drivers/acpi/bgrt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * BGRT boot graphic support
   4  * Authors: Matthew Garrett, Josh Triplett <josh@joshtriplett.org>
   5  * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
   6  * Copyright 2012 Intel Corporation
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/device.h>
  12 #include <linux/sysfs.h>
  13 #include <linux/efi-bgrt.h>
  14
  15 static void *bgrt_image;
  16 static struct kobject *bgrt_kobj;
  17
  18 #define BGRT_SHOW(_name, _member) \
  19         static ssize_t _name##_show(struct kobject *kobj,                       \
  20                                     struct kobj_attribute *attr, char *buf)     \
  21         {                                                                       \
  22                 return sysfs_emit(buf, "%d\n", bgrt_tab._member);               \
  23         }                                                                       \
  24         static struct kobj_attribute bgrt_attr_##_name = __ATTR_RO(_name)
  25
  26 BGRT_SHOW(version, version);
  27 BGRT_SHOW(status, status);
  28 BGRT_SHOW(type, image_type);
  29 BGRT_SHOW(xoffset, image_offset_x);
  30 BGRT_SHOW(yoffset, image_offset_y);
  31
  32 static BIN_ATTR_SIMPLE_RO(image);
  33
  34 static struct attribute *bgrt_attributes[] = {
  35         &bgrt_attr_version.attr,
  36         &bgrt_attr_status.attr,
  37         &bgrt_attr_type.attr,
  38         &bgrt_attr_xoffset.attr,
  39         &bgrt_attr_yoffset.attr,
  40         NULL,
  41 };
  42
  43 static struct bin_attribute *bgrt_bin_attributes[] = {
  44         &bin_attr_image,
  45         NULL,
  46 };
  47
  48 static const struct attribute_group bgrt_attribute_group = {
  49         .attrs = bgrt_attributes,
  50         .bin_attrs = bgrt_bin_attributes,
  51 };
  52
  53 int __init acpi_parse_bgrt(struct acpi_table_header *table)
  54 {
  55         efi_bgrt_init(table);
  56         return 0;
  57 }
  58
  59 static int __init bgrt_init(void)
  60 {
  61         int ret;
  62
  63         if (!bgrt_tab.image_address)
  64                 return -ENODEV;
  65
  66         bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
  67                               MEMREMAP_WB);
  68         if (!bgrt_image) {
  69                 pr_notice("Ignoring BGRT: failed to map image memory\n");
  70                 return -ENOMEM;
  71         }
  72
  73         bin_attr_image.private = bgrt_image;
  74         bin_attr_image.size = bgrt_image_size;
  75
  76         bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
  77         if (!bgrt_kobj) {
  78                 ret = -EINVAL;
  79                 goto out_memmap;
  80         }
  81
  82         ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
  83         if (ret)
  84                 goto out_kobject;
  85
  86         return 0;
  87
  88 out_kobject:
  89         kobject_put(bgrt_kobj);
  90 out_memmap:
  91         memunmap(bgrt_image);
  92         return ret;
  93 }
  94 device_initcall(bgrt_init);