arch/nios2/kernel/irq.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2013 Altera Corporation
   4  * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
   5  * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
   6  *
   7  * based on irq.c from m68k which is:
   8  *
   9  * Copyright (C) 2007 Greg Ungerer <gerg@snapgear.com>
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/of.h>
  15
  16 static u32 ienable;
  17
  18 asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
  19 {
  20         struct pt_regs *oldregs = set_irq_regs(regs);
  21         int irq;
  22
  23         irq_enter();
  24         irq = irq_find_mapping(NULL, hwirq);
  25         generic_handle_irq(irq);
  26         irq_exit();
  27
  28         set_irq_regs(oldregs);
  29 }
  30
  31 static void chip_unmask(struct irq_data *d)
  32 {
  33         ienable |= (1 << d->hwirq);
  34         WRCTL(CTL_IENABLE, ienable);
  35 }
  36
  37 static void chip_mask(struct irq_data *d)
  38 {
  39         ienable &= ~(1 << d->hwirq);
  40         WRCTL(CTL_IENABLE, ienable);
  41 }
  42
  43 static struct irq_chip m_irq_chip = {
  44         .name           = "NIOS2-INTC",
  45         .irq_unmask     = chip_unmask,
  46         .irq_mask       = chip_mask,
  47 };
  48
  49 static int irq_map(struct irq_domain *h, unsigned int virq,
  50                                 irq_hw_number_t hw_irq_num)
  51 {
  52         irq_set_chip_and_handler(virq, &m_irq_chip, handle_level_irq);
  53
  54         return 0;
  55 }
  56
  57 static const struct irq_domain_ops irq_ops = {
  58         .map    = irq_map,
  59         .xlate  = irq_domain_xlate_onecell,
  60 };
  61
  62 void __init init_IRQ(void)
  63 {
  64         struct irq_domain *domain;
  65         struct device_node *node;
  66
  67         node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.0");
  68         if (!node)
  69                 node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.1");
  70
  71         BUG_ON(!node);
  72
  73         domain = irq_domain_add_linear(node, NIOS2_CPU_NR_IRQS, &irq_ops, NULL);
  74         BUG_ON(!domain);
  75
  76         irq_set_default_host(domain);
  77         of_node_put(node);
  78         /* Load the initial ienable value */
  79         ienable = RDCTL(CTL_IENABLE);
  80 }