target/linux/adm8668/files/arch/mips/adm8668/irq.c

   1 /*
   2  * Copyright (C) 2010 Scott Nicholas <neutronscott@scottn.us>
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/kernel_stat.h>
  11 #include <linux/signal.h>
  12 #include <linux/sched.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/slab.h>
  15 #include <linux/random.h>
  16 #include <linux/pm.h>
  17 #include <linux/irq.h>
  18 #include <asm/mipsregs.h>
  19 #include <asm/irq_cpu.h>
  20 #include <asm/irq.h>
  21 #include <adm8668.h>
  22
  23 static void adm8668_irq_cascade(void)
  24 {
  25         int i;
  26         unsigned long intsrc;
  27
  28         intsrc = ADM8668_INTC_REG(IRQ_STATUS_REG) & IRQ_MASK;
  29         for (i = 0; intsrc; intsrc >>= 1, i++)
  30                 if (intsrc & 0x1)
  31                         do_IRQ(i);
  32 }
  33
  34 /*
  35  * System irq dispatch
  36  */
  37 void plat_irq_dispatch(void)
  38 {
  39         unsigned int pending;
  40
  41         pending = read_c0_cause() & read_c0_status() & ST0_IM;
  42
  43         /* timer interrupt, that we renumbered */
  44         if (pending & STATUSF_IP7)
  45                 do_IRQ(MIPS_CPU_IRQ_BASE + 7);
  46         if (pending & STATUSF_IP2)
  47                 adm8668_irq_cascade();
  48 }
  49
  50 /*
  51  * enable 8668 irq
  52  */
  53 static void enable_adm8668_irq(struct irq_data *d)
  54 {
  55         ADM8668_INTC_REG(IRQ_ENABLE_REG) = (1 << d->irq);
  56 }
  57
  58
  59 static void ack_adm8668_irq(struct irq_data *d)
  60 {
  61         ADM8668_INTC_REG(IRQ_DISABLE_REG) = (1 << d->irq);
  62 }
  63
  64 /*
  65  * system irq type
  66  */
  67
  68 static struct irq_chip adm8668_irq_type = {
  69         .name = "adm8668",
  70         .irq_ack = ack_adm8668_irq,
  71         .irq_mask = ack_adm8668_irq,
  72         .irq_unmask = enable_adm8668_irq
  73 };
  74
  75 /*
  76  * irq init
  77  */
  78 static void __init init_adm8668_irqs(void)
  79 {
  80         int i;
  81
  82         for (i = 0; i <= INT_LVL_MAX; i++)
  83                 irq_set_chip_and_handler(i, &adm8668_irq_type,
  84                         handle_level_irq);
  85
  86         /* hw0 is where our interrupts are uh.. interrupted at. */
  87         set_c0_status(IE_IRQ0);
  88 }
  89
  90 /*
  91  * system init
  92  */
  93 void __init arch_init_irq(void)
  94 {
  95         mips_cpu_irq_init();
  96         init_adm8668_irqs();
  97 }