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         flow_type &= IRQ_TYPE_SENSE_MASK;
  59         if (flow_type == IRQ_TYPE_NONE)
  60                 flow_type = IRQ_TYPE_LEVEL_LOW;
  61
  62         desc = &irq_desc[irq];
  63         spin_lock_irqsave(&sm->lock, flags);
  64
  65         mode = sm_readl(sm, EIM_MODE);
  66         edge = sm_readl(sm, EIM_EDGE);
  67         level = sm_readl(sm, EIM_LEVEL);
  68
  69         switch (flow_type) {
  70         case IRQ_TYPE_LEVEL_LOW:
  71                 mode |= 1 << i;
  72                 level &= ~(1 << i);
  73                 break;
  74         case IRQ_TYPE_LEVEL_HIGH:
  75                 mode |= 1 << i;
  76                 level |= 1 << i;
  77                 break;
  78         case IRQ_TYPE_EDGE_RISING:
  79                 mode &= ~(1 << i);
  80                 edge |= 1 << i;
  81                 break;
  82         case IRQ_TYPE_EDGE_FALLING:
  83                 mode &= ~(1 << i);
  84                 edge &= ~(1 << i);
  85                 break;
  86         default:
  87                 ret = -EINVAL;
  88                 break;
  89         }
  90
  91         if (ret == 0) {
  92                 sm_writel(sm, EIM_MODE, mode);
  93                 sm_writel(sm, EIM_EDGE, edge);
  94                 sm_writel(sm, EIM_LEVEL, level);
  95
  96                 if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
  97                         flow_type |= IRQ_LEVEL;
  98                 desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
  99                 desc->status |= flow_type;
 100         }
 101
 102         spin_unlock_irqrestore(&sm->lock, flags);
 103
 104         return ret;
 105 }
 106
 107 struct irq_chip eim_chip = {
 108         .name           = "eim",
 109         .ack            = eim_ack_irq,
 110         .mask           = eim_mask_irq,
 111         .mask_ack       = eim_mask_ack_irq,
 112         .unmask         = eim_unmask_irq,
 113         .set_type       = eim_set_irq_type,
 114 };
 115
 116 static void demux_eim_irq(unsigned int irq, struct irq_desc *desc)
 117 {
 118         struct at32_sm *sm = desc->handler_data;
 119         struct irq_desc *ext_desc;
 120         unsigned long status, pending;
 121         unsigned int i, ext_irq;
 122
 123         status = sm_readl(sm, EIM_ISR);
 124         pending = status & sm_readl(sm, EIM_IMR);
 125
 126         while (pending) {
 127                 i = fls(pending) - 1;
 128                 pending &= ~(1 << i);
 129
 130                 ext_irq = i + sm->eim_first_irq;
 131                 ext_desc = irq_desc + ext_irq;
 132                 if (ext_desc->status & IRQ_LEVEL)
 133                         handle_level_irq(ext_irq, ext_desc);
 134                 else
 135                         handle_edge_irq(ext_irq, ext_desc);
 136         }
 137 }
 138
 139 static int __init eim_init(void)
 140 {
 141         struct at32_sm *sm = &system_manager;
 142         unsigned int i;
 143         unsigned int nr_irqs;
 144         unsigned int int_irq;
 145         u32 pattern;
 146
 147         /*
 148          * The EIM is really the same module as SM, so register
 149          * mapping, etc. has been taken care of already.
 150          */
 151
 152         /*
 153          * Find out how many interrupt lines that are actually
 154          * implemented in hardware.
 155          */
 156         sm_writel(sm, EIM_IDR, ~0UL);
 157         sm_writel(sm, EIM_MODE, ~0UL);
 158         pattern = sm_readl(sm, EIM_MODE);
 159         nr_irqs = fls(pattern);
 160
 161         /* Trigger on falling edge unless overridden by driver */
 162         sm_writel(sm, EIM_MODE, 0UL);
 163         sm_writel(sm, EIM_EDGE, 0UL);
 164
 165         sm->eim_chip = &eim_chip;
 166
 167         for (i = 0; i < nr_irqs; i++) {
 168                 /* NOTE the handler we set here is ignored by the demux */
 169                 set_irq_chip_and_handler(sm->eim_first_irq + i, &eim_chip,
 170                                          handle_level_irq);
 171                 set_irq_chip_data(sm->eim_first_irq + i, sm);
 172         }
 173
 174         int_irq = platform_get_irq_byname(sm->pdev, "eim");
 175
 176         set_irq_chained_handler(int_irq, demux_eim_irq);
 177         set_irq_data(int_irq, sm);
 178
 179         printk("EIM: External Interrupt Module at 0x%p, IRQ %u\n",
 180                sm->regs, int_irq);
 181         printk("EIM: Handling %u external IRQs, starting with IRQ %u\n",
 182                nr_irqs, sm->eim_first_irq);
 183
 184         return 0;
 185 }
 186 arch_initcall(eim_init);