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 #include <linux/mod_devicetable.h>
  17
  18 /* Coreboot table header structure */
  19 struct 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 */
  30 struct coreboot_table_entry {
  31         u32 tag;
  32         u32 size;
  33 };
  34
  35 /* Points to a CBMEM entry */
  36 struct 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 */
  46 struct 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 */
  56 struct 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. */
  76 struct 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
  87 static 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. */
  93 struct 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. */
 104 int __coreboot_driver_register(struct coreboot_driver *driver,
 105                                struct module *owner);
 106
 107 /* Unregister a driver that uses the data from a coreboot table. */
 108 void 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 */