1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * coreboot_table.h
4 *
5 * Internal header for coreboot table access.
6 *
7 * Copyright 2014 Gerd Hoffmann <kraxel@redhat.com>
8 * Copyright 2017 Google Inc.
9 * Copyright 2017 Samuel Holland <samuel@sholland.org>
10 */
11
12#ifndef __COREBOOT_TABLE_H
13#define __COREBOOT_TABLE_H
14
15#include <linux/device.h>
16#include <linux/mod_devicetable.h>
17
18/* Coreboot table header structure */
19struct coreboot_table_header {
20 char signature[4];
21 u32 header_bytes;
22 u32 header_checksum;
23 u32 table_bytes;
24 u32 table_checksum;
25 u32 table_entries;
26};
27
28/* List of coreboot entry structures that is used */
29/* Generic */
30struct coreboot_table_entry {
31 u32 tag;
32 u32 size;
33};
34
35/* Points to a CBMEM entry */
36struct lb_cbmem_ref {
37 u32 tag;
38 u32 size;
39
40 u64 cbmem_addr;
41};
42
43#define LB_TAG_CBMEM_ENTRY 0x31
44
45/* Corresponds to LB_TAG_CBMEM_ENTRY */
46struct lb_cbmem_entry {
47 u32 tag;
48 u32 size;
49
50 u64 address;
51 u32 entry_size;
52 u32 id;
53};
54
55/* Describes framebuffer setup by coreboot */
56struct lb_framebuffer {
57 u32 tag;
58 u32 size;
59
60 u64 physical_address;
61 u32 x_resolution;
62 u32 y_resolution;
63 u32 bytes_per_line;
64 u8 bits_per_pixel;
65 u8 red_mask_pos;
66 u8 red_mask_size;
67 u8 green_mask_pos;
68 u8 green_mask_size;
69 u8 blue_mask_pos;
70 u8 blue_mask_size;
71 u8 reserved_mask_pos;
72 u8 reserved_mask_size;
73};
74
75/* A device, additionally with information from coreboot. */
76struct coreboot_device {
77 struct device dev;
78 union {
79 struct coreboot_table_entry entry;
80 struct lb_cbmem_ref cbmem_ref;
81 struct lb_cbmem_entry cbmem_entry;
82 struct lb_framebuffer framebuffer;
83 DECLARE_FLEX_ARRAY(u8, raw);
84 };
85};
86
87static inline struct coreboot_device *dev_to_coreboot_device(struct device *dev)
88{
89 return container_of(dev, struct coreboot_device, dev);
90}
91
92/* A driver for handling devices described in coreboot tables. */
93struct coreboot_driver {
94 int (*probe)(struct coreboot_device *);
95 void (*remove)(struct coreboot_device *);
96 struct device_driver drv;
97 const struct coreboot_device_id *id_table;
98};
99
100/* Register a driver that uses the data from a coreboot table. */
101int coreboot_driver_register(struct coreboot_driver *driver);
102
103/* Unregister a driver that uses the data from a coreboot table. */
104void coreboot_driver_unregister(struct coreboot_driver *driver);
105
106/* module_coreboot_driver() - Helper macro for drivers that don't do
107 * anything special in module init/exit. This eliminates a lot of
108 * boilerplate. Each module may only use this macro once, and
109 * calling it replaces module_init() and module_exit()
110 */
111#define module_coreboot_driver(__coreboot_driver) \
112 module_driver(__coreboot_driver, coreboot_driver_register, \
113 coreboot_driver_unregister)
114
115#endif /* __COREBOOT_TABLE_H */
116

source code of linux/drivers/firmware/google/coreboot_table.h