ARM: S5P64X0: External Interrupt Support

Add external interrupt support for S5P64X0.The external interrupt
group 0(0 to 15) is used for wake-up source in stop and sleep mode.
Add generic irq chip support

Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

3 files changed, 163 insertions, 1 deletions

diff --git a/arch/arm/mach-s5p64x0/Makefile b/arch/arm/mach-s5p64x0/Makefile
index ae6bf6feba89..5f6afdf067ed 100644
--- a/arch/arm/mach-s5p64x0/Makefile
+++ b/arch/arm/mach-s5p64x0/Makefile
@@ -13,7 +13,7 @@ obj-				:=
 # Core support for S5P64X0 system
 
 obj-$(CONFIG_ARCH_S5P64X0)      += cpu.o init.o clock.o dma.o gpiolib.o
-obj-$(CONFIG_ARCH_S5P64X0)      += setup-i2c0.o
+obj-$(CONFIG_ARCH_S5P64X0)      += setup-i2c0.o irq-eint.o
 obj-$(CONFIG_CPU_S5P6440)       += clock-s5p6440.o
 obj-$(CONFIG_CPU_S5P6450)       += clock-s5p6450.o
 
diff --git a/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h b/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
index 0953ef6b1c77..6ce254729f3b 100644
--- a/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
+++ b/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
@@ -34,4 +34,14 @@
 #define S5P6450_GPQ_BASE                (S5P_VA_GPIO + 0x0180)
 #define S5P6450_GPS_BASE                (S5P_VA_GPIO + 0x0300)
 
