drivers/acpi/bgrt.c

   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);