1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * BGRT boot graphic support 4 * Authors: Matthew Garrett, Josh Triplett <josh@joshtriplett.org> 5 * Copyright 2012 Red Hat, Inc <mjg@redhat.com> 6 * Copyright 2012 Intel Corporation 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/init.h> 11 #include <linux/device.h> 12 #include <linux/sysfs.h> 13 #include <linux/efi-bgrt.h> 14 15 static void *bgrt_image; 16 static struct kobject *bgrt_kobj; 17 18 static ssize_t show_version(struct device *dev, 19 struct device_attribute *attr, char *buf) 20 { 21 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.version); 22 } 23 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL); 24 25 static ssize_t show_status(struct device *dev, 26 struct device_attribute *attr, char *buf) 27 { 28 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.status); 29 } 30 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL); 31 32 static ssize_t show_type(struct device *dev, 33 struct device_attribute *attr, char *buf) 34 { 35 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_type); 36 } 37 static DEVICE_ATTR(type, S_IRUGO, show_type, NULL); 38 39 static ssize_t show_xoffset(struct device *dev, 40 struct device_attribute *attr, char *buf) 41 { 42 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_x); 43 } 44 static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL); 45 46 static ssize_t show_yoffset(struct device *dev, 47 struct device_attribute *attr, char *buf) 48 { 49 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_y); 50 } 51 static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL); 52 53 static ssize_t image_read(struct file *file, struct kobject *kobj, 54 struct bin_attribute *attr, char *buf, loff_t off, size_t count) 55 { 56 memcpy(buf, attr->private + off, count); 57 return count; 58 } 59 60 static BIN_ATTR_RO(image, 0); /* size gets filled in later */ 61 62 static struct attribute *bgrt_attributes[] = { 63 &dev_attr_version.attr, 64 &dev_attr_status.attr, 65 &dev_attr_type.attr, 66 &dev_attr_xoffset.attr, 67 &dev_attr_yoffset.attr, 68 NULL, 69 }; 70 71 static struct bin_attribute *bgrt_bin_attributes[] = { 72 &bin_attr_image, 73 NULL, 74 }; 75 76 static const struct attribute_group bgrt_attribute_group = { 77 .attrs = bgrt_attributes, 78 .bin_attrs = bgrt_bin_attributes, 79 }; 80 81 int __init acpi_parse_bgrt(struct acpi_table_header *table) 82 { 83 efi_bgrt_init(table); 84 return 0; 85 } 86 87 static int __init bgrt_init(void) 88 { 89 int ret; 90 91 if (!bgrt_tab.image_address) 92 return -ENODEV; 93 94 bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size, 95 MEMREMAP_WB); 96 if (!bgrt_image) { 97 pr_notice("Ignoring BGRT: failed to map image memory\n"); 98 return -ENOMEM; 99 } 100 101 bin_attr_image.private = bgrt_image; 102 bin_attr_image.size = bgrt_image_size; 103 104 bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj); 105 if (!bgrt_kobj) { 106 ret = -EINVAL; 107 goto out_memmap; 108 } 109 110 ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group); 111 if (ret) 112 goto out_kobject; 113 114 return 0; 115 116 out_kobject: 117 kobject_put(bgrt_kobj); 118 out_memmap: 119 memunmap(bgrt_image); 120 return ret; 121 } 122 device_initcall(bgrt_init); 123