arch/avr32/mach-at32ap/extint.c

   1 /*
   2  * External interrupt handling for AT32AP CPUs
   3  *
   4  * Copyright (C) 2006 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/errno.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/random.h>
  17
  18 #include <asm/io.h>
  19
  20 #include <asm/arch/sm.h>
  21
  22 #include "sm.h"
  23
  24 static void eim_ack_irq(unsigned int irq)
  25 {
  26         struct at32_sm *sm = get_irq_chip_data(irq);
  27         sm_writel(sm, EIM_ICR, 1 << (irq - sm->eim_first_irq));
  28 }
  29
  30 static void eim_mask_irq(unsigned int irq)
  31 {
  32         struct at32_sm *sm = get_irq_chip_data(irq);
  33         sm_writel(sm, EIM_IDR, 1 << (irq - sm->eim_first_irq));
  34 }
  35
  36 static void eim_mask_ack_irq(unsigned int irq)
  37 {
  38         struct at32_sm *sm = get_irq_chip_data(irq);
  39         sm_writel(sm, EIM_ICR, 1 << (irq - sm->eim_first_irq));
  40         sm_writel(sm, EIM_IDR, 1 << (irq - sm->eim_first_irq));
  41 }
  42
  43 static void eim_unmask_irq(unsigned int irq)
  44 {
  45         struct at32_sm *sm = get_irq_chip_data(irq);
  46         sm_writel(sm, EIM_IER, 1 << (irq - sm->eim_first_irq));
  47 }
  48
  49 static int eim_set_irq_type(unsigned int irq, unsigned int flow_type)
  50 {
  51         struct at32_sm *sm = get_irq_chip_data(irq);
  52         struct irq_desc *desc;
  53         unsigned int i = irq - sm->eim_first_irq;
  54         u32 mode, edge, level;
  55         unsigned long flags;
  56         int ret = 0;
  57
  58         if (flow_type == IRQ_TYPE_NONE)
  59                 flow_type = IRQ_TYPE_LEVEL_LOW;
  60
  61         desc = &irq_desc[irq];
  62         desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
  63         desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
  64
  65         if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) {
  66                 desc->status |= IRQ_LEVEL;
  67                 set_irq_handler(irq, handle_level_irq);
  68         } else {
  69                 set_irq_handler(irq, handle_edge_irq);
  70         }
  71
  72         spin_lock_irqsave(&sm->lock, flags);
  73
  74         mode = sm_readl(sm, EIM_MODE);
  75         edge = sm_readl(sm, EIM_EDGE);
  76         level = sm_readl(sm, EIM_LEVEL);
  77
  78         switch (flow_type) {
  79         case IRQ_TYPE_LEVEL_LOW:
  80                 mode |= 1 << i;
  81                 level &= ~(1 << i);
  82                 break;
  83         case IRQ_TYPE_LEVEL_HIGH:
  84                 mode |= 1 << i;
  85                 level |= 1 << i;
  86                 break;
  87         case IRQ_TYPE_EDGE_RISING:
  88                 mode &= ~(1 << i);
  89                 edge |= 1 << i;
  90                 break;
  91         case IRQ_TYPE_EDGE_FALLING:
  92                 mode &= ~(1 << i);
  93                 edge &= ~(1 << i);
  94                 break;
  95         default:
  96                 ret = -EINVAL;
  97                 break;
  98         }
  99
 100         sm_writel(sm, EIM_MODE, mode);
 101         sm_writel(sm, EIM_EDGE, edge);
 102         sm_writel(sm, EIM_LEVEL, level);
 103
 104         spin_unlock_irqrestore(&sm->lock, flags);
 105
 106         return ret;
 107 }
 108
 109 struct irq_chip eim_chip = {
 110         .name           = "eim",
 111         .ack            = eim_ack_irq,
 112         .mask           = eim_mask_irq,
 113         .mask_ack       = eim_mask_ack_irq,
 114         .unmask         = eim_unmask_irq,
 115         .set_type       = eim_set_irq_type,
 116 };
 117
 118 static void demux_eim_irq(unsigned int irq, struct irq_desc *desc)
 119 {
 120         struct at32_sm *sm = desc->handler_data;
 121         struct irq_desc *ext_desc;
 122         unsigned long status, pending;
 123         unsigned int i, ext_irq;
 124
 125         spin_lock(&sm->lock);
 126
 127         status = sm_readl(sm, EIM_ISR);
 128         pending = status & sm_readl(sm, EIM_IMR);
 129
 130         while (pending) {
 131                 i = fls(pending) - 1;
 132                 pending &= ~(1 << i);
 133
 134                 ext_irq = i + sm->eim_first_irq;
 135                 ext_desc = irq_desc + ext_irq;
 136                 ext_desc->handle_irq(ext_irq, ext_desc);
 137         }
 138
 139         spin_unlock(&sm->lock);
 140 }
 141
 142 static int __init eim_init(void)
 143 {
 144         struct at32_sm *sm = &system_manager;
 145         unsigned int i;
 146         unsigned int nr_irqs;
 147         unsigned int int_irq;
 148         u32 pattern;
 149
 150         /*
 151          * The EIM is really the same module as SM, so register
 152          * mapping, etc. has been taken care of already.
 153          */
 154
 155         /*
 156          * Find out how many interrupt lines that are actually
 157          * implemented in hardware.
 158          */
 159         sm_writel(sm, EIM_IDR, ~0UL);
 160         sm_writel(sm, EIM_MODE, ~0UL);
 161         pattern = sm_readl(sm, EIM_MODE);
 162         nr_irqs = fls(pattern);
 163
 164         /* Trigger on falling edge unless overridden by driver */
 165         sm_writel(sm, EIM_MODE, 0UL);
 166         sm_writel(sm, EIM_EDGE, 0UL);
 167
 168         sm->eim_chip = &eim_chip;
 169
 170         for (i = 0; i < nr_irqs; i++) {
 171                 set_irq_chip_and_handler(sm->eim_first_irq + i, &eim_chip,
 172                                          handle_edge_irq);
 173                 set_irq_chip_data(sm->eim_first_irq + i, sm);
 174         }
 175
 176         int_irq = platform_get_irq_byname(sm->pdev, "eim");
 177
 178         set_irq_chained_handler(int_irq, demux_eim_irq);
 179         set_irq_data(int_irq, sm);
 180
 181         printk("EIM: External Interrupt Module at 0x%p, IRQ %u\n",
 182                sm->regs, int_irq);
 183         printk("EIM: Handling %u external IRQs, starting with IRQ %u\n",
 184                nr_irqs, sm->eim_first_irq);
 185
 186         return 0;
 187 }
 188 arch_initcall(eim_init);