atmel_serial: RS485: receiving enabled when sending data
By default the atmel_serial driver in RS485 mode disables receiving data until
all data in the send buffer has been sent. This flag allows to receive data
even whilst sending data.
Signed-off-by: Bernhard Roth <br@pwrnet.de>
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt
index a493238..c8878f8 100644
--- a/Documentation/serial/serial-rs485.txt
+++ b/Documentation/serial/serial-rs485.txt
@@ -104,6 +104,9 @@
rs485conf.flags |= SER_RS485_RTS_AFTER_SEND;
rs485conf.delay_rts_after_send = ...;
+ /* Set this flag if you want to receive data even whilst sending data */
+ rs485conf.flags |= SER_RS485_RX_DURING_TX;
+
if (ioctl (fd, TIOCSRS485, &rs485conf) < 0) {
/* Error handling. See errno. */
}
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index af9b781..c7232a9 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -339,7 +339,8 @@
/* Disable interrupts */
UART_PUT_IDR(port, atmel_port->tx_done_mask);
- if (atmel_port->rs485.flags & SER_RS485_ENABLED)
+ if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
+ !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
atmel_start_rx(port);
}
@@ -356,7 +357,8 @@
really need this.*/
return;
- if (atmel_port->rs485.flags & SER_RS485_ENABLED)
+ if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
+ !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
atmel_stop_rx(port);
/* re-enable PDC transmit */
@@ -680,7 +682,8 @@
/* Enable interrupts */
UART_PUT_IER(port, atmel_port->tx_done_mask);
} else {
- if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
+ if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
+ !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) {
/* DMA done, stop TX, start RX for RS485 */
atmel_start_rx(port);
}
diff --git a/include/linux/serial.h b/include/linux/serial.h
index ef91406..97ff8e2 100644
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -211,6 +211,7 @@
#define SER_RS485_RTS_ON_SEND (1 << 1)
#define SER_RS485_RTS_AFTER_SEND (1 << 2)
#define SER_RS485_RTS_BEFORE_SEND (1 << 3)
+#define SER_RS485_RX_DURING_TX (1 << 4)
__u32 delay_rts_before_send; /* Milliseconds */
__u32 delay_rts_after_send; /* Milliseconds */
__u32 padding[5]; /* Memory is cheap, new structs