Linux/AM5718: HDMI I2C error

Hello Manisha;
We are note getting the HDMI display.

We configured C25 and F17 pins in normal i2c mode as below then we got signal as per attched images on CRO and i think it is fine.

{I2C2_SDA, (M0| PIN_INPUT)}, /* i2c2_sda.i2c2_sda */
{I2C2_SCL, (M0| PIN_INPUT)}, /* i2c2_scl.i2c2_scl */


But when we configured those both pins for hdmi_ddc as per below we didnot get any signal on those pins.
{I2C2_SDA, (M1| PIN_INPUT)}, /* i2c2_sda.hdmi1_ddc_scl */
{I2C2_SCL, (M1| PIN_INPUT)}, /* i2c2_scl.hdmi1_ddc_sda */


Also, find the below our test result:

root@am57xx-evm:/mnt/bin# ./modetest
trying to open device 'i915'...failed
trying to open device 'radeon'...failed
trying to open device 'nouveau'...failed
trying to open device 'vmwgfx'...failed
trying to open device 'omapdrm'...done
[ 52.228310] omapdss error: HDMI I2C timeout reading EDID
Encoders:
id crtc type possible crtcs possible clones
30 34 TMDS 0x00000001 0x00000000

Connectors:
id encoder status name size (mm) modes encoders
31 30 connected HDMI-A-1 0x0 5 30
modes:
name refresh (Hz) hdisp hss hse htot vdisp vss vse vtot)
1024x768 60 1024 1048 1184 1344 768 771 777 806 flags: nhsync, nvsync; type: driver
800x600 60 800 840 968 1056 600 601 605 628 flags: phsync, pvsync; type: driver
800x600 56 800 824 896 1024 600 601 603 625 flags: phsync, pvsync; type: driver
848x480 60 848 864 976 1088 480 486 494 517 flags: phsync, pvsync; type: driver
640x480 60 640 656 752 800 480 490 492 525 flags: nhsync, nvsync; type: driver
props:

root@am57xx-evm:~# dmesg | grep hdmi
[ 1.929503] HDMI: hdmi_runtime_get
[ 1.929530] HDMI: hdmi_runtime_put
[ 1.929647] omapdss_dss 58000000.dss: bound 58040000.encoder (ops hdmi5_component_ops)
[ 2.540960] HDMI: ENTER omapdss_hdmi_core_enable
[ 2.540964] HDMI: hdmi_runtime_get
[ 2.541007] HDMI: hdmi_runtime_get
[ 3.590947] HDMI: hdmi_runtime_put
[ 3.590951] HDMI: Enter omapdss_hdmi_core_disable
[ 3.590955] HDMI: hdmi_runtime_put
[ 3.600432] HDMI: ENTER hdmi_display_enable
[ 3.600435] HDMI: hdmi_runtime_get
[ 3.600464] HDMI: hdmi_power_on hactive= 1024 vactive = 768
[ 3.600611] hdmi_core_init
[ 3.600613] HDMIWP: Enter hdmi_wp_video_init_format
[ 3.600615] HDMIWP: Enter hdmi_wp_video_config_timing
[ 3.600618] HDMIWP: Enter hdmi_wp_video_config_interface
[ 3.600638] hdmi_core_enable_video_path
[ 4.721004] HDMI: hdmi_runtime_get
[ 5.782957] HDMI: hdmi_runtime_put
[ 9.732570] omap-hdmi-audio omap-hdmi-audio.0.auto: snd-soc-dummy-dai <-> 58040000.encoder mapping ok
root@am57xx-evm:~#

root@am57xx-evm:~# dmesg | grep HDMI
[ 1.929503] HDMI: hdmi_runtime_get
[ 1.929530] HDMI: hdmi_runtime_put
[ 2.540960] HDMI: ENTER omapdss_hdmi_core_enable
[ 2.540964] HDMI: hdmi_runtime_get
[ 2.541007] HDMI: hdmi_runtime_get
[ 3.585592] omapdss error: HDMI I2C timeout reading EDID
[ 3.590947] HDMI: hdmi_runtime_put
[ 3.590951] HDMI: Enter omapdss_hdmi_core_disable
[ 3.590955] HDMI: hdmi_runtime_put
[ 3.600432] HDMI: ENTER hdmi_display_enable
[ 3.600435] HDMI: hdmi_runtime_get
[ 3.600464] HDMI: hdmi_power_on hactive= 1024 vactive = 768
[ 3.600613] HDMIWP: Enter hdmi_wp_video_init_format
[ 3.600615] HDMIWP: Enter hdmi_wp_video_config_timing
[ 3.600618] HDMIWP: Enter hdmi_wp_video_config_interface
[ 4.721004] HDMI: hdmi_runtime_get
[ 5.777580] omapdss error: HDMI I2C timeout reading EDID
[ 5.782957] HDMI: hdmi_runtime_put

