ARM: S5PC100: IRQ and timer

S5PC100 has 3 VICs(Vectored Interrupt Controller). The VICs come from S3C64xx
series, so the driver source code can be shared with S3C families. The S5PC100
has 3 VICs while S3C64xx has only 2.

Signed-off-by: Byungho Min <bhmin@samsung.com>
[ben-linux@fluff.org: subject fixup]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

6 files changed, 564 insertions, 0 deletions

diff --git a/arch/arm/mach-s5pc100/include/mach/irqs.h b/arch/arm/mach-s5pc100/include/mach/irqs.h
new file mode 100644
index 000000000000..622720dba289
--- /dev/null
+++ b/arch/arm/mach-s5pc100/include/mach/irqs.h
@@ -0,0 +1,14 @@
+/* linux/arch/arm/mach-s5pc100/include/mach/irqs.h
+ *
+ * Copyright 2009 Samsung Electronics Co.
+ *      Byungho Min <bhmin@samsung.com>
+ *
+ * S5PC100 - IRQ definitions
+ */
+
+#ifndef __ASM_ARCH_IRQS_H
+#define __ASM_ARCH_IRQS_H __FILE__
+
+#include <plat/irqs.h>
+
+#endif /* __ASM_ARCH_IRQ_H */
diff --git a/arch/arm/mach-s5pc100/include/mach/pwm-clock.h b/arch/arm/mach-s5pc100/include/mach/pwm-clock.h
new file mode 100644
index 000000000000..b34d2f7aae52
--- /dev/null
+++ b/arch/arm/mach-s5pc100/include/mach/pwm-clock.h
@@ -0,0 +1,56 @@
+/* linux/arch/arm/mach-s5pc100/include/mach/pwm-clock.h
+ *
+ * Copyright 2009 Samsung Electronics Co.
+ *      Byungho Min <bhmin@samsung.com>
+ *
+ * S5PC100 - pwm clock and timer support
+ *
+ * Based on mach-s3c6400/include/mach/pwm-clock.h
+ */
+
+/**
+ * pwm_cfg_src_is_tclk() - return whether the given mux config is a tclk
+ * @tcfg: The timer TCFG1 register bits shifted down to 0.
+ *
+ * Return true if the given configuration from TCFG1 is a TCLK instead
+ * any of the TDIV clocks.
+ */
+static inline int pwm_cfg_src_is_tclk(unsigned long tcfg)
+{
+        return tcfg >= S3C64XX_TCFG1_MUX_TCLK;
+}
+
+/**
+ * tcfg_to_divisor() - convert tcfg1 setting to a divisor
+ * @tcfg1: The tcfg1 setting, shifted down.
+ *
+ * Get the divisor value for the given tcfg1 setting. We assume the
+ * caller has already checked to see if this is not a TCLK source.
+ */
+static inline unsigned long tcfg_to_divisor(unsigned long tcfg1)
+{
+        return 1 << tcfg1;
+}
+
+/**
+ * pwm_tdiv_has_div1() - does the tdiv setting have a /1
+ *
+ * Return true if we have a /1 in the tdiv setting.
+ */
+static inline unsigned int pwm_tdiv_has_div1(void)
+{
+        return 1;
+}
+
+/**
+ * pwm_tdiv_div_bits() - calculate TCFG1 divisor value.
+ * @div: The divisor to calculate the bit information for.
+ *
+ * Turn a divisor into the necessary bit field for TCFG1.
+ */
+static inline unsigned long pwm_tdiv_div_bits(unsigned int div)
+{
+        return ilog2(div);
+}
+
+#define S3C_TCFG1_MUX_TCLK S3C64XX_TCFG1_MUX_TCLK
diff --git a/arch/arm/mach-s5pc100/include/mach/regs-irq.h b/arch/arm/mach-s5pc100/include/mach/regs-irq.h
new file mode 100644
index 000000000000..751ac15438c8
--- /dev/null
+++ b/arch/arm/mach-s5pc100/include/mach/regs-irq.h
@@ -0,0 +1,24 @@
+/* linux/arch/arm/mach-s5pc100/include/mach/regs-irq.h
+ *
+ * Copyright 2009 Samsung Electronics Co.
