[PATCH 3/3] serial: of_serial: Handle hw-flow-control property

Heikki Krogerus
2013-03-25T11:34:57Z

This will add support for hardware flow control. It is
limited to be used only with 8250 driver.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
.../devicetree/bindings/tty/serial/of-serial.txt | 1 +
drivers/tty/serial/of_serial.c | 13 ++++++++++---
2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/tty/serial/of-serial.txt b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
index c13f0ce..e775c93 100644
--- a/Documentation/devicetree/bindings/tty/serial/of-serial.txt
+++ b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
@@ -34,6 +34,7 @@ Optional properties:
- no-loopback-test: set to indicate that the port does not implements loopback
test mode
- fifo-size: the fifo size of the UART.
+- hw-flow-control: support for hardware flow control

Example:

diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 267711b..2933112 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -14,7 +14,6 @@
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/serial_core.h>
-#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
@@ -22,6 +21,8 @@
#include <linux/nwpserial.h>
#include <linux/clk.h>

+#include "8250/8250.h"
+
struct of_serial_info {
struct clk *clk;
int type;
@@ -171,11 +172,17 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
#ifdef CONFIG_SERIAL_8250
case PORT_8250 ... PORT_MAX_8250:
{
- /* For now the of bindings don't support the extra
- 8250 specific bits */
struct uart_8250_port port8250;
memset(&port8250, 0, sizeof(port8250));
port8250.port = port;
+
+ if (port.fifosize)
+ port8250.capabilities = UART_CAP_FIFO;
+
+ if (of_property_read_bool(ofdev->dev.of_node,
+ "hw-flow-control"))
+ port8250.capabilities |= UART_CAP_AFE;
+
ret = serial8250_register_8250_port(&port8250);
break;
}
--
1.7.10.4