xref: /openbmc/linux/arch/mips/ar7/irq.c (revision 9b93eb47)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2006,2007 Felix Fietkau <nbd@openwrt.org>
4  * Copyright (C) 2006,2007 Eugene Konev <ejka@openwrt.org>
5  */
6 
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/irq.h>
10 
11 #include <asm/irq_cpu.h>
12 #include <asm/mipsregs.h>
13 #include <asm/mach-ar7/ar7.h>
14 
15 #define EXCEPT_OFFSET	0x80
16 #define PACE_OFFSET	0xA0
17 #define CHNLS_OFFSET	0x200
18 
19 #define REG_OFFSET(irq, reg)	((irq) / 32 * 0x4 + reg * 0x10)
20 #define SEC_REG_OFFSET(reg)	(EXCEPT_OFFSET + reg * 0x8)
21 #define SEC_SR_OFFSET		(SEC_REG_OFFSET(0))	/* 0x80 */
22 #define CR_OFFSET(irq)		(REG_OFFSET(irq, 1))	/* 0x10 */
23 #define SEC_CR_OFFSET		(SEC_REG_OFFSET(1))	/* 0x88 */
24 #define ESR_OFFSET(irq)		(REG_OFFSET(irq, 2))	/* 0x20 */
25 #define SEC_ESR_OFFSET		(SEC_REG_OFFSET(2))	/* 0x90 */
26 #define ECR_OFFSET(irq)		(REG_OFFSET(irq, 3))	/* 0x30 */
27 #define SEC_ECR_OFFSET		(SEC_REG_OFFSET(3))	/* 0x98 */
28 #define PIR_OFFSET		(0x40)
29 #define MSR_OFFSET		(0x44)
30 #define PM_OFFSET(irq)		(REG_OFFSET(irq, 5))	/* 0x50 */
31 #define TM_OFFSET(irq)		(REG_OFFSET(irq, 6))	/* 0x60 */
32 
33 #define REG(addr) ((u32 *)(KSEG1ADDR(AR7_REGS_IRQ) + addr))
34 
35 #define CHNL_OFFSET(chnl) (CHNLS_OFFSET + (chnl * 4))
36 
37 static int ar7_irq_base;
38 
39 static void ar7_unmask_irq(struct irq_data *d)
40 {
41 	writel(1 << ((d->irq - ar7_irq_base) % 32),
42 	       REG(ESR_OFFSET(d->irq - ar7_irq_base)));
43 }
44 
45 static void ar7_mask_irq(struct irq_data *d)
46 {
47 	writel(1 << ((d->irq - ar7_irq_base) % 32),
48 	       REG(ECR_OFFSET(d->irq - ar7_irq_base)));
49 }
50 
51 static void ar7_ack_irq(struct irq_data *d)
52 {
53 	writel(1 << ((d->irq - ar7_irq_base) % 32),
54 	       REG(CR_OFFSET(d->irq - ar7_irq_base)));
55 }
56 
57 static void ar7_unmask_sec_irq(struct irq_data *d)
58 {
59 	writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_ESR_OFFSET));
60 }
61 
62 static void ar7_mask_sec_irq(struct irq_data *d)
63 {
64 	writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_ECR_OFFSET));
65 }
66 
67 static void ar7_ack_sec_irq(struct irq_data *d)
68 {
69 	writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_CR_OFFSET));
70 }
71 
72 static struct irq_chip ar7_irq_type = {
73 	.name = "AR7",
74 	.irq_unmask = ar7_unmask_irq,
75 	.irq_mask = ar7_mask_irq,
76 	.irq_ack = ar7_ack_irq
77 };
78 
79 static struct irq_chip ar7_sec_irq_type = {
80 	.name = "AR7",
81 	.irq_unmask = ar7_unmask_sec_irq,
82 	.irq_mask = ar7_mask_sec_irq,
83 	.irq_ack = ar7_ack_sec_irq,
84 };
85 
86 static struct irqaction ar7_cascade_action = {
87 	.handler = no_action,
88 	.name = "AR7 cascade interrupt",
89 	.flags = IRQF_NO_THREAD,
90 };
91 
92 static void __init ar7_irq_init(int base)
93 {
94 	int i;
95 	/*
96 	 * Disable interrupts and clear pending
97 	 */
98 	writel(0xffffffff, REG(ECR_OFFSET(0)));
99 	writel(0xff, REG(ECR_OFFSET(32)));
100 	writel(0xffffffff, REG(SEC_ECR_OFFSET));
101 	writel(0xffffffff, REG(CR_OFFSET(0)));
102 	writel(0xff, REG(CR_OFFSET(32)));
103 	writel(0xffffffff, REG(SEC_CR_OFFSET));
104 
105 	ar7_irq_base = base;
106 
107 	for (i = 0; i < 40; i++) {
108 		writel(i, REG(CHNL_OFFSET(i)));
109 		/* Primary IRQ's */
110 		irq_set_chip_and_handler(base + i, &ar7_irq_type,
111 					 handle_level_irq);
112 		/* Secondary IRQ's */
113 		if (i < 32)
114 			irq_set_chip_and_handler(base + i + 40,
115 						 &ar7_sec_irq_type,
116 						 handle_level_irq);
117 	}
118 
119 	setup_irq(2, &ar7_cascade_action);
120 	setup_irq(ar7_irq_base, &ar7_cascade_action);
121 	set_c0_status(IE_IRQ0);
122 }
123 
124 void __init arch_init_irq(void)
125 {
126 	mips_cpu_irq_init();
127 	ar7_irq_init(8);
128 }
129 
130 static void ar7_cascade(void)
131 {
132 	u32 status;
133 	int i, irq;
134 
135 	/* Primary IRQ's */
136 	irq = readl(REG(PIR_OFFSET)) & 0x3f;
137 	if (irq) {
138 		do_IRQ(ar7_irq_base + irq);
139 		return;
140 	}
141 
142 	/* Secondary IRQ's are cascaded through primary '0' */
143 	writel(1, REG(CR_OFFSET(irq)));
144 	status = readl(REG(SEC_SR_OFFSET));
145 	for (i = 0; i < 32; i++) {
146 		if (status & 1) {
147 			do_IRQ(ar7_irq_base + i + 40);
148 			return;
149 		}
150 		status >>= 1;
151 	}
152 
153 	spurious_interrupt();
154 }
155 
156 asmlinkage void plat_irq_dispatch(void)
157 {
158 	unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
159 	if (pending & STATUSF_IP7)		/* cpu timer */
160 		do_IRQ(7);
161 	else if (pending & STATUSF_IP2)		/* int0 hardware line */
162 		ar7_cascade();
163 	else
164 		spurious_interrupt();
165 }
166