[v4,05/14] platform/x86: dell-wmi-descriptor: split WMI descriptor into it's own driver

Message ID	ff211830e3953c70aa8e0d43614619f1fb423668.1507156392.git.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, Andy Shevchenko <andy.shevchenko@gmail.com> Cc: LKML <linux-kernel@vger.kernel.org>, platform-driver-x86@vger.kernel.org, Andy Lutomirski <luto@kernel.org>, quasisec@google.com, pali.rohar@gmail.com, rjw@rjwysocki.net, mjg59@google.com, hch@lst.de, Greg KH <greg@kroah.com>, Mario Limonciello <mario.limonciello@dell.com> Subject: [PATCH v4 05/14] platform/x86: dell-wmi-descriptor: split WMI descriptor into it's own driver Date: Wed, 4 Oct 2017 17:48:31 -0500 Message-Id: <ff211830e3953c70aa8e0d43614619f1fb423668.1507156392.git.mario.limonciello@dell.com> In-Reply-To: <cover.1507156392.git.mario.limonciello@dell.com> References: <cover.1507156392.git.mario.limonciello@dell.com> MIME-Version: 1.0 In-Reply-To: <cover.1507156392.git.mario.limonciello@dell.com> References: <cover.1507156392.git.mario.limonciello@dell.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk

diff --git a/MAINTAINERS b/MAINTAINERS index 08b96f77f618..659dbeec4191 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4002,6 +4002,11 @@ M: Pali Rohár <pali.rohar@gmail.com> S: Maintained F: drivers/platform/x86/dell-wmi.c +DELL WMI DESCRIPTOR DRIVER +M: Mario Limonciello <mario.limonciello@dell.com> +S: Maintained +F: drivers/platform/x86/dell-wmi-descriptor.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 1f7959ff055c..bc347c326d87 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -121,6 +121,7 @@ config DELL_WMI depends on DMI depends on INPUT depends on ACPI_VIDEO || ACPI_VIDEO = n + depends on DELL_WMI_DESCRIPTOR select DELL_SMBIOS select INPUT_SPARSEKMAP ---help--- @@ -129,6 +130,17 @@ config DELL_WMI To compile this driver as a module, choose M here: the module will be called dell-wmi. +config DELL_WMI_DESCRIPTOR + tristate "Dell WMI descriptor" + depends on ACPI_WMI + default ACPI_WMI + ---help--- + Say Y here if you want to be able to read the format of WMI + communications on some Dell laptops, desktops and IoT gateways. + + To compile this driver as a module, choose M here: the module will + be called dell-wmi-descriptor. + config DELL_WMI_AIO tristate "WMI Hotkeys for Dell All-In-One series" depends on ACPI_WMI diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 2b315d0df3b7..8636f5d3424f 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_COMPAL_LAPTOP) += compal-laptop.o obj-$(CONFIG_DELL_SMBIOS) += dell-smbios.o obj-$(CONFIG_DELL_LAPTOP) += dell-laptop.o obj-$(CONFIG_DELL_WMI) += dell-wmi.o +obj-$(CONFIG_DELL_WMI_DESCRIPTOR) += dell-wmi-descriptor.o obj-$(CONFIG_DELL_WMI_AIO) += dell-wmi-aio.o obj-$(CONFIG_DELL_WMI_LED) += dell-wmi-led.o obj-$(CONFIG_DELL_SMO8800) += dell-smo8800.o diff --git a/drivers/platform/x86/dell-wmi-descriptor.c b/drivers/platform/x86/dell-wmi-descriptor.c new file mode 100644 index 000000000000..5c2bdda11916 --- /dev/null +++ b/drivers/platform/x86/dell-wmi-descriptor.c @@ -0,0 +1,162 @@ +/* + * Dell WMI descriptor 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/list.h> +#include <linux/module.h> +#include <linux/wmi.h> +#include "dell-wmi-descriptor.h" + +#define DELL_WMI_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492" + +struct descriptor_priv { + struct list_head list; + u32 interface_version; + u32 size; +}; +static LIST_HEAD(wmi_list); + +bool dell_wmi_get_interface_version(u32 *version) +{ + struct descriptor_priv *priv; + + priv = list_first_entry_or_null(&wmi_list, + struct descriptor_priv, + list); + if (!priv) + return false; + *version = priv->interface_version; + return true; +} +EXPORT_SYMBOL_GPL(dell_wmi_get_interface_version); + +bool dell_wmi_get_size(u32 *size) +{ + struct descriptor_priv *priv; + + priv = list_first_entry_or_null(&wmi_list, + struct