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/* use a macro to avoid include chaining to get THIS_MODULE */
101#define coreboot_driver_register(driver) \
102	__coreboot_driver_register(driver, THIS_MODULE)
103/* Register a driver that uses the data from a coreboot table. */
104int __coreboot_driver_register(struct coreboot_driver *driver,
105			       struct module *owner);
106
107/* Unregister a driver that uses the data from a coreboot table. */
108void coreboot_driver_unregister(struct coreboot_driver *driver);
109
110/* module_coreboot_driver() - Helper macro for drivers that don't do
111 * anything special in module init/exit.  This eliminates a lot of
112 * boilerplate.  Each module may only use this macro once, and
113 * calling it replaces module_init() and module_exit()
114 */
115#define module_coreboot_driver(__coreboot_driver) \
116	module_driver(__coreboot_driver, coreboot_driver_register, \
117			coreboot_driver_unregister)
118
119#endif /* __COREBOOT_TABLE_H */