drivers/firmware/google/coreboot_table.h

   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 */
  18 struct 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 */
  29 struct coreboot_table_entry {
  30         u32 tag;
  31         u32 size;
  32 };
  33
  34 /* Points to a CBMEM entry */
  35 struct lb_cbmem_ref {
  36         u32 tag;
  37         u32 size;
  38
  39         u64 cbmem_addr;
  40 };
  41
  42 /* Describes framebuffer setup by coreboot */
  43 struct lb_framebuffer {
  44         u32 tag;
  45         u32 size;
  46
  47         u64 physical_address;
  48         u32 x_resolution;
  49         u32 y_resolution;
  50         u32 bytes_per_line;
  51         u8  bits_per_pixel;
  52         u8  red_mask_pos;
  53         u8  red_mask_size;
  54         u8  green_mask_pos;
  55         u8  green_mask_size;
  56         u8  blue_mask_pos;
  57         u8  blue_mask_size;
  58         u8  reserved_mask_pos;
  59         u8  reserved_mask_size;
  60 };
  61
  62 /* A device, additionally with information from coreboot. */
  63 struct coreboot_device {
  64         struct device dev;
  65         union {
  66                 struct coreboot_table_entry entry;
  67                 struct lb_cbmem_ref cbmem_ref;
  68                 struct lb_framebuffer framebuffer;
  69         };
  70 };
  71
  72 /* A driver for handling devices described in coreboot tables. */
  73 struct coreboot_driver {
  74         int (*probe)(struct coreboot_device *);
  75         int (*remove)(struct coreboot_device *);
  76         struct device_driver drv;
  77         u32 tag;
  78 };
  79
  80 /* Register a driver that uses the data from a coreboot table. */
  81 int coreboot_driver_register(struct coreboot_driver *driver);
  82
  83 /* Unregister a driver that uses the data from a coreboot table. */
  84 void coreboot_driver_unregister(struct coreboot_driver *driver);
  85
  86 /* module_coreboot_driver() - Helper macro for drivers that don't do
  87  * anything special in module init/exit.  This eliminates a lot of
  88  * boilerplate.  Each module may only use this macro once, and
  89  * calling it replaces module_init() and module_exit()
  90  */
  91 #define module_coreboot_driver(__coreboot_driver) \
  92         module_driver(__coreboot_driver, coreboot_driver_register, \
  93                         coreboot_driver_unregister)
  94
  95 #endif /* __COREBOOT_TABLE_H */