gpio: add Xilinx Zynq PS GPIO driver

Most of the code is taken (and adapted) from Linux kernel driver.

Just add CONFIG_ZYNQ_GPIO to you config to enable it

Signed-off-by: Andrea Scian <andrea.scian@dave.eu>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/include/asm/arch-zynq/gpio.h b/arch/arm/include/asm/arch-zynq/gpio.h
index a26ae87..9e1e7da 100644
--- a/arch/arm/include/asm/arch-zynq/gpio.h
+++ b/arch/arm/include/asm/arch-zynq/gpio.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2013 Xilinx, Inc.
+ * Copyright (c) 2015 DAVE Embedded Systems
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
@@ -7,4 +8,69 @@
 #ifndef _ZYNQ_GPIO_H
 #define _ZYNQ_GPIO_H
 
+#define ZYNQ_GPIO_BASE_ADDRESS 0xE000A000
+
+/* Maximum banks */
+#define ZYNQ_GPIO_MAX_BANK	4
+
+#define ZYNQ_GPIO_BANK0_NGPIO	32
+#define ZYNQ_GPIO_BANK1_NGPIO	22
+#define ZYNQ_GPIO_BANK2_NGPIO	32
+#define ZYNQ_GPIO_BANK3_NGPIO	32
+
+#define ZYNQ_GPIO_NR_GPIOS	(ZYNQ_GPIO_BANK0_NGPIO + \
+				 ZYNQ_GPIO_BANK1_NGPIO + \
+				 ZYNQ_GPIO_BANK2_NGPIO + \
+				 ZYNQ_GPIO_BANK3_NGPIO)
+
+#define ZYNQ_GPIO_BANK0_PIN_MIN	0
+#define ZYNQ_GPIO_BANK0_PIN_MAX	(ZYNQ_GPIO_BANK0_PIN_MIN + \
+					ZYNQ_GPIO_BANK0_NGPIO - 1)
+#define ZYNQ_GPIO_BANK1_PIN_MIN	(ZYNQ_GPIO_BANK0_PIN_MAX + 1)
+#define ZYNQ_GPIO_BANK1_PIN_MAX	(ZYNQ_GPIO_BANK1_PIN_MIN + \
+					ZYNQ_GPIO_BANK1_NGPIO - 1)
+#define ZYNQ_GPIO_BANK2_PIN_MIN	(ZYNQ_GPIO_BANK1_PIN_MAX + 1)
+#define ZYNQ_GPIO_BANK2_PIN_MAX	(ZYNQ_GPIO_BANK2_PIN_MIN + \
+					ZYNQ_GPIO_BANK2_NGPIO - 1)
+#define ZYNQ_GPIO_BANK3_PIN_MIN	(ZYNQ_GPIO_BANK2_PIN_MAX + 1)
+#define ZYNQ_GPIO_BANK3_PIN_MAX	(ZYNQ_GPIO_BANK3_PIN_MIN + \
+					ZYNQ_GPIO_BANK3_NGPIO - 1)
+
+/* Register offsets for the GPIO device */
+/* LSW Mask & Data -WO */
+#define ZYNQ_GPIO_DATA_LSW_OFFSET(BANK)	(0x000 + (8 * BANK))
+/* MSW Mask & Data -WO */
+#define ZYNQ_GPIO_DATA_MSW_OFFSET(BANK)	(0x004 + (8 * BANK))
+/* Data Register-RW */
+#define ZYNQ_GPIO_DATA_RO_OFFSET(BANK)	(0x060 + (4 * BANK))
+/* Direction mode reg-RW */
+#define ZYNQ_GPIO_DIRM_OFFSET(BANK)	(0x204 + (0x40 * BANK))
+/* Output enable reg-RW */
+#define ZYNQ_GPIO_OUTEN_OFFSET(BANK)	(0x208 + (0x40 * BANK))
+/* Interrupt mask reg-RO */
+#define ZYNQ_GPIO_INTMASK_OFFSET(BANK)	(0x20C + (0x40 * BANK))
+/* Interrupt enable reg-WO */
+#define ZYNQ_GPIO_INTEN_OFFSET(BANK)	(0x210 + (0x40 * BANK))
+/* Interrupt disable reg-WO */
+#define ZYNQ_GPIO_INTDIS_OFFSET(BANK)	(0x214 + (0x40 * BANK))
+/* Interrupt status reg-RO */
+#define ZYNQ_GPIO_INTSTS_OFFSET(BANK)	(0x218 + (0x40 * BANK))
+/* Interrupt type reg-RW */
+#define ZYNQ_GPIO_INTTYPE_OFFSET(BANK)	(0x21C + (0x40 * BANK))
+/* Interrupt polarity reg-RW */
+#define ZYNQ_GPIO_INTPOL_OFFSET(BANK)	(0x220 + (0x40 * BANK))
+/* Interrupt on any, reg-RW */
+#define ZYNQ_GPIO_INTANY_OFFSET(BANK)	(0x224 + (0x40 * BANK))
+
+/* Disable all interrupts mask */
+#define ZYNQ_GPIO_IXR_DISABLE_ALL	0xFFFFFFFF
+
+/* Mid pin number of a bank */
+#define ZYNQ_GPIO_MID_PIN_NUM 16
+
+/* GPIO upper 16 bit mask */
+#define ZYNQ_GPIO_UPPER_MASK 0xFFFF0000
+
+#define BIT(x) (1<<x)
+
 #endif /* _ZYNQ_GPIO_H */