serial: sh-sci: per-port modem control.

The bulk of the ports do not support any sort of modem control, so
blindly twiddling the MCE bit doesn't accomplish much. We now require
ports to manually specify which line supports modem control signals.

While at it, tidy up the RTS/CTSIO handling in SCSPTR parts so it's a bit
more obvious what's going on (and without clobbering other configurations
in the process).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
index 369273a..15b1bdc 100644
--- a/include/linux/serial_sci.h
+++ b/include/linux/serial_sci.h
@@ -49,6 +49,10 @@
 
 #define SCIF_DEFAULT_ERROR_MASK (SCIF_PER | SCIF_FER | SCIF_ER | SCIF_BRK)
 
+/* SCSPTR, optional */
+#define SCSPTR_RTSIO	(1 << 7)
+#define SCSPTR_CTSIO	(1 << 5)
+
 /* Offsets into the sci_port->irqs array */
 enum {
 	SCIx_ERI_IRQ,
@@ -109,6 +113,11 @@
 };
 
 /*
+ * Port-specific capabilities
+ */
+#define SCIx_HAVE_RTSCTS	(1 << 0)
+
+/*
  * Platform device specific platform_data struct
  */
 struct plat_sci_port {
@@ -116,6 +125,7 @@
 	unsigned int	irqs[SCIx_NR_IRQS];	/* ERI, RXI, TXI, BRI */
 	unsigned int	type;			/* SCI / SCIF / IRDA */
 	upf_t		flags;			/* UPF_* flags */
+	unsigned long	capabilities;		/* Port features/capabilities */
 
 	unsigned int	scbrr_algo_id;		/* SCBRR calculation algo */
 	unsigned int	scscr;			/* SCSCR initialization */