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 <linux/io.h>
 15#include <acpi/acpi.h>
 16#include <acpi/acpi_bus.h>
 17
 18static struct acpi_table_bgrt *bgrt_tab;
 19static struct kobject *bgrt_kobj;
 20
 21struct bmp_header {
 22	u16 id;
 23	u32 size;
 24} __attribute ((packed));
 25
 26static struct bmp_header bmp_header;
 27
 28static ssize_t show_version(struct device *dev,
 29			    struct device_attribute *attr, char *buf)
 30{
 31	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version);
 32}
 33static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
 34
 35static ssize_t show_status(struct device *dev,
 36			   struct device_attribute *attr, char *buf)
 37{
 38	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status);
 39}
 40static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
 41
 42static ssize_t show_type(struct device *dev,
 43			 struct device_attribute *attr, char *buf)
 44{
 45	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type);
 46}
 47static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
 48
 49static ssize_t show_xoffset(struct device *dev,
 50			    struct device_attribute *attr, char *buf)
 51{
 52	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x);
 53}
 54static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
 55
 56static ssize_t show_yoffset(struct device *dev,
 57			    struct device_attribute *attr, char *buf)
 58{
 59	return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y);
 60}
 61static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
 62
 63static ssize_t show_image(struct file *file, struct kobject *kobj,
 64	       struct bin_attribute *attr, char *buf, loff_t off, size_t count)
 65{
 66	int size = attr->size;
 67	void __iomem *image = attr->private;
 68
 69	if (off >= size) {
 70		count = 0;
 71	} else {
 72		if (off + count > size)
 73			count = size - off;
 74
 75		memcpy_fromio(buf, image+off, count);
 76	}
 77
 78	return count;
 79}
 80
 81static struct bin_attribute image_attr = {
 82	.attr = {
 83		.name = "image",
 84		.mode = S_IRUGO,
 85	},
 86	.read = show_image,
 87};
 88
 89static struct attribute *bgrt_attributes[] = {
 90	&dev_attr_version.attr,
 91	&dev_attr_status.attr,
 92	&dev_attr_type.attr,
 93	&dev_attr_xoffset.attr,
 94	&dev_attr_yoffset.attr,
 95	NULL,
 96};
 97
 98static struct attribute_group bgrt_attribute_group = {
 99	.attrs = bgrt_attributes,
100};
101
102static int __init bgrt_init(void)
103{
104	acpi_status status;
105	int ret;
106	void __iomem *bgrt;
107
108	if (acpi_disabled)
109		return -ENODEV;
110
111	status = acpi_get_table("BGRT", 0,
112				(struct acpi_table_header **)&bgrt_tab);
113
114	if (ACPI_FAILURE(status))
115		return -ENODEV;
116
117	sysfs_bin_attr_init(&image_attr);
118
119	bgrt = ioremap(bgrt_tab->image_address, sizeof(struct bmp_header));
120
121	if (!bgrt) {
122		ret = -EINVAL;
123		goto out_err;
124	}
125
126	memcpy_fromio(&bmp_header, bgrt, sizeof(bmp_header));
127	image_attr.size = bmp_header.size;
128	iounmap(bgrt);
129
130	image_attr.private = ioremap(bgrt_tab->image_address, image_attr.size);
131
132	if (!image_attr.private) {
133		ret = -EINVAL;
134		goto out_err;
135	}
136
137
138	bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
139	if (!bgrt_kobj) {
140		ret = -EINVAL;
141		goto out_iounmap;
142	}
143
144	ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
145	if (ret)
146		goto out_kobject;
147
148	ret = sysfs_create_bin_file(bgrt_kobj, &image_attr);
149	if (ret)
150		goto out_group;
151
152	return 0;
153
154out_group:
155	sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
156out_kobject:
157	kobject_put(bgrt_kobj);
158out_iounmap:
159	iounmap(image_attr.private);
160out_err:
161	return ret;
162}
163
164static void __exit bgrt_exit(void)
165{
166	iounmap(image_attr.private);
167	sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
168	sysfs_remove_bin_file(bgrt_kobj, &image_attr);
169}
170
171module_init(bgrt_init);
172module_exit(bgrt_exit);
173
174MODULE_AUTHOR("Matthew Garrett");
175MODULE_DESCRIPTION("BGRT boot graphic support");
176MODULE_LICENSE("GPL");