ARM: S5PV210: Add IRQ_EINT interrupt support.

Add support for external interrupts on S5PV210.

Signed-off-by: Jongpill Lee <boyko.lee@samsung.com>
Signed-off-by: Pannaga Bhushan <p.bhushan@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
[ben-linux@fluff.org: Ext => IRQ_EINT in title]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
diff --git a/arch/arm/plat-s5p/irq-eint.c b/arch/arm/plat-s5p/irq-eint.c
new file mode 100644
index 0000000..eaa70aa
--- /dev/null
+++ b/arch/arm/plat-s5p/irq-eint.c
@@ -0,0 +1,213 @@
+/* linux/arch/arm/plat-s5p/irq-eint.c
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * S5P - IRQ EINT support
+ *
+ * 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/sysdev.h>
+#include <linux/gpio.h>
+
+#include <asm/hardware/vic.h>
+
+#include <plat/regs-irqtype.h>
+
+#include <mach/map.h>
+#include <plat/cpu.h>
+#include <plat/pm.h>
+
+#include <plat/gpio-cfg.h>
+#include <mach/regs-gpio.h>
+
+static inline void s5p_irq_eint_mask(unsigned int irq)
+{
+	u32 mask;
+
+	mask = __raw_readl(S5P_EINT_MASK(EINT_REG_NR(irq)));
+	mask |= eint_irq_to_bit(irq);
+	__raw_writel(mask, S5P_EINT_MASK(EINT_REG_NR(irq)));
+}
+
+static void s5p_irq_eint_unmask(unsigned int irq)
+{
+	u32 mask;
+
+	mask = __raw_readl(S5P_EINT_MASK(EINT_REG_NR(irq)));
+	mask &= ~(eint_irq_to_bit(irq));
+	__raw_writel(mask, S5P_EINT_MASK(EINT_REG_NR(irq)));
+}
+
+static inline void s5p_irq_eint_ack(unsigned int irq)
+{
+	__raw_writel(eint_irq_to_bit(irq), S5P_EINT_PEND(EINT_REG_NR(irq)));
+}
+
+static void s5p_irq_eint_maskack(unsigned int irq)
+{
+	/* compiler should in-line these */
+	s5p_irq_eint_mask(irq);
+	s5p_irq_eint_ack(irq);
+}
+
+static int s5p_irq_eint_set_type(unsigned int irq, unsigned int type)
+{
+	int offs = eint_offset(irq);
+	int shift;
+	u32 ctrl, mask;
+	u32 newvalue = 0;
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		newvalue = S5P_EXTINT_RISEEDGE;
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		newvalue = S5P_EXTINT_RISEEDGE;
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		newvalue = S5P_EXTINT_BOTHEDGE;
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		newvalue = S5P_EXTINT_LOWLEV;
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		newvalue = S5P_EXTINT_HILEV;
+		break;
+
+	default:
+		printk(KERN_ERR "No such irq type %d", type);
+		return -EINVAL;
+	}
+
+	shift = (offs & 0x7) * 4;
+	mask = 0x7 << shift;
+
+	ctrl = __raw_readl(S5P_EINT_CON(EINT_REG_NR(irq)));
+	ctrl &= ~mask;
+	ctrl |= newvalue << shift;
+	__raw_writel(ctrl, S5P_EINT_CON(EINT_REG_NR(irq)));
+
+	if ((0 <= offs) && (offs < 8))
+		s3c_gpio_cfgpin(EINT_GPIO_0(offs & 0x7), EINT_MODE);
+
+	else if ((8 <= offs) && (offs < 16))
+		s3c_gpio_cfgpin(EINT_GPIO_1(offs & 0x7), EINT_MODE);
+
+	else if ((16 <= offs) && (offs < 24))
+		s3c_gpio_cfgpin(EINT_GPIO_2(offs & 0x7), EINT_MODE);
+
+	else if ((24 <= offs) && (offs < 32))
+		s3c_gpio_cfgpin(EINT_GPIO_3(offs & 0x7), EINT_MODE);
+
+	else
+		printk(KERN_ERR "No such irq number %d", offs);
+
+	return 0;
+}
+
+static struct irq_chip s5p_irq_eint = {
+	.name		= "s5p-eint",
+	.mask		= s5p_irq_eint_mask,
+	.unmask		= s5p_irq_eint_unmask,
+	.mask_ack	= s5p_irq_eint_maskack,
+	.ack		= s5p_irq_eint_ack,
+	.set_type	= s5p_irq_eint_set_type,
+#ifdef CONFIG_PM
+	.set_wake	= s3c_irqext_wake,
+#endif
+};
+
+/* s5p_irq_demux_eint
+ *
+ * This function demuxes the IRQ from the group0 external interrupts,
+ * from EINTs 16 to 31. It is designed to be inlined into the specific
+ * handler s5p_irq_demux_eintX_Y.
+ *
+ * Each EINT pend/mask registers handle eight of them.
+ */
+static inline void s5p_irq_demux_eint(unsigned int start)
+{
+	u32 status;
+	u32 mask = __raw_readl(S5P_EINT_MASK(EINT_REG_NR(start)));
+	unsigned int irq;
+
+	status = __raw_readl(S5P_EINT_PEND(EINT_REG_NR(start)));
+	status &= ~mask;
+	status &= 0xff;
+
+	while (status) {
+		irq = fls(status);
+		generic_handle_irq(irq - 1 + start);
+		status &= ~(1 << irq);
+	}
+}
+
+static void s5p_irq_demux_eint16_31(unsigned int irq, struct irq_desc *desc)
+{
+	s5p_irq_demux_eint(IRQ_EINT(16));
+	s5p_irq_demux_eint(IRQ_EINT(24));
+}
+
+static inline void s5p_irq_vic_eint_mask(unsigned int irq)
+{
+	s5p_irq_eint_mask(irq);
+}
+
+static void s5p_irq_vic_eint_unmask(unsigned int irq)
+{
+	s5p_irq_eint_unmask(irq);
+}
+
+static inline void s5p_irq_vic_eint_ack(unsigned int irq)
+{
+	__raw_writel(eint_irq_to_bit(irq), S5P_EINT_PEND(EINT_REG_NR(irq)));
+}
+
+static void s5p_irq_vic_eint_maskack(unsigned int irq)
+{
+	s5p_irq_vic_eint_mask(irq);
+	s5p_irq_vic_eint_ack(irq);
+}
+
+static struct irq_chip s5p_irq_vic_eint = {
+	.name		= "s5p_vic_eint",
+	.mask		= s5p_irq_vic_eint_mask,
+	.unmask		= s5p_irq_vic_eint_unmask,
+	.mask_ack	= s5p_irq_vic_eint_maskack,
+	.ack		= s5p_irq_vic_eint_ack,
+	.set_type	= s5p_irq_eint_set_type,
+#ifdef CONFIG_PM
+	.set_wake	= s3c_irqext_wake,
+#endif
+};
+
+int __init s5p_init_irq_eint(void)
+{
+	int irq;
+
+	for (irq = IRQ_EINT(0); irq <= IRQ_EINT(15); irq++)
+		set_irq_chip(irq, &s5p_irq_vic_eint);
+
+	for (irq = IRQ_EINT(16); irq <= IRQ_EINT(31); irq++) {
+		set_irq_chip(irq, &s5p_irq_eint);
+		set_irq_handler(irq, handle_level_irq);
+		set_irq_flags(irq, IRQF_VALID);
+	}
+
+	set_irq_chained_handler(IRQ_EINT16_31, s5p_irq_demux_eint16_31);
+	return 0;
+}
+
+arch_initcall(s5p_init_irq_eint);