/* 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);
}
