tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/device.h>
13#include <linux/sysfs.h>
14#include <acpi/acpi.h>
15#include <acpi/acpi_bus.h>
16
17static struct acpi_table_bgrt *bgrt_tab;
18static struct kobject *bgrt_kobj;
19
20struct bmp_header {
21 u16 id;
22 u32 size;
23} __attribute ((packed));
24
25static struct bmp_header bmp_header;
26
27static ssize_t show_version(struct device *dev,
28 struct device_attribute *attr, char *buf)
29{
30 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version);
31}
32static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
33
34static ssize_t show_status(struct device *dev,
35 struct device_attribute *attr, char *buf)
36{
37 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status);
38}
39static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
40
41static ssize_t show_type(struct device *dev,
42 struct device_attribute *attr, char *buf)
43{
44 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type);
45}
46static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
47
48static ssize_t show_xoffset(struct device *dev,
49 struct device_attribute *attr, char *buf)
50{
51 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x);
52}
53static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
54
55static ssize_t show_yoffset(struct device *dev,
56 struct device_attribute *attr, char *buf)
57{
58 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y);
59}
60static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
61
62static ssize_t show_image(struct file *file, struct kobject *kobj,
63 struct bin_attribute *attr, char *buf, loff_t off, size_t count)
64{
65 int size = attr->size;
66 void __iomem *image = attr->private;
67
68 if (off >= size) {
69 count = 0;
70 } else {
71 if (off + count > size)
72 count = size - off;
73
74 memcpy_fromio(buf, image+off, count);
75 }
76
77 return count;
78}
79
80static struct bin_attribute image_attr = {
81 .attr = {
82 .name = "image",
83 .mode = S_IRUGO,
84 },
85 .read = show_image,
86};
87
88static struct attribute *bgrt_attributes[] = {
89 &dev_attr_version.attr,
90 &dev_attr_status.attr,
91 &dev_attr_type.attr,
92 &dev_attr_xoffset.attr,
93 &dev_attr_yoffset.attr,
94 NULL,
95};
96
97static struct attribute_group bgrt_attribute_group = {
98 .attrs = bgrt_attributes,
99};
100
101static int __init bgrt_init(void)
102{
103 acpi_status status;
104 int ret;
105 void __iomem *bgrt;
106
107 if (acpi_disabled)
108 return -ENODEV;
109
110 status = acpi_get_table("BGRT", 0,
111 (struct acpi_table_header **)&bgrt_tab);
112
113 if (ACPI_FAILURE(status))
114 return -ENODEV;
115
116 sysfs_bin_attr_init(&image_attr);
117
118 bgrt = ioremap(bgrt_tab->image_address, sizeof(struct bmp_header));
119
120 if (!bgrt) {
121 ret = -EINVAL;
122 goto out_err;
123 }
124
125 memcpy_fromio(&bmp_header, bgrt, sizeof(bmp_header));
126 image_attr.size = bmp_header.size;
127 iounmap(bgrt);
128
129 image_attr.private = ioremap(bgrt_tab->image_address, image_attr.size);
130
131 if (!image_attr.private) {
132 ret = -EINVAL;
133 goto out_err;
134 }
135
136
137 bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
138 if (!bgrt_kobj) {
139 ret = -EINVAL;
140 goto out_iounmap;
141 }
142
143 ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
144 if (ret)
145 goto out_kobject;
146
147 ret = sysfs_create_bin_file(bgrt_kobj, &image_attr);
148 if (ret)
149 goto out_group;
150
151 return 0;
152
153out_group:
154 sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
155out_kobject:
156 kobject_put(bgrt_kobj);
157out_iounmap:
158 iounmap(image_attr.private);
159out_err:
160 return ret;
161}
162
163static void __exit bgrt_exit(void)
164{
165 iounmap(image_attr.private);
166 sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
167 sysfs_remove_bin_file(bgrt_kobj, &image_attr);
168}
169
170module_init(bgrt_init);
171module_exit(bgrt_exit);
172
173MODULE_AUTHOR("Matthew Garrett");
174MODULE_DESCRIPTION("BGRT boot graphic support");
175MODULE_LICENSE("GPL");