+ *      Byungho Min <bhmin@samsung.com>
+ *
+ * S5PC1XX - IRQ register definitions
+ *
+ * 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.
+*/
+
+#ifndef __ASM_ARCH_REGS_IRQ_H
+#define __ASM_ARCH_REGS_IRQ_H __FILE__
+
+#include <mach/map.h>
+#include <asm/hardware/vic.h>
+
+/* interrupt controller */
+#define S5PC1XX_VIC0REG(x)                      ((x) + S5PC1XX_VA_VIC(0))
+#define S5PC1XX_VIC1REG(x)                      ((x) + S5PC1XX_VA_VIC(1))
+#define S5PC1XX_VIC2REG(x)                      ((x) + S5PC1XX_VA_VIC(2))
+
+#endif /* __ASM_ARCH_REGS_IRQ_H */
diff --git a/arch/arm/mach-s5pc100/include/mach/tick.h b/arch/arm/mach-s5pc100/include/mach/tick.h
new file mode 100644
index 000000000000..d3de0f3591ae
--- /dev/null
+++ b/arch/arm/mach-s5pc100/include/mach/tick.h
@@ -0,0 +1,29 @@
+/* linux/arch/arm/mach-s5pc100/include/mach/tick.h
+ *
+ * Copyright 2009 Samsung Electronics Co.
+ *      Byungho Min <bhmin@samsung.com>
+ *
+ * S3C64XX - Timer tick support definitions
+ *
+ * Based on mach-s3c6400/include/mach/tick.h
+ *
+ * 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.
+*/
+
+#ifndef __ASM_ARCH_TICK_H
+#define __ASM_ARCH_TICK_H __FILE__
+
+/* note, the timer interrutps turn up in 2 places, the vic and then
+ * the timer block. We take the VIC as the base at the moment.
+ */
+static inline u32 s3c24xx_ostimer_pending(void)
+{
+        u32 pend = __raw_readl(S3C_VA_VIC0 + VIC_RAW_STATUS);
+        return pend & 1 << (IRQ_TIMER4 - S5PC1XX_IRQ_VIC0(0));
+}
+
+#define TICK_MAX        (0xffffffff)
+
+#endif /* __ASM_ARCH_TICK_H */
diff --git a/arch/arm/plat-s5pc1xx/include/plat/irqs.h b/arch/arm/plat-s5pc1xx/include/plat/irqs.h
new file mode 100644
index 000000000000..f07d8c3b25d6
--- /dev/null
+++ b/arch/arm/plat-s5pc1xx/include/plat/irqs.h
@@ -0,0 +1,182 @@
+/* linux/arch/arm/plat-s5pc1xx/include/plat/irqs.h
+ *
+ * Copyright 2009 Samsung Electronics Co.
+ *      Byungho Min <bhmin@samsung.com>
+ *
+ * S5PC1XX - Common IRQ support
+ *
+ * Based on plat-s3c64xx/include/plat/irqs.h
+ */
+
+#ifndef __ASM_PLAT_S5PC1XX_IRQS_H
+#define __ASM_PLAT_S5PC1XX_IRQS_H __FILE__
+
+/* we keep the first set of CPU IRQs out of the range of
+ * the ISA space, so that the PC104 has them to itself
+ * and we don't end up having to do horrible things to the
+ * standard ISA drivers....
