serial: sh-sci: Add support for loopback mode.
This plugs in loopback control for SCFCR-enabled ports and plugs it in
via the TIOCM_LOOP control, as others do.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 680d34a..46deaae 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1113,10 +1113,23 @@
* handled via the ->init_pins() op, which is a bit of a one-way street,
* lacking any ability to defer pin control -- this will later be
* converted over to the GPIO framework).
+ *
+ * Other modes (such as loopback) are supported generically on certain
+ * port types, but not others. For these it's sufficient to test for the
+ * existence of the support register and simply ignore the port type.
*/
static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
- /* Nothing to do here. */
+ if (mctrl & TIOCM_LOOP) {
+ struct plat_sci_reg *reg;
+
+ /*
+ * Standard loopback mode for SCFCR ports.
+ */
+ reg = sci_getreg(port, SCFCR);
+ if (reg->size)
+ sci_out(port, SCFCR, sci_in(port, SCFCR) | 1);
+ }
}
static unsigned int sci_get_mctrl(struct uart_port *port)