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