+ *
+ * note, since we're using the VICs, our start must be a
+ * mulitple of 32 to allow the common code to work
+ */
+
+#define S3C_IRQ_OFFSET          (32)
+
+#define S3C_IRQ(x)              ((x) + S3C_IRQ_OFFSET)
+
+#define S3C_VIC0_BASE           S3C_IRQ(0)
+#define S3C_VIC1_BASE           S3C_IRQ(32)
+#define S3C_VIC2_BASE           S3C_IRQ(64)
+
+/* UART interrupts, each UART has 4 intterupts per channel so
+ * use the space between the ISA and S3C main interrupts. Note, these
+ * are not in the same order as the S3C24XX series! */
+
+#define IRQ_S3CUART_BASE0       (16)
+#define IRQ_S3CUART_BASE1       (20)
+#define IRQ_S3CUART_BASE2       (24)
+#define IRQ_S3CUART_BASE3       (28)
+
+#define UART_IRQ_RXD            (0)
+#define UART_IRQ_ERR            (1)
+#define UART_IRQ_TXD            (2)
+#define UART_IRQ_MODEM          (3)
+
+#define IRQ_S3CUART_RX0         (IRQ_S3CUART_BASE0 + UART_IRQ_RXD)
+#define IRQ_S3CUART_TX0         (IRQ_S3CUART_BASE0 + UART_IRQ_TXD)
+#define IRQ_S3CUART_ERR0        (IRQ_S3CUART_BASE0 + UART_IRQ_ERR)
+
+#define IRQ_S3CUART_RX1         (IRQ_S3CUART_BASE1 + UART_IRQ_RXD)
+#define IRQ_S3CUART_TX1         (IRQ_S3CUART_BASE1 + UART_IRQ_TXD)
+#define IRQ_S3CUART_ERR1        (IRQ_S3CUART_BASE1 + UART_IRQ_ERR)
+
+#define IRQ_S3CUART_RX2         (IRQ_S3CUART_BASE2 + UART_IRQ_RXD)
+#define IRQ_S3CUART_TX2         (IRQ_S3CUART_BASE2 + UART_IRQ_TXD)
+#define IRQ_S3CUART_ERR2        (IRQ_S3CUART_BASE2 + UART_IRQ_ERR)
+
+#define IRQ_S3CUART_RX3         (IRQ_S3CUART_BASE3 + UART_IRQ_RXD)
+#define IRQ_S3CUART_TX3         (IRQ_S3CUART_BASE3 + UART_IRQ_TXD)
+#define IRQ_S3CUART_ERR3        (IRQ_S3CUART_BASE3 + UART_IRQ_ERR)
+
+/* VIC based IRQs */
+
+#define S5PC1XX_IRQ_VIC0(x)     (S3C_VIC0_BASE + (x))
+#define S5PC1XX_IRQ_VIC1(x)     (S3C_VIC1_BASE + (x))
+#define S5PC1XX_IRQ_VIC2(x)     (S3C_VIC2_BASE + (x))
+
+/*
+ * VIC0: system, DMA, timer
+ */
+#define IRQ_EINT0               S5PC1XX_IRQ_VIC0(0)
+#define IRQ_EINT1               S5PC1XX_IRQ_VIC0(1)
+#define IRQ_EINT2               S5PC1XX_IRQ_VIC0(2)
+#define IRQ_EINT3               S5PC1XX_IRQ_VIC0(3)
+#define IRQ_EINT4               S5PC1XX_IRQ_VIC0(4)
+#define IRQ_EINT5               S5PC1XX_IRQ_VIC0(5)
+#define IRQ_EINT6               S5PC1XX_IRQ_VIC0(6)
+#define IRQ_EINT7               S5PC1XX_IRQ_VIC0(7)
+#define IRQ_EINT8               S5PC1XX_IRQ_VIC0(8)
+#define IRQ_EINT9               S5PC1XX_IRQ_VIC0(9)
+#define IRQ_EINT10              S5PC1XX_IRQ_VIC0(10)
+#define IRQ_EINT11              S5PC1XX_IRQ_VIC0(11)
