Thread (20 messages) 20 messages, 5 authors, 2021-07-28

Re: [RFC PATCH 2/3] media: imx: imx7-media-csi: Set TWO_8BIT_SENSOR for >= 10-bit formats

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2021-05-19 00:16:54

Hi Frieder,

On Mon, May 17, 2021 at 12:21:17PM +0200, Frieder Schrempf wrote:
On 16.05.21 04:42, Laurent Pinchart wrote:
quoted
Sample code from NXP, as well as experiments on i.MX8MM with RAW10
capture with an OV5640 sensor connected over CSI-2, showed that the
TWO_8BIT_SENSOR field of the CSICR3 register needs to be set for formats
larger than 8 bits. Do so, even if the reference manual doesn't clearly
describe the effect of the field.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
For the ADV7280-M I also have the diffs below applied. Do you think
setting BIT_MIPI_DOUBLE_CMPNT is specific to MEDIA_BUS_FMT_UYVY8_2X8?
Do you need MEDIA_BUS_FMT_UYVY8_2X8 ? Neither MEDIA_BUS_FMT_UYVY8_1X16
nor MEDIA_BUS_FMT_UYVY8_2X8 match exactly how YUV 4:2:2 data is
transmitted over CSI-2. V4L2 uses MEDIA_BUS_FMT_UYVY8_1X16 as a
convention.
In the RM it mentions YUV422 in the description of
BIT_MIPI_DOUBLE_CMPNT and without setting it, the colors are all
wrong.
That's interesting. I've tested YUV 4:2:2 with an OV5640 sensor, and I
don't recall having to set the MIPI_DOUBLE_CMPNT field. I'll try to
retest.
I know this is not really related to this patch. I'm just wondering
how to properly support my setup.
It's hard to tell :-( The MIPI_CSI2_ISP_CONFIG PIXEL_MODE and PARALLEL
fields are not well documented, and neither is the CSI_CR18
MIPI_DOUBLE_CMPNT field. While the CSIS and the CSI bridge are
documented, how they're integrated isn't described. So far, I can only
guess.
quoted hunk ↗ jump to hunk
--- a/drivers/staging/media/imx/imx7-mipi-csis.c
+++ b/drivers/staging/media/imx/imx7-mipi-csis.c
@@ -346,6 +346,11 @@ struct csis_pix_format {
 
 static const struct csis_pix_format mipi_csis_formats[] = {
        /* YUV formats. */
+       {
+               .code = MEDIA_BUS_FMT_UYVY8_2X8,
+               .data_type = MIPI_CSI2_DATA_TYPE_YUV422_8,
+               .width = 8,
+       },
        {
                .code = MEDIA_BUS_FMT_UYVY8_1X16,
                .data_type = MIPI_CSI2_DATA_TYPE_YUV422_8,

--- a/drivers/staging/media/imx/imx7-mipi-csis.c
+++ b/drivers/staging/media/imx/imx7-mipi-csis.c
@@ -504,7 +504,7 @@ static void __mipi_csis_set_format(struct csi_state *state)
        /* Color format */
        val = mipi_csis_read(state, MIPI_CSIS_ISP_CONFIG_CH(0));
        val &= ~(MIPI_CSIS_ISPCFG_ALIGN_32BIT | MIPI_CSIS_ISPCFG_FMT_MASK);
-       val |= MIPI_CSIS_ISPCFG_FMT(state->csis_fmt->data_type);
+       val |= MIPI_CSIS_ISPCFG_FMT(state->csis_fmt->data_type) | MIPI_CSIS_ISPCFG_PIXEL_MODE_DUAL;
        mipi_csis_write(state, MIPI_CSIS_ISP_CONFIG_CH(0), val);
 
        /* Pixel resolution */

--- a/drivers/staging/media/imx/imx7-media-csi.c
+++ b/drivers/staging/media/imx/imx7-media-csi.c
@@ -492,7 +492,8 @@ static void imx7_csi_configure(struct imx7_csi *csi)
                case MEDIA_BUS_FMT_UYVY8_1X16:
                case MEDIA_BUS_FMT_YUYV8_2X8:
                case MEDIA_BUS_FMT_YUYV8_1X16:
-                       cr18 |= BIT_MIPI_DATA_FORMAT_YUV422_8B;
+                       cr3 |= BIT_TWO_8BIT_SENSOR;
+                       cr18 |= BIT_MIPI_DATA_FORMAT_YUV422_8B | BIT_MIPI_DOUBLE_CMPNT;
I notice that you set both PIXEL_MODE_DUAL and MIPI_DOUBLE_CMPNT. Have
you tried setting neither ?

