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/init.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/kernel.h>
  13 #include <linux/smp.h>
  14 #include <linux/spinlock.h>
  15
  16 #include <asm/irq_cpu.h>
  17 #include <asm/i8253.h>
  18 #include <asm/i8259.h>
  19 #include <asm/io.h>
  20 #include <asm/jazz.h>
  21 #include <asm/pgtable.h>
  22
  23 static DEFINE_SPINLOCK(r4030_lock);
  24
  25 static void enable_r4030_irq(unsigned int irq)
  26 {
  27         unsigned int mask = 1 << (irq - JAZZ_IRQ_START);
  28         unsigned long flags;
  29
  30         spin_lock_irqsave(&r4030_lock, flags);
  31         mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  32         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  33         spin_unlock_irqrestore(&r4030_lock, flags);
  34 }
  35
  36 void disable_r4030_irq(unsigned int irq)
  37 {
  38         unsigned int mask = ~(1 << (irq - JAZZ_IRQ_START));
  39         unsigned long flags;
  40
  41         spin_lock_irqsave(&r4030_lock, flags);
  42         mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
  43         r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
  44         spin_unlock_irqrestore(&r4030_lock, flags);
  45 }
  46
  47 static struct irq_chip r4030_irq_type = {
  48         .name = "R4030",
  49         .ack = disable_r4030_irq,
  50         .mask = disable_r4030_irq,
  51         .mask_ack = disable_r4030_irq,
  52         .unmask = enable_r4030_irq,
  53 };
  54
  55 void __init init_r4030_ints(void)
  56 {
  57         int i;
  58
  59         for (i = JAZZ_IRQ_START; i <= JAZZ_IRQ_END; i++)
  60                 set_irq_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  */
  72 void __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
  93 asmlinkage 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
 113 static void r4030_set_mode(enum clock_event_mode mode,
 114                            struct clock_event_device *evt)
 115 {
 116         /* Nothing to do ...  */
 117 }
 118
 119 struct clock_event_device r4030_clockevent = {
 120         .name           = "r4030",
 121         .features       = CLOCK_EVT_FEAT_PERIODIC,
 122         .rating         = 300,
 123         .irq            = JAZZ_TIMER_IRQ,
 124         .set_mode       = r4030_set_mode,
 125 };
 126
 127 static irqreturn_t r4030_timer_interrupt(int irq, void *dev_id)
 128 {
 129         struct clock_event_device *cd = dev_id;
 130
 131         cd->event_handler(cd);
 132         return IRQ_HANDLED;
 133 }
 134
 135 static struct irqaction r4030_timer_irqaction = {
 136         .handler        = r4030_timer_interrupt,
 137         .flags          = IRQF_DISABLED,
 138         .name           = "R4030 timer",
 139 };
 140
 141 void __init plat_time_init(void)
 142 {
 143         struct clock_event_device *cd = &r4030_clockevent;
 144         struct irqaction *action = &r4030_timer_irqaction;
 145         unsigned int cpu = smp_processor_id();
 146
 147         BUG_ON(HZ != 100);
 148
 149         cd->cpumask             = cpumask_of(cpu);
 150         clockevents_register_device(cd);
 151         action->dev_id = cd;
 152         setup_irq(JAZZ_TIMER_IRQ, action);
 153
 154         /*
 155          * Set clock to 100Hz.
 156          *
 157          * The R4030 timer receives an input clock of 1kHz which is divieded by
 158          * a programmable 4-bit divider.  This makes it fairly inflexible.
 159          */
 160         r4030_write_reg32(JAZZ_TIMER_INTERVAL, 9);
 161         setup_pit_timer();
 162 }