xref: /linux/drivers/acpi/bgrt.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /*
2  * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
3  * Copyright 2012 Intel Corporation
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/device.h>
14 #include <linux/sysfs.h>
15 #include <linux/efi-bgrt.h>
16 
17 static struct kobject *bgrt_kobj;
18 
19 static ssize_t show_version(struct device *dev,
20 			    struct device_attribute *attr, char *buf)
21 {
22 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version);
23 }
24 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
25 
26 static ssize_t show_status(struct device *dev,
27 			   struct device_attribute *attr, char *buf)
28 {
29 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status);
30 }
31 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
32 
33 static ssize_t show_type(struct device *dev,
34 			 struct device_attribute *attr, char *buf)
35 {
36 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type);
37 }
38 static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
39 
40 static ssize_t show_xoffset(struct device *dev,
41 			    struct device_attribute *attr, char *buf)
42 {
43 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x);
44 }
45 static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
46 
47 static ssize_t show_yoffset(struct device *dev,
48 			    struct device_attribute *attr, char *buf)
49 {
50 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y);
51 }
52 static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
53 
54 static ssize_t image_read(struct file *file, struct kobject *kobj,
55 	       struct bin_attribute *attr, char *buf, loff_t off, size_t count)
56 {
57 	memcpy(buf, attr->private + off, count);
58 	return count;
59 }
60 
61 static BIN_ATTR_RO(image, 0);	/* size gets filled in later */
62 
63 static struct attribute *bgrt_attributes[] = {
64 	&dev_attr_version.attr,
65 	&dev_attr_status.attr,
66 	&dev_attr_type.attr,
67 	&dev_attr_xoffset.attr,
68 	&dev_attr_yoffset.attr,
69 	NULL,
70 };
71 
72 static struct bin_attribute *bgrt_bin_attributes[] = {
73 	&bin_attr_image,
74 	NULL,
75 };
76 
77 static struct attribute_group bgrt_attribute_group = {
78 	.attrs = bgrt_attributes,
79 	.bin_attrs = bgrt_bin_attributes,
80 };
81 
82 static int __init bgrt_init(void)
83 {
84 	int ret;
85 
86 	if (!bgrt_image)
87 		return -ENODEV;
88 
89 	bin_attr_image.private = bgrt_image;
90 	bin_attr_image.size = bgrt_image_size;
91 
92 	bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
93 	if (!bgrt_kobj)
94 		return -EINVAL;
95 
96 	ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
97 	if (ret)
98 		goto out_kobject;
99 
100 	return 0;
101 
102 out_kobject:
103 	kobject_put(bgrt_kobj);
104 	return ret;
105 }
106 
107 module_init(bgrt_init);
108 
109 MODULE_AUTHOR("Matthew Garrett, Josh Triplett <josh@joshtriplett.org>");
110 MODULE_DESCRIPTION("BGRT boot graphic support");
111 MODULE_LICENSE("GPL");
112