Hardware flow control support for Serial API

[hasnainvirk]

Description

• Priority: Blocker

SLIP driver uses hardware flow control. mbed OS 3 HAL had hooks for that in the Target HAL for FRDM-K64F. For example:

ARMmbed/mbed-hal-ksdk-mcu@9bfcfd0

ARMmbed/mbed-hal-frdm-k64f@77042cc

For morpheous integration, such changes in HAL are needed. Please look into this.

@0xc0170 @screamerbg @SeppoTakalo

[0xc0170]

It shall be compatible (the mbed HAL API its the same for this feature). The mbed 3 version uses KSDK1.0, and we have here 2.0 version, that API for UART might have changed.

@hasnainvirk Can you backport it here?

[sg-]

@bogdanm

[bogdanm]

Looking at https://github.com/mbedmicro/mbed/blob/master/hal/targets/hal/TARGET_Freescale/TARGET_KSDK2_MCUS/TARGET_K64F/drivers/fsl_uart.h, I can't see any functions related to the flow control settings. @0xc0170, do you know anything about this?

[bogdanm]

https://community.nxp.com/thread/352310 😞

[bogdanm]

@hasnainvirk, can you check if #2140 fixes your problems?

[hasnainvirk]

@bogdanm I get this kind of errors:
sl0(): transmit queue 0 timed out
sl0: transmit timed out, bad line quality ?

This is the trace on raspberry pi side. I have checked and verified the pin mapping. That is correct. I am using baudrate 921600

[hasnainvirk]

@bogdanm @SeppoTakalo I have a fix for your 'fix'. But I can't make push to k64f_flow_control branch as I don't have permissions.

[bogdanm]

Closing this, since it was fixed by #2140 according to @hasnainvirk.