arch/arm/mach-at91/irq.c

   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 <mach/hardware.h>
  29 #include <asm/irq.h>
  30 #include <asm/setup.h>
  31
  32 #include <asm/mach/arch.h>
  33 #include <asm/mach/irq.h>
  34 #include <asm/mach/map.h>
  35
  36 void __iomem *at91_aic_base;
  37
  38 static void at91_aic_mask_irq(struct irq_data *d)
  39 {
  40         /* Disable interrupt on AIC */
  41         at91_aic_write(AT91_AIC_IDCR, 1 << d->irq);
  42 }
  43
  44 static void at91_aic_unmask_irq(struct irq_data *d)
  45 {
  46         /* Enable interrupt on AIC */
  47         at91_aic_write(AT91_AIC_IECR, 1 << d->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(struct irq_data *d, unsigned type)
  55 {
  56         unsigned int smr, srctype;
  57
  58         switch (type) {
  59         case IRQ_TYPE_LEVEL_HIGH:
  60                 srctype = AT91_AIC_SRCTYPE_HIGH;
  61                 break;
  62         case IRQ_TYPE_EDGE_RISING:
  63                 srctype = AT91_AIC_SRCTYPE_RISING;
  64                 break;
  65         case IRQ_TYPE_LEVEL_LOW:
  66                 if ((d->irq == AT91_ID_FIQ) || is_extern_irq(d->irq))           /* only supported on external interrupts */
  67                         srctype = AT91_AIC_SRCTYPE_LOW;
  68                 else
  69                         return -EINVAL;
  70                 break;
  71         case IRQ_TYPE_EDGE_FALLING:
  72                 if ((d->irq == AT91_ID_FIQ) || is_extern_irq(d->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_aic_read(AT91_AIC_SMR(d->irq)) & ~AT91_AIC_SRCTYPE;
  82         at91_aic_write(AT91_AIC_SMR(d->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(struct irq_data *d, unsigned value)
  92 {
  93         if (unlikely(d->irq >= 32))
  94                 return -EINVAL;
  95
  96         if (value)
  97                 wakeups |= (1 << d->irq);
  98         else
  99                 wakeups &= ~(1 << d->irq);
 100
 101         return 0;
 102 }
 103
 104 void at91_irq_suspend(void)
 105 {
 106         backups = at91_aic_read(AT91_AIC_IMR);
 107         at91_aic_write(AT91_AIC_IDCR, backups);
 108         at91_aic_write(AT91_AIC_IECR, wakeups);
 109 }
 110
 111 void at91_irq_resume(void)
 112 {
 113         at91_aic_write(AT91_AIC_IDCR, wakeups);
 114         at91_aic_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         .irq_ack        = at91_aic_mask_irq,
 124         .irq_mask       = at91_aic_mask_irq,
 125         .irq_unmask     = at91_aic_unmask_irq,
 126         .irq_set_type   = at91_aic_set_type,
 127         .irq_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         at91_aic_base = ioremap(AT91_AIC, 512);
 138
 139         if (!at91_aic_base)
 140                 panic("Impossible to ioremap AT91_AIC\n");
 141
 142         /*
 143          * The IVR is used by macro get_irqnr_and_base to read and verify.
 144          * The irq number is NR_AIC_IRQS when a spurious interrupt has occurred.
 145          */
 146         for (i = 0; i < NR_AIC_IRQS; i++) {
 147                 /* Put irq number in Source Vector Register: */
 148                 at91_aic_write(AT91_AIC_SVR(i), i);
 149                 /* Active Low interrupt, with the specified priority */
 150                 at91_aic_write(AT91_AIC_SMR(i), AT91_AIC_SRCTYPE_LOW | priority[i]);
 151
 152                 irq_set_chip_and_handler(i, &at91_aic_chip, handle_level_irq);
 153                 set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
 154
 155                 /* Perform 8 End Of Interrupt Command to make sure AIC will not Lock out nIRQ */
 156                 if (i < 8)
 157                         at91_aic_write(AT91_AIC_EOICR, 0);
 158         }
 159
 160         /*
 161          * Spurious Interrupt ID in Spurious Vector Register is NR_AIC_IRQS
 162          * When there is no current interrupt, the IRQ Vector Register reads the value stored in AIC_SPU
 163          */
 164         at91_aic_write(AT91_AIC_SPU, NR_AIC_IRQS);
 165
 166         /* No debugging in AIC: Debug (Protect) Control Register */
 167         at91_aic_write(AT91_AIC_DCR, 0);
 168
 169         /* Disable and clear all interrupts initially */
 170         at91_aic_write(AT91_AIC_IDCR, 0xFFFFFFFF);
 171         at91_aic_write(AT91_AIC_ICCR, 0xFFFFFFFF);
 172 }