/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
 * Copyright (c) 2013, Luiz Otavio O Souza <loos@FreeBSD.org>
 * Copyright (c) 2013 The FreeBSD Foundation
 * 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 unmodified, 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 ``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 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/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>

#include <dev/gpio/gpiobusvar.h>
#include <dev/gpio/gpiobus_internal.h>
#include <dev/ofw/ofw_bus.h>

#include "gpiobus_if.h"

static struct ofw_gpiobus_devinfo *ofw_gpiobus_setup_devinfo(device_t,
        device_t, phandle_t);
static void ofw_gpiobus_destroy_devinfo(device_t, struct ofw_gpiobus_devinfo *);
static int ofw_gpiobus_parse_gpios_impl(device_t, phandle_t, char *,
        struct gpiobus_softc *, struct gpiobus_pin **);

/*
 * Utility functions for easier handling of OFW GPIO pins.
 *
 * !!! BEWARE !!!
 * GPIOBUS uses children's IVARs, so we cannot use this interface for cross
 * tree consumers.
 *
 */
int
gpio_pin_get_by_ofw_propidx(device_t consumer, phandle_t cnode,
    char *prop_name, int idx, gpio_pin_t *out_pin)
{
        phandle_t xref;
        pcell_t *cells;
        device_t busdev;
        struct gpiobus_pin pin;
        int ncells, rv;

        KASSERT(consumer != NULL && cnode > 0,
            ("both consumer and cnode required"));

        rv = ofw_bus_parse_xref_list_alloc(cnode, prop_name, "#gpio-cells",
            idx, &xref, &ncells, &cells);
        if (rv != 0)
                return (rv);

        /* Translate provider to device. */
        pin.dev = OF_device_from_xref(xref);
        if (pin.dev == NULL) {
                OF_prop_free(cells);
                return (ENODEV);
        }

        /* Test if GPIO bus already exist. */
        busdev = GPIO_GET_BUS(pin.dev);
        if (busdev == NULL) {
                OF_prop_free(cells);
                return (ENODEV);
        }

        /* Map GPIO pin. */
        rv = gpio_map_gpios(pin.dev, cnode, OF_node_from_xref(xref), ncells,
            cells, &pin.pin, &pin.flags);
        OF_prop_free(cells);
        if (rv != 0)
                return (ENXIO);

        /* Reserve GPIO pin. */
        rv = gpiobus_acquire_pin(busdev, pin.pin);
        if (rv != 0)
                return (EBUSY);

        *out_pin = malloc(sizeof(struct gpiobus_pin), M_DEVBUF,
            M_WAITOK | M_ZERO);
        **out_pin = pin;
        return (0);
}

int
gpio_pin_get_by_ofw_idx(device_t consumer, phandle_t node,
    int idx, gpio_pin_t *pin)
{

        return (gpio_pin_get_by_ofw_propidx(consumer, node, "gpios", idx, pin));
}

int
gpio_pin_get_by_ofw_property(device_t consumer, phandle_t node,
    char *name, gpio_pin_t *pin)
{

        return (gpio_pin_get_by_ofw_propidx(consumer, node, name, 0, pin));
}

int
gpio_pin_get_by_ofw_name(device_t consumer, phandle_t node,
    char *name, gpio_pin_t *pin)
{
        int rv, idx;

        KASSERT(consumer != NULL && node > 0,
            ("both consumer and node required"));

        rv = ofw_bus_find_string_index(node, "gpio-names", name, &idx);
        if (rv != 0)
                return (rv);
        return (gpio_pin_get_by_ofw_idx(consumer, node, idx, pin));
}

/*
 * OFW_GPIOBUS driver.
 */
device_t
ofw_gpiobus_add_fdt_child(device_t bus, const char *drvname, phandle_t child)
{
        device_t childdev;
        int i;
        struct gpiobus_ivar *devi;
        struct ofw_gpiobus_devinfo *dinfo;

        /*
         * Check to see if we already have a child for @p child, and if so
         * return it.
         */
        childdev = ofw_bus_find_child_device_by_phandle(bus, child);
        if (childdev != NULL)
                return (childdev);

