arch/hexagon/kernel/irq_cpu.c

   1 /*
   2  * First-level interrupt controller model for Hexagon.
   3  *
   4  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 and
   8  * only version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA.
  19  */
  20
  21 #include <linux/interrupt.h>
  22 #include <asm/irq.h>
  23 #include <asm/hexagon_vm.h>
  24
  25 static void mask_irq(struct irq_data *data)
  26 {
  27         __vmintop_locdis((long) data->irq);
  28 }
  29
  30 static void mask_irq_num(unsigned int irq)
  31 {
  32         __vmintop_locdis((long) irq);
  33 }
  34
  35 static void unmask_irq(struct irq_data *data)
  36 {
  37         __vmintop_locen((long) data->irq);
  38 }
  39
  40 /*  This is actually all we need for handle_fasteoi_irq  */
  41 static void eoi_irq(struct irq_data *data)
  42 {
  43         __vmintop_globen((long) data->irq);
  44 }
  45
  46 /* Power mamangement wake call. We don't need this, however,
  47  * if this is absent, then an -ENXIO error is returned to the
  48  * msm_serial driver, and it fails to correctly initialize.
  49  * This is a bug in the msm_serial driver, but, for now, we
  50  * work around it here, by providing this bogus handler.
  51  * XXX FIXME!!! remove this when msm_serial is fixed.
  52  */
  53 static int set_wake(struct irq_data *data, unsigned int on)
  54 {
  55         return 0;
  56 }
  57
  58 static struct irq_chip hexagon_irq_chip = {
  59         .name           = "HEXAGON",
  60         .irq_mask       = mask_irq,
  61         .irq_unmask     = unmask_irq,
  62         .irq_set_wake   = set_wake,
  63         .irq_eoi        = eoi_irq
  64 };
  65
  66 /**
  67  * The hexagon core comes with a first-level interrupt controller
  68  * with 32 total possible interrupts.  When the core is embedded
  69  * into different systems/platforms, it is typically wrapped by
  70  * macro cells that provide one or more second-level interrupt
  71  * controllers that are cascaded into one or more of the first-level
  72  * interrupts handled here. The precise wiring of these other
  73  * irqs varies from platform to platform, and are set up & configured
  74  * in the platform-specific files.
  75  *
  76  * The first-level interrupt controller is wrapped by the VM, which
  77  * virtualizes the interrupt controller for us.  It provides a very
  78  * simple, fast & efficient API, and so the fasteoi handler is
  79  * appropriate for this case.
  80  */
  81 void __init init_IRQ(void)
  82 {
  83         int irq;
  84
  85         for (irq = 0; irq < HEXAGON_CPUINTS; irq++) {
  86                 mask_irq_num(irq);
  87                 irq_set_chip_and_handler(irq, &hexagon_irq_chip,
  88                                                  handle_fasteoi_irq);
  89         }
  90 }