m68k: coldfire: create IO access functions for internal registers

The internal peripheral registers contained in all varieties of ColdFire
SoCs require simple big endian access ranging in sizes from 8, 16 and 32
bit. Currently there is a mixture of IO access methods used across the
various CPU support code, some using readx/writex and some using the
simpler __raw_readx/__raw_writew.

The readx/writex use cases are particularly kludgy in that they contain
code to differentiate internal register access and other general attached
peripheral register access - say on a PCI bus. In effect this means that
the readx/writex family for ColdFire is non-standard. This ultimately
ends up causing problems with definitions of other IO access support
functions like ioreadx/ioreadxbe/iowritex/iowritexbe which in the
generic case are defined in terms of readx/writex.

Create a set of internal only register access methods to ultimately
replace all internal register access code. The new access functions
mirror the existing readx/writex family but using the preferred 8/16/32
suffixes.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

diff --git a/arch/m68k/include/asm/io_no.h b/arch/m68k/include/asm/io_no.h
index 516371d5587aa30e26b172f74a727ebae88c200e..4f0f34b06e37c3fed3067c5a8e8432f54d11fc2b 100644 (file)
--- a/arch/m68k/include/asm/io_no.h
+++ b/arch/m68k/include/asm/io_no.h
@@ -107,6 +107,22 @@ static inline void writel(u32 value, volatile void __iomem *addr)
 
 #endif /* IOMEMBASE */
 
+#if defined(CONFIG_COLDFIRE)
+/*
+ * The ColdFire internal peripheral registers are big-endian, so you
+ * cannot use the conventional little-endian readb/readw/readl and
+ * writeb/writew/writel access functions. Define a family of access
+ * functions to give correct endian access that can be used by all
+ * architecture code.
+ */
+#define mcf_read8      __raw_readb
+#define mcf_read16     __raw_readw
+#define mcf_read32     __raw_readl
+#define mcf_write8     __raw_writeb
+#define mcf_write16    __raw_writew
+#define mcf_write32    __raw_writel
+#endif /* CONFIG_COLDFIRE */
+
 #if defined(CONFIG_PCI)
 /*
  * Support for PCI bus access uses the asm-generic access functions.