arch/mips/gt64120/ev64120/irq.c

   1 /*
   2  * BRIEF MODULE DESCRIPTION
   3  * Code to handle irqs on GT64120A boards
   4  *  Derived from mips/orion and Cort <cort@fsmlabs.com>
   5  *
   6  * Copyright (C) 2000 RidgeRun, Inc.
   7  * Author: RidgeRun, Inc.
   8  *   glonnon@ridgerun.com, skranz@ridgerun.com, stevej@ridgerun.com
   9  *
  10  *  This program is free software; you can redistribute  it and/or modify it
  11  *  under  the terms of  the GNU General  Public License as published by the
  12  *  Free Software Foundation;  either version 2 of the  License, or (at your
  13  *  option) any later version.
  14  *
  15  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  16  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  17  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  18  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  19  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  21  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  22  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  23  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  *  You should have received a copy of the  GNU General Public License along
  27  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  28  *  675 Mass Ave, Cambridge, MA 02139, USA.
  29  */
  30 #include <linux/errno.h>
  31 #include <linux/init.h>
  32 #include <linux/kernel_stat.h>
  33 #include <linux/module.h>
  34 #include <linux/signal.h>
  35 #include <linux/sched.h>
  36 #include <linux/types.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/ioport.h>
  39 #include <linux/timex.h>
  40 #include <linux/slab.h>
  41 #include <linux/random.h>
  42 #include <linux/bitops.h>
  43 #include <asm/bootinfo.h>
  44 #include <asm/io.h>
  45 #include <asm/mipsregs.h>
  46 #include <asm/system.h>
  47 #include <asm/gt64120.h>
  48
  49 asmlinkage void plat_irq_dispatch(void)
  50 {
  51         unsigned int pending = read_c0_status() & read_c0_cause();
  52
  53         if (pending & STATUSF_IP4)              /* int2 hardware line (timer) */
  54                 do_IRQ(4);
  55         else if (pending & STATUSF_IP2)         /* int0 hardware line */
  56                 do_IRQ(GT_INTA);
  57         else if (pending & STATUSF_IP5)         /* int3 hardware line */
  58                 do_IRQ(GT_INTD);
  59         else if (pending & STATUSF_IP6)         /* int4 hardware line */
  60                 do_IRQ(6);
  61         else if (pending & STATUSF_IP7)         /* compare int */
  62                 do_IRQ(7);
  63         else
  64                 spurious_interrupt();
  65 }
  66
  67 static void disable_ev64120_irq(unsigned int irq_nr)
  68 {
  69         unsigned long flags;
  70
  71         local_irq_save(flags);
  72         if (irq_nr >= 8) {      // All PCI interrupts are on line 5 or 2
  73                 clear_c0_status(9 << 10);
  74         } else {
  75                 clear_c0_status(1 << (irq_nr + 8));
  76         }
  77         local_irq_restore(flags);
  78 }
  79
  80 static void enable_ev64120_irq(unsigned int irq_nr)
  81 {
  82         unsigned long flags;
  83
  84         local_irq_save(flags);
  85         if (irq_nr >= 8)        // All PCI interrupts are on line 5 or 2
  86                 set_c0_status(9 << 10);
  87         else
  88                 set_c0_status(1 << (irq_nr + 8));
  89         local_irq_restore(flags);
  90 }
  91
  92 static unsigned int startup_ev64120_irq(unsigned int irq)
  93 {
  94         enable_ev64120_irq(irq);
  95         return 0;               /* Never anything pending  */
  96 }
  97
  98 #define shutdown_ev64120_irq     disable_ev64120_irq
  99 #define mask_and_ack_ev64120_irq disable_ev64120_irq
 100
 101 static void end_ev64120_irq(unsigned int irq)
 102 {
 103         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
 104                 enable_ev64120_irq(irq);
 105 }
 106
 107 static struct irq_chip ev64120_irq_type = {
 108         .typename       = "EV64120",
 109         .startup        = startup_ev64120_irq,
 110         .shutdown       = shutdown_ev64120_irq,
 111         .enable         = enable_ev64120_irq,
 112         .disable        = disable_ev64120_irq,
 113         .ack            = mask_and_ack_ev64120_irq,
 114         .end            = end_ev64120_irq,
 115         .set_affinity   = NULL
 116 };
 117
 118 void gt64120_irq_setup(void)
 119 {
 120         /*
 121          * Clear all of the interrupts while we change the able around a bit.
 122          */
 123         clear_c0_status(ST0_IM);
 124
 125         local_irq_disable();
 126
 127         /*
 128          * Enable timer.  Other interrupts will be enabled as they are
 129          * registered.
 130          */
 131         set_c0_status(IE_IRQ2);
 132 }
 133
 134 void __init arch_init_irq(void)
 135 {
 136         int i;
 137
 138         /*  Let's initialize our IRQ descriptors  */
 139         for (i = 0; i < NR_IRQS; i++) {
 140                 irq_desc[i].status = 0;
 141                 irq_desc[i].chip = &no_irq_chip;
 142                 irq_desc[i].action = NULL;
 143                 irq_desc[i].depth = 0;
 144                 spin_lock_init(&irq_desc[i].lock);
 145         }
 146
 147         gt64120_irq_setup();
 148 }