Many laptops (and maybe servers?) have embedded WMI Binary MOF metadata.
We do not yet have open-source tools for processing the data, although
one is in the works thanks to Pali:
https://github.com/pali/bmfdec
There is currently no interface to get the data in the first place. By
exposing it, we facilitate the development of new tools.
Signed-off-by: Andy Lutomirski <l...@kernel.org>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Mario Limonciello <mario_limoncie...@dell.com>
Cc: Pali Rohár <pali.ro...@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-...@vger.kernel.org
Cc: linux-a...@vger.kernel.org
[dvhart: make sysfs mof binary read only, fixup comment block format]
[dvhart: use bmof terminology and dev_err instead of dev_warn]
Acked-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
Signed-off-by: Darren Hart (VMware) <dvh...@infradead.org>
---
since-v1:
* address Pali's comments:
* update the cover letter for clarity and accuracy
* update mof->bmof and MOF to Binary MOF throughout the patch
* use dev_err instead of dev_warn in wmi_bmof_probe
drivers/platform/x86/Kconfig | 12 ++++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/wmi-bmof.c | 125 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 138 insertions(+)
create mode 100644 drivers/platform/x86/wmi-bmof.c
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 49a1d01..6ebe393 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -656,6 +656,18 @@ config ACPI_WMI
It is safe to enable this driver even if your DSDT doesn't define
any ACPI-WMI devices.
+config WMI_BMOF
+ tristate "WMI embedded Binary MOF driver"
+ depends on ACPI_WMI
+ default y
+ ---help---
+ Say Y here if you want to be able to read a firmware-embedded
+ WMI Binary MOF data. Using this requires userspace tools and may be
+ rather tedious.
+
+ To compile this driver as a module, choose M here: the module will
+ be called wmi-bmof.
+
config MSI_WMI
tristate "MSI WMI extras"
depends on ACPI_WMI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 652d7c8..6a1063e 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_MSI_WMI) += msi-wmi.o
obj-$(CONFIG_PEAQ_WMI) += peaq-wmi.o
obj-$(CONFIG_SURFACE3_WMI) += surface3-wmi.o
obj-$(CONFIG_TOPSTAR_LAPTOP) += topstar-laptop.o
+obj-$(CONFIG_WMI_BMOF) += wmi-bmof.o
# toshiba_acpi must link after wmi to ensure that wmi devices are found
# before toshiba_acpi initializes
diff --git a/drivers/platform/x86/wmi-bmof.c b/drivers/platform/x86/wmi-bmof.c
new file mode 100644
index 0000000..e1c0963
--- /dev/null
+++ b/drivers/platform/x86/wmi-bmof.c
@@ -0,0 +1,125 @@
+/*
+ * WMI embedded Binary MOF driver
+ *
+ * Copyright (c) 2015 Andrew Lutomirski
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/acpi.h>
+#include <linux/string.h>
+#include <linux/dmi.h>
+#include <linux/wmi.h>
+#include <acpi/video.h>
+
+#define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
+MODULE_ALIAS("wmi:" WMI_BMOF_GUID);
+
+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 >= 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)
+{
+ int ret;
+
+ struct bmof_priv *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_AUTHOR("Andrew Lutomirski <l...@kernel.org>");
+MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
+MODULE_LICENSE("GPL");
--
2.9.4
--
Darren Hart
VMware Open Source Technology Center
