LXR linux/arch/mips/jazz/irq.c

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 1992 Linus Torvalds
   7 * Copyright (C) 1994 - 2001, 2003, 07 Ralf Baechle
   8 */
   9#include <linux/clockchips.h>
  10#include <linux/i8253.h>
  11#include <linux/init.h>
  12#include <linux/interrupt.h>
  13#include <linux/kernel.h>
  14#include <linux/smp.h>
  15#include <linux/spinlock.h>
  16#include <linux/irq.h>
  17#include <linux/pgtable.h>
  18
  19#include <asm/irq_cpu.h>
  20#include <asm/i8259.h>
  21#include <asm/io.h>
  22#include <asm/jazz.h>
  23#include <asm/tlbmisc.h>
  24
  25static DEFINE_RAW_SPINLOCK(r4030_lock);
  26
  27static void enable_r4030_irq(struct irq_data *d)
  28{
  29        unsigned int mask = 1 << (d->irq - JAZZ_IRQ_START);
  30        unsigned long flags;
  31
  32        raw_spin_lock_irqsave(&r4030_lock, flags);
  33        mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  34        r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  35        raw_spin_unlock_irqrestore(&r4030_lock, flags);
  36}
  37
  38void disable_r4030_irq(struct irq_data *d)
  39{
  40        unsigned int mask = ~(1 << (d->irq - JAZZ_IRQ_START));
  41        unsigned long flags;
  42
  43        raw_spin_lock_irqsave(&r4030_lock, flags);
  44        mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  45        r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  46        raw_spin_unlock_irqrestore(&r4030_lock, flags);
  47}
  48
  49static struct irq_chip r4030_irq_type = {
  50        .name = "R4030",
  51        .irq_mask = disable_r4030_irq,
  52        .irq_unmask = enable_r4030_irq,
  53};
  54
  55void __init init_r4030_ints(void)
  56{
  57        int i;
  58
  59        for (i = JAZZ_IRQ_START; i <= JAZZ_IRQ_END; i++)
  60                irq_set_chip_and_handler(i, &r4030_irq_type, handle_level_irq);
  61
  62        r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
  63        r4030_read_reg16(JAZZ_IO_IRQ_SOURCE);           /* clear pending IRQs */
  64        r4030_read_reg32(JAZZ_R4030_INVAL_ADDR);        /* clear error bits */
  65}
  66
  67/*
  68 * On systems with i8259-style interrupt controllers we assume for
  69 * driver compatibility reasons interrupts 0 - 15 to be the i8259
  70 * interrupts even if the hardware uses a different interrupt numbering.
  71 */
  72void __init arch_init_irq(void)
  73{
  74        /*
  75         * this is a hack to get back the still needed wired mapping
  76         * killed by init_mm()
  77         */
  78
  79        /* Map 0xe0000000 -> 0x0:800005C0, 0xe0010000 -> 0x1:30000580 */
  80        add_wired_entry(0x02000017, 0x03c00017, 0xe0000000, PM_64K);
  81        /* Map 0xe2000000 -> 0x0:900005C0, 0xe3010000 -> 0x0:910005C0 */
  82        add_wired_entry(0x02400017, 0x02440017, 0xe2000000, PM_16M);
  83        /* Map 0xe4000000 -> 0x0:600005C0, 0xe4100000 -> 400005C0 */
  84        add_wired_entry(0x01800017, 0x01000017, 0xe4000000, PM_4M);
  85
  86        init_i8259_irqs();                      /* Integrated i8259  */
  87        mips_cpu_irq_init();
  88        init_r4030_ints();
  89
  90        change_c0_status(ST0_IM, IE_IRQ2 | IE_IRQ1);
  91}
  92
  93asmlinkage void plat_irq_dispatch(void)
  94{
  95        unsigned int pending = read_c0_cause() & read_c0_status();
  96        unsigned int irq;
  97
  98        if (pending & IE_IRQ4) {
  99                r4030_read_reg32(JAZZ_TIMER_REGISTER);
 100                do_IRQ(JAZZ_TIMER_IRQ);
 101        } else if (pending & IE_IRQ2) {
 102                irq = *(volatile u8 *)JAZZ_EISA_IRQ_ACK;
 103                do_IRQ(irq);
 104        } else if (pending & IE_IRQ1) {
 105                irq = *(volatile u8 *)JAZZ_IO_IRQ_SOURCE >> 2;
 106                if (likely(irq > 0))
 107                        do_IRQ(irq + JAZZ_IRQ_START - 1);
 108                else
 109                        panic("Unimplemented loc_no_irq handler");
 110        }
 111}
 112
 113struct clock_event_device r4030_clockevent = {
 114        .name           = "r4030",
 115        .features       = CLOCK_EVT_FEAT_PERIODIC,
 116        .rating         = 300,
 117        .irq            = JAZZ_TIMER_IRQ,
 118};
 119
 120static irqreturn_t r4030_timer_interrupt(int irq, void *dev_id)
 121{
 122        struct clock_event_device *cd = dev_id;
 123
 124        cd->event_handler(cd);
 125        return IRQ_HANDLED;
 126}
 127
 128void __init plat_time_init(void)
 129{
 130        struct clock_event_device *cd = &r4030_clockevent;
 131        unsigned int cpu = smp_processor_id();
 132
 133        BUG_ON(HZ != 100);
 134
 135        cd->cpumask             = cpumask_of(cpu);
 136        clockevents_register_device(cd);
 137        if (request_irq(JAZZ_TIMER_IRQ, r4030_timer_interrupt, IRQF_TIMER,
 138                        "R4030 timer", cd))
 139                pr_err("Failed to register R4030 timer interrupt\n");
 140
 141        /*
 142         * Set clock to 100Hz.
 143         *
 144         * The R4030 timer receives an input clock of 1kHz which is divieded by
 145         * a programmable 4-bit divider.  This makes it fairly inflexible.
 146         */
 147        r4030_write_reg32(JAZZ_TIMER_INTERVAL, 9);
 148        setup_pit_timer();
 149}
 150