[alsa-devel] [PATCH v2 1/3] ACPI / utils: Introduce acpi_dev_get_dev_name()

[Andy Shevchenko]

Sometimes the user want to have device name of the match rather than
just checking if device present or not. To make life easier for such
users introduce acpi_dev_get_dev_name() helper based on code for
acpi_dev_present().

To be more consistent with the purpose rename

  struct acpi_dev_present_info  -> struct acpi_dev_match_info
  acpi_dev_present_cb()         -> acpi_dev_match_cb()

in the utils.c file.

Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
---
 drivers/acpi/utils.c    | 40 +++++++++++++++++++++++++++++++++-------
 include/acpi/acpi_bus.h |  1 +
 include/linux/acpi.h    |  6 ++++++
 3 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 9d49a1acebe3..1da9e986d510 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -737,16 +737,17 @@ bool acpi_dev_found(const char *hid)
 }
 EXPORT_SYMBOL(acpi_dev_found);
 
-struct acpi_dev_present_info {
+struct acpi_dev_match_info {
+	const char *dev_name;
 	struct acpi_device_id hid[2];
 	const char *uid;
 	s64 hrv;
 };
 
-static int acpi_dev_present_cb(struct device *dev, void *data)
+static int acpi_dev_match_cb(struct device *dev, void *data)
 {
 	struct acpi_device *adev = to_acpi_device(dev);
-	struct acpi_dev_present_info *match = data;
+	struct acpi_dev_match_info *match = data;
 	unsigned long long hrv;
 	acpi_status status;
 
@@ -757,6 +758,8 @@ static int acpi_dev_present_cb(struct device *dev, void *data)
 	    strcmp(adev->pnp.unique_id, match->uid)))
 		return 0;
 
+	match->dev_name = acpi_dev_name(adev);
+
 	if (match->hrv == -1)
 		return 1;
 
@@ -789,20 +792,43 @@ static int acpi_dev_present_cb(struct device *dev, void *data)
  */
 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
 {
-	struct acpi_dev_present_info match = {};
+	struct acpi_dev_match_info match = {};
 	struct device *dev;
 
 	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
 	match.uid = uid;
 	match.hrv = hrv;
 
-	dev = bus_find_device(&acpi_bus_type, NULL, &match,
-			      acpi_dev_present_cb);
-
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
 	return !!dev;
 }
 EXPORT_SYMBOL(acpi_dev_present);
 
+/**
+ * acpi_dev_get_dev_name - Return device name of first match of ACPI device
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return device name if a matching device was present
+ * at the moment of invocation, or NULL otherwise.
+ *
+ * See additional information in acpi_dev_present() as well.
+ */
+const char *acpi_dev_get_dev_name(const char *hid, const char *uid, s64 hrv)
+{
+	struct acpi_dev_match_info match = {};
+	struct device *dev;
+
+	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	match.uid = uid;
+	match.hrv = hrv;
+
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+	return dev ? match.dev_name : NULL;
+}
+EXPORT_SYMBOL(acpi_dev_get_dev_name);
+
 /*
  * acpi_backlight= handling, this is done here rather then in video_detect.c
  * because __setup cannot be used in modules.
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 79287629c888..8883f5ebb6ce 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -90,6 +90,7 @@ acpi_evaluate_dsm_typed(acpi_handle handle, const guid_t *guid, u64 rev,
 
 bool acpi_dev_found(const char *hid);
 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv);
+const char *acpi_dev_get_dev_name(const char *hid, const char *uid, s64 hrv);
 
 #ifdef CONFIG_ACPI
 
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 1922063f6894..d6576eec45d1 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -644,6 +644,12 @@ static inline bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
 	return false;
 }
 
+static inline
+const char *acpi_dev_get_dev_name(const char *hid, const char *uid, s64 hrv)
+{
+	return NULL;
+}
+
 static inline bool is_acpi_node(struct fwnode_handle *fwnode)
 {
 	return false;
-- 
2.15.1