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
17 static struct acpi_table_bgrt *bgrt_tab;
18 static struct kobject *bgrt_kobj;
19
20 struct bmp_header {
21 u16 id;
22 u32 size;
23 } __attribute ((packed));
24
25 static struct bmp_header bmp_header;
26
show_version(struct device * dev,struct device_attribute * attr,char * buf)27 static 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 }
32 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
33
show_status(struct device * dev,struct device_attribute * attr,char * buf)34 static 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 }
39 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
40
show_type(struct device * dev,struct device_attribute * attr,char * buf)41 static 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 }
46 static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
47
show_xoffset(struct device * dev,struct device_attribute * attr,char * buf)48 static 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 }
53 static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
54
show_yoffset(struct device * dev,struct device_attribute * attr,char * buf)55 static 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 }
60 static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
61
show_image(struct file * file,struct kobject * kobj,struct bin_attribute * attr,char * buf,loff_t off,size_t count)62 static 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
80 static struct bin_attribute image_attr = {
81 .attr = {
82 .name = "image",
83 .mode = S_IRUGO,
84 },
85 .read = show_image,
86 };
87
88 static 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
97 static struct attribute_group bgrt_attribute_group = {
98 .attrs = bgrt_attributes,
99 };
100
bgrt_init(void)101 static 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
153 out_group:
154 sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
155 out_kobject:
156 kobject_put(bgrt_kobj);
157 out_iounmap:
158 iounmap(image_attr.private);
159 out_err:
160 return ret;
161 }
162
bgrt_exit(void)163 static 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
170 module_init(bgrt_init);
171 module_exit(bgrt_exit);
172
173 MODULE_AUTHOR("Matthew Garrett");
174 MODULE_DESCRIPTION("BGRT boot graphic support");
175 MODULE_LICENSE("GPL");
176