at91: add new gpio pin definitions

This patch define new names for GPIO pins on at91 devices. Follow up patches
will convert the whole infrastructure to use these new definitions.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Tested-by: Bo Shen <voice.shen@atmel.com>
diff --git a/arch/arm/include/asm/arch-at91/gpio.h b/arch/arm/include/asm/arch-at91/gpio.h
index 0700427..b340afe 100644
--- a/arch/arm/include/asm/arch-at91/gpio.h
+++ b/arch/arm/include/asm/arch-at91/gpio.h
@@ -231,4 +231,26 @@
 #define at91_set_gpio_value(x, y)	at91_set_pio_value(x, y)
 #define at91_get_gpio_value(x)		at91_get_pio_value(x)
 #endif
-#endif
+
+#define GPIO_PIOA_BASE  (0)
+#define GPIO_PIOB_BASE  (GPIO_PIOA_BASE + 32)
+#define GPIO_PIOC_BASE  (GPIO_PIOB_BASE + 32)
+#define GPIO_PIOD_BASE  (GPIO_PIOC_BASE + 32)
+#define GPIO_PIOE_BASE  (GPIO_PIOD_BASE + 32)
+#define GPIO_PIN_PA(x)  (GPIO_PIOA_BASE + (x))
+#define GPIO_PIN_PB(x)  (GPIO_PIOB_BASE + (x))
+#define GPIO_PIN_PC(x)  (GPIO_PIOC_BASE + (x))
+#define GPIO_PIN_PD(x)  (GPIO_PIOD_BASE + (x))
+#define GPIO_PIN_PE(x)  (GPIO_PIOE_BASE + (x))
+
+static inline unsigned at91_gpio_to_port(unsigned gpio)
+{
+	return gpio / 32;
+}
+
+static inline unsigned at91_gpio_to_pin(unsigned gpio)
+{
+	return gpio % 32;
+}
+
+#endif /* __ASM_ARCH_AT91_GPIO_H */