Bits 13 and 12 of the ISP_CONFIGn register configure the PIXEL_MODE which specifies the sampling size, in pixel component units, on the CSI-2 output data interface when data are transferred to memory. The register description in the chip manual specifies that DUAL mode should be used for YUV422 data. Signed-off-by: Jacopo Mondi <jacopo@xxxxxxxxxx> Signed-off-by: Xavier Roumegue <xavier.roumegue@xxxxxxxxxxx> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> --- drivers/media/platform/imx/imx-mipi-csis.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/imx/imx-mipi-csis.c b/drivers/media/platform/imx/imx-mipi-csis.c index 3e7efcf43a5f..9d5034759987 100644 --- a/drivers/media/platform/imx/imx-mipi-csis.c +++ b/drivers/media/platform/imx/imx-mipi-csis.c @@ -173,6 +173,7 @@ #define MIPI_CSIS_ISPCFG_PIXEL_MODE_SINGLE (0 << 12) #define MIPI_CSIS_ISPCFG_PIXEL_MODE_DUAL (1 << 12) #define MIPI_CSIS_ISPCFG_PIXEL_MODE_QUAD (2 << 12) /* i.MX8M[MNP] only */ +#define MIPI_CSIS_ISPCFG_PIXEL_MASK (3 << 12) #define MIPI_CSIS_ISPCFG_ALIGN_32BIT BIT(11) #define MIPI_CSIS_ISPCFG_FMT(fmt) ((fmt) << 2) #define MIPI_CSIS_ISPCFG_FMT_MASK (0x3f << 2) @@ -506,7 +507,25 @@ 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_ALIGN_32BIT | MIPI_CSIS_ISPCFG_FMT_MASK + | MIPI_CSIS_ISPCFG_PIXEL_MASK); + + /* + * YUV 4:2:2 can be transferred with 8 or 16 bits per clock sample + * (referred to in the documentation as single and dual pixel modes + * respectively, although the 8-bit mode transfers half a pixel per + * clock sample and the 16-bit mode one pixel). While both mode work + * when the CSIS is connected to a receiver that supports either option, + * single pixel mode requires clock rates twice as high. As all SoCs + * that integrate the CSIS can operate in 16-bit bit mode, and some do + * not support 8-bit mode (this is the case of the i.MX8MP), use dual + * pixel mode unconditionally. + * + * TODO: Verify which other formats require DUAL (or QUAD) modes. + */ + if (state->csis_fmt->data_type == MIPI_CSI2_DATA_TYPE_YUV422_8) + val |= MIPI_CSIS_ISPCFG_PIXEL_MODE_DUAL; + val |= MIPI_CSIS_ISPCFG_FMT(state->csis_fmt->data_type); mipi_csis_write(state, MIPI_CSIS_ISP_CONFIG_CH(0), val); -- 2.35.0
