IMX8MP HDMI 1024x600 resolution

[lgalvao]

Hello,

I have a custom imx8mp board which direct HDMI video output and it works fine with 1920x1080 display.

I need to configure a custom HDMI resolution 1024x600@60 with pixel clock 40000000.

Display: https://www.lcdwiki.com/10.1inch_HDMI_Display-H

Thank you for support.

[luo44atosu]

what's the samsung_phy_pll_cfg setting for 77MHZ pixel clock? Also could you please post the correct register setting in the imx8mp user manual? Is the imx8mp and imx8mm the same on HDMI?

[Bio_TICFSL]

Hello,

This isn't a standard resolution can be supported by current bsp, I need to generate timings parameters by tools, so please add these parameters in the table samsung_phy_pll_cfg of drivers/phy/freescale/phy-fsl-samsung-hdmi.c 

Depend of your pixel clock, can be workable.

Regards

[lgalvao]

Can you help me to add these parameters in the table samsung_phy_pll_cfg?

My linux-imx version is lf-6.12.y.

Thank you for support.

[Bio_TICFSL]

Hello,

is not an standar resolution, so please check it, for 1080x720, try the patch as below

--- a/drivers/phy/freescale/phy-fsl-samsung-hdmi.c
+++ b/drivers/phy/freescale/phy-fsl-samsung-hdmi.c
@@ -324,6 +324,15 @@ const struct phy_config samsung_phy_pll_cfg[] = {
0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0xE0, 0x83, 0x0F, 0x3E, 0xF8, 0x00, 0x00,
},
+ }, {
+ 65000000, {
+ 0x00, 0xD1, 0x51, 0x58, 0x8D, 0x04, 0x9A, 0x57,
+ 0x4F, 0x30, 0x33, 0x65, 0x10, 0xBE, 0x24, 0x80,
+ 0x6C, 0xF2, 0x67, 0x00, 0x10, 0x85, 0x30, 0x3A,
+ 0x74, 0x8F, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00,
+ 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0xE0, 0x83, 0x0F, 0x3E, 0xF8, 0x00, 0x00,
+ },
}, {
67500000, {
0x00, 0xD1, 0x54, 0x52, 0x87, 0x03, 0x80, 0x40,
--

Regards

[lgalvao]

Hello,

in linux version 6.12 the file has this format:

}, {

.pixclk = 63500000,

.pll_div_regs = { 0x69, 0x74, 0x89, 0x08, 0x80, 0x40 },

}, {

.pixclk = 67500000,

.pll_div_regs = { 0x54, 0x52, 0x87, 0x03, 0x80, 0x40 },

}, {

Can you help me to add patch in this file?

Do I need to add any modifications in the kernel command line?

[Bio_TICFSL]

Hi.

No this resolution is not standard you will have to do the change.

Regards

[lgalvao · Accepted solution]

Hello, I found a solution that worked for my case.

I generated a custom EDID using this tool: https://github.com/akatrevorjay/edid-generator.git then I copied it to /lib/firmware/edid

In the kernel config I enabled:

CONFIG_DRM_LOAD_EDID_FIRMWARE=y
CONFIG_DRM_IMX_HDMI=m

And finally, I added these parameters to the cmdline:

drm.edid_firmware=HDMI-A-1:edid/1024x600.bin video=HDMI-A-1:1024x600-16@60

Thank you for support