target/linux/mcs814x/files-3.3/arch/arm/mach-mcs814x/irq.c

   1 /*
   2  * Moschip MCS814x generic interrupt controller routines
   3  *
   4  * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org>
   5  *
   6  * Licensed under the GPLv2
   7  */
   8 #include <linux/init.h>
   9 #include <linux/irq.h>
  10 #include <linux/io.h>
  11 #include <linux/of.h>
  12 #include <linux/of_address.h>
  13 #include <linux/irqdomain.h>
  14
  15 #include <asm/exception.h>
  16 #include <asm/mach/irq.h>
  17
  18 #define MCS814X_IRQ_ICR         0x00
  19 #define MCS814X_IRQ_ISR         0x04
  20 #define MCS814X_IRQ_MASK        0x20
  21 #define MCS814X_IRQ_STS0        0x40
  22
  23 void __iomem *mcs814x_intc_base;
  24
  25 static void __init mcs814x_alloc_gc(void __iomem *base, unsigned int irq_start,
  26                                         unsigned int num)
  27 {
  28         struct irq_chip_generic *gc;
  29         struct irq_chip_type *ct;
  30
  31         gc = irq_alloc_generic_chip("mcs814x-intc", 1,
  32                         irq_start, base, handle_level_irq);
  33         if (!gc)
  34                 panic("unable to allocate generic irq chip");
  35
  36         ct = gc->chip_types;
  37         ct->chip.irq_ack = irq_gc_unmask_enable_reg;
  38         ct->chip.irq_mask = irq_gc_mask_clr_bit;
  39         ct->chip.irq_unmask = irq_gc_mask_set_bit;
  40         ct->regs.mask = MCS814X_IRQ_MASK;
  41         ct->regs.enable = MCS814X_IRQ_ICR;
  42
  43         irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
  44                 IRQ_NOREQUEST, 0);
  45
  46         /* Clear all interrupts */
  47         __raw_writel(0xffffffff, base + MCS814X_IRQ_ICR);
  48 }
  49
  50 static const struct of_device_id mcs814x_intc_ids[] = {
  51         { .compatible = "moschip,mcs814x-intc" },
  52         { /* sentinel */ },
  53 };
  54
  55 void __init mcs814x_of_irq_init(void)
  56 {
  57         struct device_node *np;
  58
  59         np = of_find_matching_node(NULL, mcs814x_intc_ids);
  60         if (!np)
  61                 panic("unable to find compatible intc node in dtb\n");
  62
  63         mcs814x_intc_base = of_iomap(np, 0);
  64         if (!mcs814x_intc_base)
  65                 panic("unable to map intc cpu registers\n");
  66
  67         irq_domain_add_simple(np, 0);
  68
  69         of_node_put(np);
  70
  71         mcs814x_alloc_gc(mcs814x_intc_base, 0, 32);
  72 }
  73