/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2016 Michael Zhilin <mizhka@gmail.com>
 * Copyright (c) 2016 Landon Fuller <landonf@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,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 */

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

#include <machine/bus.h>

#include <dev/bhnd/bhndvar.h>

#include <dev/spibus/spi.h>

#include "bhnd_chipc_if.h"

#include "spibus_if.h"

#include "chipcreg.h"
#include "chipcvar.h"
#include "chipc_slicer.h"

#include "chipc_spi.h"

static int      chipc_spi_probe(device_t dev);
static int      chipc_spi_attach(device_t dev);
static int      chipc_spi_detach(device_t dev);
static int      chipc_spi_transfer(device_t dev, device_t child,
                    struct spi_command *cmd);
static int      chipc_spi_txrx(struct chipc_spi_softc *sc, uint8_t in,
                    uint8_t* out);
static int      chipc_spi_wait(struct chipc_spi_softc *sc);

static int
chipc_spi_probe(device_t dev)
{
        device_set_desc(dev, "Broadcom ChipCommon SPI");
        return (BUS_PROBE_NOWILDCARD);
}

static int
chipc_spi_attach(device_t dev)
{
        struct chipc_spi_softc  *sc;
        struct chipc_caps       *ccaps;
        device_t                 flash_dev;
        device_t                 spibus;
        const char              *flash_name;
        int                      error;

        sc = device_get_softc(dev);

        /* Allocate SPI controller registers */
        sc->sc_rid = 1;
        sc->sc_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->sc_rid,
            RF_ACTIVE);
        if (sc->sc_res == NULL) {
                device_printf(dev, "failed to allocate device registers\n");
                return (ENXIO);
        }

        /* Allocate flash shadow region */
        sc->sc_flash_rid = 0;
        sc->sc_flash_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
            &sc->sc_flash_rid, RF_ACTIVE);
        if (sc->sc_flash_res == NULL) {
                device_printf(dev, "failed to allocate flash region\n");
                error = ENXIO;
                goto failed;
        }

        /* 
         * Add flash device
         * 
         * XXX: This should be replaced with a DEVICE_IDENTIFY implementation
         * in chipc-specific subclasses of the mx25l and at45d drivers.
         */
        if ((spibus = device_add_child(dev, "spibus",
            DEVICE_UNIT_ANY)) == NULL) {
                device_printf(dev, "failed to add spibus\n");
                error = ENXIO;
                goto failed;
        }

        /* Let spibus perform full attach before we try to call
         * BUS_ADD_CHILD() */
        bus_attach_children(dev);

        /* Determine flash type and add the flash child */
        ccaps = BHND_CHIPC_GET_CAPS(device_get_parent(dev));
        flash_name = chipc_sflash_device_name(ccaps->flash_type);
        if (flash_name != NULL) {
                flash_dev = BUS_ADD_CHILD(spibus, 0, flash_name,
                    DEVICE_UNIT_ANY);
                if (flash_dev == NULL) {
                        device_printf(dev, "failed to add %s\n", flash_name);
                        error = ENXIO;
                        goto failed;
                }

                chipc_register_slicer(ccaps->flash_type);

                if ((error = device_probe_and_attach(flash_dev))) {
                        device_printf(dev, "failed to attach %s: %d\n",
                            flash_name, error);
                        goto failed;
                }
        }

        return (0);

failed:
        device_delete_children(dev);

        if (sc->sc_res != NULL)
                bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_rid,
                    sc->sc_res);

        if (sc->sc_flash_res != NULL)
                bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_flash_rid,
                    sc->sc_flash_res);

        return (error);
}

static int
chipc_spi_detach(device_t dev)
{
        struct chipc_spi_softc  *sc;
        int                      error;

        sc = device_get_softc(dev);

        if ((error = bus_generic_detach(dev)))
                return (error);

        bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_rid, sc->sc_res);
        bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_flash_rid,
            sc->sc_flash_res);
        return (0);
}

static int
chipc_spi_wait(struct chipc_spi_softc *sc)
{
        int i;

        for (i = CHIPC_SPI_MAXTRIES; i > 0; i--)
                if (!(SPI_READ(sc, CHIPC_SPI_FLASHCTL) & CHIPC_SPI_FLASHCTL_START))
                        break;

        if (i > 0)
                return (0);

        BHND_WARN_DEV(sc->sc_dev, "busy: CTL=0x%x DATA=0x%x",
            SPI_READ(sc, CHIPC_SPI_FLASHCTL),
            SPI_READ(sc, CHIPC_SPI_FLASHDATA));
        return (-1);
}

static int
chipc_spi_txrx(struct chipc_spi_softc *sc, uint8_t out, uint8_t* in)
{
        uint32_t ctl;

        ctl = CHIPC_SPI_FLASHCTL_START | CHIPC_SPI_FLASHCTL_CSACTIVE | out;
        SPI_BARRIER_WRITE(sc);
        SPI_WRITE(sc, CHIPC_SPI_FLASHCTL, ctl);
        SPI_BARRIER_WRITE(sc);

        if (chipc_spi_wait(sc))
                return (-1);

        *in = SPI_READ(sc, CHIPC_SPI_FLASHDATA) & 0xff;
        return (0);
}

static int
chipc_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
        struct chipc_spi_softc  *sc;
        uint8_t         *buf_in;
        uint8_t         *buf_out;
        int              i;

        sc = device_get_softc(dev);
        KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
            ("TX/RX command sizes should be equal"));
        KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
            ("TX/RX data sizes should be equal"));

        if (cmd->tx_cmd_sz == 0) {
                BHND_DEBUG_DEV(child, "size of command is ZERO");
                return (EIO);
        }

        SPI_BARRIER_WRITE(sc);
        SPI_WRITE(sc, CHIPC_SPI_FLASHADDR, 0);
        SPI_BARRIER_WRITE(sc);

        /*
         * Transfer command
         */
        buf_out = (uint8_t *)cmd->tx_cmd;
        buf_in = (uint8_t *)cmd->rx_cmd;
        for (i = 0; i < cmd->tx_cmd_sz; i++)
                 if (chipc_spi_txrx(sc, buf_out[i], &(buf_in[i])))
                         return (EIO);

        /*
         * Receive/transmit data
         */
        buf_out = (uint8_t *)cmd->tx_data;
        buf_in = (uint8_t *)cmd->rx_data;
        for (i = 0; i < cmd->tx_data_sz; i++)
                if (chipc_spi_txrx(sc, buf_out[i], &(buf_in[i])))
                        return (EIO);

        /*
         * Clear CS bit and whole control register
         */
        SPI_BARRIER_WRITE(sc);
        SPI_WRITE(sc, CHIPC_SPI_FLASHCTL, 0);
        SPI_BARRIER_WRITE(sc);

        return (0);
}

static device_method_t chipc_spi_methods[] = {
                DEVMETHOD(device_probe,         chipc_spi_probe),
                DEVMETHOD(device_attach,        chipc_spi_attach),
                DEVMETHOD(device_detach,        chipc_spi_detach),

                /* SPI */
                DEVMETHOD(spibus_transfer,      chipc_spi_transfer),
                DEVMETHOD_END
};

static driver_t chipc_spi_driver = {
        "spi",
        chipc_spi_methods,
        sizeof(struct chipc_spi_softc),
};

DRIVER_MODULE(chipc_spi, bhnd_chipc, chipc_spi_driver, 0, 0);