AM5728: 1080p60 display

Hello Daisuke,

With regards to the DPI, here are a few requirements:
1. Width less than 4096
2. Height less than 4096
3. Pixel clock less than 165 MHz

Based on the above requirement, you could have a refresh rate of 60fps, ~4k width but your height can not be much. The following equation gives you a rough estimate of the calculation: pixel clock=Htotal * Vtotal * Framerate. On PSDK6.0, feel free to modify the following section of code:

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index a3d5a0897..7d775a4f8 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -1899,15 +1899,15 @@ static const struct panel_desc ortustech_com43h4m85ulc = {
 };
 
 static const struct drm_display_mode osddisplays_osd070t1718_19ts_mode  = {
-       .clock = 33000,
-       .hdisplay = 800,
-       .hsync_start = 800 + 210,
-       .hsync_end = 800 + 210 + 30,
-       .htotal = 800 + 210 + 30 + 16,
-       .vdisplay = 480,
-       .vsync_start = 480 + 22,
-       .vsync_end = 480 + 22 + 13,
-       .vtotal = 480 + 22 + 13 + 10,
+       .clock = 49300,
+       .hdisplay = 3096,
+       .hsync_start = 3096 + 210,
+       .hsync_end = 3096 + 210 + 30,
+       .htotal = 3096 + 210 + 30 + 16,
+       .vdisplay = 200,
+       .vsync_start = 200 + 22,
+       .vsync_end = 200 + 22 + 13,
+       .vtotal = 200 + 22 + 13 + 10,
        .vrefresh = 60,
        .flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,

I have setup dummy values for the LCD configuration and the below test ensures that the display driver is fully functional with the enabled settings (Note: the test does not output anything meaningful):

root@am57xx-evm:~# /etc/init.d/weston stop                                                                                                                                                                  

Stopping Weston                                                                                                                                                                                            

root@am57xx-evm:~# kmstest --flip                                                                                                                                                                          

Connector 0/@55: DPI-1                                                                                                                                                                                    

Crtc 0/@56 (plane 0/@35): 3096x200 49.300 3096/210/30/16 200/22/13/10 60 (60.03) 0xa 0x48                                                                                                                

   Fb 62 3096x200-XR24                                                                                                                                                                                    

press enter to exit                                                                                                                                                                                        

Connector 0: fps 60.034280, slowest 16.69 ms                                                                                                                                                              

Connector 0: fps 60.026526, slowest 16.74 ms                                                                                                                                                                

Connector 0: fps 60.033846, slowest 16.73 ms                                                                                                                                                              

Connector 0: fps 60.031359, slowest 16.73 ms                                                                                                                                                                

Connector 0: fps 60.030989, slowest 16.73 ms                                                                                                                                                              

Connector 0: fps 60.031191, slowest 16.77 ms                                                                                                                                                              

Connector 0: fps 60.031170, slowest 16.74 ms                                                                                                                                                              

Connector 0: fps 60.030534, slowest 16.73 ms                                                                                                                                                                

Connector 0: fps 60.032094, slowest 16.73 ms                                                                                                                                                              

Connector 0: fps 60.030251, slowest 16.77 ms                                                                                                                                                              

Connector 0: fps 60.031733, slowest 16.73 ms                                                                                                                                                              

Connector 0: fps 60.031445, slowest 16.81 ms

 

Regards,
Krunal