drivers/irqchip/irq-xtensa-pic.c

   1 /*
   2  * Xtensa built-in interrupt controller
   3  *
   4  * Copyright (C) 2002 - 2013 Tensilica, Inc.
   5  * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License.  See the file "COPYING" in the main directory of this archive
   9  * for more details.
  10  *
  11  * Chris Zankel <chris@zankel.net>
  12  * Kevin Chea
  13  */
  14
  15 #include <linux/interrupt.h>
  16 #include <linux/irqdomain.h>
  17 #include <linux/irq.h>
  18 #include <linux/irqchip.h>
  19 #include <linux/of.h>
  20
  21 unsigned int cached_irq_mask;
  22
  23 /*
  24  * Device Tree IRQ specifier translation function which works with one or
  25  * two cell bindings. First cell value maps directly to the hwirq number.
  26  * Second cell if present specifies whether hwirq number is external (1) or
  27  * internal (0).
  28  */
  29 static int xtensa_pic_irq_domain_xlate(struct irq_domain *d,
  30                 struct device_node *ctrlr,
  31                 const u32 *intspec, unsigned int intsize,
  32                 unsigned long *out_hwirq, unsigned int *out_type)
  33 {
  34         return xtensa_irq_domain_xlate(intspec, intsize,
  35                         intspec[0], intspec[0],
  36                         out_hwirq, out_type);
  37 }
  38
  39 static const struct irq_domain_ops xtensa_irq_domain_ops = {
  40         .xlate = xtensa_pic_irq_domain_xlate,
  41         .map = xtensa_irq_map,
  42 };
  43
  44 static void xtensa_irq_mask(struct irq_data *d)
  45 {
  46         cached_irq_mask &= ~(1 << d->hwirq);
  47         xtensa_set_sr(cached_irq_mask, intenable);
  48 }
  49
  50 static void xtensa_irq_unmask(struct irq_data *d)
  51 {
  52         cached_irq_mask |= 1 << d->hwirq;
  53         xtensa_set_sr(cached_irq_mask, intenable);
  54 }
  55
  56 static void xtensa_irq_enable(struct irq_data *d)
  57 {
  58         xtensa_irq_unmask(d);
  59 }
  60
  61 static void xtensa_irq_disable(struct irq_data *d)
  62 {
  63         xtensa_irq_mask(d);
  64 }
  65
  66 static void xtensa_irq_ack(struct irq_data *d)
  67 {
  68         xtensa_set_sr(1 << d->hwirq, intclear);
  69 }
  70
  71 static int xtensa_irq_retrigger(struct irq_data *d)
  72 {
  73         xtensa_set_sr(1 << d->hwirq, intset);
  74         return 1;
  75 }
  76
  77 static struct irq_chip xtensa_irq_chip = {
  78         .name           = "xtensa",
  79         .irq_enable     = xtensa_irq_enable,
  80         .irq_disable    = xtensa_irq_disable,
  81         .irq_mask       = xtensa_irq_mask,
  82         .irq_unmask     = xtensa_irq_unmask,
  83         .irq_ack        = xtensa_irq_ack,
  84         .irq_retrigger  = xtensa_irq_retrigger,
  85 };
  86
  87 int __init xtensa_pic_init_legacy(struct device_node *interrupt_parent)
  88 {
  89         struct irq_domain *root_domain =
  90                 irq_domain_add_legacy(NULL, NR_IRQS - 1, 1, 0,
  91                                 &xtensa_irq_domain_ops, &xtensa_irq_chip);
  92         irq_set_default_host(root_domain);
  93         return 0;
  94 }
  95
  96 static int __init xtensa_pic_init(struct device_node *np,
  97                 struct device_node *interrupt_parent)
  98 {
  99         struct irq_domain *root_domain =
 100                 irq_domain_add_linear(np, NR_IRQS, &xtensa_irq_domain_ops,
 101                                 &xtensa_irq_chip);
 102         irq_set_default_host(root_domain);
 103         return 0;
 104 }
 105 IRQCHIP_DECLARE(xtensa_irq_chip, "cdns,xtensa-pic", xtensa_pic_init);