xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/nouveau/nvkm/subdev/bios/nouveau_nvkm_subdev_bios_bit.c (revision 41ec02673d281bbb3d38e6c78504ce6e30c228c1)
1 /*	$NetBSD: nouveau_nvkm_subdev_bios_bit.c,v 1.3 2021/12/18 23:45:38 riastradh Exp $	*/
2 
3 /*
4  * Copyright 2012 Red Hat Inc.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  *
24  * Authors: Ben Skeggs
25  */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_bios_bit.c,v 1.3 2021/12/18 23:45:38 riastradh Exp $");
28 
29 #include <subdev/bios.h>
30 #include <subdev/bios/bit.h>
31 
32 int
bit_entry(struct nvkm_bios * bios,u8 id,struct bit_entry * bit)33 bit_entry(struct nvkm_bios *bios, u8 id, struct bit_entry *bit)
34 {
35 	if (likely(bios->bit_offset)) {
36 		u8  entries = nvbios_rd08(bios, bios->bit_offset + 10);
37 		u32 entry   = bios->bit_offset + 12;
38 		while (entries--) {
39 			if (nvbios_rd08(bios, entry + 0) == id) {
40 				bit->id      = nvbios_rd08(bios, entry + 0);
41 				bit->version = nvbios_rd08(bios, entry + 1);
42 				bit->length  = nvbios_rd16(bios, entry + 2);
43 				bit->offset  = nvbios_rd16(bios, entry + 4);
44 				return 0;
45 			}
46 
47 			entry += nvbios_rd08(bios, bios->bit_offset + 9);
48 		}
49 
50 		return -ENOENT;
51 	}
52 
53 	return -EINVAL;
54 }
55