/*
* TI Common Platform Interrupt Controller (cp_intc) driver
*
* Author: Steve Chen <schen@mvista.com>
* Copyright (C) 2008-2009, MontaVista Software, Inc. <source@mvista.com>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <mach/cp_intc.h>
static void __iomem *cp_intc_base;
static inline unsigned int cp_intc_read(unsigned offset)
{
return __raw_readl(cp_intc_base + offset);
}
static inline void cp_intc_write(unsigned long value, unsigned offset)
{
__raw_writel(value, cp_intc_base + offset);
}
static void cp_intc_ack_irq(unsigned int irq)
{
cp_intc_write(irq, CP_INTC_SYS_STAT_IDX_CLR);
}
/* Disable interrupt */
static void cp_intc_mask_irq(unsigned int irq)
{
/* XXX don't know why we need to disable nIRQ here... */
cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_CLR);
cp_intc_write(irq, CP_INTC_SYS_ENABLE_IDX_CLR);
cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_SET);
}
/* Enable interrupt */
static void cp_intc_unmask_irq(unsigned int irq)
{
cp_intc_write(irq, CP_INTC_SYS_ENABLE_IDX_SET);
}
static int cp_intc_set_irq_type(unsigned int irq, unsigned int flow_type)
{
unsigned reg = BIT_WORD(irq);
unsigned mask = BIT_MASK(irq);
unsigned polarity = cp_intc_read(CP_INTC_SYS_POLARITY(reg));
unsigned type = cp_intc_read(CP_INTC_SYS_TYPE(reg));
switch (flow_type) {
case IRQ_TYPE_EDGE_RISING:
polarity |= mask;
type |= mask;
break;
case IRQ_TYPE_EDGE_FALLING:
polarity &= ~mask;
type |= mask;
break;
case IRQ_TYPE_LEVEL_HIGH:
polarity |= mask;
type &= ~mask;
break;
case IRQ_TYPE_LEVEL_LOW:
polarity &= ~mask;
type &= ~mask;
break;
default:
return -EINVAL;
}
cp_intc_write(polarity, CP_INTC_SYS_POLARITY(reg));
cp_intc_write(type, CP_INTC_SYS_TYPE(reg));
return 0;
}
static struct irq_chip cp_intc_irq_chip = {
.name = "cp_intc",
.ack = cp_intc_ack_irq,
.mask = cp_intc_mask_irq,
.unmask = cp_intc_unmask_irq,
.set_type = cp_intc_set_irq_type,
};
void __init cp_intc_init(void __iomem *base, unsigned short num_irq,
u8 *irq_prio)
{
unsigned num_reg = BITS_TO_LONGS(num_irq);
int i;
cp_intc_base = base;
cp_intc_write(0, CP_INTC_GLOBAL_ENABLE);
/* Disable all host interrupts */
cp_intc_write(0, CP_INTC_HOST_ENABLE(0));
/* Disable system interrupts */
for (i = 0; i < num_reg; i++)
cp_intc_write(~0, CP_INTC_SYS_ENABLE_CLR(i));
/* Set to normal mode, no nesting, no priority hold */
cp_intc_write(0, CP_INTC_CTRL);
cp_intc_write(0, CP_INTC_HOST_CTRL);
/* Clear system interrupt status */
for (i = 0; i < num_reg; i++)
cp_intc_write(~0, CP_INTC_SYS_STAT_CLR(i));
/* Enable nIRQ (what about nFIQ?) */
cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_SET);
/*
* Priority is determined by host channel: lower channel number has
* higher priority i.e. channel 0 has highest priority and channel 31
* had the lowest priority.
*/
num_reg = (num_irq + 3) >> 2; /* 4 channels per register */
if (irq_prio) {
unsigned j, k;
u32 val;
for (k = i = 0; i < num_reg; i++) {
for (val = j = 0; j < 4; j++, k++) {
val >>= 8;
if (k < num_irq)
val |= irq_prio[k] << 24;
}
cp_intc_write(val, CP_INTC_CHAN_MAP(i));
}
} else {
/*
* Default everything to channel 15 if priority not specified.
* Note that channel 0-1 are mapped to nFIQ and channels 2-31
* are mapped to nIRQ.
*/
for (i = 0; i < num_reg; i++)
cp_intc_write(0x0f0f0f0f, CP_INTC_CHAN_MAP(i));
}
/* Set up genirq dispatching for cp_intc */
for (i = 0; i < num_irq; i++) {
set_irq_chip(i, &cp_intc_irq_chip);
set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
set_irq_handler(i, handle_edge_irq);
}
/* Enable global interrupt */
cp_intc_write(1, CP_INTC_GLOBAL_ENABLE);
}
