LXR linux/drivers/gpu/drm/nouveau/nvkm/subdev/bios/bit.c

   1/*
   2 * Copyright 2012 Red Hat Inc.
   3 *
   4 * Permission is hereby granted, free of charge, to any person obtaining a
   5 * copy of this software and associated documentation files (the "Software"),
   6 * to deal in the Software without restriction, including without limitation
   7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8 * and/or sell copies of the Software, and to permit persons to whom the
   9 * Software is furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice shall be included in
  12 * all copies or substantial portions of the Software.
  13 *
  14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20 * OTHER DEALINGS IN THE SOFTWARE.
  21 *
  22 * Authors: Ben Skeggs
  23 */
  24#include <subdev/bios.h>
  25#include <subdev/bios/bit.h>
  26
  27int
  28bit_entry(struct nvkm_bios *bios, u8 id, struct bit_entry *bit)
  29{
  30        if (likely(bios->bit_offset)) {
  31                u8  entries = nvbios_rd08(bios, bios->bit_offset + 10);
  32                u32 entry   = bios->bit_offset + 12;
  33                while (entries--) {
  34                        if (nvbios_rd08(bios, entry + 0) == id) {
  35                                bit->id      = nvbios_rd08(bios, entry + 0);
  36                                bit->version = nvbios_rd08(bios, entry + 1);
  37                                bit->length  = nvbios_rd16(bios, entry + 2);
  38                                bit->offset  = nvbios_rd16(bios, entry + 4);
  39                                return 0;
  40                        }
  41
  42                        entry += nvbios_rd08(bios, bios->bit_offset + 9);
  43                }
  44
  45                return -ENOENT;
  46        }
  47
  48        return -EINVAL;
  49}
  50