LXR linux/drivers/irqchip/irqchip.c

   1/*
   2 * Copyright (C) 2012 Thomas Petazzoni
   3 *
   4 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
   5 *
   6 * This file is licensed under the terms of the GNU General Public
   7 * License version 2.  This program is licensed "as is" without any
   8 * warranty of any kind, whether express or implied.
   9 */
  10
  11#include <linux/acpi.h>
  12#include <linux/init.h>
  13#include <linux/of_device.h>
  14#include <linux/of_irq.h>
  15#include <linux/irqchip.h>
  16#include <linux/platform_device.h>
  17
  18/*
  19 * This special of_device_id is the sentinel at the end of the
  20 * of_device_id[] array of all irqchips. It is automatically placed at
  21 * the end of the array by the linker, thanks to being part of a
  22 * special section.
  23 */
  24static const struct of_device_id
  25irqchip_of_match_end __used __section("__irqchip_of_table_end");
  26
  27extern struct of_device_id __irqchip_of_table[];
  28
  29void __init irqchip_init(void)
  30{
  31        of_irq_init(__irqchip_of_table);
  32        acpi_probe_device_table(irqchip);
  33}
  34
  35int platform_irqchip_probe(struct platform_device *pdev)
  36{
  37        struct device_node *np = pdev->dev.of_node;
  38        struct device_node *par_np = of_irq_find_parent(np);
  39        of_irq_init_cb_t irq_init_cb = of_device_get_match_data(&pdev->dev);
  40
  41        if (!irq_init_cb)
  42                return -EINVAL;
  43
  44        if (par_np == np)
  45                par_np = NULL;
  46
  47        /*
  48         * If there's a parent interrupt controller and  none of the parent irq
  49         * domains have been registered, that means the parent interrupt
  50         * controller has not been initialized yet.  it's not time for this
  51         * interrupt controller to initialize. So, defer probe of this
  52         * interrupt controller. The actual initialization callback of this
  53         * interrupt controller can check for specific domains as necessary.
  54         */
  55        if (par_np && !irq_find_matching_host(par_np, DOMAIN_BUS_ANY))
  56                return -EPROBE_DEFER;
  57
  58        return irq_init_cb(np, par_np);
  59}
  60EXPORT_SYMBOL_GPL(platform_irqchip_probe);
  61