drivers/acpi/bgrt.c

   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 show_image(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 struct bin_attribute image_attr = {
  62         .attr = {
  63                 .name = "image",
  64                 .mode = S_IRUGO,
  65         },
  66         .read = show_image,
  67 };
  68
  69 static struct attribute *bgrt_attributes[] = {
  70         &dev_attr_version.attr,
  71         &dev_attr_status.attr,
  72         &dev_attr_type.attr,
  73         &dev_attr_xoffset.attr,
  74         &dev_attr_yoffset.attr,
  75         NULL,
  76 };
  77
  78 static struct attribute_group bgrt_attribute_group = {
  79         .attrs = bgrt_attributes,
  80 };
  81
  82 static int __init bgrt_init(void)
  83 {
  84         int ret;
  85
  86         if (!bgrt_image)
  87                 return -ENODEV;
  88
  89         sysfs_bin_attr_init(&image_attr);
  90         image_attr.private = bgrt_image;
  91         image_attr.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         ret = sysfs_create_bin_file(bgrt_kobj, &image_attr);
 102         if (ret)
 103                 goto out_group;
 104
 105         return 0;
 106
 107 out_group:
 108         sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
 109 out_kobject:
 110         kobject_put(bgrt_kobj);
 111         return ret;
 112 }
 113
 114 module_init(bgrt_init);
 115
 116 MODULE_AUTHOR("Matthew Garrett, Josh Triplett <josh@joshtriplett.org>");
 117 MODULE_DESCRIPTION("BGRT boot graphic support");
 118 MODULE_LICENSE("GPL");