firmware: arm_scmi: Refactor device matching logic to eliminate duplication

Currently, the device matching logic is duplicated in two functions:
  - scmi_dev_match() used by the scmi_bus to match scmi_devices with
    scmi_drivers.
  - scmi_child_dev_find() used to check for the presence of a device
    with the same name and protocol_id to avoid adding duplicates to
    the bus.

Refactor the code to eliminate the redundant matching logic and
consolidates the functionality for better maintainability and efficiency.

Message-Id: <20250317-b4-scmi_minor_cleanup-v2-2-f4be99bd9864@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 20 insertions, 23 deletions

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index fada4cf0cef7..6055e44cc3a9 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -201,52 +201,49 @@ scmi_protocol_table_unregister(const struct scmi_device_id *id_table)
 		scmi_protocol_device_unrequest(entry);
 }
 
-static const struct scmi_device_id *
-scmi_dev_match_id(struct scmi_device *scmi_dev, const struct scmi_driver *scmi_drv)
+static int scmi_dev_match_by_id_table(struct scmi_device *scmi_dev,
+				      const struct scmi_device_id *id_table)
 {
-	const struct scmi_device_id *id = scmi_drv->id_table;
+	if (!id_table || !id_table->name)
+		return 0;
 
-	if (!id)
-		return NULL;
-
-	for (; id->protocol_id && id->name; id++)
-		if (id->protocol_id == scmi_dev->protocol_id &&
-		    !strcmp(id->name, scmi_dev->name))
-			return id;
+	for (; id_table->protocol_id && id_table->name; id_table++)
+		if (id_table->protocol_id == scmi_dev->protocol_id &&
+		    !strcmp(id_table->name, scmi_dev->name))
+			return 1;
+	return 0;
+}
 
-	return NULL;
+static int scmi_dev_match_id(struct scmi_device *scmi_dev,
+			     const struct scmi_driver *scmi_drv)
+{
+	return scmi_dev_match_by_id_table(scmi_dev, scmi_drv->id_table);
 }
 
 static int scmi_dev_match(struct device *dev, const struct device_driver *drv)
 {
 	const struct scmi_driver *scmi_drv = to_scmi_driver(drv);
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
-	const struct scmi_device_id *id;
-
-	id = scmi_dev_match_id(scmi_dev, scmi_drv);
-	if (id)
-		return 1;
 
-	return 0;
+	return scmi_dev_match_id(scmi_dev, scmi_drv);
 }
 
 static int scmi_match_by_id_table(struct device *dev, const void *data)
 {
-	struct scmi_device *sdev = to_scmi_dev(dev);
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 	const struct scmi_device_id *id_table = data;
 
-	return sdev->protocol_id == id_table->protocol_id &&
-		(id_table->name && !strcmp(sdev->name, id_table->name));
+	return scmi_dev_match_by_id_table(scmi_dev, id_table);
 }
 
 static struct scmi_device *scmi_child_dev_find(struct device *parent,
 					       int prot_id, const char *name)
 {
-	struct scmi_device_id id_table;
+	struct scmi_device_id id_table[2] = { 0 };
 	struct device *dev;
 
-	id_table.protocol_id = prot_id;
-	id_table.name = name;
+	id_table[0].protocol_id = prot_id;
+	id_table[0].name = name;
 
 	dev = device_find_child(parent, &id_table, scmi_match_by_id_table);
 	if (!dev)