[PATCH v7 05/13] media: cadence: csi2rx: Soft reset the streams before starting capture

From: Vaishnav Achath
Date: Tue Mar 14 2023 - 07:55:49 EST


From: Pratyush Yadav <p.yadav@xxxxxx>

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.yadav@xxxxxx>
Signed-off-by: Vaishnav Achath <vaishnav.a@xxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---

(no changes since v5)

Changes in v5:
- Make i unsigned.
- Add Laurent's R-by.

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 6933626adfc8..8ecd889690b7 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)
@@ -135,12 +136,22 @@ struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)

static void csi2rx_reset(struct csi2rx_priv *csi2rx)
{
+ unsigned 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)
--
2.17.1