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