descriptor_priv, + list); + if (!priv) + return false; + *size = priv->size; + return true; +} +EXPORT_SYMBOL_GPL(dell_wmi_get_size); + +/* + * Descriptor buffer is 128 byte long and contains: + * + * Name Offset Length Value + * Vendor Signature 0 4 "DELL" + * Object Signature 4 4 " WMI" + * WMI Interface Version 8 4 <version> + * WMI buffer length 12 4 4096 or 32768 + */ +static int dell_wmi_descriptor_probe(struct wmi_device *wdev) +{ + union acpi_object *obj = NULL; + struct descriptor_priv *priv; + u32 *buffer; + int ret; + + obj = wmidev_block_query(wdev, 0); + if (!obj) { + dev_err(&wdev->dev, "failed to read Dell WMI descriptor\n"); + ret = -EIO; + goto out; + } + + if (obj->type != ACPI_TYPE_BUFFER) { + dev_err(&wdev->dev, "Dell descriptor has wrong type\n"); + ret = -EINVAL; + goto out; + } + + /* Although it's not technically a failure, this would lead to + * unexpected behavior + */ + if (obj->buffer.length != 128) { + dev_err(&wdev->dev, + "Dell descriptor buffer has unexpected length (%d)\n", + obj->buffer.length); + ret = -EINVAL; + goto out; + } + + buffer = (u32 *)obj->buffer.pointer; + + if (strncmp(obj->string.pointer, "DELL WMI", 8) != 0) { + dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%8ph)\n", + buffer); + ret = -EINVAL; + goto out; + } + if (buffer[2] != 0 && buffer[2] != 1) + dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%u)\n", + buffer[2]); + + if (buffer[3] != 4096 && buffer[3] != 32768) + dev_warn(&wdev->dev, "Dell descriptor buffer has unexpected buffer length (%u)\n", + buffer[3]); + + priv = devm_kzalloc(&wdev->dev, sizeof(struct descriptor_priv), + GFP_KERNEL); + + priv->interface_version = buffer[2]; + priv->size = buffer[3]; + ret = 0; + dev_set_drvdata(&wdev->dev, priv); + list_add_tail(&priv->list, &wmi_list); + + /* remove me */ + dev_info(&wdev->dev, "Detected Dell WMI interface version %u and buffer size %u\n", + priv->interface_version, priv->size); + +out: + kfree(obj); + return ret; +} + +static int dell_wmi_descriptor_remove(struct wmi_device *wdev) +{ + struct descriptor_priv *priv = dev_get_drvdata(&wdev->dev); + + list_del(&priv->list); + return 0; +} + +static const struct wmi_device_id dell_wmi_descriptor_id_table[] = { + { .guid_string = DELL_WMI_DESCRIPTOR_GUID }, + { }, +}; + +static struct wmi_driver dell_wmi_descriptor_driver = { + .driver = { + .name = "dell-wmi-descriptor", + }, + .probe = dell_wmi_descriptor_probe, + .remove = dell_wmi_descriptor_remove, + .id_table = dell_wmi_descriptor_id_table, +}; + +module_wmi_driver(dell_wmi_descriptor_driver); + +MODULE_ALIAS("wmi:" DELL_WMI_DESCRIPTOR_GUID); +MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>"); +MODULE_DESCRIPTION("Dell WMI descriptor driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/platform/x86/dell-wmi-descriptor.h b/drivers/platform/x86/dell-wmi-descriptor.h new file mode 100644 index 000000000000..3e652c6da034 --- /dev/null +++ b/drivers/platform/x86/dell-wmi-descriptor.h @@ -0,0 +1,18 @@ +/* + * + * Copyright (c) 2017 Dell Inc. + * + * 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. + */ + +#ifndef _DELL_WMI_DESCRIPTOR_H_ +#define _DELL_WMI_DESCRIPTOR_H_ + +#include <linux/wmi.h> + +bool dell_wmi_get_interface_version(u32 *version); +bool dell_wmi_get_size(u32 *size); + +#endif diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c index 1366bccdf275..90d7e8e55e9b 100644 --- a/drivers/platform/x86/dell-wmi.c +++ b/drivers/platform/x86/dell-wmi.c @@ -39,6 +39,7 @@ #include <linux/wmi.h> #include <acpi/video.h> #include "dell-smbios.h" +#include "dell-wmi-descriptor.h" MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>"); MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>"); @@ -46,7 +47,6 @@ MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver"); MODULE_LICENSE("GPL"); #define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492" -#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492" static