LXR linux/drivers/acpi/bgrt.c

   1/*
   2 * BGRT boot graphic support
   3 * Authors: Matthew Garrett, Josh Triplett <josh@joshtriplett.org>
   4 * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
   5 * Copyright 2012 Intel Corporation
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/kernel.h>
  13#include <linux/init.h>
  14#include <linux/device.h>
  15#include <linux/sysfs.h>
  16#include <linux/efi-bgrt.h>
  17
  18static void *bgrt_image;
  19static struct kobject *bgrt_kobj;
  20
  21static ssize_t show_version(struct device *dev,
  22                            struct device_attribute *attr, char *buf)
  23{
  24        return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.version);
  25}
  26static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
  27
  28static ssize_t show_status(struct device *dev,
  29                           struct device_attribute *attr, char *buf)
  30{
  31        return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.status);
  32}
  33static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
  34
  35static ssize_t show_type(struct device *dev,
  36                         struct device_attribute *attr, char *buf)
  37{
  38        return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_type);
  39}
  40static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
  41
  42static ssize_t show_xoffset(struct device *dev,
  43                            struct device_attribute *attr, char *buf)
  44{
  45        return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_x);
  46}
  47static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
  48
  49static ssize_t show_yoffset(struct device *dev,
  50                            struct device_attribute *attr, char *buf)
  51{
  52        return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_y);
  53}
  54static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
  55
  56static ssize_t image_read(struct file *file, struct kobject *kobj,
  57               struct bin_attribute *attr, char *buf, loff_t off, size_t count)
  58{
  59        memcpy(buf, attr->private + off, count);
  60        return count;
  61}
  62
  63static BIN_ATTR_RO(image, 0);   /* size gets filled in later */
  64
  65static struct attribute *bgrt_attributes[] = {
  66        &dev_attr_version.attr,
  67        &dev_attr_status.attr,
  68        &dev_attr_type.attr,
  69        &dev_attr_xoffset.attr,
  70        &dev_attr_yoffset.attr,
  71        NULL,
  72};
  73
  74static struct bin_attribute *bgrt_bin_attributes[] = {
  75        &bin_attr_image,
  76        NULL,
  77};
  78
  79static const struct attribute_group bgrt_attribute_group = {
  80        .attrs = bgrt_attributes,
  81        .bin_attrs = bgrt_bin_attributes,
  82};
  83
  84int __init acpi_parse_bgrt(struct acpi_table_header *table)
  85{
  86        efi_bgrt_init(table);
  87        return 0;
  88}
  89
  90static int __init bgrt_init(void)
  91{
  92        int ret;
  93
  94        if (!bgrt_tab.image_address)
  95                return -ENODEV;
  96
  97        bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
  98                              MEMREMAP_WB);
  99        if (!bgrt_image) {
 100                pr_notice("Ignoring BGRT: failed to map image memory\n");
 101                return -ENOMEM;
 102        }
 103
 104        bin_attr_image.private = bgrt_image;
 105        bin_attr_image.size = bgrt_image_size;
 106
 107        bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
 108        if (!bgrt_kobj) {
 109                ret = -EINVAL;
 110                goto out_memmap;
 111        }
 112
 113        ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
 114        if (ret)
 115                goto out_kobject;
 116
 117        return 0;
 118
 119out_kobject:
 120        kobject_put(bgrt_kobj);
 121out_memmap:
 122        memunmap(bgrt_image);
 123        return ret;
 124}
 125device_initcall(bgrt_init);
 126