+#define IRQ_EINT12              S5PC1XX_IRQ_VIC0(12)
+#define IRQ_EINT13              S5PC1XX_IRQ_VIC0(13)
+#define IRQ_EINT14              S5PC1XX_IRQ_VIC0(14)
+#define IRQ_EINT15              S5PC1XX_IRQ_VIC0(15)
+#define IRQ_EINT16_31           S5PC1XX_IRQ_VIC0(16)
+#define IRQ_BATF                S5PC1XX_IRQ_VIC0(17)
+#define IRQ_MDMA                S5PC1XX_IRQ_VIC0(18)
+#define IRQ_PDMA0               S5PC1XX_IRQ_VIC0(19)
+#define IRQ_PDMA1               S5PC1XX_IRQ_VIC0(20)
+#define IRQ_TIMER0              S5PC1XX_IRQ_VIC0(21)
+#define IRQ_TIMER1              S5PC1XX_IRQ_VIC0(22)
+#define IRQ_TIMER2              S5PC1XX_IRQ_VIC0(23)
+#define IRQ_TIMER3              S5PC1XX_IRQ_VIC0(24)
+#define IRQ_TIMER4              S5PC1XX_IRQ_VIC0(25)
+#define IRQ_SYSTIMER            S5PC1XX_IRQ_VIC0(26)
+#define IRQ_WDT                 S5PC1XX_IRQ_VIC0(27)
+#define IRQ_RTC_ALARM           S5PC1XX_IRQ_VIC0(28)
+#define IRQ_RTC_TIC             S5PC1XX_IRQ_VIC0(29)
+#define IRQ_GPIOINT             S5PC1XX_IRQ_VIC0(30)
+
+/*
+ * VIC1: ARM, power, memory, connectivity
+ */
+#define IRQ_CORTEX0             S5PC1XX_IRQ_VIC1(0)
+#define IRQ_CORTEX1             S5PC1XX_IRQ_VIC1(1)
+#define IRQ_CORTEX2             S5PC1XX_IRQ_VIC1(2)
+#define IRQ_CORTEX3             S5PC1XX_IRQ_VIC1(3)
+#define IRQ_CORTEX4             S5PC1XX_IRQ_VIC1(4)
+#define IRQ_IEMAPC              S5PC1XX_IRQ_VIC1(5)
+#define IRQ_IEMIEC              S5PC1XX_IRQ_VIC1(6)
+#define IRQ_ONENAND             S5PC1XX_IRQ_VIC1(7)
+#define IRQ_NFC                 S5PC1XX_IRQ_VIC1(8)
+#define IRQ_CFC                 S5PC1XX_IRQ_VIC1(9)
+#define IRQ_UART0               S5PC1XX_IRQ_VIC1(10)
+#define IRQ_UART1               S5PC1XX_IRQ_VIC1(11)
+#define IRQ_UART2               S5PC1XX_IRQ_VIC1(12)
+#define IRQ_UART3               S5PC1XX_IRQ_VIC1(13)
+#define IRQ_IIC                 S5PC1XX_IRQ_VIC1(14)
+#define IRQ_SPI0                S5PC1XX_IRQ_VIC1(15)
+#define IRQ_SPI1                S5PC1XX_IRQ_VIC1(16)
+#define IRQ_SPI2                S5PC1XX_IRQ_VIC1(17)
+#define IRQ_IRDA                S5PC1XX_IRQ_VIC1(18)
+#define IRQ_CAN0                S5PC1XX_IRQ_VIC1(19)
+#define IRQ_CAN1                S5PC1XX_IRQ_VIC1(20)
+#define IRQ_HSIRX               S5PC1XX_IRQ_VIC1(21)
+#define IRQ_HSITX               S5PC1XX_IRQ_VIC1(22)
+#define IRQ_UHOST               S5PC1XX_IRQ_VIC1(23)
+#define IRQ_OTG                 S5PC1XX_IRQ_VIC1(24)
+#define IRQ_MSM                 S5PC1XX_IRQ_VIC1(25)
+#define IRQ_HSMMC0              S5PC1XX_IRQ_VIC1(26)
