Linux/AM4377: UART pinmux settings

Rudy Coppens

Part Number: AM4377
Other Parts Discussed in Thread: AM4372

Tool/software: Linux

Hi all,

I am using a Variscite VAR-SOM-AM43 with a AM437x based processor. [url=http://www.variscite.com/images/stories/DataSheets/VAR-SOM-AM43/VAR-SOM-AM43_Rev1_1_Datasheet_v1_3.pdf] "Datasheet VAR-SOM-43" [/url]
I would like to use the UART communication on it with pin 111 and 119, but I don't know how to map the right function to the right pin in Linux. There needs to be a file how to set the MUX right, but I can't find this file.

Regards,
Rudy

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

This is a third-party product. TI does not have board information for this product. Please contact the board manufacturer for support.

0 Rudy Coppens over 6 years ago in reply to Biser Gatchev-XID

Prodigy 20 points

Yes, I know but they respond very slow and I think it is a Linux device tree problem.
Can you have a look on my code if I did the right configuration.

uart1_pins_default: uart1_pins_default {
pinctrl-single,pins = <
0x180 (PIN_INPUT_PULLUP | MUX_MODE0) /* uart1_rxd.d_can1_tx */
0x184 (PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* uart1_txd.d_can1_rx */
>;
};

&uart1 {
status = "okay";
pinctrl-names = "default", "sleep";
pinctrl-0 = <&uart1_pins_default>;
//pinctrl-1 = <&uart1_pins_sleep>;
};

0 Cvetolin Shulev-XID over 6 years ago in reply to Rudy Coppens

TI__Guru 65405 points

Hi Rudy,

I found some mismatch with the uart1 address offset. As it is described in the TRM section 7.3.1.142 CTRL_CONF_UART1_RXD Register the offset should be 980h instead of 180h and 984h instead 184h.
www.ti.com/.../spruhl7h.pdf
Also you can use as reference am4372.dtsi file.

BR
Tsvetolin Shulev

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Linux/AM4377: UART pinmux settings