On 3/2/21 2:15 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 <de...@eaxlabs.cz>
> ---
> drivers/tty/serial/stm32-usart.c | 11 ++++++++++-
> drivers/tty/serial/stm32-usart.h | 5 +++++
> 2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/stm32-usart.c
> b/drivers/tty/serial/stm32-usart.c
> index b3675cf25a69..d390f7da1441 100644
> --- a/drivers/tty/serial/stm32-usart.c
> +++ b/drivers/tty/serial/stm32-usart.c
> @@ -644,6 +644,12 @@ static int stm32_usart_startup(struct uart_port *port)
> if (ret)
> return ret;
>
> + if (stm32_port->swap) {
> + val = readl_relaxed(port->membase + ofs->cr2);
> + val |= USART_CR2_SWAP;
> + writel_relaxed(val, port->membase + ofs->cr2);
> + }
> +
> /* RX FIFO Flush */
> if (ofs->rqr != UNDEF_REG)
> stm32_usart_set_bits(port, ofs->rqr, USART_RQR_RXFRQ);
> @@ -758,7 +764,7 @@ 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;
> cr3 = readl_relaxed(port->membase + ofs->cr3);
> cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE
> | USART_CR3_TXFTCFG_MASK;
> @@ -1006,6 +1012,9 @@ static int stm32_usart_init_port(struct stm32_port
> *stm32port,
> return stm32port->wakeirq ? : -ENODEV;
> }
>
> + stm32port->swap = stm32port->info->cfg.has_swap &&
> + of_property_read_bool(pdev->dev.of_node, "rx-tx-swap");
> +
> stm32port->fifoen = stm32port->info->cfg.has_fifo;
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> diff --git a/drivers/tty/serial/stm32-usart.h
> b/drivers/tty/serial/stm32-usart.h
> index cb4f327c46db..bd18dd1c1bcd 100644
> --- a/drivers/tty/serial/stm32-usart.h
> +++ b/drivers/tty/serial/stm32-usart.h
> @@ -25,6 +25,7 @@ struct stm32_usart_offsets {
> struct stm32_usart_config {
> u8 uart_enable_bit; /* USART_CR1_UE */
> bool has_7bits_data;
> + bool has_swap;
> bool has_wakeup;
> bool has_fifo;
> int fifosize;
> @@ -55,6 +56,7 @@ struct stm32_usart_info stm32f4_info = {
> .cfg = {
> .uart_enable_bit = 13,
> .has_7bits_data = false,
> + .has_swap = false,
Hi Martin,
Only one minor comment from me here. No need to add a false (zero)
initialization in this struct. I'm not sure why this is the case for the
has_7bits_data here...
With that fixed, you can add my:
Acked-by: Fabrice Gasnier <fabrice.gasn...@foss.st.com>
Thanks for your patch,
Best Regards,
Fabrice
> .fifosize = 1,
> }
> };
> @@ -76,6 +78,7 @@ struct stm32_usart_info stm32f7_info = {
> .cfg = {
> .uart_enable_bit = 0,
> .has_7bits_data = true,
> + .has_swap = true,
> .fifosize = 1,
> }
> };
> @@ -97,6 +100,7 @@ struct stm32_usart_info stm32h7_info = {
> .cfg = {
> .uart_enable_bit = 0,
> .has_7bits_data = true,
> + .has_swap = true,
> .has_wakeup = true,
> .has_fifo = true,
> .fifosize = 16,
> @@ -271,6 +275,7 @@ struct stm32_port {
> int last_res;
> bool tx_dma_busy; /* dma tx busy */
> bool hw_flow_control;
> + bool swap; /* swap RX & TX pins */
> bool fifoen;
> int wakeirq;
> int rdr_mask; /* receive data register mask */
>
