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.h b/drivers/tty/serial/sh-sci.h
index 3393f67..1e1edbd 100644
--- a/drivers/tty/serial/sh-sci.h
+++ b/drivers/tty/serial/sh-sci.h
@@ -119,28 +119,11 @@
 
 #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)