LXR linux/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/irqdomain.h>
  15#include <linux/of.h>
  16
  17static u32 ienable;
  18
  19asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
  20{
  21        struct pt_regs *oldregs = set_irq_regs(regs);
  22
  23        irq_enter();
  24        generic_handle_domain_irq(NULL, hwirq);
  25        irq_exit();
  26
  27        set_irq_regs(oldregs);
  28}
  29
  30static void chip_unmask(struct irq_data *d)
  31{
  32        ienable |= (1 << d->hwirq);
  33        WRCTL(CTL_IENABLE, ienable);
  34}
  35
  36static void chip_mask(struct irq_data *d)
  37{
  38        ienable &= ~(1 << d->hwirq);
  39        WRCTL(CTL_IENABLE, ienable);
  40}
  41
  42static struct irq_chip m_irq_chip = {
  43        .name           = "NIOS2-INTC",
  44        .irq_unmask     = chip_unmask,
  45        .irq_mask       = chip_mask,
  46};
  47
  48static int irq_map(struct irq_domain *h, unsigned int virq,
  49                                irq_hw_number_t hw_irq_num)
  50{
  51        irq_set_chip_and_handler(virq, &m_irq_chip, handle_level_irq);
  52
  53        return 0;
  54}
  55
  56static const struct irq_domain_ops irq_ops = {
  57        .map    = irq_map,
  58        .xlate  = irq_domain_xlate_onecell,
  59};
  60
  61void __init init_IRQ(void)
  62{
  63        struct irq_domain *domain;
  64        struct device_node *node;
  65
  66        node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.0");
  67        if (!node)
  68                node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.1");
  69
  70        BUG_ON(!node);
  71
  72        domain = irq_domain_add_linear(node, NIOS2_CPU_NR_IRQS, &irq_ops, NULL);
  73        BUG_ON(!domain);
  74
  75        irq_set_default_host(domain);
  76        of_node_put(node);
  77        /* Load the initial ienable value */
  78        ienable = RDCTL(CTL_IENABLE);
  79}
  80