dp.c

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/*
 * Copyright 2012 Red Hat Inc.
 *
 * 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: Ben Skeggs
 */


#include "subdev/bios.h"
#include "subdev/bios/bit.h"
#include "subdev/bios/dcb.h"
#include "subdev/bios/dp.h"

u16
dp_table(struct nouveau_bios *bios, u8 *ver, u8 *hdr, u8 *cnt, u8 *len)
{
    struct bit_entry bit_d;

    if (!bit_entry(bios, 'd', &bit_d)) {
        if (bit_d.version == 1) {
            u16 data = nv_ro16(bios, bit_d.offset);
            if (data) {
                *ver = nv_ro08(bios, data + 0);
                *hdr = nv_ro08(bios, data + 1);
                *len = nv_ro08(bios, data + 2);
                *cnt = nv_ro08(bios, data + 3);
                return data;
            }
        }
    }

    return 0x0000;
}

u16
dp_outp(struct nouveau_bios *bios, u8 idx, u8 *ver, u8 *len)
{
    u8  hdr, cnt;
    u16 table = dp_table(bios, ver, &hdr, &cnt, len);
    if (table && idx < cnt)
        return nv_ro16(bios, table + hdr + (idx * *len));
    return 0xffff;
}

u16
dp_outp_match(struct nouveau_bios *bios, struct dcb_output *outp,
          u8 *ver, u8 *len)
{
    u8  idx = 0;
    u16 data;
    while ((data = dp_outp(bios, idx++, ver, len)) != 0xffff) {
        if (data) {
            u32 hash = nv_ro32(bios, data);
            if (dcb_hash_match(outp, hash))
                return data;
        }
    }
    return 0x0000;
}