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   1 /*
   2  * linux/arch/arm/mach-at91/irq.c
   3  *
   4  *  Copyright (C) 2004 SAN People
   5  *  Copyright (C) 2004 ATMEL
   6  *  Copyright (C) Rick Bronson
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/init.h>
  24 #include <linux/module.h>
  25 #include <linux/mm.h>
  26 #include <linux/types.h>
  27
  28 #include <asm/hardware.h>
  29 #include <asm/irq.h>
  30 #include <asm/mach-types.h>
  31 #include <asm/setup.h>
  32
  33 #include <asm/mach/arch.h>
  34 #include <asm/mach/irq.h>
  35 #include <asm/mach/map.h>
  36
  37
  38 static void at91_aic_mask_irq(unsigned int irq)
  39 {
  40         /* Disable interrupt on AIC */
  41         at91_sys_write(AT91_AIC_IDCR, 1 << irq);
  42 }
  43
  44 static void at91_aic_unmask_irq(unsigned int irq)
  45 {
  46         /* Enable interrupt on AIC */
  47         at91_sys_write(AT91_AIC_IECR, 1 << irq);
  48 }
  49
  50 unsigned int at91_extern_irq;
  51
  52 #define is_extern_irq(irq) ((1 << (irq)) & at91_extern_irq)
  53
  54 static int at91_aic_set_type(unsigned irq, unsigned type)
  55 {
  56         unsigned int smr, srctype;
  57
  58         switch (type) {
  59         case IRQT_HIGH:
  60                 srctype = AT91_AIC_SRCTYPE_HIGH;
  61                 break;
  62         case IRQT_RISING:
  63                 srctype = AT91_AIC_SRCTYPE_RISING;
  64                 break;
  65         case IRQT_LOW:
  66                 if ((irq == AT91_ID_FIQ) || is_extern_irq(irq))         /* only supported on external interrupts */
  67                         srctype = AT91_AIC_SRCTYPE_LOW;
  68                 else
  69                         return -EINVAL;
  70                 break;
  71         case IRQT_FALLING:
  72                 if ((irq == AT91_ID_FIQ) || is_extern_irq(irq))         /* only supported on external interrupts */
  73                         srctype = AT91_AIC_SRCTYPE_FALLING;
  74                 else
  75                         return -EINVAL;
  76                 break;
  77         default:
  78                 return -EINVAL;
  79         }
  80
  81         smr = at91_sys_read(AT91_AIC_SMR(irq)) & ~AT91_AIC_SRCTYPE;
  82         at91_sys_write(AT91_AIC_SMR(irq), smr | srctype);
  83         return 0;
  84 }
  85
  86 #ifdef CONFIG_PM
  87
  88 static u32 wakeups;
  89 static u32 backups;
  90
  91 static int at91_aic_set_wake(unsigned irq, unsigned value)
  92 {
  93         if (unlikely(irq >= 32))
  94                 return -EINVAL;
  95
  96         if (value)
  97                 wakeups |= (1 << irq);
  98         else
  99                 wakeups &= ~(1 << irq);
 100
 101         return 0;
 102 }
 103
 104 void at91_irq_suspend(void)
 105 {
 106         backups = at91_sys_read(AT91_AIC_IMR);
 107         at91_sys_write(AT91_AIC_IDCR, backups);
 108         at91_sys_write(AT91_AIC_IECR, wakeups);
 109 }
 110
 111 void at91_irq_resume(void)
 112 {
 113         at91_sys_write(AT91_AIC_IDCR, wakeups);
 114         at91_sys_write(AT91_AIC_IECR, backups);
 115 }
 116
 117 #else
 118 #define at91_aic_set_wake       NULL
 119 #endif
 120
 121 static struct irq_chip at91_aic_chip = {
 122         .name           = "AIC",
 123         .ack            = at91_aic_mask_irq,
 124         .mask           = at91_aic_mask_irq,
 125         .unmask         = at91_aic_unmask_irq,
 126         .set_type       = at91_aic_set_type,
 127         .set_wake       = at91_aic_set_wake,
 128 };
 129
 130 /*
 131  * Initialize the AIC interrupt controller.
 132  */
 133 void __init at91_aic_init(unsigned int priority[NR_AIC_IRQS])
 134 {
 135         unsigned int i;
 136
 137         /*
 138          * The IVR is used by macro get_irqnr_and_base to read and verify.
 139          * The irq number is NR_AIC_IRQS when a spurious interrupt has occurred.
 140          */
 141         for (i = 0; i < NR_AIC_IRQS; i++) {
 142                 /* Put irq number in Source Vector Register: */
 143                 at91_sys_write(AT91_AIC_SVR(i), i);
 144                 /* Active Low interrupt, with the specified priority */
 145                 at91_sys_write(AT91_AIC_SMR(i), AT91_AIC_SRCTYPE_LOW | priority[i]);
 146
 147                 set_irq_chip(i, &at91_aic_chip);
 148                 set_irq_handler(i, handle_level_irq);
 149                 set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
 150
 151                 /* Perform 8 End Of Interrupt Command to make sure AIC will not Lock out nIRQ */
 152                 if (i < 8)
 153                         at91_sys_write(AT91_AIC_EOICR, 0);
 154         }
 155
 156         /*
 157          * Spurious Interrupt ID in Spurious Vector Register is NR_AIC_IRQS
 158          * When there is no current interrupt, the IRQ Vector Register reads the value stored in AIC_SPU
 159          */
 160         at91_sys_write(AT91_AIC_SPU, NR_AIC_IRQS);
 161
 162         /* No debugging in AIC: Debug (Protect) Control Register */
 163         at91_sys_write(AT91_AIC_DCR, 0);
 164
 165         /* Disable and clear all interrupts initially */
 166         at91_sys_write(AT91_AIC_IDCR, 0xFFFFFFFF);
 167         at91_sys_write(AT91_AIC_ICCR, 0xFFFFFFFF);
 168 }