AM62A7-Q1: DPI output can not drive the screen

meng Ke

Expert 1090 points

Part Number: AM62A7-Q1

Tool/software:

Hi Ti Experts.

I config the DPI output.

static const struct drm_display_mode boe_av069hdt_a80_2dp0_mode = {

.clock = 76782,

.hdisplay = 1280,

.hsync_start = 1280 + 26,

.hsync_end = 1280 + 26 + 8,

.htotal = 1322,

.vdisplay = 720,

.vsync_start = 720 + 8,

.vsync_end = 720 + 8 + 2,

.vtotal = 733,

.flags = 0,

};

static const struct panel_desc boe_av069hdt_a80_2dp0 = {

.modes = &boe_av069hdt_a80_2dp0_mode,

.num_modes = 1,

.bpc = 8,

.size = {

.width = 154,

.height = 85,

.bus_format = MEDIA_BUS_FMT_RGB888_1X24,

.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE | DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE,

.connector_type = DRM_MODE_CONNECTOR_DPI,

};

and the DPI signal output SOC_VOUT0_PCLK signal below:

Can you help to check if the PLCK signal is correct or not. thanks very much

1 month ago

0 Divyansh Mittal 1 month ago

TI__Genius 9610 points

Hi,
To verify correct configuration, can you share the output of kmstest?
Our EVMs do not directly expose DPI, so difficult for us to directly probe PCLK.

0 meng Ke 1 month ago in reply to Divyansh Mittal

Expert 1090 points

Hello Divyansh Mittal:

here is the log after runing kmstest:

root@am62axx-evm:/opt/edgeai-gst-apps# kmstest
Connector 0/@40: DPI-1
Crtc 0/@38: 1280x720@79.24 76.782 1280/26/8/8/? 720/8/2/3/? 79 (79.24) 0x0 0x48
Plane 0/@31: 0,0-1280x720
Fb 49 1280x720-XR24
press enter to exit

0 Divyansh Mittal 1 month ago in reply to meng Ke

TI__Genius 9610 points

Hi,
Thanks for confirming. Software-wise your DPI configuration seems to be working.
Let me check internally if we have the capability to verify the clocks. Please expect a response by mid next week.

0 Stanislav Stilyanov 30 days ago in reply to meng Ke

TI__Mastermind 20350 points

Hi Meng,

The clock looks very weak. Can you please share the rest of the display schematics? Can you capture also one of the data signals so we be sure it is not an oscilloscope measurement issue?

Thanks,

Stan

0 meng Ke 29 days ago in reply to Stanislav Stilyanov

Expert 1090 points

Hello Stanislav Stilyanov:

Here is the display schematics for convert the DPI signal to LVDS.

0 Stanislav Stilyanov 26 days ago in reply to meng Ke

TI__Mastermind 20350 points

Hi Meng,

Can you please try to short out R9723 = 0 and try measurement again?

Thanks,

Stan

0 Luis Parga 18 days ago in reply to Stanislav Stilyanov

TI__Intellectual 950 points

Hi Meng,

VOUT0_PCLK does not look correct. You should be able to see something like below. Channel 1 is VOUT0_DATA0 and channel 2 is VOUT0_PCLK.

In out SKEVM, we are able to probe these signals on the HDMI transmitter. Is this what you see on the DPI side?

Best regards,

Luis Parga

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AM62A7-Q1: DPI output can not drive the screen