[PATCH 4/8] media: imx-pxp: explicitly disable unused blocks

[Michael Tretter]

Various multiplexers in the pipeline are not used with the currently
configured data path. Disable all unused multiplexers by selecting the
"no output" (3) option.

The datasheet doesn't explicitly require this, but the PXP has been seen
to hang after processing a few hundreds of frames otherwise.

As at it, add documentation for the multiplexers that are actually
relevant for the data path.

Signed-off-by: Michael Tretter <m.tretter at pengutronix.de>
---
 drivers/media/platform/nxp/imx-pxp.c | 30 +++++++++++++++++-----------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/media/platform/nxp/imx-pxp.c b/drivers/media/platform/nxp/imx-pxp.c
index a957fee88829..6ffd07cda965 100644
--- a/drivers/media/platform/nxp/imx-pxp.c
+++ b/drivers/media/platform/nxp/imx-pxp.c
@@ -731,22 +731,28 @@ static u32 pxp_data_path_ctrl0(struct pxp_ctx *ctx)
 	u32 ctrl0;
 
 	ctrl0 = 0;
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX15_SEL(0);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX15_SEL(3);
+	/* Bypass Dithering x3CH */
 	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX14_SEL(1);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX13_SEL(0);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX13_SEL(3);
+	/* Select Rotation */
 	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX12_SEL(0);
+	/* Select LUT */
 	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX11_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX10_SEL(0);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX10_SEL(3);
+	/* Select MUX8 for LUT */
 	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX9_SEL(1);
+	/* Select CSC 2 */
 	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX8_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX7_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX6_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX5_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX4_SEL(0);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX7_SEL(3);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX6_SEL(3);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX5_SEL(3);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX4_SEL(3);
+	/* Bypass Rotation 2 */
 	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX3_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX2_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX1_SEL(0);
-	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX0_SEL(0);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX2_SEL(3);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX1_SEL(3);
+	ctrl0 |= BF_PXP_DATA_PATH_CTRL0_MUX0_SEL(3);
 
 	return ctrl0;
 }
@@ -760,8 +766,8 @@ static void pxp_set_data_path(struct pxp_ctx *ctx)
 	ctrl0 = pxp_data_path_ctrl0(ctx);
 
 	ctrl1 = 0;
-	ctrl1 |= BF_PXP_DATA_PATH_CTRL1_MUX17_SEL(1);
-	ctrl1 |= BF_PXP_DATA_PATH_CTRL1_MUX16_SEL(1);
+	ctrl1 |= BF_PXP_DATA_PATH_CTRL1_MUX17_SEL(3);
+	ctrl1 |= BF_PXP_DATA_PATH_CTRL1_MUX16_SEL(3);
 
 	writel(ctrl0, dev->mmio + HW_PXP_DATA_PATH_CTRL0);
 	writel(ctrl1, dev->mmio + HW_PXP_DATA_PATH_CTRL1);
-- 
2.30.2