root@am57xx-evm:/mnt/bin# kmscube

trying to load module omapdrm...success.
[ 1178.292778] omapdss error: HDMI I2C timeout reading EDID
### Display [0]: CRTC = 34, Connector = 31, format = 0x34325258
Mode chosen [1024x768] : Clock => 65000, Vertical refresh => 60, Type => 64
Horizontal => 1024, 1048, 1184, 1344, 0
Vertical => 768, 771, 777, 806, 0
### Primary display => ConnectorId = 31, Resolution = 1024x768
failed to load module: /usr/lib/gbm/gbm_dri.so: cannot open shared object file: No such file or directory
failed to load module: /usr/lib/gbm/gbm_gallium_drm.so: cannot open shared object file: No such file or directory
loaded module : gbm_pvr.so
found valid GBM backend : gbm_pvr.so
PVR:(Error): OpenServices: PVRDRMOpenRender failed [0, ]
PVR:(Error): PVRSRVConnect: Unable to open connection. [0, ]
PVR:(Error): Couldn't connect to services [0, ]
failed to initialize
failed to initialize EGL


Please help us to solve our issue as soon as possible.


Thanks & Best Regards;
Nikunj Patel

Hi Nikunj,

HDMI EDID read error will prevent  the right negotiations on the display resolution etc. In absence of EDID read, display will come with default resolution of 1024x768. You can test this by using modetest application.

#modetest -s connector_id@crtc_id:1024x768

You can know the connector_id and crtc_id by running modetest application without any arguments. I am guessing, it is 31 and 35 on your board.

I see the configuration for  hdmi_ddc pins are reverse, SDA is configured for scl and SCL for sda. Is it intentional or typos??

{I2C2_SDA, (M1| PIN_INPUT)}, /* i2c2_sda.hdmi1_ddc_scl */

{I2C2_SCL, (M1| PIN_INPUT)}, /* i2c2_scl.hdmi1_ddc_sda */

Regarding no display with kmscube application,  it seems the PVR is not up. Typical reason for PVR is not up is that kernel is been rebuilt but the SGX kernel module is not loaded.

I suggest to check following -

1. check PVR kernel module.

root@am57xx-evm:~# lsmod | grep pvr

2. If not found, install and load the pvrsrvkm.ko module

To install the kernel module, follow the documentation here -

To load the kernel module -

#insmod /lib/modules/4.14.40-g4796173fc5/extra/pvrsrvkm.ko

3. Restart PVR

root@am57xx-evm:~# /etc/init.d/rc.pvr start

[ 1310.816253] [drm] Initialized pvr 1.14.3699939 20110701 for 56000000.gpu on minor 1

[ 1310.847536] PVR_K: UM DDK-(3699939) and KM DDK-(3699939) match. [ OK ]

Loaded PowerVR consumer services.

3. Check PVR again

root@am57xx-evm:~# lsmod | grep pvr

pvrsrvkm              417792  1 bc_example

Hi manisha;
Thanks for your quick reply.

1) We have same configure of i2c2 in spl-uboot as per am5718-idk as below. This is not the typo mistake.

pad_conf_entry core_padconf_array_essential_am571x_idk[]
{
{I2C2_SDA, (M1 | PIN_INPUT)}, /* i2c2_sda.hdmi1_ddc_scl */
{I2C2_SCL, (M1 | PIN_INPUT)}, /* i2c2_scl.hdmi1_ddc_sda */
}

2) Please check the below command for your reference.

root@am57xx-evm:/mnt/bin# ./modetest -s 31@34:1024x768
trying to open device 'i915'...failed
trying to open device 'radeon'...failed
trying to open device 'nouveau'...failed
trying to open device 'vmwgfx'...failed
trying to open device 'omapdrm'...done
[ 773.590288] omapdss error: HDMI I2C timeout reading EDID
setting mode 1024x768-60Hz@XR24 on connectors 31, crtc 34

3) we are using "ti-processor-sdk-linux-rt-am57xx-evm-04.01.00.06" for our development so we did not found "pvrsrvkm.ko" so can do more help to get this driver.



