1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/platform/x86/wmi-bmof.c b/drivers/platform/x86/wmi-bmof.c
new file mode 100644
index 000000000..80137afb9
--- /dev/null
+++ b/drivers/platform/x86/wmi-bmof.c
@@ -0,0 +1,116 @@
+// 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 void 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);
+}
+
+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");