1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * WMI embedded Binary MOF driver 4 * 5 * Copyright (c) 2015 Andrew Lutomirski 6 * Copyright (C) 2017 VMware, Inc. All Rights Reserved. 7 */ 8 9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 10 11 #include <linux/acpi.h> 12 #include <linux/device.h> 13 #include <linux/fs.h> 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/string.h> 17 #include <linux/sysfs.h> 18 #include <linux/types.h> 19 #include <linux/wmi.h> 20 21 #define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910" 22 23 struct bmof_priv { 24 union acpi_object *bmofdata; 25 struct bin_attribute bmof_bin_attr; 26 }; 27 28 static ssize_t read_bmof(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, 29 char *buf, loff_t off, size_t count) 30 { 31 struct bmof_priv *priv = container_of(attr, struct bmof_priv, bmof_bin_attr); 32 33 return memory_read_from_buffer(buf, count, &off, priv->bmofdata->buffer.pointer, 34 priv->bmofdata->buffer.length); 35 } 36 37 static int wmi_bmof_probe(struct wmi_device *wdev, const void *context) 38 { 39 struct bmof_priv *priv; 40 int ret; 41 42 priv = devm_kzalloc(&wdev->dev, sizeof(struct bmof_priv), GFP_KERNEL); 43 if (!priv) 44 return -ENOMEM; 45 46 dev_set_drvdata(&wdev->dev, priv); 47 48 priv->bmofdata = wmidev_block_query(wdev, 0); 49 if (!priv->bmofdata) { 50 dev_err(&wdev->dev, "failed to read Binary MOF\n"); 51 return -EIO; 52 } 53 54 if (priv->bmofdata->type != ACPI_TYPE_BUFFER) { 55 dev_err(&wdev->dev, "Binary MOF is not a buffer\n"); 56 ret = -EIO; 57 goto err_free; 58 } 59 60 sysfs_bin_attr_init(&priv->bmof_bin_attr); 61 priv->bmof_bin_attr.attr.name = "bmof"; 62 priv->bmof_bin_attr.attr.mode = 0400; 63 priv->bmof_bin_attr.read = read_bmof; 64 priv->bmof_bin_attr.size = priv->bmofdata->buffer.length; 65 66 ret = device_create_bin_file(&wdev->dev, &priv->bmof_bin_attr); 67 if (ret) 68 goto err_free; 69 70 return 0; 71 72 err_free: 73 kfree(priv->bmofdata); 74 return ret; 75 } 76 77 static void wmi_bmof_remove(struct wmi_device *wdev) 78 { 79 struct bmof_priv *priv = dev_get_drvdata(&wdev->dev); 80 81 device_remove_bin_file(&wdev->dev, &priv->bmof_bin_attr); 82 kfree(priv->bmofdata); 83 } 84 85 static const struct wmi_device_id wmi_bmof_id_table[] = { 86 { .guid_string = WMI_BMOF_GUID }, 87 { }, 88 }; 89 90 static struct wmi_driver wmi_bmof_driver = { 91 .driver = { 92 .name = "wmi-bmof", 93 }, 94 .probe = wmi_bmof_probe, 95 .remove = wmi_bmof_remove, 96 .id_table = wmi_bmof_id_table, 97 }; 98 99 module_wmi_driver(wmi_bmof_driver); 100 101 MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table); 102 MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>"); 103 MODULE_DESCRIPTION("WMI embedded Binary MOF driver"); 104 MODULE_LICENSE("GPL"); 105