serial: sirf: add serial loopback function support
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c
index a500721..0e43799 100644
--- a/drivers/tty/serial/sirfsoc_uart.c
+++ b/drivers/tty/serial/sirfsoc_uart.c
@@ -108,6 +108,26 @@
unsigned int val = assert ? SIRFUART_AFC_CTRL_RX_THD : 0x0;
unsigned int current_val;
+ if (mctrl & TIOCM_LOOP) {
+ if (sirfport->uart_reg->uart_type == SIRF_REAL_UART)
+ wr_regl(port, ureg->sirfsoc_line_ctrl,
+ rd_regl(port, ureg->sirfsoc_line_ctrl) |
+ SIRFUART_LOOP_BACK);
+ else
+ wr_regl(port, ureg->sirfsoc_mode1,
+ rd_regl(port, ureg->sirfsoc_mode1) |
+ SIRFSOC_USP_LOOP_BACK_CTRL);
+ } else {
+ if (sirfport->uart_reg->uart_type == SIRF_REAL_UART)
+ wr_regl(port, ureg->sirfsoc_line_ctrl,
+ rd_regl(port, ureg->sirfsoc_line_ctrl) &
+ ~SIRFUART_LOOP_BACK);
+ else
+ wr_regl(port, ureg->sirfsoc_mode1,
+ rd_regl(port, ureg->sirfsoc_mode1) &
+ ~SIRFSOC_USP_LOOP_BACK_CTRL);
+ }
+
if (!sirfport->hw_flow_ctrl || !sirfport->ms_enabled)
return;
if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
diff --git a/drivers/tty/serial/sirfsoc_uart.h b/drivers/tty/serial/sirfsoc_uart.h
index b49c23a..3ab3141 100644
--- a/drivers/tty/serial/sirfsoc_uart.h
+++ b/drivers/tty/serial/sirfsoc_uart.h
@@ -322,7 +322,7 @@
#define SIRFSOC_USP_RX_CLK_DIVISOR_OFFSET 24
#define SIRFSOC_USP_ASYNC_DIV2_MASK 0x3f
#define SIRFSOC_USP_ASYNC_DIV2_OFFSET 16
-
+#define SIRFSOC_USP_LOOP_BACK_CTRL BIT(2)
/* USP-UART Common */
#define SIRFSOC_UART_RX_TIMEOUT(br, to) (((br) * (((to) + 999) / 1000)) / 1000)
#define SIRFUART_RECV_TIMEOUT_VALUE(x) \