arch/ppc/platforms/adir_pic.c

   1 /*
   2  * arch/ppc/platforms/adir_pic.c
   3  *
   4  * Interrupt controller support for SBS Adirondack
   5  *
   6  * By Michael Sokolov <msokolov@ivan.Harhan.ORG>
   7  * based on the K2 and SCM versions by Matt Porter <mporter@mvista.com>
   8  */
   9
  10 #include <linux/stddef.h>
  11 #include <linux/init.h>
  12 #include <linux/sched.h>
  13 #include <linux/pci.h>
  14 #include <linux/interrupt.h>
  15
  16 #include <asm/io.h>
  17 #include <asm/i8259.h>
  18 #include "adir.h"
  19
  20 static void adir_onboard_pic_enable(unsigned int irq);
  21 static void adir_onboard_pic_disable(unsigned int irq);
  22
  23 __init static void
  24 adir_onboard_pic_init(void)
  25 {
  26         volatile u_short *maskreg = (volatile u_short *) ADIR_PROCA_INT_MASK;
  27
  28         /* Disable all Adirondack onboard interrupts */
  29         out_be16(maskreg, 0xFFFF);
  30 }
  31
  32 static int
  33 adir_onboard_pic_get_irq(void)
  34 {
  35         volatile u_short *statreg = (volatile u_short *) ADIR_PROCA_INT_STAT;
  36         int irq;
  37         u_short int_status, int_test;
  38
  39         int_status = in_be16(statreg);
  40         for (irq = 0, int_test = 1; irq < 16; irq++, int_test <<= 1) {
  41                 if (int_status & int_test)
  42                         break;
  43         }
  44
  45         if (irq == 16)
  46                 return -1;
  47
  48         return (irq+16);
  49 }
  50
  51 static void
  52 adir_onboard_pic_enable(unsigned int irq)
  53 {
  54         volatile u_short *maskreg = (volatile u_short *) ADIR_PROCA_INT_MASK;
  55
  56         /* Change irq to Adirondack onboard native value */
  57         irq -= 16;
  58
  59         /* Enable requested irq number */
  60         out_be16(maskreg, in_be16(maskreg) & ~(1 << irq));
  61 }
  62
  63 static void
  64 adir_onboard_pic_disable(unsigned int irq)
  65 {
  66         volatile u_short *maskreg = (volatile u_short *) ADIR_PROCA_INT_MASK;
  67
  68         /* Change irq to Adirondack onboard native value */
  69         irq -= 16;
  70
  71         /* Disable requested irq number */
  72         out_be16(maskreg, in_be16(maskreg) | (1 << irq));
  73 }
  74
  75 static struct hw_interrupt_type adir_onboard_pic = {
  76         " ADIR PIC ",
  77         NULL,
  78         NULL,
  79         adir_onboard_pic_enable,                /* unmask */
  80         adir_onboard_pic_disable,               /* mask */
  81         adir_onboard_pic_disable,               /* mask and ack */
  82         NULL,
  83         NULL
  84 };
  85
  86 static struct irqaction noop_action = {
  87         .handler        = no_action,
  88         .flags          = SA_INTERRUPT,
  89         .mask           = CPU_MASK_NONE,
  90         .name           = "82c59 primary cascade",
  91 };
  92
  93 /*
  94  * Linux interrupt values are assigned as follows:
  95  *
  96  *      0-15            VT82C686 8259 interrupts
  97  *      16-31           Adirondack CPLD interrupts
  98  */
  99 __init void
 100 adir_init_IRQ(void)
 101 {
 102         int     i;
 103
 104         /* Initialize the cascaded 8259's on the VT82C686 */
 105         for (i=0; i<16; i++)
 106                 irq_desc[i].handler = &i8259_pic;
 107         i8259_init(NULL);
 108
 109         /* Initialize Adirondack CPLD PIC and enable 8259 interrupt cascade */
 110         for (i=16; i<32; i++)
 111                 irq_desc[i].handler = &adir_onboard_pic;
 112         adir_onboard_pic_init();
 113
 114         /* Enable 8259 interrupt cascade */
 115         setup_irq(ADIR_IRQ_VT82C686_INTR, &noop_action);
 116 }
 117
 118 int
 119 adir_get_irq(struct pt_regs *regs)
 120 {
 121         int     irq;
 122
 123         if ((irq = adir_onboard_pic_get_irq()) < 0)
 124                 return irq;
 125
 126         if (irq == ADIR_IRQ_VT82C686_INTR)
 127                 irq = i8259_irq(regs);
 128
 129         return irq;
 130 }