sh: make gpio_get/set_value() O(1)

This patch modifies the table based SuperH gpio implementation to
make use of direct table lookups. With this change the functions
gpio_get_value() and gpio_set_value() are O(1).

Tested on Migo-R using bitbanging mmc. Performance is improved from
11 KBytes/s to 26 Kbytes/s.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/include/asm/gpio.h b/arch/sh/include/asm/gpio.h
index 9067365..942fefa 100644
--- a/arch/sh/include/asm/gpio.h
+++ b/arch/sh/include/asm/gpio.h
@@ -20,7 +20,7 @@
 #endif
 
 typedef unsigned short pinmux_enum_t;
-typedef unsigned char pinmux_flag_t;
+typedef unsigned short pinmux_flag_t;
 
 #define PINMUX_TYPE_NONE            0
 #define PINMUX_TYPE_FUNCTION        1
@@ -34,6 +34,11 @@
 #define PINMUX_FLAG_WANT_PULLUP     (1 << 3)
 #define PINMUX_FLAG_WANT_PULLDOWN   (1 << 4)
 
+#define PINMUX_FLAG_DBIT_SHIFT      5
+#define PINMUX_FLAG_DBIT            (0x1f << PINMUX_FLAG_DBIT_SHIFT)
+#define PINMUX_FLAG_DREG_SHIFT      10
+#define PINMUX_FLAG_DREG            (0x3f << PINMUX_FLAG_DREG_SHIFT)
+
 struct pinmux_gpio {
 	pinmux_enum_t enum_id;
 	pinmux_flag_t flags;