serial: sh-sci: modify sci_break_ctl()

SCIF modules which have SCSPTR can output the break signal. Now that we
have a way of determining port features/capabilities, add trivial break
control via SCSPTR support. Tested on sh7757lcr.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 26 insertions, 4 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 3158e17b665..3e471fc1299 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1564,10 +1564,32 @@ static void sci_enable_ms(struct uart_port *port)
 
 static void sci_break_ctl(struct uart_port *port, int break_state)
 {
-        /*
-         * Not supported by hardware. Most parts couple break and rx
-         * interrupts together, with break detection always enabled.
-         */
+        struct sci_port *s = to_sci_port(port);
+        unsigned short scscr, scsptr;
+
+        switch (s->cfg->regtype) {
+        case SCIx_SH4_SCIF_REGTYPE:
+                scsptr = serial_port_in(port, SCSPTR);
+                scscr = serial_port_in(port, SCSCR);
+
+                if (break_state == -1) {
+                        scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
+                        scscr &= ~SCSCR_TE;
+                } else {
+                        scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
+                        scscr |= SCSCR_TE;
+                }
+
+                serial_port_out(port, SCSPTR, scsptr);
+                serial_port_out(port, SCSCR, scscr);
+                break;
+        default:
+                /*
+                 * Not supported by hardware. Most parts couple break and rx
+                 * interrupts together, with break detection always enabled.
+                 */
+                break;
+        }
 }
 
 #ifdef CONFIG_SERIAL_SH_SCI_DMA