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