diff options
Diffstat (limited to 'drivers/tty/serial/sprd_serial.c')
| -rw-r--r-- | drivers/tty/serial/sprd_serial.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c index 284709f61831..de077d7b5f00 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) |