xref: /openbmc/linux/arch/mips/loongson32/common/irq.c (revision 293d5b43)
1 /*
2  * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.com>
3  *
4  * This program is free software; you can redistribute	it and/or modify it
5  * under  the terms of	the GNU General	 Public License as published by the
6  * Free Software Foundation;  either version 2 of the  License, or (at your
7  * option) any later version.
8  */
9 
10 #include <linux/interrupt.h>
11 #include <linux/irq.h>
12 #include <asm/irq_cpu.h>
13 
14 #include <loongson1.h>
15 #include <irq.h>
16 
17 #define LS1X_INTC_REG(n, x) \
18 		((void __iomem *)KSEG1ADDR(LS1X_INTC_BASE + (n * 0x18) + (x)))
19 
20 #define LS1X_INTC_INTISR(n)		LS1X_INTC_REG(n, 0x0)
21 #define LS1X_INTC_INTIEN(n)		LS1X_INTC_REG(n, 0x4)
22 #define LS1X_INTC_INTSET(n)		LS1X_INTC_REG(n, 0x8)
23 #define LS1X_INTC_INTCLR(n)		LS1X_INTC_REG(n, 0xc)
24 #define LS1X_INTC_INTPOL(n)		LS1X_INTC_REG(n, 0x10)
25 #define LS1X_INTC_INTEDGE(n)		LS1X_INTC_REG(n, 0x14)
26 
27 static void ls1x_irq_ack(struct irq_data *d)
28 {
29 	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
30 	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
31 
32 	__raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
33 			| (1 << bit), LS1X_INTC_INTCLR(n));
34 }
35 
36 static void ls1x_irq_mask(struct irq_data *d)
37 {
38 	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
39 	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
40 
41 	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
42 			& ~(1 << bit), LS1X_INTC_INTIEN(n));
43 }
44 
45 static void ls1x_irq_mask_ack(struct irq_data *d)
46 {
47 	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
48 	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
49 
50 	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
51 			& ~(1 << bit), LS1X_INTC_INTIEN(n));
52 	__raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
53 			| (1 << bit), LS1X_INTC_INTCLR(n));
54 }
55 
56 static void ls1x_irq_unmask(struct irq_data *d)
57 {
58 	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
59 	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
60 
61 	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
62 			| (1 << bit), LS1X_INTC_INTIEN(n));
63 }
64 
65 static struct irq_chip ls1x_irq_chip = {
66 	.name		= "LS1X-INTC",
67 	.irq_ack	= ls1x_irq_ack,
68 	.irq_mask	= ls1x_irq_mask,
69 	.irq_mask_ack	= ls1x_irq_mask_ack,
70 	.irq_unmask	= ls1x_irq_unmask,
71 };
72 
73 static void ls1x_irq_dispatch(int n)
74 {
75 	u32 int_status, irq;
76 
77 	/* Get pending sources, masked by current enables */
78 	int_status = __raw_readl(LS1X_INTC_INTISR(n)) &
79 			__raw_readl(LS1X_INTC_INTIEN(n));
80 
81 	if (int_status) {
82 		irq = LS1X_IRQ(n, __ffs(int_status));
83 		do_IRQ(irq);
84 	}
85 }
86 
87 asmlinkage void plat_irq_dispatch(void)
88 {
89 	unsigned int pending;
90 
91 	pending = read_c0_cause() & read_c0_status() & ST0_IM;
92 
93 	if (pending & CAUSEF_IP7)
94 		do_IRQ(TIMER_IRQ);
95 	else if (pending & CAUSEF_IP2)
96 		ls1x_irq_dispatch(0); /* INT0 */
97 	else if (pending & CAUSEF_IP3)
98 		ls1x_irq_dispatch(1); /* INT1 */
99 	else if (pending & CAUSEF_IP4)
100 		ls1x_irq_dispatch(2); /* INT2 */
101 	else if (pending & CAUSEF_IP5)
102 		ls1x_irq_dispatch(3); /* INT3 */
103 	else if (pending & CAUSEF_IP6)
104 		ls1x_irq_dispatch(4); /* INT4 */
105 	else
106 		spurious_interrupt();
107 
108 }
109 
110 struct irqaction cascade_irqaction = {
111 	.handler = no_action,
112 	.name = "cascade",
113 	.flags = IRQF_NO_THREAD,
114 };
115 
116 static void __init ls1x_irq_init(int base)
117 {
118 	int n;
119 
120 	/* Disable interrupts and clear pending,
121 	 * setup all IRQs as high level triggered
122 	 */
123 	for (n = 0; n < 4; n++) {
124 		__raw_writel(0x0, LS1X_INTC_INTIEN(n));
125 		__raw_writel(0xffffffff, LS1X_INTC_INTCLR(n));
126 		__raw_writel(0xffffffff, LS1X_INTC_INTPOL(n));
127 		/* set DMA0, DMA1 and DMA2 to edge trigger */
128 		__raw_writel(n ? 0x0 : 0xe000, LS1X_INTC_INTEDGE(n));
129 	}
130 
131 
132 	for (n = base; n < LS1X_IRQS; n++) {
133 		irq_set_chip_and_handler(n, &ls1x_irq_chip,
134 					 handle_level_irq);
135 	}
136 
137 	setup_irq(INT0_IRQ, &cascade_irqaction);
138 	setup_irq(INT1_IRQ, &cascade_irqaction);
139 	setup_irq(INT2_IRQ, &cascade_irqaction);
140 	setup_irq(INT3_IRQ, &cascade_irqaction);
141 }
142 
143 void __init arch_init_irq(void)
144 {
145 	mips_cpu_irq_init();
146 	ls1x_irq_init(LS1X_IRQ_BASE);
147 }
148