dell-wmi: enable receiving WMI events on Dell Vostro V131

On some laptop models (e.g. Dell Vostro V131), WMI events are not
generated until a specific SMBIOS request is issued to register an event
listener [1].  As there seems to be no ACPI method or SMBIOS request to
determine without possible side effects whether a given machine needs to
issue this SMBIOS request in order to receive WMI events, DMI matching
is used to whitelist the models which need it.

[1] https://lists.us.dell.com/pipermail/libsmbios-devel/2015-July/000612.html

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
This commit is contained in:
Michał Kępień 2016-03-04 14:09:08 +01:00 committed by Darren Hart
parent 0db2180fce
commit e09c4d5b15
2 changed files with 67 additions and 0 deletions

View File

@ -124,6 +124,7 @@ config DELL_WMI
depends on DMI
depends on INPUT
depends on ACPI_VIDEO || ACPI_VIDEO = n
depends on DELL_SMBIOS
select INPUT_SPARSEKMAP
---help---
Say Y here if you want to support WMI-based hotkeys on Dell laptops.

View File

@ -37,6 +37,7 @@
#include <linux/string.h>
#include <linux/dmi.h>
#include <acpi/video.h>
#include "dell-smbios.h"
MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
@ -47,10 +48,29 @@ MODULE_LICENSE("GPL");
#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
static u32 dell_wmi_interface_version;
static bool wmi_requires_smbios_request;
MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);
static int __init dmi_matched(const struct dmi_system_id *dmi)
{
wmi_requires_smbios_request = 1;
return 1;
}
static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
{
.callback = dmi_matched,
.ident = "Dell Vostro V131",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
},
},
{ }
};
/*
* Certain keys are flagged as KE_IGNORE. All of these are either
* notifications (rather than requests for change) or are also sent
@ -597,6 +617,38 @@ static int __init dell_wmi_check_descriptor_buffer(void)
return 0;
}
/*
* According to Dell SMBIOS documentation:
*
* 17 3 Application Program Registration
*
* cbArg1 Application ID 1 = 0x00010000
* cbArg2 Application ID 2
* QUICKSET/DCP = 0x51534554 "QSET"
* ALS Driver = 0x416c7353 "AlsS"
* Latitude ON = 0x4c6f6e52 "LonR"
* cbArg3 Application version or revision number
* cbArg4 0 = Unregister application
* 1 = Register application
* cbRes1 Standard return codes (0, -1, -2)
*/
static int dell_wmi_events_set_enabled(bool enable)
{
struct calling_interface_buffer *buffer;
int ret;
buffer = dell_smbios_get_buffer();
buffer->input[0] = 0x10000;
buffer->input[1] = 0x51534554;
buffer->input[3] = enable;
dell_smbios_send_request(17, 3);
ret = buffer->output[0];
dell_smbios_release_buffer();
return dell_smbios_error(ret);
}
static int __init dell_wmi_init(void)
{
int err;
@ -624,12 +676,26 @@ static int __init dell_wmi_init(void)
return -ENODEV;
}
dmi_check_system(dell_wmi_smbios_list);
if (wmi_requires_smbios_request) {
err = dell_wmi_events_set_enabled(true);
if (err) {
pr_err("Failed to enable WMI events\n");
wmi_remove_notify_handler(DELL_EVENT_GUID);
dell_wmi_input_destroy();
return err;
}
}
return 0;
}
module_init(dell_wmi_init);
static void __exit dell_wmi_exit(void)
{
if (wmi_requires_smbios_request)
dell_wmi_events_set_enabled(false);
wmi_remove_notify_handler(DELL_EVENT_GUID);
dell_wmi_input_destroy();
}