diff options
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 680d34af71f9..46deaaec836d 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1113,10 +1113,23 @@ static unsigned int sci_tx_empty(struct uart_port *port) * 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) |