xref: /openbmc/linux/arch/mips/kernel/irq-gt641xx.c (revision bbb774d9) 
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 }
119