/*-
 * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@freebsd.org>
 *
 * 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>
#include <sys/stdint.h>
#include <sys/stddef.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>

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

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>

#include <dev/usb/usb_core.h>
#include <dev/usb/usb_busdma.h>
#include <dev/usb/usb_process.h>
#include <dev/usb/usb_util.h>

#define USB_DEBUG_VAR usbssdebug

#include <dev/usb/usb_controller.h>
#include <dev/usb/usb_bus.h>
#include <dev/usb/controller/musb_otg.h>
#include <dev/usb/usb_debug.h>

#include <sys/rman.h>

#include <arm/ti/am335x/am335x_scm.h>
#include <arm/ti/ti_sysc.h>
#include <dev/clk/clk.h>
#include <dev/syscon/syscon.h>
#include "syscon_if.h"

#define USBCTRL_REV             0x00
#define USBCTRL_CTRL            0x14
#define USBCTRL_STAT            0x18
#define USBCTRL_IRQ_STAT0       0x30
#define         IRQ_STAT0_RXSHIFT       16
#define         IRQ_STAT0_TXSHIFT       0
#define USBCTRL_IRQ_STAT1       0x34
#define         IRQ_STAT1_DRVVBUS       (1 << 8)
#define USBCTRL_INTEN_SET0      0x38
#define USBCTRL_INTEN_SET1      0x3C
#define         USBCTRL_INTEN_USB_ALL   0x1ff
#define         USBCTRL_INTEN_USB_SOF   (1 << 3)
#define USBCTRL_INTEN_CLR0      0x40
#define USBCTRL_INTEN_CLR1      0x44
#define USBCTRL_UTMI            0xE0
#define         USBCTRL_UTMI_FSDATAEXT          (1 << 1)
#define USBCTRL_MODE            0xE8
#define         USBCTRL_MODE_IDDIG              (1 << 8)
#define         USBCTRL_MODE_IDDIGMUX           (1 << 7)

/* USBSS resource + 2 MUSB ports */

#define RES_USBCORE     0
#define RES_USBCTRL     1

#define USB_WRITE4(sc, idx, reg, val)   do {            \
        bus_write_4((sc)->sc_mem_res[idx], (reg), (val));       \
} while (0)

#define USB_READ4(sc, idx, reg) bus_read_4((sc)->sc_mem_res[idx], (reg))

#define USBCTRL_WRITE4(sc, reg, val)    \
    USB_WRITE4((sc), RES_USBCTRL, (reg), (val))
#define USBCTRL_READ4(sc, reg)          \
    USB_READ4((sc), RES_USBCTRL, (reg))

static struct resource_spec am335x_musbotg_mem_spec[] = {
        { SYS_RES_MEMORY,   0,  RF_ACTIVE },
        { SYS_RES_MEMORY,   1,  RF_ACTIVE },
        { -1,               0,  0 }
};

#ifdef USB_DEBUG
static int usbssdebug = 0;

static SYSCTL_NODE(_hw_usb, OID_AUTO, am335x_usbss,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "AM335x USBSS");
SYSCTL_INT(_hw_usb_am335x_usbss, OID_AUTO, debug, CTLFLAG_RW,
    &usbssdebug, 0, "Debug level");
#endif

static device_probe_t musbotg_probe;
static device_attach_t musbotg_attach;
static device_detach_t musbotg_detach;

struct musbotg_super_softc {
        struct musbotg_softc    sc_otg;
        struct resource         *sc_mem_res[2];
        int                     sc_irq_rid;
        struct syscon           *syscon;
};

static void
musbotg_vbus_poll(struct musbotg_super_softc *sc)
{
        uint32_t stat;

        if (sc->sc_otg.sc_mode == MUSB2_DEVICE_MODE)
                musbotg_vbus_interrupt(&sc->sc_otg, 1);
        else {
                stat = USBCTRL_READ4(sc, USBCTRL_STAT);
                musbotg_vbus_interrupt(&sc->sc_otg, stat & 1);
        }
}

