[PATCH v3 3/5] dell-wmi: enable receiving WMI events on Dell Vostro V131

From: MichaÅ KÄpieÅ
Date: Tue Feb 16 2016 - 09:51:58 EST


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: MichaÅ KÄpieÅ <kernel@xxxxxxxxxx>
---
drivers/platform/x86/Kconfig | 1 +
drivers/platform/x86/dell-wmi.c | 49 +++++++++++++++++++++++++++++++++++++++
2 files changed, 50 insertions(+)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 3e4d9c3..5ceb53a 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -122,6 +122,7 @@ config DELL_WMI
depends on ACPI_WMI
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.
diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
index 368e193..ca8233a 100644
--- a/drivers/platform/x86/dell-wmi.c
+++ b/drivers/platform/x86/dell-wmi.c
@@ -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@xxxxxxxxxx>");
MODULE_AUTHOR("Pali RohÃr <pali.rohar@xxxxxxxxx>");
@@ -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
@@ -513,6 +533,7 @@ static int __init dell_wmi_init(void)
{
int err;
acpi_status status;
+ struct calling_interface_buffer *buffer;

if (!wmi_has_guid(DELL_EVENT_GUID) ||
!wmi_has_guid(DELL_DESCRIPTOR_GUID)) {
@@ -538,12 +559,40 @@ static int __init dell_wmi_init(void)
return -ENODEV;
}

+ dmi_check_system(dell_wmi_smbios_list);
+
+ if (wmi_requires_smbios_request) {
+ buffer = dell_smbios_get_buffer();
+ buffer->input[0] = 0x10000;
+ buffer->input[1] = 0x51534554;
+ buffer->input[3] = 0x1;
+ dell_smbios_send_request(17, 3);
+ err = buffer->output[0];
+ dell_smbios_release_buffer();
+ if (err) {
+ pr_err("Failed to enable WMI (error %d)\n", err);
+ wmi_remove_notify_handler(DELL_EVENT_GUID);
+ dell_wmi_input_destroy();
+ return dell_smbios_error(err);
+ }
+ }
+
return 0;
}
module_init(dell_wmi_init);

static void __exit dell_wmi_exit(void)
{
+ struct calling_interface_buffer *buffer;
+
+ if (wmi_requires_smbios_request) {
+ buffer = dell_smbios_get_buffer();
+ buffer->input[0] = 0x10000;
+ buffer->input[1] = 0x51534554;
+ dell_smbios_send_request(17, 3);
+ dell_smbios_release_buffer();
+ }
+
wmi_remove_notify_handler(DELL_EVENT_GUID);
dell_wmi_input_destroy();
}
--
1.7.10.4