+#define IRQ_HSMMC1              S5PC1XX_IRQ_VIC1(27)
+#define IRQ_HSMMC2              S5PC1XX_IRQ_VIC1(28)
+#define IRQ_MIPICSI             S5PC1XX_IRQ_VIC1(29)
+#define IRQ_MIPIDSI             S5PC1XX_IRQ_VIC1(30)
+
+/*
+ * VIC2: multimedia, audio, security
+ */
+#define IRQ_LCD0                S5PC1XX_IRQ_VIC2(0)
+#define IRQ_LCD1                S5PC1XX_IRQ_VIC2(1)
+#define IRQ_LCD2                S5PC1XX_IRQ_VIC2(2)
+#define IRQ_LCD3                S5PC1XX_IRQ_VIC2(3)
+#define IRQ_ROTATOR             S5PC1XX_IRQ_VIC2(4)
+#define IRQ_FIMC0               S5PC1XX_IRQ_VIC2(5)
+#define IRQ_FIMC1               S5PC1XX_IRQ_VIC2(6)
+#define IRQ_FIMC2               S5PC1XX_IRQ_VIC2(7)
+#define IRQ_JPEG                S5PC1XX_IRQ_VIC2(8)
+#define IRQ_2D                  S5PC1XX_IRQ_VIC2(9)
+#define IRQ_3D                  S5PC1XX_IRQ_VIC2(10)
+#define IRQ_MIXER               S5PC1XX_IRQ_VIC2(11)
+#define IRQ_HDMI                S5PC1XX_IRQ_VIC2(12)
+#define IRQ_IIC1                S5PC1XX_IRQ_VIC2(13)
+#define IRQ_MFC                 S5PC1XX_IRQ_VIC2(14)
+#define IRQ_TVENC               S5PC1XX_IRQ_VIC2(15)
+#define IRQ_I2S0                S5PC1XX_IRQ_VIC2(16)
+#define IRQ_I2S1                S5PC1XX_IRQ_VIC2(17)
+#define IRQ_I2S2                S5PC1XX_IRQ_VIC2(18)
+#define IRQ_AC97                S5PC1XX_IRQ_VIC2(19)
+#define IRQ_PCM0                S5PC1XX_IRQ_VIC2(20)
+#define IRQ_PCM1                S5PC1XX_IRQ_VIC2(21)
+#define IRQ_SPDIF               S5PC1XX_IRQ_VIC2(22)
+#define IRQ_ADC                 S5PC1XX_IRQ_VIC2(23)
+#define IRQ_PENDN               S5PC1XX_IRQ_VIC2(24)
+#define IRQ_TC                  IRQ_PENDN
+#define IRQ_KEYPAD              S5PC1XX_IRQ_VIC2(25)
+#define IRQ_CG                  S5PC1XX_IRQ_VIC2(26)
+#define IRQ_SEC                 S5PC1XX_IRQ_VIC2(27)
+#define IRQ_SECRX               S5PC1XX_IRQ_VIC2(28)
+#define IRQ_SECTX               S5PC1XX_IRQ_VIC2(29)
+#define IRQ_SDMIRQ              S5PC1XX_IRQ_VIC2(30)
+#define IRQ_SDMFIQ              S5PC1XX_IRQ_VIC2(31)
+
+#define S3C_IRQ_EINT_BASE       (IRQ_SDMFIQ + 1)
+
+#define S3C_EINT(x)             ((x) + S3C_IRQ_EINT_BASE)
+#define IRQ_EINT(x)             S3C_EINT(x)
+
+#define NR_IRQS                 (IRQ_EINT(31)+1)
+
+#endif /* __ASM_PLAT_S5PC1XX_IRQS_H */
+
diff --git a/arch/arm/plat-s5pc1xx/irq.c b/arch/arm/plat-s5pc1xx/irq.c
new file mode 100644
index 000000000000..80d6dd942cb8
--- /dev/null
+++ b/arch/arm/plat-s5pc1xx/irq.c
@@ -0,0 +1,259 @@
+/* arch/arm/plat-s5pc1xx/irq.c
+ *
+ * Copyright 2009 Samsung Electronics Co.
