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  */
  24 static const struct of_device_id
  25 irqchip_of_match_end __used __section(__irqchip_of_table_end);
  26
  27 extern struct of_device_id __irqchip_of_table[];
  28
  29 void __init irqchip_init(void)
  30 {
  31         of_irq_init(__irqchip_of_table);
  32         acpi_probe_device_table(irqchip);
  33 }
  34
  35 int 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(np, DOMAIN_BUS_ANY))
  56                 return -EPROBE_DEFER;
  57
  58         return irq_init_cb(np, par_np);
  59 }
  60 EXPORT_SYMBOL_GPL(platform_irqchip_probe);