[PATCH 1/2] tty/serial: atmel: Add is_half_duplex helper

From: Razvan Stefanescu
Date: Fri Mar 15 2019 - 05:23:45 EST


Use a helper function to check that a port needs to use half duplex
communication, replacing several occurrences of multi-line bit checking.

Signed-off-by: Razvan Stefanescu <razvan.stefanescu@xxxxxxxxxxxxx>
---
drivers/tty/serial/atmel_serial.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 05147fe24343..a6577b1c4461 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -231,6 +231,13 @@ static inline void atmel_uart_write_char(struct uart_port *port, u8 value)
__raw_writeb(value, port->membase + ATMEL_US_THR);
}

+static inline int atmel_uart_is_half_duplex(struct uart_port *port)
+{
+ return ((port->rs485.flags & SER_RS485_ENABLED) &&
+ !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
+ (port->iso7816.flags & SER_ISO7816_ENABLED);
+}
+
#ifdef CONFIG_SERIAL_ATMEL_PDC
static bool atmel_use_pdc_rx(struct uart_port *port)
{
@@ -608,10 +615,10 @@ static void atmel_stop_tx(struct uart_port *port)
/* Disable interrupts */
atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);

- if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED)
- atmel_start_rx(port);
+ if (atmel_uart_is_half_duplex(port))
+ if (!atomic_read(&atmel_port->tasklet_shutdown))
+ atmel_start_rx(port);
+
}

/*
@@ -628,9 +635,7 @@ static void atmel_start_tx(struct uart_port *port)
return;

if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))
- if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED)
+ if (atmel_uart_is_half_duplex(port))
atmel_stop_rx(port);

if (atmel_use_pdc_tx(port))
@@ -928,9 +933,7 @@ static void atmel_complete_tx_dma(void *arg)
*/
if (!uart_circ_empty(xmit))
atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
- else if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED) {
+ else if (atmel_uart_is_half_duplex(port)) {
/* DMA done, stop TX, start RX for RS485 */
atmel_start_rx(port);
}
@@ -1508,9 +1511,7 @@ static void atmel_tx_pdc(struct uart_port *port)
atmel_uart_writel(port, ATMEL_US_IER,
atmel_port->tx_done_mask);
} else {
- if (((port->rs485.flags & SER_RS485_ENABLED) &&
- !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
- port->iso7816.flags & SER_ISO7816_ENABLED) {
+ if (atmel_uart_is_half_duplex(port)) {
/* DMA done, stop TX, start RX for RS485 */
atmel_start_rx(port);
}
--
2.19.1