[PATCH 5.15 111/120] serial: stm32: Factor out GPIO RTS toggling into separate function

Greg Kroah-Hartman
2022-12-05T19:41:25Z

From: Marek Vasut <marex@denx.de>

[ Upstream commit 3bcea529b295a993b1b05db63f245ae8030c5acf ]

Pull out the GPIO RTS enable and disable handling into separate function.
Limit the scope of GPIO RTS toggling only to GPIO emulated RS485 too.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Erwan Le Ray <erwan.leray@foss.st.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jean Philippe Romain <jean-philippe.romain@foss.st.com>
Cc: Valentin Caron <valentin.caron@foss.st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/20220430162845.244655-1-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/stm32-usart.c | 61 ++++++++++++++++++++------------
1 file changed, 38 insertions(+), 23 deletions(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index fc166cc2c856..f2cef5f7ae5a 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -325,6 +325,42 @@ static void stm32_usart_tx_interrupt_disable(struct uart_port *port)
stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
}

+static void stm32_usart_rs485_rts_enable(struct uart_port *port)
+{
+ struct stm32_port *stm32_port = to_stm32_port(port);
+ struct serial_rs485 *rs485conf = &port->rs485;
+
+ if (stm32_port->hw_flow_control ||
+ !(rs485conf->flags & SER_RS485_ENABLED))
+ return;
+
+ if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl | TIOCM_RTS);
+ } else {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl & ~TIOCM_RTS);
+ }
+}
+
+static void stm32_usart_rs485_rts_disable(struct uart_port *port)
+{
+ struct stm32_port *stm32_port = to_stm32_port(port);
+ struct serial_rs485 *rs485conf = &port->rs485;
+
+ if (stm32_port->hw_flow_control ||
+ !(rs485conf->flags & SER_RS485_ENABLED))
+ return;
+
+ if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl & ~TIOCM_RTS);
+ } else {
+ mctrl_gpio_set(stm32_port->gpios,
+ stm32_port->port.mctrl | TIOCM_RTS);
+ }
+}
+
static void stm32_usart_transmit_chars_pio(struct uart_port *port)
{
struct stm32_port *stm32_port = to_stm32_port(port);
@@ -566,41 +602,20 @@ static void stm32_usart_disable_ms(struct uart_port *port)
/* Transmit stop */
static void stm32_usart_stop_tx(struct uart_port *port)
{
- struct stm32_port *stm32_port = to_stm32_port(port);
- struct serial_rs485 *rs485conf = &port->rs485;
-
stm32_usart_tx_interrupt_disable(port);

- if (rs485conf->flags & SER_RS485_ENABLED) {
- if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl & ~TIOCM_RTS);
- } else {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl | TIOCM_RTS);
- }
- }
+ stm32_usart_rs485_rts_disable(port);
}

/* There are probably characters waiting to be transmitted. */
static void stm32_usart_start_tx(struct uart_port *port)
{
- struct stm32_port *stm32_port = to_stm32_port(port);
- struct serial_rs485 *rs485conf = &port->rs485;
struct circ_buf *xmit = &port->state->xmit;

if (uart_circ_empty(xmit) && !port->x_char)
return;

- if (rs485conf->flags & SER_RS485_ENABLED) {
- if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl | TIOCM_RTS);
- } else {
- mctrl_gpio_set(stm32_port->gpios,
- stm32_port->port.mctrl & ~TIOCM_RTS);
- }
- }
+ stm32_usart_rs485_rts_enable(port);

stm32_usart_transmit_chars(port);
}
--
2.35.1