On 3/1/21 11:40 PM, Martin DEVERA wrote: > On 3/1/21 11:28 AM, Fabrice Gasnier wrote: >> On 2/27/21 5:41 PM, Martin Devera wrote: >>> STM32 F7/H7 usarts supports RX & TX pin swapping. >>> Add option to turn it on. >>> Tested on STM32MP157. >>> >>> Signed-off-by: Martin Devera <devik@xxxxxxxxxx> >>> --- >>> drivers/tty/serial/stm32-usart.c | 3 ++- >>> drivers/tty/serial/stm32-usart.h | 1 + >>> 2 files changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/tty/serial/stm32-usart.c >>> b/drivers/tty/serial/stm32-usart.c >>> index b3675cf25a69..3650c8798061 100644 >>> --- a/drivers/tty/serial/stm32-usart.c >>> +++ b/drivers/tty/serial/stm32-usart.c >>> @@ -758,7 +758,7 @@ static void stm32_usart_set_termios(struct >>> uart_port *port, >>> cr1 = USART_CR1_TE | USART_CR1_RE; >>> if (stm32_port->fifoen) >>> cr1 |= USART_CR1_FIFOEN; >>> - cr2 = 0; >>> + cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; >> Hi Martin, >> >> Same could be done in the startup routine, that enables the port for >> reception (as described in Documentation/driver-api/serial/driver.rst) > Hello Fabrice, > > I already incorporated all your comments but I'm struggling with the one > above. > The code must be in stm32_usart_set_termios too, because CR2 is modified. Hi Martin, Yes, sure, > What is the reason to have it in startup() ? RX is enabled at both places. So the swap setting should be there too. > Is it because USART can be started without calling set_termios at all ? Yes, that's what the driver API expects: "startup(port)" ... "Enable the port for reception." Best Regards, Fabrice > Like > to reuse bootloader's last settings ? > > Thanks, Martin >