ARM: S5PC1xx: add gpiolib and external/gpio interrupt support

Add support for gpiolib calls. This is based on the gpiolib implementation
from plat-s3c64xx tree.
Add support for external interrupts for GPIO H banks.
Add support for GPIO interrupts for all banks.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
diff --git a/arch/arm/plat-s5pc1xx/irq-gpio.c b/arch/arm/plat-s5pc1xx/irq-gpio.c
new file mode 100644
index 0000000..fecca7a
--- /dev/null
+++ b/arch/arm/plat-s5pc1xx/irq-gpio.c
@@ -0,0 +1,266 @@
+/*
+ * arch/arm/plat-s5pc1xx/irq-gpio.c
+ *
+ * Copyright (C) 2009 Samsung Electronics
+ *
+ * S5PC1XX - Interrupt handling for IRQ_GPIO${group}(x)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+
+#include <mach/map.h>
+#include <plat/gpio-cfg.h>
+
+#define S5PC1XX_GPIOREG(x)		(S5PC1XX_VA_GPIO + (x))
+
+#define CON_OFFSET			0x700
+#define MASK_OFFSET			0x900
+#define PEND_OFFSET			0xA00
+#define CON_OFFSET_2			0xE00
+#define MASK_OFFSET_2			0xF00
+#define PEND_OFFSET_2			0xF40
+
+#define GPIOINT_LEVEL_LOW		0x0
+#define GPIOINT_LEVEL_HIGH		0x1
+#define GPIOINT_EDGE_FALLING		0x2
+#define GPIOINT_EDGE_RISING		0x3
+#define GPIOINT_EDGE_BOTH		0x4
+
+static int group_to_con_offset(int group)
+{
+	return group << 2;
+}
+
+static int group_to_mask_offset(int group)
+{
+	return group << 2;
+}
+
+static int group_to_pend_offset(int group)
+{
+	return group << 2;
+}
+
+static int s5pc1xx_get_start(unsigned int group)
+{
+	switch (group) {
+	case 0: return S5PC100_GPIO_A0_START;
+	case 1: return S5PC100_GPIO_A1_START;
+	case 2: return S5PC100_GPIO_B_START;
+	case 3: return S5PC100_GPIO_C_START;
+	case 4: return S5PC100_GPIO_D_START;
+	case 5: return S5PC100_GPIO_E0_START;
+	case 6: return S5PC100_GPIO_E1_START;
+	case 7: return S5PC100_GPIO_F0_START;
+	case 8: return S5PC100_GPIO_F1_START;
+	case 9: return S5PC100_GPIO_F2_START;
+	case 10: return S5PC100_GPIO_F3_START;
+	case 11: return S5PC100_GPIO_G0_START;
+	case 12: return S5PC100_GPIO_G1_START;
+	case 13: return S5PC100_GPIO_G2_START;
+	case 14: return S5PC100_GPIO_G3_START;
+	case 15: return S5PC100_GPIO_I_START;
+	case 16: return S5PC100_GPIO_J0_START;
+	case 17: return S5PC100_GPIO_J1_START;
+	case 18: return S5PC100_GPIO_J2_START;
+	case 19: return S5PC100_GPIO_J3_START;
+	case 20: return S5PC100_GPIO_J4_START;
+	default:
+		BUG();
+	}
+
+	return -EINVAL;
+}
+
+static int s5pc1xx_get_group(unsigned int irq)
+{
+	irq -= S3C_IRQ_GPIO(0);
+
+	switch (irq) {
+	case S5PC100_GPIO_A0_START ... S5PC100_GPIO_A1_START - 1:
+		return 0;
+	case S5PC100_GPIO_A1_START ... S5PC100_GPIO_B_START - 1:
+		return 1;
+	case S5PC100_GPIO_B_START ... S5PC100_GPIO_C_START - 1:
+		return 2;
+	case S5PC100_GPIO_C_START ... S5PC100_GPIO_D_START - 1:
+		return 3;
+	case S5PC100_GPIO_D_START ... S5PC100_GPIO_E0_START - 1:
+		return 4;
+	case S5PC100_GPIO_E0_START ... S5PC100_GPIO_E1_START - 1:
+		return 5;
+	case S5PC100_GPIO_E1_START ... S5PC100_GPIO_F0_START - 1:
+		return 6;
+	case S5PC100_GPIO_F0_START ... S5PC100_GPIO_F1_START - 1:
+		return 7;
+	case S5PC100_GPIO_F1_START ... S5PC100_GPIO_F2_START - 1:
+		return 8;
+	case S5PC100_GPIO_F2_START ... S5PC100_GPIO_F3_START - 1:
+		return 9;
+	case S5PC100_GPIO_F3_START ... S5PC100_GPIO_G0_START - 1:
+		return 10;
+	case S5PC100_GPIO_G0_START ... S5PC100_GPIO_G1_START - 1:
+		return 11;
+	case S5PC100_GPIO_G1_START ... S5PC100_GPIO_G2_START - 1:
+		return 12;
+	case S5PC100_GPIO_G2_START ... S5PC100_GPIO_G3_START - 1:
+		return 13;
+	case S5PC100_GPIO_G3_START ... S5PC100_GPIO_H0_START - 1:
+		return 14;
+	case S5PC100_GPIO_I_START ... S5PC100_GPIO_J0_START - 1:
+		return 15;
+	case S5PC100_GPIO_J0_START ... S5PC100_GPIO_J1_START - 1:
+		return 16;
+	case S5PC100_GPIO_J1_START ... S5PC100_GPIO_J2_START - 1:
