serial: sh-sci: Add overrun handling of SCIFA and SCIFB

SCIFA and SCIFB can detect the overrun, but it does not support.
This adds overrun handling of SCIFA and SCIFB.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 36 insertions, 12 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 5b50c792ad5f..5bf997253a46 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -844,14 +844,32 @@ static int sci_handle_fifo_overrun(struct uart_port *port)
         struct tty_port *tport = &port->state->port;
         struct sci_port *s = to_sci_port(port);
         struct plat_sci_reg *reg;
-        int copied = 0;
+        int copied = 0, offset;
+        u16 status, bit;
 
-        reg = sci_getreg(port, SCLSR);
+        switch (port->type) {
+        case PORT_SCIF:
+        case PORT_HSCIF:
+                offset = SCLSR;
+                break;
+        case PORT_SCIFA:
+        case PORT_SCIFB:
+                offset = SCxSR;
+                break;
+        default:
+                return 0;
+        }
+
+        reg = sci_getreg(port, offset);
         if (!reg->size)
                 return 0;
 
-        if ((serial_port_in(port, SCLSR) & (1 << s->overrun_bit))) {
-                serial_port_out(port, SCLSR, 0);
+        status = serial_port_in(port, offset);
+        bit = 1 << s->overrun_bit;
+
+        if (status & bit) {
+                status &= ~bit;
+                serial_port_out(port, offset, status);
 
                 port->icount.overrun++;
 
@@ -996,16 +1014,24 @@ static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 
 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
 {
-        unsigned short ssr_status, scr_status, err_enabled;
-        unsigned short slr_status = 0;
+        unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
         struct uart_port *port = ptr;
         struct sci_port *s = to_sci_port(port);
         irqreturn_t ret = IRQ_NONE;
 
         ssr_status = serial_port_in(port, SCxSR);
         scr_status = serial_port_in(port, SCSCR);
-        if (port->type == PORT_SCIF || port->type == PORT_HSCIF)
-                slr_status = serial_port_in(port, SCLSR);
+        switch (port->type) {
+        case PORT_SCIF:
+        case PORT_HSCIF:
+                orer_status = serial_port_in(port, SCLSR);
+                break;
+        case PORT_SCIFA:
+        case PORT_SCIFB:
+                orer_status = ssr_status;
+                break;
+        }
+
         err_enabled = scr_status & port_rx_irq_mask(port);
 
         /* Tx Interrupt */
@@ -1033,10 +1059,8 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
                 ret = sci_br_interrupt(irq, ptr);
 
         /* Overrun Interrupt */
-        if (port->type == PORT_SCIF || port->type == PORT_HSCIF) {
-                if (slr_status & 0x01)
-                        sci_handle_fifo_overrun(port);
-        }
+        if (orer_status & (1 << s->overrun_bit))
+                sci_handle_fifo_overrun(port);
 
         return ret;
 }