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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * WMI embedded Binary MOF driver4 *5 * Copyright (c) 2015 Andrew Lutomirski6 * Copyright (C) 2017 VMware, Inc. All Rights Reserved.7 */8 9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt10 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 23struct bmof_priv {24 union acpi_object *bmofdata;25 struct bin_attribute bmof_bin_attr;26};27 28static 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 37static 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 77static 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 85static const struct wmi_device_id wmi_bmof_id_table[] = {86 { .guid_string = WMI_BMOF_GUID },87 { },88};89 90static 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 .no_singleton = true,98};99 100module_wmi_driver(wmi_bmof_driver);101 102MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table);103MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");104MODULE_DESCRIPTION("WMI embedded Binary MOF driver");105MODULE_LICENSE("GPL");106