HDMI support

[rainho]

Excuse me, I can use the mxsfb_sii902x driver normally when using the 4.1.15 kernel, but when I enable sii902x when using the 4.9.88 kernel, I can’t start the kernel and stay at the start kernel. I checked the source code of the driver and found that the fb device registration function has a high loading level At 6, its value is 5.
static int __init sii902x_init(void)
{
sii902x_in_init_state = 1;

return fb_register_client(&nb);
}
fs_initcall_sync(sii902x_init);
After changing and deleting the worker queue, the kernel can be started but an error is reported
[root@heshao_imx6]:/$:dmesg | grep 902x
[ 1.897754] sii902x 1-0039: No reset pin found
[ 2.049687] genirq: Failed to request resources for SII902x_det (irq 84) on irqchip gpio-mxc
[ 2.050037] sii902x 1-0039: Sii902x: cound not request det irq 84
Both use the same device tree, which works in 4.1.15 but not in 4.9.88. can you help me?

[Dhruvit]

Hi @rainho,

I hope you are doing well.

Please make sure that CONFIG_DRM_SII902X option is enabled.

Can you please provide me with the device tree & kernel configuration for further debugging?

Thanks & Regards,
Dhruvit Vasavada

[rainho]

Sorry, I probably already know the problem, because the application interruption failed, resulting in subsequent errors, but I can add and set irqIO as input in mxsfb_sii902x. But I don't understand why it still shows reset pin not found, even though it works normally. There is no such problem in 4.1.15, and I have not enabled brm sii9022. As far as I know, this has applied for drm management, which is not a big problem. My imx6ull does not have GPU support.

[Dhruvit]

Hi @rainho,

I hope you are doing well.

Please make sure that you have referred to sii902x@39 and sii902x_reset nodes in /arch/arm/boot/dts/imx6sx-sdb.dtsi and imx6sx-sdb-lcdif1.dts

Please make sure that reset gpio is not used for other resources (e.g. mipi-csi ..)

Please provide me with a device tree file for further debugging.

Thanks & Regards,
Dhruvit Vasavada

[rainho]

ok,I will check dts.This is my device tree, please help me to debug.

the log about sii902x :[ 1.912998] sii902x 1-0039: No reset pin found

[Dhruvit]

Hi @rainho,

I hope you are doing well.

There seem to be multiple instances of reset pinctrl.

Please refer to sii902x_reset and sii902x@39  in imx6sx-sdb.dtsi for dts changes.

Thanks & Regards,
Dhruvit Vasavada

[rainho]

Hi, thanks for your reply!
I refer to the SII902X configuration of imx6sx-sdb.dtsi, but the reset pin not found still appears. You can find that gpio5 9 is used in two places in my dts. The other one is lcd reset, but I explicitly blocked it, so it should not work.
Thanks & Regards

[Dhruvit]

Hi @rainho,

I hope you are doing well.

from the attached device tree(imx.dts), It seems that sii902x_reset node does have pinctrl-0 property but pinctrl-names = "default"; seems to be missing.

It is required to add the above property. Please add it.

Please refer to https://stackoverflow.com/questions/65951913/gpio-is-uncontrolled-when-setting-device-tree-node-with...

Thanks & Regards,
Dhruvit Vasavada

[rainho]

Hi, thanks for your reply!
Maybe I really forgot to add pinctrl-names, but the problem still exists after I added it
Thanks & Regards

[Dhruvit]

Hi @rainho,

I hope you are doing well.

This is a kernel warning and not an error.

This warning could be due to the needed reset pin is not yet available because the pinctrl
controllers are not set up and the reset fails with a deferral error.

It will try to acquire the pin later on in order to allow proper initialization of the
Sil902 HDMI transmitter.

MLK-14548: video: fb: hdmi: Allow reset pin deferral.

The above change was not present in the 4.1.15 kernel.

Thanks & Regards,
Dhruvit Vasavada