From e7488e58c7cfe4be0c52db68622a0397bb75258e Mon Sep 17 00:00:00 2001 From: Yurii Pavlovskyi Date: Tue, 14 May 2019 20:59:01 +0200 Subject: platform/x86: wmi: Add function to get _UID of WMI device Add a new function to acpi.h / wmi.c that returns _UID of the ACPI WMI device. For example, it returns "ATK" for the following declaration in DSDT: Device (ATKD) { Name (_HID, "PNP0C14" /* Windows Management Instrumentation Device */) // _HID: Hardware ID Name (_UID, "ATK") // _UID: Unique ID .. Generally, it is possible that multiple PNP0C14 ACPI devices are present in the system as mentioned in the commit message of commit bff431e49ff5 ("ACPI: WMI: Add ACPI-WMI mapping driver"). Therefore the _UID is returned for a specific ACPI device that declares the given GUID, to which it is also mapped by other methods of wmi module. Signed-off-by: Yurii Pavlovskyi Signed-off-by: Andy Shevchenko --- drivers/platform/x86/wmi.c | 19 +++++++++++++++++++ include/linux/acpi.h | 1 + 2 files changed, 20 insertions(+) diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index 7b26b6ccf1a0..b08ffb769cbe 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -635,6 +635,25 @@ bool wmi_has_guid(const char *guid_string) } EXPORT_SYMBOL_GPL(wmi_has_guid); +/** + * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba + * + * Find the _UID of ACPI device associated with this WMI GUID. + * + * Return: The ACPI _UID field value or NULL if the WMI GUID was not found + */ +char *wmi_get_acpi_device_uid(const char *guid_string) +{ + struct wmi_block *wblock = NULL; + + if (!find_guid(guid_string, &wblock)) + return NULL; + + return acpi_device_uid(wblock->acpi_device); +} +EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid); + static struct wmi_block *dev_to_wblock(struct device *dev) { return container_of(dev, struct wmi_block, dev.dev); diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 98440df7fe42..d867a9a904f9 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -380,6 +380,7 @@ extern acpi_status wmi_install_notify_handler(const char *guid, extern acpi_status wmi_remove_notify_handler(const char *guid); extern acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out); extern bool wmi_has_guid(const char *guid); +extern char *wmi_get_acpi_device_uid(const char *guid); #endif /* CONFIG_ACPI_WMI */ -- cgit v1.2.3-59-g8ed1b