+ *      Byungho Min <bhmin@samsung.com>
+ *
+ * S5PC1XX - Interrupt handling
+ *
+ * Based on plat-s3c64xx/irq.c
+ *
+ * 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 <asm/hardware/vic.h>
+
+#include <mach/map.h>
+#include <plat/regs-timer.h>
+#include <plat/cpu.h>
+
+/* Timer interrupt handling */
+
+static void s3c_irq_demux_timer(unsigned int base_irq, unsigned int sub_irq)
+{
+        generic_handle_irq(sub_irq);
+}
+
+static void s3c_irq_demux_timer0(unsigned int irq, struct irq_desc *desc)
+{
+        s3c_irq_demux_timer(irq, IRQ_TIMER0);
+}
+
+static void s3c_irq_demux_timer1(unsigned int irq, struct irq_desc *desc)
+{
+        s3c_irq_demux_timer(irq, IRQ_TIMER1);
+}
+
+static void s3c_irq_demux_timer2(unsigned int irq, struct irq_desc *desc)
+{
+        s3c_irq_demux_timer(irq, IRQ_TIMER2);
+}
+
+static void s3c_irq_demux_timer3(unsigned int irq, struct irq_desc *desc)
+{
+        s3c_irq_demux_timer(irq, IRQ_TIMER3);
+}
+
+static void s3c_irq_demux_timer4(unsigned int irq, struct irq_desc *desc)
+{
+        s3c_irq_demux_timer(irq, IRQ_TIMER4);
+}
+
+/* We assume the IRQ_TIMER0..IRQ_TIMER4 range is continuous. */
+
+static void s3c_irq_timer_mask(unsigned int irq)
+{
+        u32 reg = __raw_readl(S3C64XX_TINT_CSTAT);
+
+        reg &= 0x1f;  /* mask out pending interrupts */
+        reg &= ~(1 << (irq - IRQ_TIMER0));
+        __raw_writel(reg, S3C64XX_TINT_CSTAT);
+}
+
+static void s3c_irq_timer_unmask(unsigned int irq)
+{
+        u32 reg = __raw_readl(S3C64XX_TINT_CSTAT);
+
+        reg &= 0x1f;  /* mask out pending interrupts */
+        reg |= 1 << (irq - IRQ_TIMER0);
+        __raw_writel(reg, S3C64XX_TINT_CSTAT);
+}
+
+static void s3c_irq_timer_ack(unsigned int irq)
+{
+        u32 reg = __raw_readl(S3C64XX_TINT_CSTAT);
+
+        reg &= 0x1f;
+        reg |= (1 << 5) << (irq - IRQ_TIMER0);
+        __raw_writel(reg, S3C64XX_TINT_CSTAT);
+}
+
+static struct irq_chip s3c_irq_timer = {
+        .name           = "s3c-timer",
+        .mask           = s3c_irq_timer_mask,
+        .unmask         = s3c_irq_timer_unmask,
+        .ack            = s3c_irq_timer_ack,
+};
+
+struct uart_irq {
+        void __iomem    *regs;
+        unsigned int     base_irq;
+        unsigned int     parent_irq;
+};
+
+/* Note, we make use of the fact that the parent IRQs, IRQ_UART[0..3]
+ * are consecutive when looking up the interrupt in the demux routines.
+ */
+static struct uart_irq uart_irqs[] = {
+        [0] = {
+                .regs           = (void *)S3C_VA_UART0,
+                .base_irq       = IRQ_S3CUART_BASE0,
+                .parent_irq     = IRQ_UART0,
+        },
+        [1] = {
+                .regs           = (void *)S3C_VA_UART1,
+                .base_irq       = IRQ_S3CUART_BASE1,
+                .parent_irq     = IRQ_UART1,
+        },
+        [2] = {
+                .regs           = (void *)S3C_VA_UART2,
+                .base_irq       = IRQ_S3CUART_BASE2,
+                .parent_irq     = IRQ_UART2,
+        },
+        [3] = {
+                .regs           = (void *)S3C_VA_UART3,
+                .base_irq       = IRQ_S3CUART_BASE3,
+                .parent_irq     = IRQ_UART3,
+        },
+};
+
+static inline void __iomem *s3c_irq_uart_base(unsigned int irq)
+{
+        struct uart_irq *uirq = get_irq_chip_data(irq);
+        return uirq->regs;
+}
+
+static inline unsigned int s3c_irq_uart_bit(unsigned int irq)
+{
+        return irq & 3;
+}
+
+/* UART interrupt registers, not worth adding to seperate include header */
+#define S3C64XX_UINTP   0x30
+#define S3C64XX_UINTSP  0x34
+#define S3C64XX_UINTM   0x38
+
+static void s3c_irq_uart_mask(unsigned int irq)
+{
+        void __iomem *regs = s3c_irq_uart_base(irq);