/*
 * Arg to musbotg_clocks_on and musbot_clocks_off is
 * a uint32_t * pointing to the SCM register offset.
 */
static uint32_t USB_CTRL[] = {SCM_USB_CTRL0, SCM_USB_CTRL1};

static void
musbotg_clocks_on(void *arg)
{
        struct musbotg_softc *sc;
        struct musbotg_super_softc *ssc;
        uint32_t reg;

        sc = arg;
        ssc = sc->sc_platform_data;

        reg = SYSCON_READ_4(ssc->syscon, USB_CTRL[sc->sc_id]);
        reg &= ~3; /* Enable power */
        reg |= 1 << 19; /* VBUS detect enable */
        reg |= 1 << 20; /* Session end enable */

        SYSCON_WRITE_4(ssc->syscon, USB_CTRL[sc->sc_id], reg);
}

static void
musbotg_clocks_off(void *arg)
{
        struct musbotg_softc *sc;
        struct musbotg_super_softc *ssc;
        uint32_t reg;

        sc = arg;
        ssc = sc->sc_platform_data;

        /* Disable power to PHY */
        reg = SYSCON_READ_4(ssc->syscon, USB_CTRL[sc->sc_id]);
        SYSCON_WRITE_4(ssc->syscon, USB_CTRL[sc->sc_id], reg | 3);
}

static void
musbotg_ep_int_set(struct musbotg_softc *sc, int ep, int on)
{
        struct musbotg_super_softc *ssc = sc->sc_platform_data;
        uint32_t epmask;

        epmask = ((1 << ep) << IRQ_STAT0_RXSHIFT);
        epmask |= ((1 << ep) << IRQ_STAT0_TXSHIFT);
        if (on)
                USBCTRL_WRITE4(ssc, USBCTRL_INTEN_SET0, epmask);
        else
                USBCTRL_WRITE4(ssc, USBCTRL_INTEN_CLR0, epmask);
}

static void
musbotg_wrapper_interrupt(void *arg)
{
        struct musbotg_softc *sc = arg;
        struct musbotg_super_softc *ssc = sc->sc_platform_data;
        uint32_t stat, stat0, stat1;

        stat = USBCTRL_READ4(ssc, USBCTRL_STAT);
        stat0 = USBCTRL_READ4(ssc, USBCTRL_IRQ_STAT0);
        stat1 = USBCTRL_READ4(ssc, USBCTRL_IRQ_STAT1);
        if (stat0)
                USBCTRL_WRITE4(ssc, USBCTRL_IRQ_STAT0, stat0);
        if (stat1)
                USBCTRL_WRITE4(ssc, USBCTRL_IRQ_STAT1, stat1);

        DPRINTFN(4, "port%d: stat0=%08x stat1=%08x, stat=%08x\n",
            sc->sc_id, stat0, stat1, stat);

        if (stat1 & IRQ_STAT1_DRVVBUS)
                musbotg_vbus_interrupt(sc, stat & 1);

        musbotg_interrupt(arg, ((stat0 >> 16) & 0xffff),
            stat0 & 0xffff, stat1 & 0xff);
}

static int
musbotg_probe(device_t dev)
{
        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (!ofw_bus_is_compatible(dev, "ti,musb-am33xx"))
                return (ENXIO);

        device_set_desc(dev, "TI AM33xx integrated USB OTG controller");

        return (BUS_PROBE_DEFAULT);
}

static int
musbotg_attach(device_t dev)
{
        struct musbotg_super_softc *sc = device_get_softc(dev);
        char mode[16];
        int err;
        uint32_t reg;
        phandle_t opp_table;
        clk_t clk_usbotg_fck;

        sc->sc_otg.sc_id = device_get_unit(dev);

        /* FIXME: The devicetree needs to be updated to get a handle to the gate
         * usbotg_fck@47c. see TRM 8.1.12.2 CM_WKUP CM_CLKDCOLDO_DPLL_PER.
         */
        err = clk_get_by_name(dev, "usbotg_fck@47c", &clk_usbotg_fck);
        if (err) {
                device_printf(dev, "Can not find usbotg_fck@47c\n");
                return (ENXIO);
        }

        err = clk_enable(clk_usbotg_fck);
        if (err) {
                device_printf(dev, "Can not enable usbotg_fck@47c\n");
                return (ENXIO);
        }

