Add loopback function support for Spreadtrum serial controller.
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
drivers/tty/serial/sprd_serial.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
index 73d71a4..85fc57c 100644
--- a/drivers/tty/serial/sprd_serial.c
+++ b/drivers/tty/serial/sprd_serial.c
@@ -79,6 +79,7 @@
/* control register 1 */
#define SPRD_CTL1 0x001C
#define SPRD_DMA_EN BIT(15)
+#define SPRD_LOOPBACK_EN BIT(14)
#define RX_HW_FLOW_CTL_THLD BIT(6)
#define RX_HW_FLOW_CTL_EN BIT(7)
#define TX_HW_FLOW_CTL_EN BIT(8)
@@ -164,7 +165,14 @@ static unsigned int sprd_get_mctrl(struct uart_port *port)
static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
- /* nothing to do */
+ u32 val = serial_in(port, SPRD_CTL1);
+
+ if (mctrl & TIOCM_LOOP)
+ val |= SPRD_LOOPBACK_EN;
+ else
+ val &= ~SPRD_LOOPBACK_EN;
+
+ serial_out(port, SPRD_CTL1, val);
}
static void sprd_stop_rx(struct uart_port *port)
--
1.7.9.5
