arch/mips/kernel/irq-gt641xx.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  GT641xx IRQ routines.
   4  *
   5  *  Copyright (C) 2007  Yoichi Yuasa <yuasa@linux-mips.org>
   6  */
   7 #include <linux/hardirq.h>
   8 #include <linux/init.h>
   9 #include <linux/irq.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/types.h>
  12
  13 #include <asm/gt64120.h>
  14
  15 #define GT641XX_IRQ_TO_BIT(irq) (1U << (irq - GT641XX_IRQ_BASE))
  16
  17 static DEFINE_RAW_SPINLOCK(gt641xx_irq_lock);
  18
  19 static void ack_gt641xx_irq(struct irq_data *d)
  20 {
  21         unsigned long flags;
  22         u32 cause;
  23
  24         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  25         cause = GT_READ(GT_INTRCAUSE_OFS);
  26         cause &= ~GT641XX_IRQ_TO_BIT(d->irq);
  27         GT_WRITE(GT_INTRCAUSE_OFS, cause);
  28         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  29 }
  30
  31 static void mask_gt641xx_irq(struct irq_data *d)
  32 {
  33         unsigned long flags;
  34         u32 mask;
  35
  36         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  37         mask = GT_READ(GT_INTRMASK_OFS);
  38         mask &= ~GT641XX_IRQ_TO_BIT(d->irq);
  39         GT_WRITE(GT_INTRMASK_OFS, mask);
  40         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  41 }
  42
  43 static void mask_ack_gt641xx_irq(struct irq_data *d)
  44 {
  45         unsigned long flags;
  46         u32 cause, mask;
  47
  48         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  49         mask = GT_READ(GT_INTRMASK_OFS);
  50         mask &= ~GT641XX_IRQ_TO_BIT(d->irq);
  51         GT_WRITE(GT_INTRMASK_OFS, mask);
  52
  53         cause = GT_READ(GT_INTRCAUSE_OFS);
  54         cause &= ~GT641XX_IRQ_TO_BIT(d->irq);
  55         GT_WRITE(GT_INTRCAUSE_OFS, cause);
  56         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  57 }
  58
  59 static void unmask_gt641xx_irq(struct irq_data *d)
  60 {
  61         unsigned long flags;
  62         u32 mask;
  63
  64         raw_spin_lock_irqsave(&gt641xx_irq_lock, flags);
  65         mask = GT_READ(GT_INTRMASK_OFS);
  66         mask |= GT641XX_IRQ_TO_BIT(d->irq);
  67         GT_WRITE(GT_INTRMASK_OFS, mask);
  68         raw_spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
  69 }
  70
  71 static struct irq_chip gt641xx_irq_chip = {
  72         .name           = "GT641xx",
  73         .irq_ack        = ack_gt641xx_irq,
  74         .irq_mask       = mask_gt641xx_irq,
  75         .irq_mask_ack   = mask_ack_gt641xx_irq,
  76         .irq_unmask     = unmask_gt641xx_irq,
  77 };
  78
  79 void gt641xx_irq_dispatch(void)
  80 {
  81         u32 cause, mask;
  82         int i;
  83
  84         cause = GT_READ(GT_INTRCAUSE_OFS);
  85         mask = GT_READ(GT_INTRMASK_OFS);
  86         cause &= mask;
  87
  88         /*
  89          * bit0 : logical or of all the interrupt bits.
  90          * bit30: logical or of bits[29:26,20:1].
  91          * bit31: logical or of bits[25:1].
  92          */
  93         for (i = 1; i < 30; i++) {
  94                 if (cause & (1U << i)) {
  95                         do_IRQ(GT641XX_IRQ_BASE + i);
  96                         return;
  97                 }
  98         }
  99
 100         atomic_inc(&irq_err_count);
 101 }
 102
 103 void __init gt641xx_irq_init(void)
 104 {
 105         int i;
 106
 107         GT_WRITE(GT_INTRMASK_OFS, 0);
 108         GT_WRITE(GT_INTRCAUSE_OFS, 0);
 109
 110         /*
 111          * bit0 : logical or of all the interrupt bits.
 112          * bit30: logical or of bits[29:26,20:1].
 113          * bit31: logical or of bits[25:1].
 114          */
 115         for (i = 1; i < 30; i++)
 116                 irq_set_chip_and_handler(GT641XX_IRQ_BASE + i,
 117                                          &gt641xx_irq_chip, handle_level_irq);
 118 }