subdev/bios/bit.c

0001 /*
0002  * Copyright 2012 Red Hat Inc.
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining a
0005  * copy of this software and associated documentation files (the "Software"),
0006  * to deal in the Software without restriction, including without limitation
0007  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0008  * and/or sell copies of the Software, and to permit persons to whom the
0009  * Software is furnished to do so, subject to the following conditions:
0010  *
0011  * The above copyright notice and this permission notice shall be included in
0012  * all copies or substantial portions of the Software.
0013  *
0014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0017  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
0018  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
0019  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
0020  * OTHER DEALINGS IN THE SOFTWARE.
0021  *
0022  * Authors: Ben Skeggs
0023  */
0024 #include <subdev/bios.h>
0025 #include <subdev/bios/bit.h>
0026
0027 int
0028 bit_entry(struct nvkm_bios *bios, u8 id, struct bit_entry *bit)
0029 {
0030     if (likely(bios->bit_offset)) {
0031         u8  entries = nvbios_rd08(bios, bios->bit_offset + 10);
0032         u32 entry   = bios->bit_offset + 12;
0033         while (entries--) {
0034             if (nvbios_rd08(bios, entry + 0) == id) {
0035                 bit->id      = nvbios_rd08(bios, entry + 0);
0036                 bit->version = nvbios_rd08(bios, entry + 1);
0037                 bit->length  = nvbios_rd16(bios, entry + 2);
0038                 bit->offset  = nvbios_rd16(bios, entry + 4);
0039                 return 0;
0040             }
0041
0042             entry += nvbios_rd08(bios, bios->bit_offset + 9);
0043         }
0044
0045         return -ENOENT;
0046     }
0047
0048     return -EINVAL;
0049 }