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>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 3158e17b665cc6fb1c5eb214674610bd42611235..3e471fc12991e99dc505c4e952c65e5a661d44a9 100644 (file)
--- 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

diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
index 78779074f6e8ff9b4f0d95fe9575e008eb0d1c81..eb763adf98158d113655233b21e7f9fe1ebd2cce 100644 (file)
--- a/include/linux/serial_sci.h
+++ b/include/linux/serial_sci.h
@@ -52,6 +52,8 @@ enum {
 /* SCSPTR, optional */
 #define SCSPTR_RTSIO   (1 << 7)
 #define SCSPTR_CTSIO   (1 << 5)
+#define SCSPTR_SPB2IO  (1 << 1)
+#define SCSPTR_SPB2DT  (1 << 0)
 
 /* Offsets into the sci_port->irqs array */
 enum {