// SPDX-License-Identifier: GPL-2.0-only /* * WMI embedded Binary MOF driver * * Copyright (c) 2015 Andrew Lutomirski * Copyright (C) 2017 VMware, Inc. All Rights Reserved. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/acpi.h> #include <linux/device.h> #include <linux/fs.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/string.h> #include <linux/sysfs.h> #include <linux/types.h> #include <linux/wmi.h> #define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910" struct bmof_priv { union acpi_object *bmofdata; struct bin_attribute bmof_bin_attr; }; static ssize_t read_bmof(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { struct bmof_priv *priv = container_of(attr, struct bmof_priv, bmof_bin_attr); if (off < 0) return -EINVAL; if (off >= priv->bmofdata->buffer.length) return 0; if (count > priv->bmofdata->buffer.length - off) count = priv->bmofdata->buffer.length - off; memcpy(buf, priv->bmofdata->buffer.pointer + off, count); return count; } static int wmi_bmof_probe(struct wmi_device *wdev, const void *context) { struct bmof_priv *priv; int ret; priv = devm_kzalloc(&wdev->dev, sizeof(struct bmof_priv), GFP_KERNEL); if (!priv) return -ENOMEM; dev_set_drvdata(&wdev->dev, priv); priv->bmofdata = wmidev_block_query(wdev, 0); if (!priv->bmofdata) { dev_err(&wdev->dev, "failed to read Binary MOF\n"); return -EIO; } if (priv->bmofdata->type != ACPI_TYPE_BUFFER) { dev_err(&wdev->dev, "Binary MOF is not a buffer\n"); ret = -EIO; goto err_free; } sysfs_bin_attr_init(&priv->bmof_bin_attr); priv->bmof_bin_attr.attr.name = "bmof"; priv->bmof_bin_attr.attr.mode = 0400; priv->bmof_bin_attr.read = read_bmof; priv->bmof_bin_attr.size = priv->bmofdata->buffer.length; ret = sysfs_create_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr); if (ret) goto err_free; return 0; err_free: kfree(priv->bmofdata); return ret; } static int wmi_bmof_remove(struct wmi_device *wdev) { struct bmof_priv *priv = dev_get_drvdata(&wdev->dev); sysfs_remove_bin_file(&wdev->dev.kobj, &priv->bmof_bin_attr); kfree(priv->bmofdata); return 0; } static const struct wmi_device_id wmi_bmof_id_table[] = { { .guid_string = WMI_BMOF_GUID }, { }, }; static struct wmi_driver wmi_bmof_driver = { .driver = { .name = "wmi-bmof", }, .probe = wmi_bmof_probe, .remove = wmi_bmof_remove, .id_table = wmi_bmof_id_table, }; module_wmi_driver(wmi_bmof_driver); MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table); MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>"); MODULE_DESCRIPTION("WMI embedded Binary MOF driver"); MODULE_LICENSE("GPL");