+		return 17;
+	case S5PC100_GPIO_J2_START ... S5PC100_GPIO_J3_START - 1:
+		return 18;
+	case S5PC100_GPIO_J3_START ... S5PC100_GPIO_J4_START - 1:
+		return 19;
+	case S5PC100_GPIO_J4_START ... S5PC100_GPIO_K0_START - 1:
+		return 20;
+	default:
+		BUG();
+	}
+
+	return -EINVAL;
+}
+
+static int s5pc1xx_get_offset(unsigned int irq)
+{
+	struct gpio_chip *chip = get_irq_data(irq);
+	return irq - S3C_IRQ_GPIO(chip->base);
+}
+
+static void s5pc1xx_gpioint_ack(unsigned int irq)
+{
+	int group, offset, pend_offset;
+	unsigned int value;
+
+	group = s5pc1xx_get_group(irq);
+	offset = s5pc1xx_get_offset(irq);
+	pend_offset = group_to_pend_offset(group);
+
+	value = __raw_readl(S5PC1XX_GPIOREG(PEND_OFFSET) + pend_offset);
+	value |= 1 << offset;
+	__raw_writel(value, S5PC1XX_GPIOREG(PEND_OFFSET) + pend_offset);
+}
+
+static void s5pc1xx_gpioint_mask(unsigned int irq)
+{
+	int group, offset, mask_offset;
+	unsigned int value;
+
+	group = s5pc1xx_get_group(irq);
+	offset = s5pc1xx_get_offset(irq);
+	mask_offset = group_to_mask_offset(group);
+
+	value = __raw_readl(S5PC1XX_GPIOREG(MASK_OFFSET) + mask_offset);
+	value |= 1 << offset;
+	__raw_writel(value, S5PC1XX_GPIOREG(MASK_OFFSET) + mask_offset);
+}
+
+static void s5pc1xx_gpioint_unmask(unsigned int irq)
+{
+	int group, offset, mask_offset;
+	unsigned int value;
+
+	group = s5pc1xx_get_group(irq);
+	offset = s5pc1xx_get_offset(irq);
+	mask_offset = group_to_mask_offset(group);
+
+	value = __raw_readl(S5PC1XX_GPIOREG(MASK_OFFSET) + mask_offset);
+	value &= ~(1 << offset);
+	__raw_writel(value, S5PC1XX_GPIOREG(MASK_OFFSET) + mask_offset);
+}
+
+static void s5pc1xx_gpioint_mask_ack(unsigned int irq)
+{
+	s5pc1xx_gpioint_mask(irq);
+	s5pc1xx_gpioint_ack(irq);
+}
+
+static int s5pc1xx_gpioint_set_type(unsigned int irq, unsigned int type)
+{
+	int group, offset, con_offset;
+	unsigned int value;
+
+	group = s5pc1xx_get_group(irq);
+	offset = s5pc1xx_get_offset(irq);
+	con_offset = group_to_con_offset(group);
+
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		printk(KERN_WARNING "No irq type\n");
+		return -EINVAL;
+	case IRQ_TYPE_EDGE_RISING:
+		type = GPIOINT_EDGE_RISING;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		type = GPIOINT_EDGE_FALLING;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		type = GPIOINT_EDGE_BOTH;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		type = GPIOINT_LEVEL_HIGH;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		type = GPIOINT_LEVEL_LOW;
+		break;
+	default:
+		BUG();
+	}
+
+
+	value = __raw_readl(S5PC1XX_GPIOREG(CON_OFFSET) + con_offset);
+	value &= ~(0xf << (offset * 0x4));
+	value |= (type << (offset * 0x4));
+	__raw_writel(value, S5PC1XX_GPIOREG(CON_OFFSET) + con_offset);
+
+	return 0;
+}
+
+struct irq_chip s5pc1xx_gpioint = {
+	.name		= "GPIO",
+	.ack		= s5pc1xx_gpioint_ack,
+	.mask		= s5pc1xx_gpioint_mask,
+	.mask_ack	= s5pc1xx_gpioint_mask_ack,
+	.unmask		= s5pc1xx_gpioint_unmask,
+	.set_type	= s5pc1xx_gpioint_set_type,
+};
+
+void s5pc1xx_irq_gpioint_handler(unsigned int irq, struct irq_desc *desc)
+{
+	int group, offset, pend_offset, mask_offset;
+	int real_irq, group_end;
+	unsigned int pend, mask;
+
+	group_end = 21;
+
+	for (group = 0; group < group_end; group++) {
+		pend_offset = group_to_pend_offset(group);
+		pend = __raw_readl(S5PC1XX_GPIOREG(PEND_OFFSET) + pend_offset);
+		if (!pend)
+			continue;
+
+		mask_offset = group_to_mask_offset(group);
+		mask = __raw_readl(S5PC1XX_GPIOREG(MASK_OFFSET) + mask_offset);
+		pend &= ~mask;
+
+		for (offset = 0; offset < 8; offset++) {
+			if (pend & (1 << offset)) {
+				real_irq = s5pc1xx_get_start(group) + offset;
+				generic_handle_irq(S3C_IRQ_GPIO(real_irq));
+			}
+		}
+	}
+}