extdev.c

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/*
 * Copyright 2012 Nouveau Community
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Martin Peres
 */

#include <subdev/bios.h>
#include <subdev/bios/dcb.h>
#include <subdev/bios/extdev.h>

static u16
extdev_table(struct nouveau_bios *bios, u8 *ver, u8 *hdr, u8 *len, u8 *cnt)
{
    u8  dcb_ver, dcb_hdr, dcb_cnt, dcb_len;
    u16 dcb, extdev = 0;

    dcb = dcb_table(bios, &dcb_ver, &dcb_hdr, &dcb_cnt, &dcb_len);
    if (!dcb || (dcb_ver != 0x30 && dcb_ver != 0x40))
        return 0x0000;

    extdev = nv_ro16(bios, dcb + 18);
    if (!extdev)
        return 0x0000;

    *ver = nv_ro08(bios, extdev + 0);
    *hdr = nv_ro08(bios, extdev + 1);
    *cnt = nv_ro08(bios, extdev + 2);
    *len = nv_ro08(bios, extdev + 3);

    return extdev + *hdr;
}

u16
nvbios_extdev_entry(struct nouveau_bios *bios, int idx, u8 *ver, u8 *len)
{
    u8 hdr, cnt;
    u16 extdev = extdev_table(bios, ver, &hdr, len, &cnt);
    if (extdev && idx < cnt)
        return extdev + idx * *len;
    return 0x0000;
}

static void
extdev_parse_entry(struct nouveau_bios *bios, u16 offset,
              struct nvbios_extdev_func *entry)
{
    entry->type = nv_ro08(bios, offset + 0);
    entry->addr = nv_ro08(bios, offset + 1);
    entry->bus = (nv_ro08(bios, offset + 2) >> 4) & 1;
}

int
nvbios_extdev_parse(struct nouveau_bios *bios, int idx,
            struct nvbios_extdev_func *func)
{
    u8 ver, len;
    u16 entry;

    if (!(entry = nvbios_extdev_entry(bios, idx, &ver, &len)))
        return -EINVAL;

    extdev_parse_entry(bios, entry, func);

    return 0;
}

int
nvbios_extdev_find(struct nouveau_bios *bios, enum nvbios_extdev_type type,
           struct nvbios_extdev_func *func)
{
    u8 ver, len, i;
    u16 entry;

    i = 0;
    while (!(entry = nvbios_extdev_entry(bios, i++, &ver, &len))) {
        extdev_parse_entry(bios, entry, func);
        if (func->type == type)
            return 0;
    }

    return -EINVAL;
}