arm: lpc32xx: gpio macro for pin mapping

Add LPC32xx GPIO interface macro for pin mapping.

Signed-off-by: Sylvain Lemieux <slemieux@tycoint.com>

arch/arm/include/asm/arch-lpc32xx/gpio_grp.h

+/*
+ * LPC32xx GPIO interface macro for pin mapping.
+ *
+ * (C) Copyright 2015  DENX Software Engineering GmbH
+ * Written-by: Sylvain Lemieux <slemieux@@tycoint.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _LPC32XX_GPIO_GRP_H
+#define _LPC32XX_GPIO_GRP_H
+
+/*
+ * Macro to map the pin for the lpc32xx_gpio driver.
+ * Note: - GPIOS are considered here as homogeneous and linear, from 0 to 127;
+ *         mapping is done per register, as group of 32.
+ *         (see drivers/gpio/lpc32xx_gpio.c for details).
+ *       - macros can be use with the following pins:
+ *         P0.0 - P0.7
+ *         P1.0 - P1.23
+ *         P2.0 - P2.12
+ *         P3 GPI_0 - GPI_9 / GPI_15 - GPI_23 / GPI_25 / GPI_27 - GPI_28
+ *         P3 GPO_0 - GPO_23
+ *         P3 GPIO_0 - GPIO_5 (output register only)
+ */
+#define LPC32XX_GPIO_P0_GRP 0
+#define LPC32XX_GPIO_P1_GRP 32
+#define LPC32XX_GPIO_P2_GRP 64
+#define LPC32XX_GPI_P3_GRP  96
+#define LPC32XX_GPO_P3_GRP  96
+#define LPC32XX_GPIO_P3_GRP (LPC32XX_GPO_P3_GRP + 25)
+
+/*
+ * A specific GPIO can be selected with this macro
+ * ie, GPIO P0.1 can be selected with LPC32XX_GPIO(LPC32XX_GPIO_P0_GRP, 1)
+ * See the LPC32x0 User's guide for GPIO group numbers
+ */
+#define LPC32XX_GPIO(x, y) ((x) + (y))
+
+#endif /* _LPC32XX_GPIO_GRP_H */