        /* FIXME: For now; Go and kidnap syscon from opp-table */
        opp_table = OF_finddevice("/opp-table");
        if (opp_table == -1) {
                device_printf(dev, "Cant find /opp-table\n");
                return (ENXIO);
        }
        if (!OF_hasprop(opp_table, "syscon")) {
                device_printf(dev, "/opp-table missing syscon property\n");
                return (ENXIO);
        }
        err = syscon_get_by_ofw_property(dev, opp_table, "syscon", &sc->syscon);
        if (err) {
                device_printf(dev, "Failed to get syscon\n");
                return (ENXIO);
        }

        /* Request the memory resources */
        err = bus_alloc_resources(dev, am335x_musbotg_mem_spec,
                sc->sc_mem_res);
        if (err) {
                device_printf(dev,
                    "Error: could not allocate mem resources\n");
                return (ENXIO);
        }

        /* Request the IRQ resources */
        sc->sc_otg.sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
            &sc->sc_irq_rid, RF_ACTIVE);
        if (sc->sc_otg.sc_irq_res == NULL) {
                device_printf(dev,
                    "Error: could not allocate irq resources\n");
                return (ENXIO);
        }

        /* setup MUSB OTG USB controller interface softc */
        sc->sc_otg.sc_clocks_on = &musbotg_clocks_on;
        sc->sc_otg.sc_clocks_off = &musbotg_clocks_off;
        sc->sc_otg.sc_clocks_arg = &sc->sc_otg;

        sc->sc_otg.sc_ep_int_set = musbotg_ep_int_set;

        /* initialise some bus fields */
        sc->sc_otg.sc_bus.parent = dev;
        sc->sc_otg.sc_bus.devices = sc->sc_otg.sc_devices;
        sc->sc_otg.sc_bus.devices_max = MUSB2_MAX_DEVICES;
        sc->sc_otg.sc_bus.dma_bits = 32;

        /* get all DMA memory */
        if (usb_bus_mem_alloc_all(&sc->sc_otg.sc_bus,
            USB_GET_DMA_TAG(dev), NULL)) {
                device_printf(dev,
                    "Failed allocate bus mem for musb\n");
                return (ENOMEM);
        }
        sc->sc_otg.sc_io_res = sc->sc_mem_res[RES_USBCORE];
        sc->sc_otg.sc_io_tag =
            rman_get_bustag(sc->sc_otg.sc_io_res);
        sc->sc_otg.sc_io_hdl =
            rman_get_bushandle(sc->sc_otg.sc_io_res);
        sc->sc_otg.sc_io_size =
            rman_get_size(sc->sc_otg.sc_io_res);

        sc->sc_otg.sc_bus.bdev = device_add_child(dev, "usbus", DEVICE_UNIT_ANY);
        if (!(sc->sc_otg.sc_bus.bdev)) {
                device_printf(dev, "No busdev for musb\n");
                goto error;
        }
        device_set_ivars(sc->sc_otg.sc_bus.bdev,
            &sc->sc_otg.sc_bus);

        err = bus_setup_intr(dev, sc->sc_otg.sc_irq_res,
            INTR_TYPE_BIO | INTR_MPSAFE,
            NULL, (driver_intr_t *)musbotg_wrapper_interrupt,
            &sc->sc_otg, &sc->sc_otg.sc_intr_hdl);
        if (err) {
                sc->sc_otg.sc_intr_hdl = NULL;
                device_printf(dev,
                    "Failed to setup interrupt for musb\n");
                goto error;
        }

        sc->sc_otg.sc_platform_data = sc;
        if (OF_getprop(ofw_bus_get_node(dev), "dr_mode", mode,
            sizeof(mode)) > 0) {
                if (strcasecmp(mode, "host") == 0)
                        sc->sc_otg.sc_mode = MUSB2_HOST_MODE;
                else
                        sc->sc_otg.sc_mode = MUSB2_DEVICE_MODE;
        } else {
                /* Beaglebone defaults: USB0 device, USB1 HOST. */
                if (sc->sc_otg.sc_id == 0)
                        sc->sc_otg.sc_mode = MUSB2_DEVICE_MODE;
                else
                        sc->sc_otg.sc_mode = MUSB2_HOST_MODE;
        }

