ti-processor-sdk-linux-am335x-evm-02.00.01.07

Hi,

I'll take i2c2 as a reference. It is pinned out on device balls D17 & D18, and is connected to expansion header pins P9.19 & P9.20.

Its pin mux registers are on the following addresses:
I2C2_SDA (ball D18) -> pinmux register at 0x44E10978
I2C2_SCL (ball D17) -> pinmux register at 0x44E1097C

So in arch/arm/boot/dts/am335x-boneblack.dts, add the following node:
&am33xx_pinmux {
+ i2c2_pins: i2c2_pins{
+ pinctrl-single,pins = <
+ 0x178 (PIN_INPUT_PULLUP | MUX_MODE3) /*UART1_CTSN.I2C2_SDA*/
+ 0x17C (PIN_INPUT_PULLUP | MUX_MODE3) /*UART1_RTSN.I2C2_SCL*/
+ >;
+ }
nxp_hdmi_bonelt_pins: nxp_hdmi_bonelt_pins {

Make sure that no other pinctrl setting uses these pins (at 0x178 & 0x17C). Look at am335x-boneblack.dts & am335x-bone-common.dtsi

Then in arch/arm/boot/dts/am335x-boneblack.dts add:
};

+&i2c2 {
+ status = "okay";
+ pinctrl-names = "default";
+ pinctrl-0 = <&i2c2_pins>;
+};

&lcdc {
status = "okay";
};

Then you can read the documentation in Documentation/i2c/dev-interface, to see how to use the i2c-dev & dev/i2c entries in you linux fs.

You should enable the uart the same way:
1. create uartX_pins { structure to configure the uart on device balls.
2. create
&uartX {
pinctrl-names = "default";
pinctrl-0 = <&uartX_pins>;
status = "okay";
}
And your uart should be enabled.

Best Regards,
Yordan