ACPI: utils: Introduce acpi_dev_uid_match() for matching _UID

Introduce acpi_dev_uid_match() helper that matches the device with
supplied _UID string.

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 27 insertions, 4 deletions

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 2ea14648a661..07ee0d23a188 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -769,19 +769,42 @@ bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
 EXPORT_SYMBOL(acpi_check_dsm);
 
 /**
+ * acpi_dev_uid_match - Match device by supplied UID
+ * @adev: ACPI device to match.
+ * @uid2: Unique ID of the device.
+ *
+ * Matches UID in @adev with given @uid2.
+ *
+ * Returns:
+ *  - %true if matches.
+ *  - %false otherwise.
+ */
+bool acpi_dev_uid_match(struct acpi_device *adev, const char *uid2)
+{
+	const char *uid1 = acpi_device_uid(adev);
+
+	return uid1 && uid2 && !strcmp(uid1, uid2);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_uid_match);
+
+/**
  * acpi_dev_hid_uid_match - Match device by supplied HID and UID
  * @adev: ACPI device to match.
  * @hid2: Hardware ID of the device.
  * @uid2: Unique ID of the device, pass NULL to not check _UID.
  *
- * Matches HID and UID in @adev with given @hid2 and @uid2.
- * Returns true if matches.
+ * Matches HID and UID in @adev with given @hid2 and @uid2. Absence of @uid2
+ * will be treated as a match. If user wants to validate @uid2, it should be
+ * done before calling this function.
+ *
+ * Returns:
+ *  - %true if matches or @uid2 is NULL.
+ *  - %false otherwise.
  */
 bool acpi_dev_hid_uid_match(struct acpi_device *adev,
 			    const char *hid2, const char *uid2)
 {
 	const char *hid1 = acpi_device_hid(adev);
-	const char *uid1 = acpi_device_uid(adev);
 
 	if (strcmp(hid1, hid2))
 		return false;
@@ -789,7 +812,7 @@ bool acpi_dev_hid_uid_match(struct acpi_device *adev,
 	if (!uid2)
 		return true;
 
-	return uid1 && !strcmp(uid1, uid2);
+	return acpi_dev_uid_match(adev, uid2);
 }
 EXPORT_SYMBOL(acpi_dev_hid_uid_match);