1 files changed, 143 insertions, 0 deletions

diff --git a/arch/arm/plat-samsung/irq-uart.c b/arch/arm/plat-samsung/irq-uart.c
new file mode 100644
index 000000000000..4f8c102674ae
--- /dev/null
+++ b/arch/arm/plat-samsung/irq-uart.c
@@ -0,0 +1,143 @@
+/* arch/arm/plat-samsung/irq-uart.c
+ *      originally part of arch/arm/plat-s3c64xx/irq.c
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *      http://armlinux.simtec.co.uk/
+ *
+ * Samsung- UART Interrupt handling
+ *
+ * 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/serial_core.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <mach/map.h>
+#include <plat/irq-uart.h>
+#include <plat/regs-serial.h>
+#include <plat/cpu.h>
+
+/* 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 inline void __iomem *s3c_irq_uart_base(unsigned int irq)
+{
+        struct s3c_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;
+}
+
+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 s3c_uart_irq *uirq = desc->handler_data;
+        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 s3c_init_uart_irq(struct s3c_uart_irq *uirq)
+{
+        struct irq_desc *desc = irq_to_desc(uirq->parent_irq);
+        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);
+        }
+
+        desc->handler_data = uirq;
+        set_irq_chained_handler(uirq->parent_irq, s3c_irq_demux_uart);
+}
+
+/**
+ * s3c_init_uart_irqs() - initialise UART IRQs and the necessary demuxing
+ * @irq: The interrupt data for registering
+ * @nr_irqs: The number of interrupt descriptions in @irq.
+ *
+ * Register the UART interrupts specified by @irq including the demuxing
+ * routines. This supports the S3C6400 and newer style of devices.
+ */
+void __init s3c_init_uart_irqs(struct s3c_uart_irq *irq, unsigned int nr_irqs)
+{
+        for (; nr_irqs > 0; nr_irqs--, irq++)
+                s3c_init_uart_irq(irq);
+}