2 * Copyright (C) 2007 Lemote Inc.
3 * Author: Fuxin Zhang, zhangfx@lemote.com
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
11 #include <linux/export.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
15 #include <asm/irq_cpu.h>
16 #include <asm/i8259.h>
17 #include <asm/mipsregs.h>
22 #define LOONGSON_TIMER_IRQ (MIPS_CPU_IRQ_BASE + 7) /* cpu timer */
23 #define LOONGSON_NORTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 6) /* bonito */
24 #define LOONGSON_UART_IRQ (MIPS_CPU_IRQ_BASE + 3) /* cpu serial port */
25 #define LOONGSON_SOUTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 2) /* i8259 */
27 #define LOONGSON_INT_BIT_INT0 (1 << 11)
28 #define LOONGSON_INT_BIT_INT1 (1 << 12)
31 * The generic i8259_irq() make the kernel hang on booting. Since we cannot
32 * get the irq via the IRR directly, we access the ISR instead.
34 int mach_i8259_irq(void)
40 if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) {
41 raw_spin_lock(&i8259A_lock);
42 isr = inb(PIC_MASTER_CMD) &
43 ~inb(PIC_MASTER_IMR) & ~(1 << PIC_CASCADE_IR);
45 isr = (inb(PIC_SLAVE_CMD) & ~inb(PIC_SLAVE_IMR)) << 8;
47 if (unlikely(irq == 7)) {
49 * This may be a spurious interrupt.
51 * Read the interrupt status register (ISR). If the most
52 * significant bit is not set then there is no valid
55 outb(0x0B, PIC_MASTER_ISR); /* ISR register */
56 if (~inb(PIC_MASTER_ISR) & 0x80)
59 raw_spin_unlock(&i8259A_lock);
64 EXPORT_SYMBOL(mach_i8259_irq);
66 static void i8259_irqdispatch(void)
70 irq = mach_i8259_irq();
77 void mach_irq_dispatch(unsigned int pending)
79 if (pending & CAUSEF_IP7)
80 do_IRQ(LOONGSON_TIMER_IRQ);
81 else if (pending & CAUSEF_IP6) { /* North Bridge, Perf counter */
84 } else if (pending & CAUSEF_IP3) /* CPU UART */
85 do_IRQ(LOONGSON_UART_IRQ);
86 else if (pending & CAUSEF_IP2) /* South Bridge */
92 static irqreturn_t ip6_action(int cpl, void *dev_id)
97 static struct irqaction ip6_irqaction = {
98 .handler = ip6_action,
100 .flags = IRQF_SHARED | IRQF_NO_THREAD,
103 static struct irqaction cascade_irqaction = {
104 .handler = no_action,
106 .flags = IRQF_NO_THREAD | IRQF_NO_SUSPEND,
109 void __init mach_init_irq(void)
111 /* init all controller
112 * 0-15 ------> i8259 interrupt
113 * 16-23 ------> mips cpu interrupt
114 * 32-63 ------> bonito irq
117 /* setup cs5536 as high level trigger */
118 LOONGSON_INTPOL = LOONGSON_INT_BIT_INT0 | LOONGSON_INT_BIT_INT1;
119 LOONGSON_INTEDGE &= ~(LOONGSON_INT_BIT_INT0 | LOONGSON_INT_BIT_INT1);
121 /* Sets the first-level interrupt dispatcher. */
126 /* setup north bridge irq (bonito) */
127 setup_irq(LOONGSON_NORTH_BRIDGE_IRQ, &ip6_irqaction);
128 /* setup source bridge irq (i8259) */
129 setup_irq(LOONGSON_SOUTH_BRIDGE_IRQ, &cascade_irqaction);