[PATCH v9 07/13] media: cadence: csi2rx: Soft reset the streams before starting capture
From: Jai Luthra <hidden>
Date: 2023-08-11 10:48:22
Also in:
linux-arm-kernel, linux-media, lkml
Subsystem:
cadence mipi-csi2 bridges, media input infrastructure (v4l/dvb), the rest · Maintainers:
Maxime Ripard, Mauro Carvalho Chehab, Linus Torvalds
From: Pratyush Yadav <redacted>
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 <redacted>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Jai Luthra <redacted>
---
Changes from v8:
- Simplify reset sequence, minimizing delays
drivers/media/platform/cadence/cdns-csi2rx.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 933edec89520..b57e0c3b1944 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c@@ -40,6 +40,7 @@ #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)
@@ -134,12 +135,23 @@ struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev) static void csi2rx_reset(struct csi2rx_priv *csi2rx) { + unsigned int i; + + /* Reset module */ writel(CSI2RX_SOFT_RESET_PROTOCOL | CSI2RX_SOFT_RESET_FRONT, 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)); + } - udelay(10); + usleep_range(10, 20); + /* Clear resets */ writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG); + for (i = 0; i < csi2rx->max_streams; i++) + writel(0, csi2rx->base + CSI2RX_STREAM_CTRL_REG(i)); } static int csi2rx_configure_ext_dphy(struct csi2rx_priv *csi2rx)
--
2.41.0