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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2007 Lemote Inc.
* Author: Fuxin Zhang, zhangfx@lemote.com
*/
#include <linux/export.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/irq_cpu.h>
#include <asm/i8259.h>
#include <asm/mipsregs.h>
#include <loongson.h>
#include <machine.h>
#define LOONGSON_TIMER_IRQ (MIPS_CPU_IRQ_BASE + 7) /* cpu timer */
#define LOONGSON_NORTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 6) /* bonito */
#define LOONGSON_UART_IRQ (MIPS_CPU_IRQ_BASE + 3) /* cpu serial port */
#define LOONGSON_SOUTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 2) /* i8259 */
#define LOONGSON_INT_BIT_INT0 (1 << 11)
#define LOONGSON_INT_BIT_INT1 (1 << 12)
/*
* The generic i8259_irq() make the kernel hang on booting. Since we cannot
* get the irq via the IRR directly, we access the ISR instead.
*/
int mach_i8259_irq(void)
{
int irq, isr;
irq = -1;
if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) {
raw_spin_lock(&i8259A_lock);
isr = inb(PIC_MASTER_CMD) &
~inb(PIC_MASTER_IMR) & ~(1 << PIC_CASCADE_IR);
if (!isr)
isr = (inb(PIC_SLAVE_CMD) & ~inb(PIC_SLAVE_IMR)) << 8;
irq = ffs(isr) - 1;
if (unlikely(irq == 7)) {
/*
* This may be a spurious interrupt.
*
* Read the interrupt status register (ISR). If the most
* significant bit is not set then there is no valid
* interrupt.
*/
outb(0x0B, PIC_MASTER_ISR); /* ISR register */
if (~inb(PIC_MASTER_ISR) & 0x80)
irq = -1;
}
raw_spin_unlock(&i8259A_lock);
}
return irq;
}
EXPORT_SYMBOL(mach_i8259_irq);
static void i8259_irqdispatch(void)
{
int irq;
irq = mach_i8259_irq();
if (irq >= 0)
do_IRQ(irq);
else
spurious_interrupt();
}
void mach_irq_dispatch(unsigned int pending)
{
if (pending & CAUSEF_IP7)
do_IRQ(LOONGSON_TIMER_IRQ);
else if (pending & CAUSEF_IP6) { /* North Bridge, Perf counter */
do_perfcnt_IRQ();
bonito_irqdispatch();
} else if (pending & CAUSEF_IP3) /* CPU UART */
do_IRQ(LOONGSON_UART_IRQ);
else if (pending & CAUSEF_IP2) /* South Bridge */
i8259_irqdispatch();
else
spurious_interrupt();
}
static irqreturn_t ip6_action(int cpl, void *dev_id)
{
return IRQ_HANDLED;
}
static struct irqaction ip6_irqaction = {
.handler = ip6_action,
.name = "cascade",
.flags = IRQF_SHARED | IRQF_NO_THREAD,
};
static struct irqaction cascade_irqaction = {
.handler = no_action,
.name = "cascade",
.flags = IRQF_NO_THREAD | IRQF_NO_SUSPEND,
};
void __init mach_init_irq(void)
{
/* init all controller
* 0-15 ------> i8259 interrupt
* 16-23 ------> mips cpu interrupt
* 32-63 ------> bonito irq
*/
/* setup cs5536 as high level trigger */
LOONGSON_INTPOL = LOONGSON_INT_BIT_INT0 | LOONGSON_INT_BIT_INT1;
LOONGSON_INTEDGE &= ~(LOONGSON_INT_BIT_INT0 | LOONGSON_INT_BIT_INT1);
/* Sets the first-level interrupt dispatcher. */
mips_cpu_irq_init();
init_i8259_irqs();
bonito_irq_init();
/* setup north bridge irq (bonito) */
setup_irq(LOONGSON_NORTH_BRIDGE_IRQ, &ip6_irqaction);
/* setup source bridge irq (i8259) */
setup_irq(LOONGSON_SOUTH_BRIDGE_IRQ, &cascade_irqaction);
}
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