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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>
hifive-unleashed-5.1
Mario Limonciello 2017-11-01 14:25:27 -05:00 committed by Darren Hart (VMware)
parent fa9f924c7f
commit 92b8c540bc
6 changed files with 208 additions and 74 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
MAINTAINERS
View File

@ -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

5
drivers/platform/x86/Kconfig
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@ -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

1
drivers/platform/x86/Makefile
View File

@ -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

170
drivers/platform/x86/dell-wmi-descriptor.c 100644
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@ -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");

21
drivers/platform/x86/dell-wmi-descriptor.h 100644
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@ -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

80
drivers/platform/x86/dell-wmi.c
View File

@ -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;
@ -617,75 +617,6 @@ 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 <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:
*
@ -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);
}