topic Re: How do I enable CSC in Imx 6 board in i.MX Processors

How do I enable CSC in Imx 6 board

jerrald_t_g — Wed, 10 Apr 2019 18:08:13 GMT

I am using imx6q sabre chipset. I tried with i.MX6 CSC setting sample source code . I send commands MXCFB_SET_GAMMA,MXCFB_SET_GBL_ALPHA, I can feel the change in display,seems its working. As per the above code I sent IOCTL command MXCFB_CSC_UPDATE and no effect in display, seems code not working. then I send IOCTL command MXCFB_SET_CLR_KEY it is also not working it went inside the file ipu_disp.c with value ipu->fg_csc_type =4. so it didnt entered the code commented with

/* Transform color key from rgb to yuv if CSC is enabled */ in file ipu_disp.c line no 728. I found this post enabling CSC.

I found the below code in line no 623 in file drivers/mxc/ipu3/ipu_disp.c.

* Row is for BG: RGB2YUV YUV2RGB RGB2RGB YUV2YUV CSC_NONE

* Column is for FG: RGB2YUV YUV2RGB RGB2RGB YUV2YUV CSC_NONE

static struct dp_csc_param_t dp_csc_array[CSC_NUM][CSC_NUM] = {

{{DP_COM_CONF_CSC_DEF_BOTH, &rgb2ycbcr_coeff}, {0, 0}, {0, 0}, {DP_COM_CONF_CSC_DEF_BG, &rgb2ycbcr_coeff}, {DP_COM_CONF_CSC_DEF_BG, &rgb2ycbcr_coeff} },

{{0, 0}, {DP_COM_CONF_CSC_DEF_BOTH, &ycbcr2rgb_coeff}, {DP_COM_CONF_CSC_DEF_BG, &ycbcr2rgb_coeff}, {0, 0}, {DP_COM_CONF_CSC_DEF_BG, &ycbcr2rgb_coeff} },

{{0, 0}, {DP_COM_CONF_CSC_DEF_FG, &ycbcr2rgb_coeff}, {0, 0}, {0, 0}, {0, 0} },

{{DP_COM_CONF_CSC_DEF_FG, &rgb2ycbcr_coeff}, {0, 0}, {0, 0}, {0, 0}, {0, 0} },

{{DP_COM_CONF_CSC_DEF_FG, &rgb2ycbcr_coeff}, {DP_COM_CONF_CSC_DEF_FG, &ycbcr2rgb_coeff}, {0, 0}, {0, 0}, {0, 0} }

};

please help me to enable CSC and apply contrast for display similar to iMX6Q display adjustment.

Re: How do I enable CSC in Imx 6 board

igorpadykov — Wed, 10 Apr 2019 23:17:14 GMT

Hi jerald

more full examples can be found on

ipu-examples release notes - v0.1

recommended to use nxp official linux from

linux-imx - i.MX Linux kernel

Best regards
igor
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Re: How do I enable CSC in Imx 6 board

AntoineP — Wed, 30 Mar 2022 14:03:42 GMT

Hi,

We have the exact same behaviour on our VAR-SOM-MX6 connected to an LVDS screen. MXCFB_CSC_UPDATE ioctl command doesn't seem to impact any change on the screen but MXCFB_SET_GAMMA do. How did you resolve this?

Thanks.

Re: How do I enable CSC in Imx 6 board

lukeh — Thu, 30 Jun 2022 15:54:10 GMT

Hello,

Did you (or anyone else reading this) find a way to adjust the contrast on the i.MX6?

We are trying to adjust the contrast on a new display we are using but haven't had any luck. We can adjust the gamma with MXCFB_SET_GAMMA, but the contrast/color temperature doesn't change with the MXCFB_CSC_UPDATE command. We have looked through the ipu-examples but nothing has worked.

Thanks