        /*
         * Set up the GPIO child and OFW bus layer devinfo and add it to bus.
         */
        childdev = device_add_child(bus, drvname, DEVICE_UNIT_ANY);
        if (childdev == NULL)
                return (NULL);
        dinfo = ofw_gpiobus_setup_devinfo(bus, childdev, child);
        if (dinfo == NULL) {
                device_delete_child(bus, childdev);
                return (NULL);
        }
        if (device_probe_and_attach(childdev) != 0) {
                ofw_gpiobus_destroy_devinfo(bus, dinfo);
                device_delete_child(bus, childdev);
                return (NULL);
        }
        /* Use the child name as pin name. */
        devi = &dinfo->opd_dinfo;
        for (i = 0; i < devi->npins; i++)
                GPIOBUS_PIN_SETNAME(bus, devi->pins[i],
                    device_get_nameunit(childdev));

        return (childdev);
}

int
ofw_gpiobus_parse_gpios(device_t consumer, char *pname,
        struct gpiobus_pin **pins)
{

        return (ofw_gpiobus_parse_gpios_impl(consumer,
            ofw_bus_get_node(consumer), pname, NULL, pins));
}

void
ofw_gpiobus_register_provider(device_t provider)
{
        phandle_t node;

        node = ofw_bus_get_node(provider);
        if (node != -1)
                OF_device_register_xref(OF_xref_from_node(node), provider);
}

void
ofw_gpiobus_unregister_provider(device_t provider)
{
        phandle_t node;

        node = ofw_bus_get_node(provider);
        if (node != -1)
                OF_device_register_xref(OF_xref_from_node(node), NULL);
}

static struct ofw_gpiobus_devinfo *
ofw_gpiobus_setup_devinfo(device_t bus, device_t child, phandle_t node)
{
        int i, npins;
        struct gpiobus_ivar *devi;
        struct gpiobus_pin *pins;
        struct gpiobus_softc *sc;
        struct ofw_gpiobus_devinfo *dinfo;

        sc = device_get_softc(bus);
        dinfo = malloc(sizeof(*dinfo), M_DEVBUF, M_NOWAIT | M_ZERO);
        if (dinfo == NULL)
                return (NULL);
        if (ofw_bus_gen_setup_devinfo(&dinfo->opd_obdinfo, node) != 0) {
                free(dinfo, M_DEVBUF);
                return (NULL);
        }
        /* Parse the gpios property for the child. */
        npins = ofw_gpiobus_parse_gpios_impl(child, node, "gpios", sc, &pins);
        if (npins <= 0) {
                ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
                free(dinfo, M_DEVBUF);
                return (NULL);
        }
        /* Initialize the irq resource list. */
        resource_list_init(&dinfo->opd_dinfo.rl);
        /* Allocate the child ivars and copy the parsed pin data. */
        devi = &dinfo->opd_dinfo;
        devi->npins = (uint32_t)npins;
        if (gpiobus_alloc_ivars(devi) != 0) {
                free(pins, M_DEVBUF);
                ofw_gpiobus_destroy_devinfo(bus, dinfo);
                return (NULL);
        }
        for (i = 0; i < devi->npins; i++)
                devi->pins[i] = pins[i].pin;
        free(pins, M_DEVBUF);
        /* Parse the interrupt resources. */
        if (ofw_bus_intr_to_rl(bus, node, &dinfo->opd_dinfo.rl, NULL) != 0) {
                ofw_gpiobus_destroy_devinfo(bus, dinfo);
                return (NULL);
        }
        device_set_ivars(child, dinfo);

        return (dinfo);
}

static void
ofw_gpiobus_destroy_devinfo(device_t bus, struct ofw_gpiobus_devinfo *dinfo)
{
        int i;
        struct gpiobus_ivar *devi;
        struct gpiobus_softc *sc;

        sc = device_get_softc(bus);
        devi = &dinfo->opd_dinfo;
        for (i = 0; i < devi->npins; i++) {
                if (devi->pins[i] > sc->sc_npins)
                        continue;
                sc->sc_pins[devi->pins[i]].mapped = 0;
        }
        gpiobus_free_ivars(devi);
        resource_list_free(&dinfo->opd_dinfo.rl);
        ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
        free(dinfo, M_DEVBUF);
}

