release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/kernel/irq-gt641xx.c

   1 /*
   2  *  GT641xx IRQ routines.
   3  *
   4  *  Copyright (C) 2007  Yoichi Yuasa <yuasa@linux-mips.org>
   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 as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20 #include <linux/hardirq.h>
  21 #include <linux/init.h>
  22 #include <linux/irq.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/types.h>
  25
  26 #include <asm/gt64120.h>
  27
  28 #define GT641XX_IRQ_TO_BIT(irq) (1U << (irq - GT641XX_IRQ_BASE))
  29
  30 static DEFINE_RAW_SPINLOCK(gt641xx_irq_lock);
  31
  32 static void ack_gt641xx_irq(unsigned int irq)
  33 {
  34         unsigned long flags;
  35         u32 cause;
  36
  37         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  38         cause = GT_READ(GT_INTRCAUSE_OFS);
  39         cause &= ~GT641XX_IRQ_TO_BIT(irq);
  40         GT_WRITE(GT_INTRCAUSE_OFS, cause);
  41         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  42 }
  43
  44 static void mask_gt641xx_irq(unsigned int irq)
  45 {
  46         unsigned long flags;
  47         u32 mask;
  48
  49         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  50         mask = GT_READ(GT_INTRMASK_OFS);
  51         mask &= ~GT641XX_IRQ_TO_BIT(irq);
  52         GT_WRITE(GT_INTRMASK_OFS, mask);
  53         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  54 }
  55
  56 static void mask_ack_gt641xx_irq(unsigned int irq)
  57 {
  58         unsigned long flags;
  59         u32 cause, mask;
  60
  61         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  62         mask = GT_READ(GT_INTRMASK_OFS);
  63         mask &= ~GT641XX_IRQ_TO_BIT(irq);
  64         GT_WRITE(GT_INTRMASK_OFS, mask);
  65
  66         cause = GT_READ(GT_INTRCAUSE_OFS);
  67         cause &= ~GT641XX_IRQ_TO_BIT(irq);
  68         GT_WRITE(GT_INTRCAUSE_OFS, cause);
  69         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  70 }
  71
  72 static void unmask_gt641xx_irq(unsigned int irq)
  73 {
  74         unsigned long flags;
  75         u32 mask;
  76
  77         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  78         mask = GT_READ(GT_INTRMASK_OFS);
  79         mask |= GT641XX_IRQ_TO_BIT(irq);
  80         GT_WRITE(GT_INTRMASK_OFS, mask);
  81         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  82 }
  83
  84 static struct irq_chip gt641xx_irq_chip = {
  85         .name           = "GT641xx",
  86         .ack            = ack_gt641xx_irq,
  87         .mask           = mask_gt641xx_irq,
  88         .mask_ack       = mask_ack_gt641xx_irq,
  89         .unmask         = unmask_gt641xx_irq,
  90 };
  91
  92 void gt641xx_irq_dispatch(void)
  93 {
  94         u32 cause, mask;
  95         int i;
  96
  97         cause = GT_READ(GT_INTRCAUSE_OFS);
  98         mask = GT_READ(GT_INTRMASK_OFS);
  99         cause &= mask;
 100
 101         /*
 102          * bit0 : logical or of all the interrupt bits.
 103          * bit30: logical or of bits[29:26,20:1].
 104          * bit31: logical or of bits[25:1].
 105          */
 106         for (i = 1; i < 30; i++) {
 107                 if (cause & (1U << i)) {
 108                         do_IRQ(GT641XX_IRQ_BASE + i);
 109                         return;
 110                 }
 111         }
 112
 113         atomic_inc(&irq_err_count);
 114 }
 115
 116 void __init gt641xx_irq_init(void)
 117 {
 118         int i;
 119
 120         GT_WRITE(GT_INTRMASK_OFS, 0);
 121         GT_WRITE(GT_INTRCAUSE_OFS, 0);
 122
 123         /*
 124          * bit0 : logical or of all the interrupt bits.
 125          * bit30: logical or of bits[29:26,20:1].
 126          * bit31: logical or of bits[25:1].
 127          */
 128         for (i = 1; i < 30; i++)
 129                 set_irq_chip_and_handler(GT641XX_IRQ_BASE + i,
 130                                          &gt641xx_irq_chip, handle_level_irq);
 131 }