        /*
         * software-controlled function
         */

        if (sc->sc_otg.sc_mode == MUSB2_HOST_MODE) {
                reg = USBCTRL_READ4(sc, USBCTRL_MODE);
                reg |= USBCTRL_MODE_IDDIGMUX;
                reg &= ~USBCTRL_MODE_IDDIG;
                USBCTRL_WRITE4(sc, USBCTRL_MODE, reg);
                USBCTRL_WRITE4(sc, USBCTRL_UTMI,
                    USBCTRL_UTMI_FSDATAEXT);
        } else {
                reg = USBCTRL_READ4(sc, USBCTRL_MODE);
                reg |= USBCTRL_MODE_IDDIGMUX;
                reg |= USBCTRL_MODE_IDDIG;
                USBCTRL_WRITE4(sc, USBCTRL_MODE, reg);
        }

        reg = USBCTRL_INTEN_USB_ALL & ~USBCTRL_INTEN_USB_SOF;
        USBCTRL_WRITE4(sc, USBCTRL_INTEN_SET1, reg);
        USBCTRL_WRITE4(sc, USBCTRL_INTEN_CLR0, 0xffffffff);

        err = musbotg_init(&sc->sc_otg);
        if (!err)
                err = device_probe_and_attach(sc->sc_otg.sc_bus.bdev);

        if (err)
                goto error;

        /* poll VBUS one time */
        musbotg_vbus_poll(sc);

        return (0);

error:
        musbotg_detach(dev);
        return (ENXIO);
}

static int
musbotg_detach(device_t dev)
{
        struct musbotg_super_softc *sc = device_get_softc(dev);
        int error;

        /* during module unload there are lots of children leftover */
        error = bus_generic_detach(dev);
        if (error != 0)
                return (error);

        if (sc->sc_otg.sc_irq_res && sc->sc_otg.sc_intr_hdl) {
                /*
                 * only call musbotg_uninit() after musbotg_init()
                 */
                musbotg_uninit(&sc->sc_otg);

                bus_teardown_intr(dev, sc->sc_otg.sc_irq_res,
                    sc->sc_otg.sc_intr_hdl);
                sc->sc_otg.sc_intr_hdl = NULL;
        }

        usb_bus_mem_free_all(&sc->sc_otg.sc_bus, NULL);

        /* Free resources if any */
        if (sc->sc_mem_res[0])
                bus_release_resources(dev, am335x_musbotg_mem_spec,
                    sc->sc_mem_res);

        if (sc->sc_otg.sc_irq_res)
                bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irq_rid,
                    sc->sc_otg.sc_irq_res);

        return (0);
}

static device_method_t musbotg_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe, musbotg_probe),
        DEVMETHOD(device_attach, musbotg_attach),
        DEVMETHOD(device_detach, musbotg_detach),
        DEVMETHOD(device_suspend, bus_generic_suspend),
        DEVMETHOD(device_resume, bus_generic_resume),
        DEVMETHOD(device_shutdown, bus_generic_shutdown),

        DEVMETHOD_END
};

static driver_t musbotg_driver = {
        .name = "musbotg",
        .methods = musbotg_methods,
        .size = sizeof(struct musbotg_super_softc),
};

DRIVER_MODULE(musbotg, ti_sysc, musbotg_driver, 0, 0);
MODULE_DEPEND(musbotg, ti_sysc, 1, 1, 1);
MODULE_DEPEND(musbotg, ti_am3359_cppi41, 1, 1, 1);
MODULE_DEPEND(usbss, usb, 1, 1, 1);