xref: /openbmc/linux/drivers/acpi/bgrt.c (revision f3539c12)
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 
18 static struct kobject *bgrt_kobj;
19 
20 static ssize_t show_version(struct device *dev,
21 			    struct device_attribute *attr, char *buf)
22 {
23 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version);
24 }
25 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
26 
27 static ssize_t show_status(struct device *dev,
28 			   struct device_attribute *attr, char *buf)
29 {
30 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status);
31 }
32 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
33 
34 static ssize_t show_type(struct device *dev,
35 			 struct device_attribute *attr, char *buf)
36 {
37 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type);
38 }
39 static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
40 
41 static ssize_t show_xoffset(struct device *dev,
42 			    struct device_attribute *attr, char *buf)
43 {
44 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x);
45 }
46 static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
47 
48 static ssize_t show_yoffset(struct device *dev,
49 			    struct device_attribute *attr, char *buf)
50 {
51 	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y);
52 }
53 static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
54 
55 static ssize_t image_read(struct file *file, struct kobject *kobj,
56 	       struct bin_attribute *attr, char *buf, loff_t off, size_t count)
57 {
58 	memcpy(buf, attr->private + off, count);
59 	return count;
60 }
61 
62 static BIN_ATTR_RO(image, 0);	/* size gets filled in later */
63 
64 static struct attribute *bgrt_attributes[] = {
65 	&dev_attr_version.attr,
66 	&dev_attr_status.attr,
67 	&dev_attr_type.attr,
68 	&dev_attr_xoffset.attr,
69 	&dev_attr_yoffset.attr,
70 	NULL,
71 };
72 
73 static struct bin_attribute *bgrt_bin_attributes[] = {
74 	&bin_attr_image,
75 	NULL,
76 };
77 
78 static struct attribute_group bgrt_attribute_group = {
79 	.attrs = bgrt_attributes,
80 	.bin_attrs = bgrt_bin_attributes,
81 };
82 
83 static int __init bgrt_init(void)
84 {
85 	int ret;
86 
87 	if (!bgrt_image)
88 		return -ENODEV;
89 
90 	bin_attr_image.private = bgrt_image;
91 	bin_attr_image.size = bgrt_image_size;
92 
93 	bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
94 	if (!bgrt_kobj)
95 		return -EINVAL;
96 
97 	ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
98 	if (ret)
99 		goto out_kobject;
100 
101 	return 0;
102 
103 out_kobject:
104 	kobject_put(bgrt_kobj);
105 	return ret;
106 }
107 device_initcall(bgrt_init);
108