diff mbox series

[v2,04/12] serial: 8250_dwlib: Implement SW half duplex support

Message ID 20220404082912.6885-5-ilpo.jarvinen@linux.intel.com
State New
Headers show
Series Add RS485 support to DW UART | expand

Commit Message

Ilpo Järvinen April 4, 2022, 8:29 a.m. UTC 
This patch enables support for SW half-duplex mode using em485.

Cc: Eric Tremblay <etremblay@distech-controls.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/tty/serial/8250/8250_dwlib.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/tty/serial/8250/8250_dwlib.c b/drivers/tty/serial/8250/8250_dwlib.c
index 08432e2fe511..04852af4c024 100644
--- a/drivers/tty/serial/8250/8250_dwlib.c
+++ b/drivers/tty/serial/8250/8250_dwlib.c
@@ -172,8 +172,14 @@  void dw8250_setup_port(struct uart_port *p)
 	u32 reg;
 
 	d->hw_rs485_support = dw8250_detect_rs485_hw(p);
-	if (d->hw_rs485_support)
+	if (d->hw_rs485_support) {
 		p->rs485_config = dw8250_rs485_config;
+	} else {
+		p->rs485_config = serial8250_em485_config;
+		up->rs485_start_tx = serial8250_em485_start_tx;
+		up->rs485_stop_tx = serial8250_em485_stop_tx;
+	}
+	up->capabilities |= UART_CAP_NOTEMT;
 
 	/*
 	 * If the Component Version Register returns zero, we know that
@@ -205,7 +211,7 @@  void dw8250_setup_port(struct uart_port *p)
 		p->type = PORT_16550A;
 		p->flags |= UPF_FIXED_TYPE;
 		p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
-		up->capabilities = UART_CAP_FIFO;
+		up->capabilities = UART_CAP_FIFO | UART_CAP_NOTEMT;
 	}
 
 	if (reg & DW_UART_CPR_AFCE_MODE)