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 inline void pci_intA(struct pt_regs *regs)
  50 {
  51         do_IRQ(GT_INTA, regs);
  52 }
  53
  54 asmlinkage inline void pci_intD(struct pt_regs *regs)
  55 {
  56         do_IRQ(GT_INTD, regs);
  57 }
  58
  59 static void disable_ev64120_irq(unsigned int irq_nr)
  60 {
  61         unsigned long flags;
  62
  63         local_irq_save(flags);
  64         if (irq_nr >= 8) {      // All PCI interrupts are on line 5 or 2
  65                 clear_c0_status(9 << 10);
  66         } else {
  67                 clear_c0_status(1 << (irq_nr + 8));
  68         }
  69         local_irq_restore(flags);
  70 }
  71
  72 static void enable_ev64120_irq(unsigned int irq_nr)
  73 {
  74         unsigned long flags;
  75
  76         local_irq_save(flags);
  77         if (irq_nr >= 8)        // All PCI interrupts are on line 5 or 2
  78                 set_c0_status(9 << 10);
  79         else
  80                 set_c0_status(1 << (irq_nr + 8));
  81         local_irq_restore(flags);
  82 }
  83
  84 static unsigned int startup_ev64120_irq(unsigned int irq)
  85 {
  86         enable_ev64120_irq(irq);
  87         return 0;               /* Never anything pending  */
  88 }
  89
  90 #define shutdown_ev64120_irq     disable_ev64120_irq
  91 #define mask_and_ack_ev64120_irq disable_ev64120_irq
  92
  93 static void end_ev64120_irq(unsigned int irq)
  94 {
  95         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  96                 enable_ev64120_irq(irq);
  97 }
  98
  99 static struct hw_interrupt_type ev64120_irq_type = {
 100         .typename       = "EV64120",
 101         .startup        = startup_ev64120_irq,
 102         .shutdown       = shutdown_ev64120_irq,
 103         .enable         = enable_ev64120_irq,
 104         .disable        = disable_ev64120_irq,
 105         .ack            = mask_and_ack_ev64120_irq,
 106         .end            = end_ev64120_irq,
 107         .set_affinity   = NULL
 108 };
 109
 110 void gt64120_irq_setup(void)
 111 {
 112         extern asmlinkage void galileo_handle_int(void);
 113
 114         /*
 115          * Clear all of the interrupts while we change the able around a bit.
 116          */
 117         clear_c0_status(ST0_IM);
 118
 119         /* Sets the exception_handler array. */
 120         set_except_vector(0, galileo_handle_int);
 121
 122         local_irq_disable();
 123
 124         /*
 125          * Enable timer.  Other interrupts will be enabled as they are
 126          * registered.
 127          */
 128         set_c0_status(IE_IRQ2);
 129 }
 130
 131 void __init arch_init_irq(void)
 132 {
 133         int i;
 134
 135         /*  Let's initialize our IRQ descriptors  */
 136         for (i = 0; i < NR_IRQS; i++) {
 137                 irq_desc[i].status = 0;
 138                 irq_desc[i].handler = &no_irq_type;
 139                 irq_desc[i].action = NULL;
 140                 irq_desc[i].depth = 0;
 141                 spin_lock_init(&irq_desc[i].lock);
 142         }
 143
 144         gt64120_irq_setup();
 145 }