[PATCH v4 4/6] media: ipu-bridge: Assign endpoint property indices dynamically

[Fernando Rimoli <fernandorimoli11@gmail.com>]

The endpoint property array is populated with hardcoded indices, so a
property that is only set conditionally has to be placed at a fixed slot.
As the array is NULL-terminated, such a property is silently dropped when
an earlier optional slot is left empty: "link-frequencies" is skipped for
configs with nr_link_freqs == 0, which would truncate the array before
anything following it.

Name the endpoint property slots in an enum, size the array accordingly
and assign the indices through a bounds-checked running index, as done
for the MIPI DisCo for Imaging properties in mipi-disco-img.c. No
functional change intended: the same properties are set in the same
order.

Signed-off-by: Fernando Rimoli <fernandorimoli11@gmail.com>
---
 drivers/media/pci/intel/ipu-bridge.c | 27 ++++++++++++++-------------
 include/media/ipu-bridge.h           | 19 ++++++++++++++++++-
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/drivers/media/pci/intel/ipu-bridge.c b/drivers/media/pci/intel/ipu-bridge.c
index 131c70844..cd3c36d44 100644
--- a/drivers/media/pci/intel/ipu-bridge.c
+++ b/drivers/media/pci/intel/ipu-bridge.c
@@ -449,6 +449,7 @@ static void ipu_bridge_create_fwnode_properties(
 	struct ipu_bridge *bridge,
 	const struct ipu_sensor_config *cfg)
 {
+	unsigned int i = IPU_SENSOR_EP_BUS_TYPE;
 	struct ipu_property_names *names = &sensor->prop_names;
 	struct software_node *nodes = sensor->swnodes;
 
@@ -508,21 +509,21 @@ static void ipu_bridge_create_fwnode_properties(
 			PROPERTY_ENTRY_REF_ARRAY("lens-focus", sensor->vcm_ref);
 	}
 
-	sensor->ep_properties[0] = PROPERTY_ENTRY_U32(
-					sensor->prop_names.bus_type,
-					V4L2_FWNODE_BUS_TYPE_CSI2_DPHY);
-	sensor->ep_properties[1] = PROPERTY_ENTRY_U32_ARRAY_LEN(
-					sensor->prop_names.data_lanes,
-					bridge->data_lanes, sensor->lanes);
-	sensor->ep_properties[2] = PROPERTY_ENTRY_REF_ARRAY(
-					sensor->prop_names.remote_endpoint,
-					sensor->local_ref);
+	sensor->ep_properties[IPU_NEXT_EP_PROPERTY(i, NUM_OF)] =
+		PROPERTY_ENTRY_U32(names->bus_type,
+				   V4L2_FWNODE_BUS_TYPE_CSI2_DPHY);
+	sensor->ep_properties[IPU_NEXT_EP_PROPERTY(i, NUM_OF)] =
+		PROPERTY_ENTRY_U32_ARRAY_LEN(names->data_lanes,
+					     bridge->data_lanes, sensor->lanes);
+	sensor->ep_properties[IPU_NEXT_EP_PROPERTY(i, NUM_OF)] =
+		PROPERTY_ENTRY_REF_ARRAY(names->remote_endpoint,
+					 sensor->local_ref);
 
 	if (cfg->nr_link_freqs > 0)
-		sensor->ep_properties[3] = PROPERTY_ENTRY_U64_ARRAY_LEN(
-			sensor->prop_names.link_frequencies,
-			cfg->link_freqs,
-			cfg->nr_link_freqs);
+		sensor->ep_properties[IPU_NEXT_EP_PROPERTY(i, NUM_OF)] =
+			PROPERTY_ENTRY_U64_ARRAY_LEN(names->link_frequencies,
+						     cfg->link_freqs,
+						     cfg->nr_link_freqs);
 
 	sensor->ipu_properties[0] = PROPERTY_ENTRY_U32_ARRAY_LEN(
 					sensor->prop_names.data_lanes,
diff --git a/include/media/ipu-bridge.h b/include/media/ipu-bridge.h
index 16fac7654..61e10cef1 100644
--- a/include/media/ipu-bridge.h
+++ b/include/media/ipu-bridge.h
@@ -64,6 +64,23 @@ enum ipu_sensor_swnodes {
 	SWNODE_COUNT
 };
 
+enum ipu_sensor_ep_props {
+	IPU_SENSOR_EP_BUS_TYPE,
+	IPU_SENSOR_EP_DATA_LANES,
+	IPU_SENSOR_EP_REMOTE_EP,
+	IPU_SENSOR_EP_LINK_FREQUENCIES,
+	IPU_SENSOR_EP_NUM_OF,
+	IPU_SENSOR_EP_NUM_ENTRIES
+};
+
+/*
+ * Get the index of the next endpoint property in the property array, with a
+ * given maximum value.
+ */
+#define IPU_NEXT_EP_PROPERTY(index, max)		\
+	(WARN_ON((index) > IPU_SENSOR_EP_##max) ?	\
+	 IPU_SENSOR_EP_##max : (index)++)
+
 /* Data representation as it is in ACPI SSDB buffer */
 struct ipu_sensor_ssdb {
 	u8 version;
@@ -141,7 +158,7 @@ struct ipu_sensor {
 	const char *vcm_type;
 
 	struct ipu_property_names prop_names;
-	struct property_entry ep_properties[5];
+	struct property_entry ep_properties[IPU_SENSOR_EP_NUM_ENTRIES];
 	struct property_entry dev_properties[5];
 	struct property_entry ipu_properties[3];
 	struct property_entry ivsc_properties[1];
-- 
2.43.0