/*
* External interrupt handling for AT32AP CPUs
*
* Copyright (C) 2006 Atmel Corporation
*
* 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/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/random.h>
#include <asm/io.h>
#include <asm/arch/sm.h>
#include "sm.h"
static void eim_ack_irq(unsigned int irq)
{
struct at32_sm *sm = get_irq_chip_data(irq);
sm_writel(sm, EIM_ICR, 1 << (irq - sm->eim_first_irq));
}
static void eim_mask_irq(unsigned int irq)
{
struct at32_sm *sm = get_irq_chip_data(irq);
sm_writel(sm, EIM_IDR, 1 << (irq - sm->eim_first_irq));
}
static void eim_mask_ack_irq(unsigned int irq)
{
struct at32_sm *sm = get_irq_chip_data(irq);
sm_writel(sm, EIM_ICR, 1 << (irq - sm->eim_first_irq));
sm_writel(sm, EIM_IDR, 1 << (irq - sm->eim_first_irq));
}
static void eim_unmask_irq(unsigned int irq)
{
struct at32_sm *sm = get_irq_chip_data(irq);
sm_writel(sm, EIM_IER, 1 << (irq - sm->eim_first_irq));
}
static int eim_set_irq_type(unsigned int irq, unsigned int flow_type)
{
struct at32_sm *sm = get_irq_chip_data(irq);
unsigned int i = irq - sm->eim_first_irq;
u32 mode, edge, level;
unsigned long flags;
int ret = 0;
flow_type &= IRQ_TYPE_SENSE_MASK;
spin_lock_irqsave(&sm->lock, flags);
mode = sm_readl(sm, EIM_MODE);
edge = sm_readl(sm, EIM_EDGE);
level = sm_readl(sm, EIM_LEVEL);
switch (flow_type) {
case IRQ_TYPE_LEVEL_LOW:
mode |= 1 << i;
level &= ~(1 << i);
break;
case IRQ_TYPE_LEVEL_HIGH:
mode |= 1 << i;
level |= 1 << i;
break;
case IRQ_TYPE_EDGE_RISING:
mode &= ~(1 << i);
edge |= 1 << i;
break;
case IRQ_TYPE_EDGE_FALLING:
mode &= ~(1 << i);
edge &= ~(1 << i);
break;
default:
ret = -EINVAL;
break;
}
sm_writel(sm, EIM_MODE, mode);
sm_writel(sm, EIM_EDGE, edge);
sm_writel(sm, EIM_LEVEL, level);
spin_unlock_irqrestore(&sm->lock, flags);
return ret;
}
struct irq_chip eim_chip = {
.name = "eim",
.ack = eim_ack_irq,
.mask = eim_mask_irq,
.mask_ack = eim_mask_ack_irq,
.unmask = eim_unmask_irq,
.set_type = eim_set_irq_type,
};
static void demux_eim_irq(unsigned int irq, struct irq_desc *desc)
{
struct at32_sm *sm = desc->handler_data;
struct irq_desc *ext_desc;
unsigned long status, pending;
unsigned int i, ext_irq;
spin_lock(&sm->lock);
status = sm_readl(sm, EIM_ISR);
pending = status & sm_readl(sm, EIM_IMR);
while (pending) {
i = fls(pending) - 1;
pending &= ~(1 << i);
ext_irq = i + sm->eim_first_irq;
ext_desc = irq_desc + ext_irq;
ext_desc->handle_irq(ext_irq, ext_desc);
}
spin_unlock(&sm->lock);
}
static int __init eim_init(void)
{
struct at32_sm *sm = &system_manager;
unsigned int i;
unsigned int nr_irqs;
unsigned int int_irq;
u32 pattern;
/*
* The EIM is really the same module as SM, so register
* mapping, etc. has been taken care of already.
*/
/*
* Find out how many interrupt lines that are actually
* implemented in hardware.
*/
sm_writel(sm, EIM_IDR, ~0UL);
sm_writel(sm, EIM_MODE, ~0UL);
pattern = sm_readl(sm, EIM_MODE);
nr_irqs = fls(pattern);
sm->eim_chip = &eim_chip;
for (i = 0; i < nr_irqs; i++) {
set_irq_chip(sm->eim_first_irq + i, &eim_chip);
set_irq_chip_data(sm->eim_first_irq + i, sm);
}
int_irq = platform_get_irq_byname(sm->pdev, "eim");
set_irq_chained_handler(int_irq, demux_eim_irq);
set_irq_data(int_irq, sm);
printk("EIM: External Interrupt Module at 0x%p, IRQ %u\n",
sm->regs, int_irq);
printk("EIM: Handling %u external IRQs, starting with IRQ %u\n",
nr_irqs, sm->eim_first_irq);
return 0;
}
arch_initcall(eim_init);
