lkml.org 
[lkml]   [2020]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/2] Add software flow control support for STM32 UART
Hi Andy,

On Mon, Apr 13, 2020 at 12:17:21PM +0300, Andy Shevchenko wrote:
> On Mon, Apr 13, 2020 at 7:06 AM <mani@kernel.org> wrote:
> >
> > From: Manivannan Sadhasivam <mani@kernel.org>
> >
> > Hello,
> >
> > This patchset adds software flow control support for STM32 UART controller.
> > This is necessary for the upcoming STM32MP1 based board called Stinger96
> > IoT-Box. On that board, a bluetooth chip is connected to one of the UART
> > controller but the CTS/RTS lines got swapped mistakenly. So in order to
> > workaround that hardware bug and also to support the usecase of using only
> > Tx/Rx pins, this patchset adds software flow control support.
> >
> > This patchset has been validated w/ Stinger96 IoT-Box connected to Murata
> > WiFi-BT combo chip.
> >
>
> I think it's a mix of terminology or so. Looking into the patches I
> found that it's required to have GPIOs for SW flow control.
> No, SW flow control does not require any additional signals, except RxD/TxD.
>

Yikes. Yes I got it wrong. 'st,hw-flow-ctrl' property confused me :)

> On top of that, it seems you adding mctrl-gpio functionality. Why
> can't you use that one? And thus no bindings needs to be updated.
>

Sure. This looks feasible. Will submit a follow up patch.

Thanks,
Mani

> > Thanks,
> > Mani
> >
> > Manivannan Sadhasivam (2):
> > dt-bindings: serial: Add binding for software flow control in STM32
> > UART
> > tty: serial: Add software flow control support for STM32 USART
> >
> > .../bindings/serial/st,stm32-uart.yaml | 15 +-
> > drivers/tty/serial/stm32-usart.c | 143 +++++++++++++++++-
> > drivers/tty/serial/stm32-usart.h | 4 +
> > 3 files changed, 155 insertions(+), 7 deletions(-)
> >
> > --
> > 2.17.1
> >
>
>
> --
> With Best Regards,
> Andy Shevchenko

\
 
 \ /
  Last update: 2020-04-16 19:38    [W:0.053 / U:1.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site