[PATCH v4 3/6] media: rcar-vin: Generate a VIN group ID for Gen2

["Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>]

Prepare to move Gen2 and earlier models to media controller by
generating a unique VIN group id for each VIN instance. On Gen3 and Gen4
it is important to have a specific id in the group as media graph routes
depend on this. On Gen2 and earlier models all that will matter is to
have a unique id in the range.

Break out the id generation to a own function keeping the logic for Gen3
and Gen4 while generating a sequential id for Gen2 models.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
---
* Changes since v1
- Move ID allocation to probe.
- Use ida_alloc_range() instead of implementing our own schema by
  counting DT nodes.
---
 .../platform/renesas/rcar-vin/rcar-core.c     | 78 ++++++++++++++-----
 1 file changed, 59 insertions(+), 19 deletions(-)

diff --git a/drivers/media/platform/renesas/rcar-vin/rcar-core.c b/drivers/media/platform/renesas/rcar-vin/rcar-core.c
index 1be408d6c508..d9ad56fb2aa9 100644
--- a/drivers/media/platform/renesas/rcar-vin/rcar-core.c
+++ b/drivers/media/platform/renesas/rcar-vin/rcar-core.c
@@ -10,6 +10,7 @@
  * Based on the soc-camera rcar_vin driver
  */
 
+#include <linux/idr.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_graph.h>
@@ -55,6 +56,7 @@
  * be only one group for all instances.
  */
 
+static DEFINE_IDA(rvin_ida);
 static DEFINE_MUTEX(rvin_group_lock);
 static struct rvin_group *rvin_group_data;
 
@@ -119,23 +121,8 @@ static int rvin_group_get(struct rvin_dev *vin,
 			  const struct media_device_ops *ops)
 {
 	struct rvin_group *group;
-	u32 id;
 	int ret;
 
-	/* Make sure VIN id is present and sane */
-	ret = of_property_read_u32(vin->dev->of_node, "renesas,id", &id);
-	if (ret) {
-		vin_err(vin, "%pOF: No renesas,id property found\n",
-			vin->dev->of_node);
-		return -EINVAL;
-	}
-
-	if (id >= RCAR_VIN_NUM) {
-		vin_err(vin, "%pOF: Invalid renesas,id '%u'\n",
-			vin->dev->of_node, id);
-		return -EINVAL;
-	}
-
 	/* Join or create a VIN group */
 	mutex_lock(&rvin_group_lock);
 	if (rvin_group_data) {
@@ -164,16 +151,15 @@ static int rvin_group_get(struct rvin_dev *vin,
 	/* Add VIN to group */
 	mutex_lock(&group->lock);
 
-	if (group->vin[id]) {
-		vin_err(vin, "Duplicate renesas,id property value %u\n", id);
+	if (group->vin[vin->id]) {
+		vin_err(vin, "Duplicate renesas,id property value %u\n", vin->id);
 		mutex_unlock(&group->lock);
 		kref_put(&group->refcount, rvin_group_release);
 		return -EINVAL;
 	}
 
-	group->vin[id] = vin;
+	group->vin[vin->id] = vin;
 
-	vin->id = id;
 	vin->group = group;
 	vin->v4l2_dev.mdev = &group->mdev;
 
@@ -1375,6 +1361,54 @@ static const struct of_device_id rvin_of_id_table[] = {
 };
 MODULE_DEVICE_TABLE(of, rvin_of_id_table);
 
+static int rvin_id_get(struct rvin_dev *vin)
+{
+	u32 oid;
+	int id;
+
+	switch (vin->info->model) {
+	case RCAR_GEN3:
+	case RCAR_GEN4:
+		if (of_property_read_u32(vin->dev->of_node, "renesas,id", &oid))
+			break;
+
+		if (oid < 0 || oid >= RCAR_VIN_NUM) {
+			vin_err(vin, "%pOF: Invalid renesas,id '%u'\n",
+				vin->dev->of_node, oid);
+			return -EINVAL;
+		}
+
+		vin->id = oid;
+
+		return 0;
+	default:
+		id = ida_alloc_range(&rvin_ida, 0, RCAR_VIN_NUM - 1,
+				     GFP_KERNEL);
+		if (id < 0)
+			break;
+
+		vin->id = id;
+
+		return 0;
+	}
+
+	vin_err(vin, "Can't figure out VIN id\n");
+
+	return -EINVAL;
+}
+
+static void rvin_id_put(struct rvin_dev *vin)
+{
+	switch (vin->info->model) {
+	case RCAR_GEN3:
+	case RCAR_GEN4:
+		break;
+	default:
+		ida_free(&rvin_ida, vin->id);
+		break;
+	}
+}
+
 static int rcar_vin_probe(struct platform_device *pdev)
 {
 	struct rvin_dev *vin;
@@ -1402,6 +1436,9 @@ static int rcar_vin_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, vin);
 
+	if (rvin_id_get(vin))
+		return -EINVAL;
+
 	if (vin->info->use_isp) {
 		ret = rvin_isp_init(vin);
 	} else if (vin->info->use_mc) {
@@ -1419,6 +1456,7 @@ static int rcar_vin_probe(struct platform_device *pdev)
 
 	if (ret) {
 		rvin_dma_unregister(vin);
+		rvin_id_put(vin);
 		return ret;
 	}
 
@@ -1443,6 +1481,8 @@ static void rcar_vin_remove(struct platform_device *pdev)
 	else
 		rvin_parallel_cleanup(vin);
 
+	rvin_id_put(vin);
+
 	rvin_dma_unregister(vin);
 }
 
-- 
2.49.0