/* $NetBSD: mesongxl_usb2phy.c,v 1.2 2021/01/27 03:10:18 thorpej Exp $ */

/*-
 * Copyright (c) 2019 Jared McNeill <jmcneill@invisible.ca>
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>

__KERNEL_RCSID(0, "$NetBSD: mesongxl_usb2phy.c,v 1.2 2021/01/27 03:10:18 thorpej Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>
#include <sys/time.h>

#include <dev/fdt/fdtvar.h>

#define USB2PHY_REG0                    0x00
#define  REG0_POWER_ON_RESET            __BIT(22)
#define  REG0_ID_PULLUP                 __BIT(13)
#define  REG0_DP_PULLDOWN               __BIT(6)
#define  REG0_DM_PULLDOWN               __BIT(5)

static int mesongxl_usb2phy_match(device_t, cfdata_t, void *);
static void mesongxl_usb2phy_attach(device_t, device_t, void *);

static const struct device_compatible_entry compat_data[] = {
        { .compat = "amlogic,meson-gxl-usb2-phy" },
        DEVICE_COMPAT_EOL
};

struct mesongxl_usb2phy_softc {
        device_t                sc_dev;
        bus_space_tag_t         sc_bst;
        bus_space_handle_t      sc_bsh;
        int                     sc_phandle;
        struct clk              *sc_clk;
        struct fdtbus_reset     *sc_rst;
        struct fdtbus_regulator *sc_supply;
};

#define PHY_READ(sc, reg)                               \
        bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
#define PHY_WRITE(sc, reg, val)                 \
        bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))

CFATTACH_DECL_NEW(mesongxl_usb2phy, sizeof(struct mesongxl_usb2phy_softc),
        mesongxl_usb2phy_match, mesongxl_usb2phy_attach, NULL, NULL);

static void *
mesongxl_usb2phy_acquire(device_t dev, const void *data, size_t len)
{
        if (len != 0)
                return NULL;

        return (void *)(uintptr_t)1;
}

static void
mesongxl_usb2phy_release(device_t dev, void *priv)
{
}

static int
mesongxl_usb2phy_enable(device_t dev, void *priv, bool enable)
{
        struct mesongxl_usb2phy_softc * const sc = device_private(dev);
        uint32_t val;

        if (enable) {
                /* Power on PHY */
                val = PHY_READ(sc, USB2PHY_REG0);
                val &= ~REG0_POWER_ON_RESET;
                PHY_WRITE(sc, USB2PHY_REG0, val);

                /* Configure PHY for host mode */
                val = PHY_READ(sc, USB2PHY_REG0);
                val |= REG0_DM_PULLDOWN;
                val |= REG0_DP_PULLDOWN;
                val &= ~REG0_ID_PULLUP;
                PHY_WRITE(sc, USB2PHY_REG0, val);

                /* Reset the PHY */
                val = PHY_READ(sc, USB2PHY_REG0);
                val |= REG0_POWER_ON_RESET;
                PHY_WRITE(sc, USB2PHY_REG0, val);
                delay(500);
                val = PHY_READ(sc, USB2PHY_REG0);
                val &= ~REG0_POWER_ON_RESET;
                PHY_WRITE(sc, USB2PHY_REG0, val);
                delay(500);

                if (sc->sc_supply != NULL) {
                        if (fdtbus_regulator_enable(sc->sc_supply) != 0)
                                aprint_error(": couldn't enable supply\n");
                }
        } else {
                /* Power off PHY */
                val = PHY_READ(sc, USB2PHY_REG0);
                val |= REG0_POWER_ON_RESET;
                PHY_WRITE(sc, USB2PHY_REG0, val);
        }

        return 0;
}

const struct fdtbus_phy_controller_func mesongxl_usb2phy_funcs = {
        .acquire = mesongxl_usb2phy_acquire,
        .release = mesongxl_usb2phy_release,
        .enable = mesongxl_usb2phy_enable,
};

static int
mesongxl_usb2phy_match(device_t parent, cfdata_t cf, void *aux)
{
        struct fdt_attach_args * const faa = aux;

        return of_compatible_match(faa->faa_phandle, compat_data);
}

static void
mesongxl_usb2phy_attach(device_t parent, device_t self, void *aux)
{
        struct mesongxl_usb2phy_softc * const sc = device_private(self);
        struct fdt_attach_args * const faa = aux;
        const int phandle = faa->faa_phandle;
        bus_addr_t addr;
        bus_size_t size;

        sc->sc_dev = self;
        sc->sc_bst = faa->faa_bst;
        sc->sc_phandle = phandle;

        if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
                aprint_error(": couldn't get registers\n");
                return;
        }
        if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
                aprint_error(": couldn't map registers\n");
                return;
        }

        sc->sc_clk = fdtbus_clock_get_index(phandle, 0);
        if (sc->sc_clk == NULL) {
                aprint_error(": couldn't get clock\n");
                return;
        }
        sc->sc_rst = fdtbus_reset_get_index(phandle, 0);

        if (sc->sc_rst != NULL) {
                if (fdtbus_reset_deassert(sc->sc_rst) != 0) {
                        aprint_error(": couldn't de-assert reset\n");
                        return;
                }
        }
        if (clk_enable(sc->sc_clk) != 0) {
                aprint_error(": couldn't enable clock\n");
                return;
        }

        sc->sc_supply = fdtbus_regulator_acquire(phandle, "phy-supply");

        aprint_naive("\n");
        aprint_normal(": USB2 PHY\n");

        fdtbus_register_phy_controller(self, phandle, &mesongxl_usb2phy_funcs);
}