tty/serial: atmel: Add is_half_duplex helper

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

Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 41b728d..55ca341 100644 (file)
--- 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 +615,9 @@ 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)
+       if (atmel_uart_is_half_duplex(port))
                atmel_start_rx(port);
+
 }
 
 /*
@@ -628,9 +634,7 @@ 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 +932,7 @@ 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);
        }
@@ -1512,9 +1514,7 @@ 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);
                }