drivers/sh/intc/irqdomain.c

   1 /*
   2  * IRQ domain support for SH INTC subsystem
   3  *
   4  * Copyright (C) 2012  Paul Mundt
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #define pr_fmt(fmt) "intc: " fmt
  11
  12 #include <linux/irqdomain.h>
  13 #include <linux/sh_intc.h>
  14 #include <linux/export.h>
  15 #include "internals.h"
  16
  17 /**
  18  * intc_irq_domain_evt_xlate() - Generic xlate for vectored IRQs.
  19  *
  20  * This takes care of exception vector to hwirq translation through
  21  * by way of evt2irq() translation.
  22  *
  23  * Note: For platforms that use a flat vector space without INTEVT this
  24  * basically just mimics irq_domain_xlate_onecell() by way of a nopped
  25  * out evt2irq() implementation.
  26  */
  27 static int intc_evt_xlate(struct irq_domain *d, struct device_node *ctrlr,
  28                           const u32 *intspec, unsigned int intsize,
  29                           unsigned long *out_hwirq, unsigned int *out_type)
  30 {
  31         if (WARN_ON(intsize < 1))
  32                 return -EINVAL;
  33
  34         *out_hwirq = evt2irq(intspec[0]);
  35         *out_type = IRQ_TYPE_NONE;
  36
  37         return 0;
  38 }
  39
  40 static const struct irq_domain_ops intc_evt_ops = {
  41         .xlate          = intc_evt_xlate,
  42 };
  43
  44 void __init intc_irq_domain_init(struct intc_desc_int *d,
  45                                  struct intc_hw_desc *hw)
  46 {
  47         unsigned int irq_base, irq_end;
  48
  49         /*
  50          * Quick linear revmap check
  51          */
  52         irq_base = evt2irq(hw->vectors[0].vect);
  53         irq_end = evt2irq(hw->vectors[hw->nr_vectors - 1].vect);
  54
  55         /*
  56          * Linear domains have a hard-wired assertion that IRQs start at
  57          * 0 in order to make some performance optimizations. Lamely
  58          * restrict the linear case to these conditions here, taking the
  59          * tree penalty for linear cases with non-zero hwirq bases.
  60          */
  61         if (irq_base == 0 && irq_end == (irq_base + hw->nr_vectors - 1))
  62                 d->domain = irq_domain_add_linear(NULL, hw->nr_vectors,
  63                                                   &intc_evt_ops, NULL);
  64         else
  65                 d->domain = irq_domain_add_tree(NULL, &intc_evt_ops, NULL);
  66
  67         BUG_ON(!d->domain);
  68 }