diff options
author | Mario Limonciello <mario.limonciello@dell.com> | 2017-11-01 20:25:27 +0100 |
---|---|---|
committer | Darren Hart (VMware) <dvhart@infradead.org> | 2017-11-04 00:33:58 +0100 |
commit | 92b8c540bce7b1662212dff35f503f5b1266725b (patch) | |
tree | 21e0a8e27544bfda4c8f1a3c9b627b438b443167 | |
parent | platform/x86: dell-wmi: don't check length returned (diff) | |
download | linux-92b8c540bce7b1662212dff35f503f5b1266725b.tar.xz linux-92b8c540bce7b1662212dff35f503f5b1266725b.zip |
platform/x86: dell-wmi-descriptor: split WMI descriptor into it's own driver
All communication on individual GUIDs should occur in separate drivers.
Allowing a driver to communicate with the bus to another GUID is just
a hack that discourages drivers to adopt the bus model.
The information found from the WMI descriptor driver is now exported
for use by other drivers.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
-rw-r--r-- | MAINTAINERS | 5 | ||||
-rw-r--r-- | drivers/platform/x86/Kconfig | 5 | ||||
-rw-r--r-- | drivers/platform/x86/Makefile | 1 | ||||
-rw-r--r-- | drivers/platform/x86/dell-wmi-descriptor.c | 170 | ||||
-rw-r--r-- | drivers/platform/x86/dell-wmi-descriptor.h | 21 | ||||
-rw-r--r-- | drivers/platform/x86/dell-wmi.c | 80 |
6 files changed, 208 insertions, 74 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index b77e493cff9c..69a81400cc65 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4013,6 +4013,11 @@ 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 87c8c36efce4..a0babdc5136f 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 + select DELL_WMI_DESCRIPTOR select DELL_SMBIOS select INPUT_SPARSEKMAP ---help--- @@ -129,6 +130,10 @@ 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 + depends on ACPI_WMI + 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..3204c408e261 --- /dev/null +++ b/drivers/platform/x86/dell-wmi-descriptor.c @@ -0,0 +1,170 @@ +/* + * 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" + +struct descriptor_priv { + struct list_head list; + u32 interface_version; + u32 size; +}; +static LIST_HEAD(wmi_list); +static DEFINE_MUTEX(list_mutex); + +bool dell_wmi_get_interface_version(u32 *version) +{ + struct descriptor_priv *priv; + bool ret = false; + + mutex_lock(&list_mutex); + priv = list_first_entry_or_null(&wmi_list, + struct descriptor_priv, + list); + if (priv) { + *version = priv->interface_version; + ret = true; + } + mutex_unlock(&list_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(dell_wmi_get_interface_version); + +bool dell_wmi_get_size(u32 *size) +{ + struct descriptor_priv *priv; + bool ret = false; + + mutex_lock(&list_mutex); + priv = list_first_entry_or_null(&wmi_list, + struct descriptor_priv, + list); + if (priv) { + *size = priv->size; + ret = true; + } + mutex_unlock(&list_mutex); + return ret; +} +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 <length> + */ +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 (%lu)\n", + (unsigned long) buffer[2]); + + 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); + mutex_lock(&list_mutex); + list_add_tail(&priv->list, &wmi_list); + mutex_unlock(&list_mutex); + + dev_dbg(&wdev->dev, "Detected Dell WMI interface version %lu and buffer size %lu\n", + (unsigned long) priv->interface_version, + (unsigned long) 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); + + mutex_lock(&list_mutex); + list_del(&priv->list); + mutex_unlock(&list_mutex); + 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..5f7b69c2c83a --- /dev/null +++ b/drivers/platform/x86/dell-wmi-descriptor.h @@ -0,0 +1,21 @@ +/* + * Dell WMI descriptor driver + * + * 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> + +#define DELL_WMI_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492" + +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 da4f629d0831..6d657eb97672 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; @@ -618,75 +618,6 @@ static void dell_wmi_input_destroy(struct wmi_device *wdev) } /* - * 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 <length> - */ -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 (%lu)\n", - (unsigned long) buffer[2]); - - 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: * * 17 3 Application Program Registration @@ -721,7 +652,9 @@ 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; + + if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID)) + return -ENODEV; priv = devm_kzalloc( &wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL); @@ -729,9 +662,8 @@ 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; + if (!dell_wmi_get_interface_version(&priv->interface_version)) + return -EPROBE_DEFER; return dell_wmi_input_setup(wdev); } |