+        unsigned int bit = s3c_irq_uart_bit(irq);
+        u32 reg;
+
+        reg = __raw_readl(regs + S3C64XX_UINTM);
+        reg |= (1 << bit);
+        __raw_writel(reg, regs + S3C64XX_UINTM);
+}
+
+static void s3c_irq_uart_maskack(unsigned int irq)
+{
+        void __iomem *regs = s3c_irq_uart_base(irq);
+        unsigned int bit = s3c_irq_uart_bit(irq);
+        u32 reg;
+
+        reg = __raw_readl(regs + S3C64XX_UINTM);
+        reg |= (1 << bit);
+        __raw_writel(reg, regs + S3C64XX_UINTM);
+        __raw_writel(1 << bit, regs + S3C64XX_UINTP);
+}
+
+static void s3c_irq_uart_unmask(unsigned int irq)
+{
+        void __iomem *regs = s3c_irq_uart_base(irq);
+        unsigned int bit = s3c_irq_uart_bit(irq);
+        u32 reg;
+
+        reg = __raw_readl(regs + S3C64XX_UINTM);
+        reg &= ~(1 << bit);
+        __raw_writel(reg, regs + S3C64XX_UINTM);
+}
+
+static void s3c_irq_uart_ack(unsigned int irq)
+{
+        void __iomem *regs = s3c_irq_uart_base(irq);
+        unsigned int bit = s3c_irq_uart_bit(irq);
+
+        __raw_writel(1 << bit, regs + S3C64XX_UINTP);
+}
+
+static void s3c_irq_demux_uart(unsigned int irq, struct irq_desc *desc)
+{
+        struct uart_irq *uirq = &uart_irqs[irq - IRQ_UART0];
+        u32 pend = __raw_readl(uirq->regs + S3C64XX_UINTP);
+        int base = uirq->base_irq;
+
+        if (pend & (1 << 0))
+                generic_handle_irq(base);
+        if (pend & (1 << 1))
+                generic_handle_irq(base + 1);
+        if (pend & (1 << 2))
+                generic_handle_irq(base + 2);
+        if (pend & (1 << 3))
+                generic_handle_irq(base + 3);
+}
+
+static struct irq_chip s3c_irq_uart = {
+        .name           = "s3c-uart",
+        .mask           = s3c_irq_uart_mask,
+        .unmask         = s3c_irq_uart_unmask,
+        .mask_ack       = s3c_irq_uart_maskack,
+        .ack            = s3c_irq_uart_ack,
+};
+
+static void __init s5pc1xx_uart_irq(struct uart_irq *uirq)
+{
+        void __iomem *reg_base = uirq->regs;
+        unsigned int irq;
+        int offs;
+
+        /* mask all interrupts at the start. */
+        __raw_writel(0xf, reg_base + S3C64XX_UINTM);
+
+        for (offs = 0; offs < 3; offs++) {
+                irq = uirq->base_irq + offs;
+
+                set_irq_chip(irq, &s3c_irq_uart);
+                set_irq_chip_data(irq, uirq);
+                set_irq_handler(irq, handle_level_irq);
+                set_irq_flags(irq, IRQF_VALID);
+        }
+
+        set_irq_chained_handler(uirq->parent_irq, s3c_irq_demux_uart);
+}
+
+void __init s5pc1xx_init_irq(u32 *vic_valid, int num)
+{
+        int i;
+        int uart, irq;
+
+        printk(KERN_DEBUG "%s: initialising interrupts\n", __func__);
+
+        /* initialise the pair of VICs */
+        for (i = 0; i < num; i++)
+                vic_init((void *)S5PC1XX_VA_VIC(i), S3C_IRQ(i * S3C_IRQ_OFFSET),
+                                vic_valid[i], 0);
+
+        /* add the timer sub-irqs */
+
+        set_irq_chained_handler(IRQ_TIMER0, s3c_irq_demux_timer0);
+        set_irq_chained_handler(IRQ_TIMER1, s3c_irq_demux_timer1);
+        set_irq_chained_handler(IRQ_TIMER2, s3c_irq_demux_timer2);
+        set_irq_chained_handler(IRQ_TIMER3, s3c_irq_demux_timer3);
+        set_irq_chained_handler(IRQ_TIMER4, s3c_irq_demux_timer4);
+
+        for (irq = IRQ_TIMER0; irq <= IRQ_TIMER4; irq++) {
+                set_irq_chip(irq, &s3c_irq_timer);
+                set_irq_handler(irq, handle_level_irq);
+                set_irq_flags(irq, IRQF_VALID);
+        }
+
+        for (uart = 0; uart < ARRAY_SIZE(uart_irqs); uart++)
+                s5pc1xx_uart_irq(&uart_irqs[uart]);
+}
+
+