static int
ofw_gpiobus_parse_gpios_impl(device_t consumer, phandle_t cnode, char *pname,
        struct gpiobus_softc *bussc, struct gpiobus_pin **pins)
{
        int gpiocells, i, j, ncells, npins;
        pcell_t *gpios;
        phandle_t gpio;

        ncells = OF_getencprop_alloc_multi(cnode, pname, sizeof(*gpios),
            (void **)&gpios);
        if (ncells == -1) {
                device_printf(consumer,
                    "Warning: No %s specified in fdt data; "
                    "device may not function.\n", pname);
                return (-1);
        }
        /*
         * The gpio-specifier is controller independent, the first pcell has
         * the reference to the GPIO controller phandler.
         * Count the number of encoded gpio-specifiers on the first pass.
         */
        i = 0;
        npins = 0;
        while (i < ncells) {
                /* Allow NULL specifiers. */
                if (gpios[i] == 0) {
                        npins++;
                        i++;
                        continue;
                }
                gpio = OF_node_from_xref(gpios[i]);
                /* If we have bussc, ignore devices from other gpios. */
                if (bussc != NULL)
                        if (ofw_bus_get_node(bussc->sc_dev) != gpio)
                                return (0);
                /*
                 * Check for gpio-controller property and read the #gpio-cells
                 * for this GPIO controller.
                 */
                if (!OF_hasprop(gpio, "gpio-controller") ||
                    OF_getencprop(gpio, "#gpio-cells", &gpiocells,
                    sizeof(gpiocells)) < 0) {
                        device_printf(consumer,
                            "gpio reference is not a gpio-controller.\n");
                        OF_prop_free(gpios);
                        return (-1);
                }
                if (ncells - i < gpiocells + 1) {
                        device_printf(consumer,
                            "%s cells doesn't match #gpio-cells.\n", pname);
                        return (-1);
                }
                npins++;
                i += gpiocells + 1;
        }
        if (npins == 0 || pins == NULL) {
                if (npins == 0)
                        device_printf(consumer, "no pin specified in %s.\n",
                            pname);
                OF_prop_free(gpios);
                return (npins);
        }
        *pins = malloc(sizeof(struct gpiobus_pin) * npins, M_DEVBUF,
            M_NOWAIT | M_ZERO);
        if (*pins == NULL) {
                OF_prop_free(gpios);
                return (-1);
        }
        /* Decode the gpio specifier on the second pass. */
        i = 0;
        j = 0;
        while (i < ncells) {
                /* Allow NULL specifiers. */
                if (gpios[i] == 0) {
                        j++;
                        i++;
                        continue;
                }
                gpio = OF_node_from_xref(gpios[i]);
                /* Read gpio-cells property for this GPIO controller. */
                if (OF_getencprop(gpio, "#gpio-cells", &gpiocells,
                    sizeof(gpiocells)) < 0) {
                        device_printf(consumer,
                            "gpio does not have the #gpio-cells property.\n");
                        goto fail;
                }
                /* Return the device reference for the GPIO controller. */
                (*pins)[j].dev = OF_device_from_xref(gpios[i]);
                if ((*pins)[j].dev == NULL) {
                        device_printf(consumer,
                            "no device registered for the gpio controller.\n");
                        goto fail;
                }
                /*
                 * If the gpiobus softc is NULL we use the GPIO_GET_BUS() to
                 * retrieve it.  The GPIO_GET_BUS() method is only valid after
                 * the child is probed and attached.
                 */
                if (bussc == NULL) {
                        if (GPIO_GET_BUS((*pins)[j].dev) == NULL) {
                                device_printf(consumer,
                                    "no gpiobus reference for %s.\n",
                                    device_get_nameunit((*pins)[j].dev));
                                goto fail;
                        }
                        bussc = device_get_softc(GPIO_GET_BUS((*pins)[j].dev));
                }
                /* Get the GPIO pin number and flags. */
                if (gpio_map_gpios((*pins)[j].dev, cnode, gpio, gpiocells,
                    &gpios[i + 1], &(*pins)[j].pin, &(*pins)[j].flags) != 0) {
                        device_printf(consumer,
                            "cannot map the gpios specifier.\n");
                        goto fail;
                }
                /* Reserve the GPIO pin. */
                if (gpiobus_acquire_pin(bussc->sc_busdev, (*pins)[j].pin) != 0)
                        goto fail;
                j++;
                i += gpiocells + 1;
        }
        OF_prop_free(gpios);

