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 <luto@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Mario Limonciello <mario_limonciello@xxxxxxxx> Cc: Pali Rohár <pali.rohar@xxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: platform-driver-x86@xxxxxxxxxxxxxxx Cc: linux-acpi@xxxxxxxxxxxxxxx [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.wysocki@xxxxxxxxx> Signed-off-by: Darren Hart (VMware) <dvhart@xxxxxxxxxxxxx> --- 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 <luto@xxxxxxxxxx>"); +MODULE_DESCRIPTION("WMI embedded Binary MOF driver"); +MODULE_LICENSE("GPL"); -- 2.9.4 -- Darren Hart VMware Open Source Technology Center