+/* External interrupt control registers for group0 */
+
+#define EINT0CON0_OFFSET                (0x900)
+#define EINT0MASK_OFFSET                (0x920)
+#define EINT0PEND_OFFSET                (0x924)
+
+#define S5P64X0_EINT0CON0               (S5P_VA_GPIO + EINT0CON0_OFFSET)
+#define S5P64X0_EINT0MASK               (S5P_VA_GPIO + EINT0MASK_OFFSET)
+#define S5P64X0_EINT0PEND               (S5P_VA_GPIO + EINT0PEND_OFFSET)
+
 #endif /* __ASM_ARCH_REGS_GPIO_H */
diff --git a/arch/arm/mach-s5p64x0/irq-eint.c b/arch/arm/mach-s5p64x0/irq-eint.c
new file mode 100644
index 000000000000..69ed4545112b
--- /dev/null
+++ b/arch/arm/mach-s5p64x0/irq-eint.c
@@ -0,0 +1,152 @@
+/* arch/arm/mach-s5p64x0/irq-eint.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd
+ *              http://www.samsung.com/
+ *
+ * Based on linux/arch/arm/mach-s3c64xx/irq-eint.c
+ *
+ * S5P64X0 - Interrupt handling for External Interrupts.
+ *
+ * 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/gpio.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <plat/regs-irqtype.h>
+#include <plat/gpio-cfg.h>
+
+#include <mach/regs-gpio.h>
+#include <mach/regs-clock.h>
+
+#define eint_offset(irq)        ((irq) - IRQ_EINT(0))
+
+static int s5p64x0_irq_eint_set_type(struct irq_data *data, unsigned int type)
+{
+        int offs = eint_offset(data->irq);
+        int shift;
+        u32 ctrl, mask;
+        u32 newvalue = 0;
+
+        if (offs > 15)
+                return -EINVAL;
+
+        switch (type) {
+        case IRQ_TYPE_NONE:
+                printk(KERN_WARNING "No edge setting!\n");
+                break;
+        case IRQ_TYPE_EDGE_RISING:
+                newvalue = S3C2410_EXTINT_RISEEDGE;
+                break;
+        case IRQ_TYPE_EDGE_FALLING:
+                newvalue = S3C2410_EXTINT_FALLEDGE;
+                break;
+        case IRQ_TYPE_EDGE_BOTH:
+                newvalue = S3C2410_EXTINT_BOTHEDGE;
+                break;
+        case IRQ_TYPE_LEVEL_LOW:
+                newvalue = S3C2410_EXTINT_LOWLEV;
+                break;
+        case IRQ_TYPE_LEVEL_HIGH:
+                newvalue = S3C2410_EXTINT_HILEV;
+                break;
+        default:
+                printk(KERN_ERR "No such irq type %d", type);
+                return -EINVAL;
+        }
+
+        shift = (offs / 2) * 4;
+        mask = 0x7 << shift;
+
+        ctrl = __raw_readl(S5P64X0_EINT0CON0) & ~mask;
+        ctrl |= newvalue << shift;
+        __raw_writel(ctrl, S5P64X0_EINT0CON0);
+
+        /* Configure the GPIO pin for 6450 or 6440 based on CPU ID */
+        if (0x50000 == (__raw_readl(S5P64X0_SYS_ID) & 0xFF000))
+                s3c_gpio_cfgpin(S5P6450_GPN(offs), S3C_GPIO_SFN(2));
+        else
+                s3c_gpio_cfgpin(S5P6440_GPN(offs), S3C_GPIO_SFN(2));
+
+        return 0;
+}
+
+/*
+ * s5p64x0_irq_demux_eint
+ *
+ * This function demuxes the IRQ from the group0 external interrupts,
+ * from IRQ_EINT(0) to IRQ_EINT(15). It is designed to be inlined into
+ * the specific handlers s5p64x0_irq_demux_eintX_Y.
+ */
+static inline void s5p64x0_irq_demux_eint(unsigned int start, unsigned int end)
+{
+        u32 status = __raw_readl(S5P64X0_EINT0PEND);
+        u32 mask = __raw_readl(S5P64X0_EINT0MASK);
+        unsigned int irq;
+
+        status &= ~mask;
+        status >>= start;
+        status &= (1 << (end - start + 1)) - 1;
+
+        for (irq = IRQ_EINT(start); irq <= IRQ_EINT(end); irq++) {
+                if (status & 1)
+                        generic_handle_irq(irq);
+                status >>= 1;
+        }
+}
+
+static void s5p64x0_irq_demux_eint0_3(unsigned int irq, struct irq_desc *desc)
+{
+        s5p64x0_irq_demux_eint(0, 3);
+}
+
+static void s5p64x0_irq_demux_eint4_11(unsigned int irq, struct irq_desc *desc)
+{
+        s5p64x0_irq_demux_eint(4, 11);
+}
+
+static void s5p64x0_irq_demux_eint12_15(unsigned int irq,
+                                        struct irq_desc *desc)
+{
+        s5p64x0_irq_demux_eint(12, 15);
+}
+
+static int s5p64x0_alloc_gc(void)
+{
+        struct irq_chip_generic *gc;
+        struct irq_chip_type *ct;
+
+        gc = irq_alloc_generic_chip("s5p64x0-eint", 1, S5P_IRQ_EINT_BASE,
+                                    S5P_VA_GPIO, handle_level_irq);
+        if (!gc) {
+                printk(KERN_ERR "%s: irq_alloc_generic_chip for group 0"
+                        "external interrupts failed\n", __func__);
+                return -EINVAL;
+        }
+
+        ct = gc->chip_types;
+        ct->chip.irq_ack = irq_gc_ack;
+        ct->chip.irq_mask = irq_gc_mask_set_bit;
+        ct->chip.irq_unmask = irq_gc_mask_clr_bit;
+        ct->chip.irq_set_type = s5p64x0_irq_eint_set_type;
+        ct->regs.ack = EINT0PEND_OFFSET;
+        ct->regs.mask = EINT0MASK_OFFSET;
+        irq_setup_generic_chip(gc, IRQ_MSK(16), IRQ_GC_INIT_MASK_CACHE,
+                               IRQ_NOREQUEST | IRQ_NOPROBE, 0);
+        return 0;
+}
+
+static int __init s5p64x0_init_irq_eint(void)
+{
+        int ret = s5p64x0_alloc_gc();
+        irq_set_chained_handler(IRQ_EINT0_3, s5p64x0_irq_demux_eint0_3);
+        irq_set_chained_handler(IRQ_EINT4_11, s5p64x0_irq_demux_eint4_11);
+        irq_set_chained_handler(IRQ_EINT12_15, s5p64x0_irq_demux_eint12_15);
+
+        return ret;
+}
+arch_initcall(s5p64x0_init_irq_eint);