/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2016 Michael Zhilin <mizhka@gmail.com>
 * 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/cdefs.h>
/*
 * Slicer is required to split firmware images into pieces.
 * The first supported FW is TRX-based used by Asus routers
 * TODO: add NetGear FW (CHK)
 */

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

#include <machine/bus.h>

#include <dev/bhnd/bhnd_debug.h>

#include "chipc_slicer.h"

#include <dev/cfi/cfi_var.h>
#include "chipc_spi.h"

static int      chipc_slicer_walk(device_t dev, struct resource *res,
                    struct flash_slice *slices, int *nslices);

void
chipc_register_slicer(chipc_flash flash_type)
{
        switch (flash_type) {
        case CHIPC_SFLASH_AT:
        case CHIPC_SFLASH_ST:
                flash_register_slicer(chipc_slicer_spi, FLASH_SLICES_TYPE_SPI,
                   TRUE);
                break;
        case CHIPC_PFLASH_CFI:
                flash_register_slicer(chipc_slicer_cfi, FLASH_SLICES_TYPE_CFI,
                   TRUE);
                break;
        default:
                /* Unsupported */
                break;
        }
}

int
chipc_slicer_cfi(device_t dev, const char *provider __unused,
    struct flash_slice *slices, int *nslices)
{
        struct cfi_softc        *sc;
        device_t                 parent;

        /* must be CFI flash */
        if (device_get_devclass(dev) != devclass_find("cfi"))
                return (ENXIO);

        /* must be attached to chipc */
        if ((parent = device_get_parent(dev)) == NULL) {
                BHND_ERROR_DEV(dev, "no found ChipCommon device");
                return (ENXIO);
        }

        if (device_get_devclass(parent) != devclass_find("bhnd_chipc")) {
                BHND_ERROR_DEV(dev, "no found ChipCommon device");
                return (ENXIO);
        }

        sc = device_get_softc(dev);
        return (chipc_slicer_walk(dev, sc->sc_res, slices, nslices));
}

int
chipc_slicer_spi(device_t dev, const char *provider __unused,
    struct flash_slice *slices, int *nslices)
{
        struct chipc_spi_softc  *sc;
        device_t                 chipc, spi, spibus;

        BHND_DEBUG_DEV(dev, "initting SPI slicer: %s", device_get_name(dev));

        /* must be SPI-attached flash */
        spibus = device_get_parent(dev);
        if (spibus == NULL) {
                BHND_ERROR_DEV(dev, "no found ChipCommon SPI BUS device");
                return (ENXIO);
        }

        spi = device_get_parent(spibus);
        if (spi == NULL) {
                BHND_ERROR_DEV(dev, "no found ChipCommon SPI device");
                return (ENXIO);
        }

        chipc = device_get_parent(spi);
        if (device_get_devclass(chipc) != devclass_find("bhnd_chipc")) {
                BHND_ERROR_DEV(dev, "no found ChipCommon device");
                return (ENXIO);
        }

        sc = device_get_softc(spi);
        return (chipc_slicer_walk(dev, sc->sc_flash_res, slices, nslices));
}

/*
 * Main processing part
 */
static int
chipc_slicer_walk(device_t dev, struct resource *res,
    struct flash_slice *slices, int *nslices)
{
        uint32_t         fw_len;
        uint32_t         fs_ofs;
        uint32_t         val;
        uint32_t         ofs_trx;
        int              flash_size;

        *nslices = 0;

        flash_size = rman_get_size(res);
        ofs_trx = flash_size;

        BHND_TRACE_DEV(dev, "slicer: scanning memory [%x bytes] for headers...",
            flash_size);

        /* Find FW header in flash memory with step=128Kb (0x1000) */
        for(uint32_t ofs = 0; ofs < flash_size; ofs+= 0x1000){
                val = bus_read_4(res, ofs);
                switch (val) {
                case TRX_MAGIC:
                        /* check for second TRX */
                        if (ofs_trx < ofs) {
                                BHND_TRACE_DEV(dev, "stop on 2nd TRX: %x", ofs);
                                break;
                        }

                        BHND_TRACE("TRX found: %x", ofs);
                        ofs_trx = ofs;
                        /* read last offset of TRX header */
                        fs_ofs = bus_read_4(res, ofs + 24);
                        BHND_TRACE("FS offset: %x", fs_ofs);

                        /*
                         * GEOM IO will panic if offset is not aligned
                         * on sector size, i.e. 512 bytes
                         */
                        if (fs_ofs % 0x200 != 0) {
                                BHND_WARN("WARNING! filesystem offset should be"
                                    " aligned on sector size (%d bytes)", 0x200);
                                BHND_WARN("ignoring TRX firmware image");
                                break;
                        }

                        slices[*nslices].base = ofs + fs_ofs;
                        //XXX: fully sized? any other partition?
                        fw_len = bus_read_4(res, ofs + 4);
                        slices[*nslices].size = fw_len - fs_ofs;
                        slices[*nslices].label = "rootfs";
                        *nslices += 1;
                        break;
                case CFE_MAGIC:
                        BHND_TRACE("CFE found: %x", ofs);
                        break;
                case NVRAM_MAGIC:
                        BHND_TRACE("NVRAM found: %x", ofs);
                        break;
                default:
                        break;
                }
        }

        BHND_TRACE("slicer: done");
        return (0);
}