serial: sh-sci: Generalize overrun handling.

This consolidates all of the broken out overrun handling and ensures that
we have sensible defaults per-port type, in addition to making sure that
overruns are flagged appropriately in the error mask for parts that
haven't explicitly disabled support for it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 45 insertions, 6 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 280c02af0eae..bb27885ea2e5 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -563,13 +563,19 @@ static int sci_handle_errors(struct uart_port *port)
         int copied = 0;
         unsigned short status = sci_in(port, SCxSR);
         struct tty_struct *tty = port->state->port.tty;
+        struct sci_port *s = to_sci_port(port);
 
-        if (status & SCxSR_ORER(port)) {
-                /* overrun error */
-                if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
-                        copied++;
+        /*
+         * Handle overruns, if supported.
+         */
+        if (s->cfg->overrun_bit != SCIx_NOT_SUPPORTED) {
+                if (status & (1 << s->cfg->overrun_bit)) {
+                        /* overrun error */
+                        if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
+                                copied++;
 
-                dev_notice(port->dev, "overrun error");
+                        dev_notice(port->dev, "overrun error");
+                }
         }
 
         if (status & SCxSR_FER(port)) {
@@ -617,12 +623,19 @@ static int sci_handle_errors(struct uart_port *port)
 static int sci_handle_fifo_overrun(struct uart_port *port)
 {
         struct tty_struct *tty = port->state->port.tty;
+        struct sci_port *s = to_sci_port(port);
         int copied = 0;
 
+        /*
+         * XXX: Technically not limited to non-SCIFs, it's simply the
+         * SCLSR check that is for the moment SCIF-specific. This
+         * probably wants to be revisited for SCIFA/B as well as for
+         * factoring in SCI overrun detection.
+         */
         if (port->type != PORT_SCIF)
                 return 0;
 
-        if ((sci_in(port, SCLSR) & SCIF_ORER) != 0) {
+        if ((sci_in(port, SCLSR) & (1 << s->cfg->overrun_bit))) {
                 sci_out(port, SCLSR, 0);
 
                 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
@@ -1755,6 +1768,32 @@ static int __devinit sci_init_single(struct platform_device *dev,
         sci_port->break_timer.function = sci_break_timer;
         init_timer(&sci_port->break_timer);
 
+        /*
+         * Establish some sensible defaults for the error detection.
+         */
+        if (!p->error_mask)
+                p->error_mask = (p->type == PORT_SCI) ?
+                        SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK;
+
+        /*
+         * Establish sensible defaults for the overrun detection, unless
+         * the part has explicitly disabled support for it.
+         */
+        if (p->overrun_bit != SCIx_NOT_SUPPORTED) {
+                if (p->type == PORT_SCI)
+                        p->overrun_bit = 5;
+                else if (p->scbrr_algo_id == SCBRR_ALGO_4)
+                        p->overrun_bit = 9;
+                else
+                        p->overrun_bit = 0;
+
+                /*
+                 * Make the error mask inclusive of overrun detection, if
+                 * supported.
+                 */
+                p->error_mask |= (1 << p->overrun_bit);
+        }
+
         sci_port->cfg           = p;
 
         port->mapbase           = p->mapbase;