arch/ppc/syslib/cpc700_pic.c

   1 /*
   2  * Interrupt controller support for IBM Spruce
   3  *
   4  * Authors: Mark Greer, Matt Porter, and Johnnie Peters
   5  *          mgreer@mvista.com
   6  *          mporter@mvista.com
   7  *          jpeters@mvista.com
   8  *
   9  * 2001-2002 (c) MontaVista, Software, Inc.  This file is licensed under
  10  * the terms of the GNU General Public License version 2.  This program
  11  * is licensed "as is" without any warranty of any kind, whether express
  12  * or implied.
  13  */
  14
  15 #include <linux/stddef.h>
  16 #include <linux/init.h>
  17 #include <linux/sched.h>
  18 #include <linux/signal.h>
  19 #include <linux/irq.h>
  20
  21 #include <asm/io.h>
  22 #include <asm/system.h>
  23 #include <asm/irq.h>
  24
  25 #include "cpc700.h"
  26
  27 static void
  28 cpc700_unmask_irq(unsigned int irq)
  29 {
  30         unsigned int tr_bits;
  31
  32         /*
  33          * IRQ 31 is largest IRQ supported.
  34          * IRQs 17-19 are reserved.
  35          */
  36         if ((irq <= 31) && ((irq < 17) || (irq > 19))) {
  37                 tr_bits = CPC700_IN_32(CPC700_UIC_UICTR);
  38
  39                 if ((tr_bits & (1 << (31 - irq))) == 0) {
  40                         /* level trigger interrupt, clear bit in status
  41                          * register */
  42                         CPC700_OUT_32(CPC700_UIC_UICSR, 1 << (31 - irq));
  43                 }
  44
  45                 /* Know IRQ fits in entry 0 of ppc_cached_irq_mask[] */
  46                 ppc_cached_irq_mask[0] |= CPC700_UIC_IRQ_BIT(irq);
  47
  48                 CPC700_OUT_32(CPC700_UIC_UICER, ppc_cached_irq_mask[0]);
  49         }
  50         return;
  51 }
  52
  53 static void
  54 cpc700_mask_irq(unsigned int irq)
  55 {
  56         /*
  57          * IRQ 31 is largest IRQ supported.
  58          * IRQs 17-19 are reserved.
  59          */
  60         if ((irq <= 31) && ((irq < 17) || (irq > 19))) {
  61                 /* Know IRQ fits in entry 0 of ppc_cached_irq_mask[] */
  62                 ppc_cached_irq_mask[0] &=
  63                         ~CPC700_UIC_IRQ_BIT(irq);
  64
  65                 CPC700_OUT_32(CPC700_UIC_UICER, ppc_cached_irq_mask[0]);
  66         }
  67         return;
  68 }
  69
  70 static void
  71 cpc700_mask_and_ack_irq(unsigned int irq)
  72 {
  73         u_int   bit;
  74
  75         /*
  76          * IRQ 31 is largest IRQ supported.
  77          * IRQs 17-19 are reserved.
  78          */
  79         if ((irq <= 31) && ((irq < 17) || (irq > 19))) {
  80                 /* Know IRQ fits in entry 0 of ppc_cached_irq_mask[] */
  81                 bit = CPC700_UIC_IRQ_BIT(irq);
  82
  83                 ppc_cached_irq_mask[0] &= ~bit;
  84                 CPC700_OUT_32(CPC700_UIC_UICER, ppc_cached_irq_mask[0]);
  85                 CPC700_OUT_32(CPC700_UIC_UICSR, bit); /* Write 1 clears IRQ */
  86         }
  87         return;
  88 }
  89
  90 static struct hw_interrupt_type cpc700_pic = {
  91         .typename = "CPC700 PIC",
  92         .enable = cpc700_unmask_irq,
  93         .disable = cpc700_mask_irq,
  94         .ack = cpc700_mask_and_ack_irq,
  95 };
  96
  97 __init static void
  98 cpc700_pic_init_irq(unsigned int irq)
  99 {
 100         unsigned int tmp;
 101
 102         /* Set interrupt sense */
 103         tmp = CPC700_IN_32(CPC700_UIC_UICTR);
 104         if (cpc700_irq_assigns[irq][0] == 0) {
 105                 tmp &= ~CPC700_UIC_IRQ_BIT(irq);
 106         } else {
 107                 tmp |= CPC700_UIC_IRQ_BIT(irq);
 108         }
 109         CPC700_OUT_32(CPC700_UIC_UICTR, tmp);
 110
 111         /* Set interrupt polarity */
 112         tmp = CPC700_IN_32(CPC700_UIC_UICPR);
 113         if (cpc700_irq_assigns[irq][1]) {
 114                 tmp |= CPC700_UIC_IRQ_BIT(irq);
 115         } else {
 116                 tmp &= ~CPC700_UIC_IRQ_BIT(irq);
 117         }
 118         CPC700_OUT_32(CPC700_UIC_UICPR, tmp);
 119
 120         /* Set interrupt critical */
 121         tmp = CPC700_IN_32(CPC700_UIC_UICCR);
 122         tmp |= CPC700_UIC_IRQ_BIT(irq);
 123         CPC700_OUT_32(CPC700_UIC_UICCR, tmp);
 124
 125         return;
 126 }
 127
 128 __init void
 129 cpc700_init_IRQ(void)
 130 {
 131         int i;
 132
 133         ppc_cached_irq_mask[0] = 0;
 134         CPC700_OUT_32(CPC700_UIC_UICER, 0x00000000);    /* Disable all irq's */
 135         CPC700_OUT_32(CPC700_UIC_UICSR, 0xffffffff);    /* Clear cur intrs */
 136         CPC700_OUT_32(CPC700_UIC_UICCR, 0xffffffff);    /* Gen INT not MCP */
 137         CPC700_OUT_32(CPC700_UIC_UICPR, 0x00000000);    /* Active low */
 138         CPC700_OUT_32(CPC700_UIC_UICTR, 0x00000000);    /* Level Sensitive */
 139         CPC700_OUT_32(CPC700_UIC_UICVR, CPC700_UIC_UICVCR_0_HI);
 140                                                         /* IRQ 0 is highest */
 141
 142         for (i = 0; i < 17; i++) {
 143                 irq_desc[i].chip = &cpc700_pic;
 144                 cpc700_pic_init_irq(i);
 145         }
 146
 147         for (i = 20; i < 32; i++) {
 148                 irq_desc[i].chip = &cpc700_pic;
 149                 cpc700_pic_init_irq(i);
 150         }
 151
 152         return;
 153 }
 154
 155
 156
 157 /*
 158  * Find the highest IRQ that generating an interrupt, if any.
 159  */
 160 int
 161 cpc700_get_irq(void)
 162 {
 163         int irq = 0;
 164         u_int irq_status, irq_test = 1;
 165
 166         irq_status = CPC700_IN_32(CPC700_UIC_UICMSR);
 167
 168         do
 169         {
 170                 if (irq_status & irq_test)
 171                         break;
 172                 irq++;
 173                 irq_test <<= 1;
 174         } while (irq < NR_IRQS);
 175
 176
 177         if (irq == NR_IRQS)
 178             irq = 33;
 179
 180         return (31 - irq);
 181 }