linux-zen-desktop/drivers/gpu/drm/nouveau/nvkm/subdev/bios/bit.c

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2023-08-30 17:31:07 +02:00
/*
* 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>
int
bit_entry(struct nvkm_bios *bios, u8 id, struct bit_entry *bit)
{
if (likely(bios->bit_offset)) {
u8 entries = nvbios_rd08(bios, bios->bit_offset + 10);
u32 entry = bios->bit_offset + 12;
while (entries--) {
if (nvbios_rd08(bios, entry + 0) == id) {
bit->id = nvbios_rd08(bios, entry + 0);
bit->version = nvbios_rd08(bios, entry + 1);
bit->length = nvbios_rd16(bios, entry + 2);
bit->offset = nvbios_rd16(bios, entry + 4);
return 0;
}
entry += nvbios_rd08(bios, bios->bit_offset + 9);
}
return -ENOENT;
}
return -EINVAL;
}