Thanks & Best Regards;
Nikunj Patel

Hi Manisha;

Now we ported the "ti-processor-sdk-linux-am57xx-evm-05.00.00.15" on our board. and it has 4.14.40 kernel support. which already have support of  "pvrsrvkm" driver.

root@am57xx-evm:~# uname -a
Linux am57xx-evm 4.14.40-g4796173fc5 #1 SMP PREEMPT Wed Jul 25 17:05:51 UTC 2018 armv7l GNU/Linux

root@am57xx-evm:~# lsmod | grep pvr
pvrsrvkm              417792  1 bc_example

Then we started "kmscube" application by below command but still we didn't get any disaply on HDMI.

root@am57xx-evm:~# modetest -s 35@39:1024x768
trying to open device 'i915'...failed
trying to open device 'amdgpu'...failed
trying to open device 'radeon'...failed
trying to open device 'nouveau'...failed
trying to open device 'vmwgfx'...failed
trying to open device 'omapdrm'...done
[  333.812059] omapdss error: HDMI I2C timeout reading EDID
setting mode 1024x768-60Hz@XR24 on connectors 35, crtc 39

root@am57xx-evm:~# kmscube                                                                                                                                                                                                       
trying to load module omapdrm...success.
[  568.290128] omapdss error: HDMI I2C timeout reading EDID
### Display [0]: CRTC = 39, Connector = 35, format = 0x34325258
        Mode chosen [1024x768] : Clock => 65000, Vertical refresh => 60, Type => 64
        Horizontal => 1024, 1048, 1184, 1344, 0
        Vertical => 768, 771, 777, 806, 0
### Primary display => ConnectorId = 35, Resolution = 1024x768
failed to load module: /usr/lib/gbm/gbm_dri.so: cannot open shared object file: No such file or directory
failed to load module: /usr/lib/gbm/gbm_gallium_drm.so: cannot open shared object file: No such file or directory
loaded module : gbm_pvr.so
found valid GBM backend : gbm_pvr.so
Using display 0x1 with EGL version 1.4
EGL Version "1.4 build 1.14@3699939 (MAIN)"
EGL Vendor "Imagination Technologies"
EGL Extensions "EGL_IMG_client_api_ogl EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_vg_parent_image EGL_IMG_cl_image EGL_KHR_fence_sync EGL_IM"

Please provide us support to solve this issue.

Thanks & Best Regards;

Nikunj Patel

Hi manisha;
Thanks for your help;

Can you please check the below dtsi changes are ok for HDMI? or still we missing something?

aliases {
rtc0 = &tps659038_rtc;
rtc1 = &rtc;
display0 = &hdmi0;
};
hdmi0: connector@0 {
compatible = "hdmi-connector";
label = "hdmi";

type = "a";

port {
hdmi_connector_in: endpoint {
remote-endpoint = <&tpd12s015_out>;
};
};
};

tpd12s015: encoder@0 {
compatible = "ti,tpd12s016", "ti,tpd12s015";

gpios = <&gpio6 9 GPIO_ACTIVE_HIGH>;, /* optional CT_CP_HPD */
<0>, /* optional LS_OE */
<&gpio7 12 GPIO_ACTIVE_HIGH>; /* HPD */

ports {
#address-cells = <1>;
#size-cells = <0>;

port@0 {
reg = <0>;

tpd12s015_in: endpoint@0 {
remote-endpoint = <&hdmi_out>;
};
};

port@1 {
reg = <1>;

tpd12s015_out: endpoint@0 {
remote-endpoint = <&hdmi_connector_in>;
};
};
};
};

&hdmi {
status = "okay";
/*
* XXX: Support AM572x-Rev 1.2a. this is wrong for AM571x-rev 1.3a,
* AM572x-Rev1.3a - but thanks to always-on, they work.
* TODO: SWITCH TO LDO4 once rev 1.2a is deprecated
* (on rev 1.3a availability)
*/
vdda-supply = <&ldo4_reg>;

port {
hdmi_out: endpoint {
remote-endpoint = <&tpd12s015_in>;
};
};
};


&dss {
status = "okay";

vdda_video-supply = <&ldoln_reg>;

ports {
#address-cells = <1>;
#size-cells = <0>;

port@0 {
reg = <0>;

dpi_out: endpoint {
remote-endpoint = <&tc358778_in>;
data-lines = <24>;
};
};
};
};

Also check the Pin muxing of spl-uboot for HDMI

{I2C2_SDA, (M1| PIN_INPUT)}, /* i2c2_sda.hdmi1_ddc_scl */
{I2C2_SCL, (M1| PIN_INPUT)}, /* i2c2_scl.hdmi1_ddc_sda */
{MCASP2_AXR2, (M14 | PIN_INPUT)}, /* mcasp2_axr2.gpio6_9 */
{SPI1_CS2, (M14 | PIN_INPUT_SLEW)}, /* spi1_cs2.gpio7_12 */



Thanks & Best Regards;
Nikunj Patel