SAMMIX R95S DTB modification

Puff · 6 April 2021 05:34

Hi everyone,

I have 2 sammix R95S (S905X 1GB /16GB) box running on Android 7 and 2GB of ram. The CoreELEC version is 9.2.7. I am using the DTB gxl_p212_1g. In order to support audio from toshlink I need to modify the dtb gxl_p212_1g to

audio_pin1 {
            amlogic,setmask = <0x06 0x10000000>;
            amlogic,clrmask = <0x06 0x8000000>;
            amlogic,pins = "GPIOAO_9";
            linux,phandle = <0x5d>;
            phandle = <0x5d>;
        };

The change is amlogic,pins = “GPIOH_4”; to amlogic,pins = “GPIOAO_9”

How can contribute this change for the others to use?

Thanks!

Portisch · 6 April 2021 05:36

You can create a autostart.sh like this example:

Puff · 26 April 2021 04:14

I wanted to modify the dtb (gxl_p212_1g.dtb) from CoreELEC nightly builds 9.2 and it seems that the audio_pin1 is not part of the dtb anymore. How can modify the gxl_p212_1g.dtb to support toslink with the GPIOAO_9 value?

Puff · 28 April 2021 13:44

Hi @Portisch, I am still trying to find where the spdif/toslink pins are defined in the dtb from 9.2 nightly build or 19.1? Any more hints thanks

Portisch · 28 April 2021 14:20

github.com

CoreELEC/linux-amlogic/blob/amlogic-4.9-19/arch/arm64/boot/dts/amlogic/gxl_p212_2g_buildroot.dts#L854


		compatible = "amlogic, aml-i2s";
		interrupts = <0 29 1>;
	};
	pcm_plat: pcm_platform {
		compatible = "amlogic, aml-pcm";
	};
	spdif_codec: spdif_codec{
		#sound-dai-cells = <0>;
		compatible = "amlogic, aml-spdif-codec";
		pinctrl-names = "audio_spdif";
		pinctrl-0 = <&audio_spdif_pins>;
	};
	pcm_codec: pcm_codec{
		#sound-dai-cells = <0>;
		compatible = "amlogic, pcm2BT-codec";
	};
	/* endof AUDIO MESON DEVICES */


	/* AUDIO board specific */
	dummy_codec:dummy{
		#sound-dai-cells = <0>;

github.com

CoreELEC/linux-amlogic/blob/amlogic-4.9-19/arch/arm64/boot/dts/amlogic/mesongxl.dtsi#L1012-L1017


	audio_spdif_pins:audio_spdif {
		mux {
			groups = "spdif_out";
			function = "spdif_out";
		};
	};

github.com

CoreELEC/linux-amlogic/blob/amlogic-4.9-19/drivers/amlogic/pinctrl/pinctrl-meson-gxl.c#L225-L226


/*spdif_out*/
static const unsigned int spdif_out_pins[] = { GPIOH_4 };

So I think maybe this can work:

	audio_spdif_pins:audio_spdif {
		mux {
			groups = "spdif_out_ao";
			function = "spdif_out_ao";
		};
	};

github.com

CoreELEC/linux-amlogic/blob/amlogic-4.9-19/drivers/amlogic/pinctrl/pinctrl-meson-gxl.c#L760-L761


/*spdif_out_ao*/
static const unsigned int spdid_out_ao9_pins[] = { GPIOAO_9 };

Maybe…

Portisch · 28 April 2021 14:26

So maybe:

fdtput -t s gxl_p212_1g.dtb /pinctrl@4b0/audio_spdif_out_pins/mux groups "spdif_out_ao"
fdtput -t s gxl_p212_1g.dtb /pinctrl@4b0/audio_spdif_out_pins/mux function "spdif_out_ao"

Puff · 10 May 2021 05:38

@Portisch thank you for all the help! I am learning more about device trees.
I wasn’t able to run the fdtput command directly.
dtname command returns gxl_p212_1g

fdtput -t s gxl_p212_1g.dtb /pinctrl@4b0/audio_spdif_out_pins/mux groups “spdif_out_ao”
Couldn’t open blob from ‘gxl_p212_1g.dtb’: No such file or directory

so I tried : mount -o remount,rw /flash
fdtput -t s /flash/dtb.img /pinctrl@4b0/audio_spdif_out_pins/mux groups “spdif_out_ao”
fdtput -t s /flash/dtb.img /pinctrl@4b0/audio_spdif_out_pins/mux function “spdif_out_ao”

That didn’t work. It removed the ALSA: AML-MESONAUDIO, HDMI I only had pulse: default,bluetooth Audio (PULSEAUDIO).

I modified the dtb to :
audio_spdif {
phandle = <0x8c>;
mux {
groups = “spdid_out_ao”;
function = “spdid_out_ao”;
};
};
It didn’t work, I tried the following and didn’t work either
audio_spdif {
phandle = <0x8c>;
mux {
groups = “spdid_out_ao9”;
function = “spdid_out_ao9”;
};
};

Any more hints? Specially on the No such file or directory when running fdtput?