENUTMILEVEL2               (1 << 14)

struct usbphy_softc {
        device_t        dev;
        struct resource *mem_res;
        u_int           phy_num;
};

static struct ofw_compat_data compat_data[] = {
        {"fsl,imx6q-usbphy",    true},
        {"fsl,imx6ul-usbphy",   true},
        {NULL,                  false}
};

static int
usbphy_detach(device_t dev)
{
        struct usbphy_softc *sc;

        sc = device_get_softc(dev);

        if (sc->mem_res != NULL)
                bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);

        return (0);
}

static int
usbphy_attach(device_t dev)
{
        struct usbphy_softc *sc;
        int err, regoff, rid;

        sc = device_get_softc(dev);
        err = 0;

        /* Allocate bus_space resources. */
        rid = 0;
        sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
            RF_ACTIVE);
        if (sc->mem_res == NULL) {
                device_printf(dev, "Cannot allocate memory resources\n");
                err = ENXIO;
                goto out;
        }

        /*
         * XXX Totally lame way to get the unit number (but not quite as lame as
         * adding an ad-hoc property to the fdt data).  This works as long as
         * this driver is used for imx6 only.
         */
        const uint32_t PWD_PHY1_REG_PHYSADDR = 0x020c9000;
        if (BUS_SPACE_PHYSADDR(sc->mem_res, 0) == PWD_PHY1_REG_PHYSADDR) {
                sc->phy_num = 0;
                regoff = 0;
        } else {
                sc->phy_num = 1;
                regoff = 0x60;
        }

        /*
         * Based on a note in the u-boot source code, disable charger detection
         * to avoid degrading the differential signaling on the DP line.  Note
         * that this disables (by design) both charger detection and contact
         * detection, because of the screwball mix of active-high and active-low
         * bits in this register.
         */
        imx6_anatop_write_4(IMX6_ANALOG_USB1_CHRG_DETECT + regoff, 
            IMX6_ANALOG_USB_CHRG_DETECT_N_ENABLE | 
            IMX6_ANALOG_USB_CHRG_DETECT_N_CHK_CHRG);

        imx6_anatop_write_4(IMX6_ANALOG_USB1_CHRG_DETECT + regoff, 
            IMX6_ANALOG_USB_CHRG_DETECT_N_ENABLE | 
            IMX6_ANALOG_USB_CHRG_DETECT_N_CHK_CHRG);

        /* XXX Configure the overcurrent detection here. */

        /*
         * Turn on the phy clocks.
         */
        imx_ccm_usbphy_enable(dev);

        /*
         * Set the software reset bit, then clear both it and the clock gate bit
         * to bring the device out of reset with the clock running.
         */
        bus_write_4(sc->mem_res, CTRL_SET_REG, CTRL_SFTRST);
        bus_write_4(sc->mem_res, CTRL_CLR_REG, CTRL_SFTRST | CTRL_CLKGATE);

        /* Set UTMI+ level 2+3 bits to enable low and full speed devices. */
        bus_write_4(sc->mem_res, CTRL_SET_REG,
            CTRL_ENUTMILEVEL2 | CTRL_ENUTMILEVEL3);

        /* Power up: clear all bits in the powerdown register. */
        bus_write_4(sc->mem_res, PWD_REG, 0);

        err = 0;

out:

        if (err != 0)
                usbphy_detach(dev);

        return (err);
}

static int
usbphy_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
                return (ENXIO);

        device_set_desc(dev, "Freescale i.MX6 USB PHY");

        return (BUS_PROBE_DEFAULT);
}

static device_method_t usbphy_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,  usbphy_probe),
        DEVMETHOD(device_attach, usbphy_attach),
        DEVMETHOD(device_detach, usbphy_detach),

        DEVMETHOD_END
};

static driver_t usbphy_driver = {
        "usbphy",
        usbphy_methods,
        sizeof(struct usbphy_softc)
};

/*
 * This driver needs to start before the ehci driver, but later than the usual
 * "special" drivers like clocks and cpu.  Ehci starts at DEFAULT so SUPPORTDEV
 * is where this driver fits most.
 */
EARLY_DRIVER_MODULE(usbphy, simplebus, usbphy_driver, 0, 0,
    BUS_PASS_SUPPORTDEV + BUS_PASS_ORDER_MIDDLE);