        return (npins);

fail:
        OF_prop_free(gpios);
        free(*pins, M_DEVBUF);
        return (-1);
}

static int
ofw_gpiobus_probe(device_t dev)
{

        if (ofw_bus_get_node(dev) == -1)
                return (ENXIO);
        device_set_desc(dev, "OFW GPIO bus");

        return (BUS_PROBE_DEFAULT);
}

static int
ofw_gpiobus_attach(device_t dev)
{
        int err;
        phandle_t child;

        err = gpiobus_init_softc(dev);
        if (err != 0)
                return (err);
        err = gpiobus_add_gpioc(dev);
        if (err != 0)
                return (err);
        bus_identify_children(dev);
        bus_enumerate_hinted_children(dev);
        /*
         * Attach the children represented in the device tree.
         */
        for (child = OF_child(ofw_bus_get_node(dev)); child != 0;
            child = OF_peer(child)) {
                if (OF_hasprop(child, "gpio-hog"))
                        continue;
                if (!OF_hasprop(child, "gpios"))
                        continue;
                if (ofw_gpiobus_add_fdt_child(dev, NULL, child) == NULL)
                        continue;
        }

        bus_attach_children(dev);
        return (0);
}

static device_t
ofw_gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
{
        device_t child;
        struct ofw_gpiobus_devinfo *devi;

        child = gpiobus_add_child_common(dev, order, name, unit,
            sizeof(struct ofw_gpiobus_devinfo));
        if (child == NULL)
                return (NULL);

        /*
         * NULL all the OFW-related parts of the ivars for non-OFW
         * children.
         */
        devi = device_get_ivars(child);
        devi->opd_obdinfo.obd_node = -1;
        devi->opd_obdinfo.obd_name = NULL;
        devi->opd_obdinfo.obd_compat = NULL;
        devi->opd_obdinfo.obd_type = NULL;
        devi->opd_obdinfo.obd_model = NULL;

        return (child);
}

static const struct ofw_bus_devinfo *
ofw_gpiobus_get_devinfo(device_t bus, device_t dev)
{
        struct ofw_gpiobus_devinfo *dinfo;

        dinfo = device_get_ivars(dev);

        return (&dinfo->opd_obdinfo);
}

static device_method_t ofw_gpiobus_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ofw_gpiobus_probe),
        DEVMETHOD(device_attach,        ofw_gpiobus_attach),

        /* Bus interface */
        DEVMETHOD(bus_child_pnpinfo,    ofw_bus_gen_child_pnpinfo),
        DEVMETHOD(bus_add_child,        ofw_gpiobus_add_child),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_get_devinfo,  ofw_gpiobus_get_devinfo),
        DEVMETHOD(ofw_bus_get_compat,   ofw_bus_gen_get_compat),
        DEVMETHOD(ofw_bus_get_model,    ofw_bus_gen_get_model),
        DEVMETHOD(ofw_bus_get_name,     ofw_bus_gen_get_name),
        DEVMETHOD(ofw_bus_get_node,     ofw_bus_gen_get_node),
        DEVMETHOD(ofw_bus_get_type,     ofw_bus_gen_get_type),

        DEVMETHOD_END
};

DEFINE_CLASS_1(gpiobus, ofw_gpiobus_driver, ofw_gpiobus_methods,
    sizeof(struct gpiobus_softc), gpiobus_driver);
EARLY_DRIVER_MODULE(ofw_gpiobus, gpio, ofw_gpiobus_driver, 0, 0, BUS_PASS_BUS);
MODULE_VERSION(ofw_gpiobus, 1);
MODULE_DEPEND(ofw_gpiobus, gpiobus, 1, 1, 1);