[PATCH 2/5] media: synopsys: Add support for multiple streams

[Guoniu Zhou]

The current driver only supports single stream operation. Add support
for multiple concurrent streams by tracking enabled streams with a
bitmask and only initializing the hardware once for the first stream.

This enables use cases such as surround view systems where multiple
camera streams need to be processed simultaneously through the same
CSI-2 receiver interface.

Signed-off-by: Guoniu Zhou <guoniu.zhou@xxxxxxxxxxx>
---
 drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 45 ++++++++++++++----------
 1 file changed, 27 insertions(+), 18 deletions(-)

diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
index 46e2a4315ac2..85a2a95bf080 100644
--- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
+++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
@@ -113,6 +113,7 @@ struct dw_mipi_csi2rx_device {
 
 	enum v4l2_mbus_type bus_type;
 	u32 lanes_num;
+	u64 enabled_streams;
 
 	const struct dw_mipi_csi2rx_drvdata *drvdata;
 };
@@ -528,28 +529,31 @@ static int dw_mipi_csi2rx_enable_streams(struct v4l2_subdev *sd,
 					       DW_MIPI_CSI2RX_PAD_SRC,
 					       &streams_mask);
 
-	ret = pm_runtime_resume_and_get(dev);
-	if (ret)
-		goto err;
+	if (!csi2->enabled_streams) {
+		ret = pm_runtime_resume_and_get(dev);
+		if (ret)
+			return ret;
 
-	ret = dw_mipi_csi2rx_start(csi2);
-	if (ret) {
-		dev_err(dev, "failed to enable CSI hardware\n");
-		goto err_pm_runtime_put;
+		ret = dw_mipi_csi2rx_start(csi2);
+		if (ret) {
+			pm_runtime_put(dev);
+			dev_err(dev, "failed to enable CSI hardware\n");
+			return ret;
+		}
 	}
 
 	ret = v4l2_subdev_enable_streams(remote_sd, remote_pad->index, mask);
-	if (ret)
-		goto err_csi_stop;
+	if (ret) {
+		if (!csi2->enabled_streams) {
+			dw_mipi_csi2rx_stop(csi2);
+			pm_runtime_put(dev);
+		}
+		return ret;
+	}
 
-	return 0;
+	csi2->enabled_streams |= streams_mask;
 
-err_csi_stop:
-	dw_mipi_csi2rx_stop(csi2);
-err_pm_runtime_put:
-	pm_runtime_put(dev);
-err:
-	return ret;
+	return 0;
 }
 
 static int dw_mipi_csi2rx_disable_streams(struct v4l2_subdev *sd,
@@ -572,10 +576,15 @@ static int dw_mipi_csi2rx_disable_streams(struct v4l2_subdev *sd,
 					       &streams_mask);
 
 	ret = v4l2_subdev_disable_streams(remote_sd, remote_pad->index, mask);
+	if (ret)
+		dev_err(dev, "failed to disable streams on remote subdev: %d\n", ret);
 
-	dw_mipi_csi2rx_stop(csi2);
+	csi2->enabled_streams &= ~streams_mask;
 
-	pm_runtime_put(dev);
+	if (!csi2->enabled_streams) {
+		dw_mipi_csi2rx_stop(csi2);
+		pm_runtime_put(dev);
+	}
 
 	return ret;
 }

-- 
2.34.1