UART0 RTS/CTS is not working as expected in am3352

Thiru N

Intellectual 330 points

Other Parts Discussed in Thread: AM3352

Hi All,

I'm working on am3352 sitara processor based custom designed board using SDK-8.0

The am335x UART0 is connected to GSM module with Hardware flow control

I've configured in Device tree to enable Hard ware flow control as below

uart0_pins: pinmux_uart0_pins {
    pinctrl-single,pins = <
        0x168 (PIN_INPUT | MUX_MODE0)             /* uart0_ctsn.uart0_ctsn */
        0x16C (PIN_OUTPUT_PULLDOWN | MUX_MODE0)    /* uart0_rtsn.uart0_rtsn */
        0x170 (PIN_INPUT_PULLUP | MUX_MODE0)                /* uart0_rxd.uart0_rxd */
        0x174 (PIN_OUTPUT_PULLDOWN | MUX_MODE0)    /* uart0_txd.uart0_txd */
    >;
};

The hardware flow control is not working(Not toggling RTS and CTS) as expected, is i'm missing any configurations or setting ?

Please suggest ASAP

Thanks and Regards,

Thiru N

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

I will forward this to the software team.

0 Yordan Kovachev over 9 years ago

TI__Guru**** 161600 points

Hi,

The hw flow control is supported in the omap-serial driver in sdk8.0, see serial_omap_startup(). You should just choose the hw flow control option, whet starting the serial connection. Test with the minicom options.

Verify that the following dts settings have taken effect:
0x168 (PIN_INPUT | MUX_MODE0) /* uart0_ctsn.uart0_ctsn */
0x16C (PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* uart0_rtsn.uart0_rtsn */
You can use devmem2 to read the values of the corresponding padconf registers.

Also have a look at the following mail thread:
lists.infradead.org/.../125092.html
It contains quite useful information.

Hope this helps.

Best Regards,
Yordan

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UART0 RTS/CTS is not working as expected in am3352