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From: Marek Vasut <marex@denx.de>
To: linux-serial@vger.kernel.org
Cc: Marek Vasut <marex@denx.de>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Erwan Le Ray <erwan.leray@foss.st.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jean Philippe Romain <jean-philippe.romain@foss.st.com>,
	Valentin Caron <valentin.caron@foss.st.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-stm32@st-md-mailman.stormreply.com
Subject: [PATCH 1/2] serial: stm32: Factor out GPIO RTS toggling into separate function
Date: Sat, 30 Apr 2022 18:28:44 +0200	[thread overview]
Message-ID: <20220430162845.244655-1-marex@denx.de> (raw)

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
---
 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


             reply	other threads:[~2022-04-30 16:28 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-30 16:28 Marek Vasut [this message]
2022-04-30 16:28 ` [PATCH 2/2] serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode Marek Vasut
2022-05-02  8:44   ` Erwan LE RAY
2022-05-02 11:13     ` Marek Vasut
2022-05-04 15:54       ` Erwan LE RAY
2022-05-05  1:02         ` Marek Vasut

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