serial: sh-sci: Replace buggy big #ifdef by runtime logic

The #ifdef logic to clear SCxSR bits using RMW on SCIFA/SCIFB and SCIF
variants with some SCIFA features (sh7705/SH7720/sh7721) has several
drawbacks:
  - It wasn't updated for newer R-Mobile variants (APE6),
  - It doesn't correctly handle SoCs with both SCIF and SCIFA/B (e.g.
    R-Car Gen2, but also legacy sh7723/sh7724),
  - It doesn't play well with ARM multi-platform kernels: on R-Car Gen2,
    SCIF/SCIFA/SCIFB/HSCIF were handled differently, depending on
    whether r8a7740 or sh73a0 support was enabled or not,

Replace the #ifdef logic by runtime logic to fix this.

SCIFA/SCIFB and SCIF on sh7705/sh7720/sh7721 use RMW to clear error
bits, other variants use plain stores, as before.

Note that this changes behavior for SCIFA on sh7723/sh7724 (these SoCs
have both SCIF and SCIFA), which didn't use RMW before.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 1b2f894bdc9e0e6ed15cf93feb405337b1d0d07b..b014fce1509d6535ab7d6b334d56808939f91999 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -489,6 +489,22 @@ static void sci_port_disable(struct sci_port *sci_port)
        pm_runtime_put_sync(sci_port->port.dev);
 }
 
+static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
+{
+       if (port->type == PORT_SCI) {
+               /* Just store the mask */
+               serial_port_out(port, SCxSR, mask);
+       } else if (to_sci_port(port)->overrun_mask == SCIFA_ORER) {
+               /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
+               /* Only clear the status bits we want to clear */
+               serial_port_out(port, SCxSR,
+                               serial_port_in(port, SCxSR) & mask);
+       } else {
+               /* Store the mask, clear parity/framing errors */
+               serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
+       }
+}
+
 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
 
 #ifdef CONFIG_CONSOLE_POLL
@@ -500,7 +516,7 @@ static int sci_poll_get_char(struct uart_port *port)
        do {
                status = serial_port_in(port, SCxSR);
                if (status & SCxSR_ERRORS(port)) {
-                       serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
+                       sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
                        continue;
                }
                break;
@@ -513,7 +529,7 @@ static int sci_poll_get_char(struct uart_port *port)
 
        /* Dummy read */
        serial_port_in(port, SCxSR);
-       serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+       sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 
        return c;
 }
@@ -528,7 +544,7 @@ static void sci_poll_put_char(struct uart_port *port, unsigned char c)
        } while (!(status & SCxSR_TDxE(port)));
 
        serial_port_out(port, SCxTDR, c);
-       serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
+       sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 }
 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
 
@@ -655,7 +671,7 @@ static void sci_transmit_chars(struct uart_port *port)
                port->icount.tx++;
        } while (--count > 0);
 
-       serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
+       sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 
        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                uart_write_wakeup(port);
@@ -666,7 +682,7 @@ static void sci_transmit_chars(struct uart_port *port)
 
                if (port->type != PORT_SCI) {
                        serial_port_in(port, SCxSR); /* Dummy read */
-                       serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
+                       sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
                }
 
                ctrl |= SCSCR_TIE;
@@ -750,7 +766,7 @@ static void sci_receive_chars(struct uart_port *port)
                }
 
                serial_port_in(port, SCxSR); /* dummy read */
-               serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+               sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 
                copied += count;
                port->icount.rx += count;
@@ -761,7 +777,7 @@ static void sci_receive_chars(struct uart_port *port)
                tty_flip_buffer_push(tport);
        } else {
                serial_port_in(port, SCxSR); /* dummy read */
-               serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+               sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
        }
 }
 
@@ -982,14 +998,14 @@ static irqreturn_t sci_er_interrupt(int irq, void *ptr)
                if (sci_handle_errors(port)) {
                        /* discard character in rx buffer */
                        serial_port_in(port, SCxSR);
-                       serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
+                       sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
                }
        } else {
                sci_handle_fifo_overrun(port);
                sci_rx_interrupt(irq, ptr);
        }
 
-       serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
+       sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
 
        /* Kick the transmission */
        sci_tx_interrupt(irq, ptr);
@@ -1003,7 +1019,7 @@ static irqreturn_t sci_br_interrupt(int irq, void *ptr)
 
        /* Handle BREAKs */
        sci_handle_breaks(port);
-       serial_port_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
+       sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
 
        return IRQ_HANDLED;
 }

diff --git a/drivers/tty/serial/sh-sci.h b/drivers/tty/serial/sh-sci.h
index 3393f67b4e84357890747bd79cd8002fdf33843f..1e1edbd152673e8fc99417fee5d685d0b441036a 100644 (file)
--- a/drivers/tty/serial/sh-sci.h
+++ b/drivers/tty/serial/sh-sci.h
@@ -119,28 +119,11 @@ enum {
 
 #define SCxSR_ERRORS(port)     (to_sci_port(port)->error_mask)
 
-#if defined(CONFIG_CPU_SUBTYPE_SH7705) || \
-    defined(CONFIG_CPU_SUBTYPE_SH7720) || \
-    defined(CONFIG_CPU_SUBTYPE_SH7721) || \
-    defined(CONFIG_ARCH_SH73A0) || \
-    defined(CONFIG_ARCH_R8A7740)
-
-# define SCxSR_RDxF_CLEAR(port) \
-       (serial_port_in(port, SCxSR) & SCIF_RDxF_CLEAR)
-# define SCxSR_ERROR_CLEAR(port) \
-       (serial_port_in(port, SCxSR) & SCIF_ERROR_CLEAR)
-# define SCxSR_TDxE_CLEAR(port) \
-       (serial_port_in(port, SCxSR) & SCIF_TDxE_CLEAR)
-# define SCxSR_BREAK_CLEAR(port) \
-       (serial_port_in(port, SCxSR) & SCIF_BREAK_CLEAR)
-#else
-# define SCxSR_RDxF_CLEAR(port) \
-       ((((port)->type == PORT_SCI) ? SCI_RDxF_CLEAR : SCIF_RDxF_CLEAR) & 0xff)
-# define SCxSR_ERROR_CLEAR(port) \
-       ((((port)->type == PORT_SCI) ? SCI_ERROR_CLEAR : SCIF_ERROR_CLEAR) & 0xff)
-# define SCxSR_TDxE_CLEAR(port) \
-       ((((port)->type == PORT_SCI) ? SCI_TDxE_CLEAR : SCIF_TDxE_CLEAR) & 0xff)
-# define SCxSR_BREAK_CLEAR(port) \
-       ((((port)->type == PORT_SCI) ? SCI_BREAK_CLEAR : SCIF_BREAK_CLEAR) & 0xff)
-#endif
-
+#define SCxSR_RDxF_CLEAR(port) \
+       (((port)->type == PORT_SCI) ? SCI_RDxF_CLEAR : SCIF_RDxF_CLEAR)
+#define SCxSR_ERROR_CLEAR(port) \
+       (((port)->type == PORT_SCI) ? SCI_ERROR_CLEAR : SCIF_ERROR_CLEAR)
+#define SCxSR_TDxE_CLEAR(port) \
+       (((port)->type == PORT_SCI) ? SCI_TDxE_CLEAR : SCIF_TDxE_CLEAR)
+#define SCxSR_BREAK_CLEAR(port) \
+       (((port)->type == PORT_SCI) ? SCI_BREAK_CLEAR : SCIF_BREAK_CLEAR)