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);