Configure UART

Gangadhar Gangu

Hi,

I want to configure one of the UARTs with below values. I could not find these properties in am33xx.dtsi or Documentation/devicetree/bindings/serial/omap_serial.txt

I could change only baudrate by using clock-frequency = <921600>; in dts file.

Please tell me the file where I can change the values.

UA_8_DATA_BITS, /**< Size of data */
UA_1_STOP_BIT, /**< Number of stop bits */
UA_NO_PARITY, /**< Byte parity */
57600u, /**< Bit rate of uart channel */
UA_HANDSHAKE_NONE, /**< Handshake type */

I also want to do same configuration in Uboot?

Regards,

Gangadhar

over 11 years ago

0 Miroslav Kiradzhiyski XID over 11 years ago

TI__Mastermind 25235 points

Hi,

Is this the serial console port or another one?

Best regards,
Miroslav

0 Gangadhar Gangu over 11 years ago in reply to Miroslav Kiradzhiyski XID

Expert 1865 points

Hi Miroslav,

This is not console port.

Regards,

Gangadhar

0 Miroslav Kiradzhiyski XID over 11 years ago

TI__Mastermind 25235 points

You can use the cfsetispeed() and cfsetospeed() functions from termios in a user-space application:

http://en.wikibooks.org/wiki/Serial_Programming/termios

You can also use the "stty" command. Here is a useful reading about the UART serial port: http://www.tldp.org/HOWTO/Serial-HOWTO.html

Regarding U-Boot, the serial driver is inside <u-boot_dir>/drivers/serial.serial.c.

Best regards,
Miroslav

0 Gangadhar Gangu over 11 years ago in reply to Miroslav Kiradzhiyski XID

Expert 1865 points

In linux changed clock property value in dts file. For uboot used setbrg and start() functions in drivers/serial/serial.c,

did reset of required uarts in arch/arm/cpu/ armv7/am335x/board.c

and also made changes in drivers/serial/serial_ns16550.c and got it working.

Regards,

Gangadhar

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Configure UART