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/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 46deaae..fd60d72 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -474,8 +474,15 @@ static void sci_init_pins(struct uart_port *port, unsigned int cflag)
        if (!reg->size)
                return;
 
-       if (!(cflag & CRTSCTS))
-               sci_out(port, SCSPTR, 0x0080); /* Set RTS = 1 */
+       if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) &&
+           ((!(cflag & CRTSCTS)))) {
+               unsigned short status;
+
+               status = sci_in(port, SCSPTR);
+               status &= ~SCSPTR_CTSIO;
+               status |= SCSPTR_RTSIO;
+               sci_out(port, SCSPTR, status); /* Set RTS = 1 */
+       }
 }
 
 static int sci_txfill(struct uart_port *port)
@@ -1764,16 +1771,18 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 
        sci_init_pins(port, termios->c_cflag);
 
-       reg = sci_getreg(port, SCFCR);
-       if (reg->size) {
-               unsigned short ctrl;
+       if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) {
+               reg = sci_getreg(port, SCFCR);
+               if (reg->size) {
+                       unsigned short ctrl;
 
-               ctrl = sci_in(port, SCFCR);
-               if (termios->c_cflag & CRTSCTS)
-                       ctrl |= SCFCR_MCE;
-               else
-                       ctrl &= ~SCFCR_MCE;
-               sci_out(port, SCFCR, ctrl);
+                       ctrl = sci_in(port, SCFCR);
+                       if (termios->c_cflag & CRTSCTS)
+                               ctrl |= SCFCR_MCE;
+                       else
+                               ctrl &= ~SCFCR_MCE;
+                       sci_out(port, SCFCR, ctrl);
+               }
        }
 
        sci_out(port, SCSCR, s->cfg->scscr);

diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
index 369273a..15b1bdc 100644 (file)
--- a/include/linux/serial_sci.h
+++ b/include/linux/serial_sci.h
@@ -49,6 +49,10 @@ enum {
 
 #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 @@ struct plat_sci_port_ops {
 };
 
 /*
+ * Port-specific capabilities
+ */
+#define SCIx_HAVE_RTSCTS       (1 << 0)
+
+/*
  * Platform device specific platform_data struct
  */
 struct plat_sci_port {
@@ -116,6 +125,7 @@ struct plat_sci_port {
        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 */