[PATCH 06/16] media: cadence: csi2rx: Soft reset the streams before starting capture

[Pratyush Yadav]

This resets the stream state machines and FIFOs, giving them a clean
slate. On J721E if the streams are not reset before starting the
capture, the captured frame gets wrapped around vertically on every run
after the first.

Signed-off-by: Pratyush Yadav <p.ya...@ti.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c 
b/drivers/media/platform/cadence/cdns-csi2rx.c
index 31bd80e3f780..b03d2d2e6762 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -39,6 +39,7 @@
 #define CSI2RX_STREAM_BASE(n)          (((n) + 1) * 0x100)
 
 #define CSI2RX_STREAM_CTRL_REG(n)              (CSI2RX_STREAM_BASE(n) + 0x000)
+#define CSI2RX_STREAM_CTRL_SOFT_RST                    BIT(4)
 #define CSI2RX_STREAM_CTRL_START                       BIT(0)
 
 #define CSI2RX_STREAM_DATA_CFG_REG(n)          (CSI2RX_STREAM_BASE(n) + 0x008)
@@ -150,12 +151,22 @@ struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct 
v4l2_subdev *subdev)
 
 static void csi2rx_reset(struct csi2rx_priv *csi2rx)
 {
+       int i;
+
        writel(CSI2RX_SOFT_RESET_PROTOCOL | CSI2RX_SOFT_RESET_FRONT,
               csi2rx->base + CSI2RX_SOFT_RESET_REG);
 
        udelay(10);
 
        writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG);
+
+       /* Reset individual streams. */
+       for (i = 0; i < csi2rx->max_streams; i++) {
+               writel(CSI2RX_STREAM_CTRL_SOFT_RST,
+                      csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
+               usleep_range(10, 20);
+               writel(0, csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
+       }
 }
 
 static int csi2rx_configure_external_dphy(struct csi2rx_priv *csi2rx)
-- 
2.30.0