android_kernel_motorola_sm6225/arch/arm/mach-ns9xxx/irq.c
Uwe Kleine-König ed6f598723 ns9xxx: add support for irq priorisation
prio2irq(0) is the highest prioritized interrupt.  For now there is no
binary change intended.

If you intend to change the priorisation, you have to assert:

	∀ x ∈ {0, 1, ⋯ 31}: (irq2prio ∘ prio2irq)(x) = x

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
2008-03-31 10:33:11 +02:00

119 lines
2.7 KiB
C

/*
* arch/arm/mach-ns9xxx/irq.c
*
* Copyright (C) 2006,2007 by Digi International Inc.
* All rights reserved.
*
* 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/interrupt.h>
#include <linux/kernel_stat.h>
#include <asm/io.h>
#include <asm/mach/irq.h>
#include <asm/mach-types.h>
#include <asm/arch-ns9xxx/regs-sys-common.h>
#include <asm/arch-ns9xxx/irqs.h>
#include <asm/arch-ns9xxx/board.h>
#include "generic.h"
/* simple interrupt prio table: prio(x) < prio(y) <=> x < y */
#define irq2prio(i) (i)
#define prio2irq(p) (p)
static void ns9xxx_mask_irq(unsigned int irq)
{
/* XXX: better use cpp symbols */
int prio = irq2prio(irq);
u32 ic = __raw_readl(SYS_IC(prio / 4));
ic &= ~(1 << (7 + 8 * (3 - (prio & 3))));
__raw_writel(ic, SYS_IC(prio / 4));
}
static void ns9xxx_ack_irq(unsigned int irq)
{
__raw_writel(0, SYS_ISRADDR);
}
static void ns9xxx_maskack_irq(unsigned int irq)
{
ns9xxx_mask_irq(irq);
ns9xxx_ack_irq(irq);
}
static void ns9xxx_unmask_irq(unsigned int irq)
{
/* XXX: better use cpp symbols */
int prio = irq2prio(irq);
u32 ic = __raw_readl(SYS_IC(prio / 4));
ic |= 1 << (7 + 8 * (3 - (prio & 3)));
__raw_writel(ic, SYS_IC(prio / 4));
}
static struct irq_chip ns9xxx_chip = {
.ack = ns9xxx_ack_irq,
.mask = ns9xxx_mask_irq,
.mask_ack = ns9xxx_maskack_irq,
.unmask = ns9xxx_unmask_irq,
};
#if 0
#define handle_irq handle_level_irq
#else
void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
{
unsigned int cpu = smp_processor_id();
struct irqaction *action;
irqreturn_t action_ret;
spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_cpu(cpu).irqs[irq]++;
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED)))
goto out_unlock;
desc->status |= IRQ_INPROGRESS;
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
if (!(desc->status & IRQ_DISABLED) && desc->chip->ack)
desc->chip->ack(irq);
out_unlock:
spin_unlock(&desc->lock);
}
#define handle_irq handle_prio_irq
#endif
void __init ns9xxx_init_irq(void)
{
int i;
/* disable all IRQs */
for (i = 0; i < 8; ++i)
__raw_writel(prio2irq(4 * i) << 24 |
prio2irq(4 * i + 1) << 16 |
prio2irq(4 * i + 2) << 8 |
prio2irq(4 * i + 3),
SYS_IC(i));
for (i = 0; i < 32; ++i)
__raw_writel(prio2irq(i), SYS_IVA(i));
for (i = 0; i <= 31; ++i) {
set_irq_chip(i, &ns9xxx_chip);
set_irq_handler(i, handle_irq);
set_irq_flags(i, IRQF_VALID);
}
}