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/* 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 <asm/mach/irq.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 void s3c_irq_demux_uart(unsigned int irq, struct irq_desc *desc)
{
struct s3c_uart_irq *uirq = desc->irq_data.handler_data;
struct irq_chip *chip = irq_get_chip(irq);
u32 pend = __raw_readl(uirq->regs + S3C64XX_UINTP);
int base = uirq->base_irq;
chained_irq_enter(chip, desc);
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);
chained_irq_exit(chip, desc);
}
static void __init s3c_init_uart_irq(struct s3c_uart_irq *uirq)
{
void __iomem *reg_base = uirq->regs;
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
/* mask all interrupts at the start. */
__raw_writel(0xf, reg_base + S3C64XX_UINTM);
gc = irq_alloc_generic_chip("s3c-uart", 1, uirq->base_irq, reg_base,
handle_level_irq);
if (!gc) {
pr_err("%s: irq_alloc_generic_chip for IRQ %u failed\n",
__func__, uirq->base_irq);
return;
}
ct = gc->chip_types;
ct->chip.irq_ack = irq_gc_ack_set_bit;
ct->chip.irq_mask = irq_gc_mask_set_bit;
ct->chip.irq_unmask = irq_gc_mask_clr_bit;
ct->regs.ack = S3C64XX_UINTP;
ct->regs.mask = S3C64XX_UINTM;
irq_setup_generic_chip(gc, IRQ_MSK(4), IRQ_GC_INIT_MASK_CACHE,
IRQ_NOREQUEST | IRQ_NOPROBE, 0);
irq_set_handler_data(uirq->parent_irq, uirq);
irq_set_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);
}
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