bgrt.c

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/*
 * Copyright 2012 Red Hat, Inc <[email protected]>
 * Copyright 2012 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/efi-bgrt.h>

static struct kobject *bgrt_kobj;

static ssize_t show_version(struct device *dev,
                struct device_attribute *attr, char *buf)
{
    return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version);
}
static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);

static ssize_t show_status(struct device *dev,
               struct device_attribute *attr, char *buf)
{
    return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status);
}
static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);

static ssize_t show_type(struct device *dev,
             struct device_attribute *attr, char *buf)
{
    return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type);
}
static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);

static ssize_t show_xoffset(struct device *dev,
                struct device_attribute *attr, char *buf)
{
    return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x);
}
static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);

static ssize_t show_yoffset(struct device *dev,
                struct device_attribute *attr, char *buf)
{
    return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y);
}
static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);

static ssize_t show_image(struct file *file, struct kobject *kobj,
           struct bin_attribute *attr, char *buf, loff_t off, size_t count)
{
    memcpy(buf, attr->private + off, count);
    return count;
}

static struct bin_attribute image_attr = {
    .attr = {
        .name = "image",
        .mode = S_IRUGO,
    },
    .read = show_image,
};

static struct attribute *bgrt_attributes[] = {
    &dev_attr_version.attr,
    &dev_attr_status.attr,
    &dev_attr_type.attr,
    &dev_attr_xoffset.attr,
    &dev_attr_yoffset.attr,
    NULL,
};

static struct attribute_group bgrt_attribute_group = {
    .attrs = bgrt_attributes,
};

static int __init bgrt_init(void)
{
    int ret;

    if (!bgrt_image)
        return -ENODEV;

    sysfs_bin_attr_init(&image_attr);
    image_attr.private = bgrt_image;
    image_attr.size = bgrt_image_size;

    bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
    if (!bgrt_kobj)
        return -EINVAL;

    ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
    if (ret)
        goto out_kobject;

    ret = sysfs_create_bin_file(bgrt_kobj, &image_attr);
    if (ret)
        goto out_group;

    return 0;

out_group:
    sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
out_kobject:
    kobject_put(bgrt_kobj);
    return ret;
}

module_init(bgrt_init);

MODULE_AUTHOR("Matthew Garrett, Josh Triplett <[email protected]>");
MODULE_DESCRIPTION("BGRT boot graphic support");
MODULE_LICENSE("GPL");