/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009-2010 The FreeBSD Foundation
 *
 * This software was developed by Semihalf under sponsorship from
 * the FreeBSD Foundation.
 *
 * 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 "opt_platform.h"

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

#include <machine/bus.h>

#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_cpu_fdt.h>

static int uart_fdt_probe(device_t);

static device_method_t uart_fdt_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         uart_fdt_probe),
        DEVMETHOD(device_attach,        uart_bus_attach),
        DEVMETHOD(device_detach,        uart_bus_detach),
        DEVMETHOD_END
};

static driver_t uart_fdt_driver = {
        uart_driver_name,
        uart_fdt_methods,
        sizeof(struct uart_softc),
};

int
uart_fdt_get_clock(phandle_t node, pcell_t *cell)
{

        /* clock-frequency is a FreeBSD-only extension. */
        if ((OF_getencprop(node, "clock-frequency", cell,
            sizeof(*cell))) <= 0) {
                /* Try to retrieve parent 'bus-frequency' */
                /* XXX this should go to simple-bus fixup or so */
                if ((OF_getencprop(OF_parent(node), "bus-frequency", cell,
                    sizeof(*cell))) <= 0)
                        *cell = 0;
        }

        return (0);
}

int
uart_fdt_get_shift(phandle_t node, pcell_t *cell)
{

        if ((OF_getencprop(node, "reg-shift", cell, sizeof(*cell))) <= 0)
                return (-1);
        return (0);
}

int
uart_fdt_get_io_width(phandle_t node, pcell_t *cell)
{

        if ((OF_getencprop(node, "reg-io-width", cell, sizeof(*cell))) <= 0)
                return (-1);
        return (0);
}

static uintptr_t
uart_fdt_find_device(device_t dev)
{
        struct ofw_compat_data **cd;
        const struct ofw_compat_data *ocd;

        SET_FOREACH(cd, uart_fdt_class_and_device_set) {
                ocd = ofw_bus_search_compatible(dev, *cd);
                if (ocd->ocd_data != 0)
                        return (ocd->ocd_data);
        }
        return (0);
}

static int
phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
{
        char buf[64];
        char *sep;

        if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
                return (ENXIO);
        /*
         * stdout-path may have a ':' to separate the device from the
         * connection settings. Split the string so we just pass the former
         * to OF_finddevice.
         */
        sep = strchr(buf, ':');
        if (sep != NULL)
                *sep = '\0';
        if ((*node = OF_finddevice(buf)) == -1)
                return (ENXIO);

        return (0);
}

static const struct ofw_compat_data *
uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
{
        const struct ofw_compat_data *ocd;

        for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
                if (ofw_bus_node_is_compatible(node, ocd->ocd_str))
                        return (ocd);
        }
        return (NULL);
}

static uintptr_t
uart_fdt_find_by_node(phandle_t node, int class_list)
{
        struct ofw_compat_data **cd;
        const struct ofw_compat_data *ocd;

        if (class_list) {
                SET_FOREACH(cd, uart_fdt_class_set) {
                        ocd = uart_fdt_find_compatible(node, *cd);
                        if ((ocd != NULL) && (ocd->ocd_data != 0))
                                return (ocd->ocd_data);
                }
        } else {
                SET_FOREACH(cd, uart_fdt_class_and_device_set) {
                        ocd = uart_fdt_find_compatible(node, *cd);
                        if ((ocd != NULL) && (ocd->ocd_data != 0))
                                return (ocd->ocd_data);
                }
        }

        return (0);
}

int
uart_cpu_fdt_probe(struct uart_class **classp, bus_space_tag_t *bst,
    bus_space_handle_t *bsh, int *baud, u_int *rclk, u_int *shiftp,
    u_int *iowidthp, const int devtype)
{
        const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
            "stdin-path", "stdin", NULL};
        const char *propnames_dbgport[] = {"freebsd,debug-path", NULL};
        const char **name;
        struct uart_class *class;
        phandle_t node, chosen;
        pcell_t br, clk, shift, iowidth;
        char *cp = NULL;
        int err;

        /* Has the user forced a specific device node? */
        switch (devtype) {
        case UART_DEV_DBGPORT:
                cp = kern_getenv("hw.fdt.dbgport");
                name = propnames_dbgport;
                break;
        case UART_DEV_CONSOLE:
                cp = kern_getenv("hw.fdt.console");
                name = propnames;
                break;
        default:
                return (ENXIO);
        }

        if (cp == NULL) {
                /*
                 * Retrieve a node from /chosen.
                 */
                node = -1;
                if ((chosen = OF_finddevice("/chosen")) != -1) {
                        for (; *name != NULL; name++) {
                                if (phandle_chosen_propdev(chosen, *name,
                                    &node) == 0)
                                        break;
                        }
                }
                if (chosen == -1 || *name == NULL)
                        node = OF_finddevice("serial0"); /* Last ditch */
        } else {
                node = OF_finddevice(cp);
        }

        if (node == -1)
                return (ENXIO);

        /*
         * Check old style of UART definition first. Unfortunately, the common
         * FDT processing is not possible if we have clock, power domains and
         * pinmux stuff.
         */
        class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
        if (class != NULL) {
                if ((err = uart_fdt_get_clock(node, &clk)) != 0)
                        return (err);
        } else {
                /* Check class only linker set */
                class =
                    (struct uart_class *)uart_fdt_find_by_node(node, 1);
                if (class == NULL)
                        return (ENXIO);
                if (uart_fdt_get_clock(node, &clk) != 0)
                        clk = 0;
        }

        /*
         * Grab the default rclk from the uart class.
         */
        if (clk == 0)
                clk = class->uc_rclk;

        /*
         * Retrieve serial attributes.
         */
        if (uart_fdt_get_shift(node, &shift) != 0)
                shift = uart_getregshift(class);

        if (uart_fdt_get_io_width(node, &iowidth) != 0)
                iowidth = uart_getregiowidth(class);

        if (OF_getencprop(node, "current-speed", &br, sizeof(br)) <= 0)
                br = 0;

        err = OF_decode_addr(node, 0, bst, bsh, NULL);
        if (err != 0)
                return (err);

        *classp = class;
        *baud = br;
        *rclk = clk;
        *shiftp = shift;
        *iowidthp = iowidth;

        return (0);
}

static int
uart_fdt_probe(device_t dev)
{
        struct uart_softc *sc;
        phandle_t node;
        pcell_t clock, shift, iowidth;
        int err;

        sc = device_get_softc(dev);

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

        sc->sc_class = (struct uart_class *)uart_fdt_find_device(dev);
        if (sc->sc_class == NULL)
                return (ENXIO);

        node = ofw_bus_get_node(dev);

        if ((err = uart_fdt_get_clock(node, &clock)) != 0)
                return (err);
        if (uart_fdt_get_shift(node, &shift) != 0)
                shift = uart_getregshift(sc->sc_class);
        if (uart_fdt_get_io_width(node, &iowidth) != 0)
                iowidth = uart_getregiowidth(sc->sc_class);

        return (uart_bus_probe(dev, (int)shift, (int)iowidth, (int)clock, 0, 0, 0));
}

DRIVER_MODULE(uart, simplebus, uart_fdt_driver, 0, 0);
DRIVER_MODULE(uart, ofwbus, uart_fdt_driver, 0, 0);