bool wmi_requires_smbios_request; @@ -54,7 +54,6 @@ MODULE_ALIAS("wmi:"DELL_EVENT_GUID); struct dell_wmi_priv { struct input_dev *input_dev; - u32 interface_version; }; static int __init dmi_matched(const struct dmi_system_id *dmi) @@ -347,9 +346,9 @@ static void dell_wmi_process_key(struct wmi_device *wdev, int type, int code) static void dell_wmi_notify(struct wmi_device *wdev, union acpi_object *obj) { - struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev); u16 *buffer_entry, *buffer_end; acpi_size buffer_size; + u32 interface_version; int len, i; if (obj->type != ACPI_TYPE_BUFFER) { @@ -376,7 +375,11 @@ static void dell_wmi_notify(struct wmi_device *wdev, * So to prevent reading garbage from buffer we will process only first * one event on devices with WMI interface version 0. */ - if (priv->interface_version == 0 && buffer_entry < buffer_end) + if (!dell_wmi_get_interface_version(&interface_version)) { + pr_warn("WMI descriptor driver not ready or unavailable"); + return; + } + if (interface_version == 0 && buffer_entry < buffer_end) if (buffer_end > buffer_entry + buffer_entry[0] + 1) buffer_end = buffer_entry + buffer_entry[0] + 1; @@ -617,78 +620,6 @@ static void dell_wmi_input_destroy(struct wmi_device *wdev) input_unregister_device(priv->input_dev); } -/* - * Descriptor buffer is 128 byte long and contains: - * - * Name Offset Length Value - * Vendor Signature 0 4 "DELL" - * Object Signature 4 4 " WMI" - * WMI Interface Version 8 4 <version> - * WMI buffer length 12 4 4096 or 32768 - */ -static int dell_wmi_check_descriptor_buffer(struct wmi_device *wdev) -{ - struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev); - union acpi_object *obj = NULL; - struct wmi_device *desc_dev; - u32 *buffer; - int ret; - - desc_dev = wmidev_get_other_guid(wdev, DELL_DESCRIPTOR_GUID); - if (!desc_dev) { - dev_err(&wdev->dev, "Dell WMI descriptor does not exist\n"); - return -ENODEV; - } - - obj = wmidev_block_query(desc_dev, 0); - if (!obj) { - dev_err(&wdev->dev, "failed to read Dell WMI descriptor\n"); - ret = -EIO; - goto out; - } - - if (obj->type != ACPI_TYPE_BUFFER) { - dev_err(&wdev->dev, "Dell descriptor has wrong type\n"); - ret = -EINVAL; - goto out; - } - - if (obj->buffer.length != 128) { - dev_err(&wdev->dev, - "Dell descriptor buffer has invalid length (%d)\n", - obj->buffer.length); - ret = -EINVAL; - goto out; - } - - buffer = (u32 *)obj->buffer.pointer; - - if (strncmp(obj->string.pointer, "DELL WMI", 8) != 0) { - dev_err(&wdev->dev, "Dell descriptor buffer has invalid signature (%8ph)\n", - buffer); - ret = -EINVAL; - goto out; - } - if (buffer[2] != 0 && buffer[2] != 1) - dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%u)\n", - buffer[2]); - - if (desc_buffer[3] != 4096 && desc_buffer[3] != 32768) - dev_warn(&wdev->dev, "Dell descriptor buffer has invalid buffer length (%u)\n", - buffer[3]); - - priv->interface_version = buffer[2]; - ret = 0; - - dev_info(&wdev->dev, "Detected Dell WMI interface version %u\n", - priv->interface_version); - -out: - kfree(obj); - put_device(&desc_dev->dev); - return ret; -} - /* * According to Dell SMBIOS documentation: * @@ -724,7 +655,6 @@ static int dell_wmi_events_set_enabled(bool enable) static int dell_wmi_probe(struct wmi_device *wdev) { struct dell_wmi_priv *priv; - int err; priv = devm_kzalloc( &wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL); @@ -732,10 +662,6 @@ static int dell_wmi_probe(struct wmi_device *wdev) return -ENOMEM; dev_set_drvdata(&wdev->dev, priv); - err = dell_wmi_check_descriptor_buffer(wdev); - if (err) - return err; - return dell_wmi_input_setup(wdev); }

[v4,05/14] platform/x86: dell-wmi-descriptor: split WMI descriptor into it's own driver

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