Have you also tried using MEDIA_BUS_FMT_UYVY8_1X16 ? The difference
between MEDIA_BUS_FMT_UYVY8_2X8 and MEDIA_BUS_FMT_UYVY8_1X16 in this
driver is the width value passed to v4l2_get_link_freq(). With
MEDIA_BUS_FMT_UYVY8_2X8 you'll end up with a computed link frequency
equal to half of the actual value, and thus a wrong Ths_settle value. It
shuold have no other influence though.
                        break;
                }
        }
quoted
---
 drivers/staging/media/imx/imx7-media-csi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/media/imx/imx7-media-csi.c b/drivers/staging/media/imx/imx7-media-csi.c
index f85a2f5f1413..256b9aa978f0 100644
--- a/drivers/staging/media/imx/imx7-media-csi.c
+++ b/drivers/staging/media/imx/imx7-media-csi.c
@@ -422,6 +422,7 @@ static void imx7_csi_configure(struct imx7_csi *csi)
 	int width = out_pix->width;
 	u32 stride = 0;
 	u32 cr1, cr18;
+	u32 cr3 = 0;
 
 	cr18 = imx7_csi_reg_read(csi, CSI_CSICR18);
 
@@ -464,6 +465,7 @@ static void imx7_csi_configure(struct imx7_csi *csi)
 		case MEDIA_BUS_FMT_SGBRG10_1X10:
 		case MEDIA_BUS_FMT_SGRBG10_1X10:
 		case MEDIA_BUS_FMT_SRGGB10_1X10:
+			cr3 |= BIT_TWO_8BIT_SENSOR;
 			cr18 |= BIT_MIPI_DATA_FORMAT_RAW10;
 			break;
 		case MEDIA_BUS_FMT_Y12_1X12:
@@ -471,6 +473,7 @@ static void imx7_csi_configure(struct imx7_csi *csi)
 		case MEDIA_BUS_FMT_SGBRG12_1X12:
 		case MEDIA_BUS_FMT_SGRBG12_1X12:
 		case MEDIA_BUS_FMT_SRGGB12_1X12:
+			cr3 |= BIT_TWO_8BIT_SENSOR;
 			cr18 |= BIT_MIPI_DATA_FORMAT_RAW12;
 			break;
 		case MEDIA_BUS_FMT_Y14_1X14:
@@ -478,6 +481,7 @@ static void imx7_csi_configure(struct imx7_csi *csi)
 		case MEDIA_BUS_FMT_SGBRG14_1X14:
 		case MEDIA_BUS_FMT_SGRBG14_1X14:
 		case MEDIA_BUS_FMT_SRGGB14_1X14:
+			cr3 |= BIT_TWO_8BIT_SENSOR;
 			cr18 |= BIT_MIPI_DATA_FORMAT_RAW14;
 			break;
 		/*
@@ -510,7 +514,7 @@ static void imx7_csi_configure(struct imx7_csi *csi)
 
 	imx7_csi_reg_write(csi, cr1, CSI_CSICR1);
 	imx7_csi_reg_write(csi, BIT_DMA_BURST_TYPE_RFF_INCR16, CSI_CSICR2);
-	imx7_csi_reg_write(csi, BIT_FRMCNT_RST, CSI_CSICR3);
+	imx7_csi_reg_write(csi, BIT_FRMCNT_RST | cr3, CSI_CSICR3);
 	imx7_csi_reg_write(csi, cr18, CSI_CSICR18);
 
 	imx7_csi_reg_write(csi, (width * out_pix->height) >> 2, CSI_CSIRXCNT);
-- 
Regards,

Laurent Pinchart
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