[PATCH 1/2] serial: stm32: Factor out GPIO RTS toggling into separate function
Marek Vasut
marex at denx.de
Sat Apr 30 09:28:44 PDT 2022
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 at denx.de>
Cc: Alexandre Torgue <alexandre.torgue at foss.st.com>
Cc: Erwan Le Ray <erwan.leray at foss.st.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Jean Philippe Romain <jean-philippe.romain at foss.st.com>
Cc: Valentin Caron <valentin.caron at foss.st.com>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-stm32 at st-md-mailman.stormreply.com
To: linux-serial at vger.kernel.org
---
drivers/tty/serial/stm32-usart.c | 59 ++++++++++++++++++++------------
1 file changed, 38 insertions(+), 21 deletions(-)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index f75691e727295..224f359c6051e 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -442,6 +442,42 @@ 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);
@@ -713,43 +749,24 @@ static void stm32_usart_disable_ms(struct uart_port *port)
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;
const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
stm32_usart_tx_interrupt_disable(port);
if (stm32_usart_tx_dma_started(stm32_port) && stm32_usart_tx_dma_enabled(stm32_port))
stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
- 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
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