[AVR32] Make I/O access macros work with external devices

Fix the I/O access macros so that they work with externally connected
devices accessed in little-endian mode over any bus width:

* Use a set of macros to define I/O port- and memory operations
  borrowed from MIPS.
* Allow subarchitecture to specify address- and data-mangling
* Implement at32ap-specific port mangling (with build-time
  configurable bus width. Only one bus width at a time supported
  for now.)
* Rewrite iowriteN and friends to use write[bwl] and friends
  (not the __raw counterparts.)

This has been tested using pata_pcmcia to access a CompactFlash card
connected to the EBI (16-bit bus width.)
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

arch/avr32/mach-at32ap/Kconfig

@@ -2,6 +2,30 @@ if PLATFORM_AT32AP
 
 menu "Atmel AVR32 AP options"
 
+choice
+	prompt "AT32AP7000 static memory bus width"
+	depends on CPU_AT32AP7000
+	default AP7000_16_BIT_SMC
+	help
+	  Define the width of the AP7000 external static memory interface.
+	  This is used to determine how to mangle the address and/or data
+	  when doing little-endian port access.
+
+	  The current code can only support a single external memory bus
+	  width for all chip selects, excluding the flash (which is using
+	  raw access and is thus not affected by any of this.)
+
+config AP7000_32_BIT_SMC
+	bool "32 bit"
+
+config AP7000_16_BIT_SMC
+	bool "16 bit"
+
+config AP7000_8_BIT_SMC
+	bool "8 bit"
+
+endchoice
+
 endmenu
 
-endif
+endif # PLATFORM_AT32AP

include/asm-avr32/arch-at32ap/io.h

+#ifndef __ASM_AVR32_ARCH_AT32AP_IO_H
+#define __ASM_AVR32_ARCH_AT32AP_IO_H
+
+/* For "bizarre" halfword swapping */
+#include <linux/byteorder/swabb.h>
+
+#if defined(CONFIG_AP7000_32_BIT_SMC)
+# define __swizzle_addr_b(addr)	(addr ^ 3UL)
+# define __swizzle_addr_w(addr)	(addr ^ 2UL)
+# define __swizzle_addr_l(addr)	(addr)
+# define ioswabb(a, x)		(x)
+# define ioswabw(a, x)		(x)
+# define ioswabl(a, x)		(x)
+# define __mem_ioswabb(a, x)	(x)
+# define __mem_ioswabw(a, x)	swab16(x)
+# define __mem_ioswabl(a, x)	swab32(x)
+#elif defined(CONFIG_AP7000_16_BIT_SMC)
+# define __swizzle_addr_b(addr)	(addr ^ 1UL)
+# define __swizzle_addr_w(addr)	(addr)
+# define __swizzle_addr_l(addr)	(addr)
+# define ioswabb(a, x)		(x)
+# define ioswabw(a, x)		(x)
+# define ioswabl(a, x)		swahw32(x)
+# define __mem_ioswabb(a, x)	(x)
+# define __mem_ioswabw(a, x)	swab16(x)
+# define __mem_ioswabl(a, x)	swahb32(x)
+#else
+# define __swizzle_addr_b(addr)	(addr)
+# define __swizzle_addr_w(addr)	(addr)
+# define __swizzle_addr_l(addr)	(addr)
+# define ioswabb(a, x)		(x)
+# define ioswabw(a, x)		swab16(x)
+# define ioswabl(a, x)		swab32(x)
+# define __mem_ioswabb(a, x)	(x)
+# define __mem_ioswabw(a, x)	(x)
+# define __mem_ioswabl(a, x)	(x)
+#endif
+
+#endif /* __ASM_AVR32_ARCH_AT32AP_IO_H */