From: Marek Vasut <marex@denx.de>
Date: Sat, 30 Apr 2022 16:28:44 +0000 (+0200)
Subject: serial: stm32: Factor out GPIO RTS toggling into separate function
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3bcea529b295a993b1b05db63f245ae8030c5acf;p=linux.git

serial: stm32: Factor out GPIO RTS toggling into separate function

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>
---

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);
 }