[v2] Add driver to force WMI Thunderbolt controller power status

Message ID	1504810042-4696-1-git-send-email-mario.limonciello@dell.com (mailing list archive)
State	Changes Requested, archived
Delegated to:	Darren Hart
Headers	show Return-Path: <platform-driver-x86-owner@kernel.org> From: Mario Limonciello <mario.limonciello@dell.com> To: dvhart@infradead.org Cc: LKML <linux-kernel@vger.kernel.org>, platform-driver-x86@vger.kernel.org, Richard Hughes <hughsient@gmail.com>, Yehezkel Bernat <yehezkelshb@gmail.com>, Mika Westerberg <mika.westerberg@linux.intel.com>, Mario Limonciello <mario.limonciello@dell.com> Subject: [PATCH v2] Add driver to force WMI Thunderbolt controller power status Date: Thu, 7 Sep 2017 13:47:22 -0500 Message-Id: <1504810042-4696-1-git-send-email-mario.limonciello@dell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk

diff --git a/Documentation/ABI/testing/sysfs-platform-intel-wmi-thunderbolt b/Documentation/ABI/testing/sysfs-platform-intel-wmi-thunderbolt new file mode 100644 index 0000000..7b8e61a --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform-intel-wmi-thunderbolt @@ -0,0 +1,11 @@ +What: /sys/devices/platform/<platform>/force_power +Date: September 2017 +KernelVersion: 4.14 +Contact: "Mario LimonciellO" <mario.limonciello@dell.com> +Description: + Modify the platform force power state, influencing + Thunderbolt controllers to turn on or off when no + devices are connected (write-only) + There are two available states: + * 0 -> Force power disabled + * 1 -> Force power enabled diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index 6a4cd1f..dadcd66 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -197,3 +197,18 @@ information is missing. To recover from this mode, one needs to flash a valid NVM image to the host host controller in the same way it is done in the previous chapter. + +Forcing power +------------- +Many OEMs include a method that can be used to force the power of a +thunderbolt controller to an "On" state even if nothing is connected. +If supported by your machine this will be exposed by the WMI bus with +a sysfs attribute called "force_power". + +For example the intel-wmi-thunderbolt driver exposes this attribute in: + /sys/devices/platform/PNP0C14:00/wmi_bus/wmi_bus-PNP0C14:00/86CCFD48-205E-4A77-9C48-2021CBEDE341/force_power + + To force the power to on, write 1 to this attribute file. + To disable force power, write 0 to this attribute file. + +Note: it's currently not possible to query the force power state of a platform. diff --git a/MAINTAINERS b/MAINTAINERS index 1c3feff..9a6b73e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3949,6 +3949,11 @@ M: Pali Rohár <pali.rohar@gmail.com> S: Maintained F: drivers/platform/x86/dell-wmi.c +INTEL WMI THUNDERBOLT FORCE POWER DRIVER +M: Mario Limonciello <mario.limonciello@dell.com> +S: Maintained +F: drivers/platform/x86/intel-wmi-thunderbolt.c + DELTA ST MEDIA DRIVER M: Hugues Fruchet <hugues.fruchet@st.com> L: linux-media@vger.kernel.org diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index 80b8795..f401ae4 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -658,6 +658,19 @@ config WMI_BMOF To compile this driver as a module, choose M here: the module will be called wmi-bmof. +config INTEL_WMI_THUNDERBOLT + tristate "Intel WMI thunderbolt force power driver" + depends on ACPI_WMI + default ACPI_WMI + ---help--- + Say Y here if you want to be able to use the WMI interface on select + systems to force the power control of Intel Thunderbolt controllers. + This is useful for updating the firmware when devices are not plugged + into the controller. + + To compile this driver as a module, choose M here: the module will + be called intel-wmi-thunderbolt. + config MSI_WMI tristate "MSI WMI extras" depends on ACPI_WMI diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 91cec17..2b315d0 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -39,6 +39,7 @@ 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 +obj-$(CONFIG_INTEL_WMI_THUNDERBOLT) += intel-wmi-thunderbolt.o # toshiba_acpi must link after wmi to ensure that wmi devices are found # before toshiba_acpi initializes diff --git a/drivers/platform/x86/intel-wmi-thunderbolt.c b/drivers/platform/x86/intel-wmi-thunderbolt.c new file mode 100644 index 0000000..e8c98dc --- /dev/null +++ b/drivers/platform/x86/intel-wmi-thunderbolt.c @@ -0,0 +1,96 @@ +/* + * WMI Thunderbolt driver + * + * Copyright (C) 2017 Dell Inc. All Rights Reserved. + * + * 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/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 INTEL_WMI_THUNDERBOLT_GUID "86CCFD48-205E-4A77-9C48-2021CBEDE341" + +static ssize_t force_power_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct acpi_buffer input; + acpi_status status; + u8 mode; + + input.length = sizeof(u8); + input.pointer = &mode; + mode = hex_to_bin(buf[0]); + if (mode == 0 || mode == 1) { + status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1, + &input, NULL); + if (ACPI_FAILURE(status)) { + pr_err("intel-wmi-thunderbolt: failed setting %s\n", + buf); + return -ENODEV; + } + } else { + pr_err("intel-wmi-thunderbolt: unsupported mode: %d", mode); + } + return count; +} + +static DEVICE_ATTR_WO(force_power); + +static struct attribute *tbt_attrs[] = { + &dev_attr_force_power.attr, + NULL +}; + +static const struct attribute_group tbt_attribute_group = { + .attrs = tbt_attrs, +}; + +static int intel_wmi_thunderbolt_probe(struct wmi_device *wdev) +{ + return sysfs_create_group(&wdev->dev.kobj, &tbt_attribute_group); +} + +static int intel_wmi_thunderbolt_remove(struct wmi_device *wdev) +{ + sysfs_remove_group(&wdev->dev.kobj, &tbt_attribute_group); + return 0; +} + +static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = { + { .guid_string = INTEL_WMI_THUNDERBOLT_GUID }, + { }, +}; + +static struct wmi_driver intel_wmi_thunderbolt_driver = { + .driver = { + .name = "intel-wmi-thunderbolt", + }, + .probe = intel_wmi_thunderbolt_probe, + .remove = intel_wmi_thunderbolt_remove, + .id_table = intel_wmi_thunderbolt_id_table, +}; + +module_wmi_driver(intel_wmi_thunderbolt_driver); + +MODULE_ALIAS("wmi:" INTEL_WMI_THUNDERBOLT_GUID); +MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>"); +MODULE_DESCRIPTION("Intel WMI Thunderbolt force power driver"); +MODULE_LICENSE("GPL");

[v2] Add driver to force WMI Thunderbolt controller power status

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