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/*
* Copyright (C) 2000 David J. Mckay (david.mckay@st.com)
*
* May be copied or modified under the terms of the GNU General Public
* License. See linux/COPYING for more information.
*
* Looks after interrupts on the HARP board.
*
* Bases on the IPR irq system
*/
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/harp/harp.h>
#define NUM_EXTERNAL_IRQS 16
// Early versions of the STB1 Overdrive required this nasty frig
//#define INVERT_INTMASK_WRITES
static void enable_harp_irq(unsigned int irq);
static void disable_harp_irq(unsigned int irq);
/* shutdown is same as "disable" */
#define shutdown_harp_irq disable_harp_irq
static void mask_and_ack_harp(unsigned int);
static void end_harp_irq(unsigned int irq);
static unsigned int startup_harp_irq(unsigned int irq)
{
enable_harp_irq(irq);
return 0; /* never anything pending */
}
static struct hw_interrupt_type harp_irq_type = {
.typename = "Harp-IRQ",
.startup = startup_harp_irq,
.shutdown = shutdown_harp_irq,
.enable = enable_harp_irq,
.disable = disable_harp_irq,
.ack = mask_and_ack_harp,
.end = end_harp_irq
};
static void disable_harp_irq(unsigned int irq)
{
unsigned val, flags;
unsigned maskReg;
unsigned mask;
int pri;
if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
return;
pri = 15 - irq;
if (pri < 8) {
maskReg = EPLD_INTMASK0;
} else {
maskReg = EPLD_INTMASK1;
pri -= 8;
}
local_irq_save(flags);
mask = ctrl_inl(maskReg);
mask &= (~(1 << pri));
#if defined(INVERT_INTMASK_WRITES)
mask ^= 0xff;
#endif
ctrl_outl(mask, maskReg);
local_irq_restore(flags);
}
static void enable_harp_irq(unsigned int irq)
{
unsigned flags;
unsigned maskReg;
unsigned mask;
int pri;
if (irq < 0 || irq >= NUM_EXTERNAL_IRQS)
return;
pri = 15 - irq;
if (pri < 8) {
maskReg = EPLD_INTMASK0;
} else {
maskReg = EPLD_INTMASK1;
pri -= 8;
}
local_irq_save(flags);
mask = ctrl_inl(maskReg);
mask |= (1 << pri);
#if defined(INVERT_INTMASK_WRITES)
mask ^= 0xff;
#endif
ctrl_outl(mask, maskReg);
local_irq_restore(flags);
}
/* This functions sets the desired irq handler to be an overdrive type */
static void __init make_harp_irq(unsigned int irq)
{
disable_irq_nosync(irq);
irq_desc[irq].chip = &harp_irq_type;
disable_harp_irq(irq);
}
static void mask_and_ack_harp(unsigned int irq)
{
disable_harp_irq(irq);
}
static void end_harp_irq(unsigned int irq)
{
enable_harp_irq(irq);
}
void __init init_harp_irq(void)
{
int i;
#if !defined(INVERT_INTMASK_WRITES)
// On the harp these are set to enable an interrupt
ctrl_outl(0x00, EPLD_INTMASK0);
ctrl_outl(0x00, EPLD_INTMASK1);
#else
// On the Overdrive the data is inverted before being stored in the reg
ctrl_outl(0xff, EPLD_INTMASK0);
ctrl_outl(0xff, EPLD_INTMASK1);
#endif
for (i = 0; i < NUM_EXTERNAL_IRQS; i++) {
make_harp_irq(i);
}
}
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