xref: /openbmc/linux/arch/mips/ar7/irq.c (revision 588b48ca)
1 /*
2  * Copyright (C) 2006,2007 Felix Fietkau <nbd@openwrt.org>
3  * Copyright (C) 2006,2007 Eugene Konev <ejka@openwrt.org>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18  */
19 
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/irq.h>
23 
24 #include <asm/irq_cpu.h>
25 #include <asm/mipsregs.h>
26 #include <asm/mach-ar7/ar7.h>
27 
28 #define EXCEPT_OFFSET	0x80
29 #define PACE_OFFSET	0xA0
30 #define CHNLS_OFFSET	0x200
31 
32 #define REG_OFFSET(irq, reg)	((irq) / 32 * 0x4 + reg * 0x10)
33 #define SEC_REG_OFFSET(reg)	(EXCEPT_OFFSET + reg * 0x8)
34 #define SEC_SR_OFFSET		(SEC_REG_OFFSET(0))	/* 0x80 */
35 #define CR_OFFSET(irq)		(REG_OFFSET(irq, 1))	/* 0x10 */
36 #define SEC_CR_OFFSET		(SEC_REG_OFFSET(1))	/* 0x88 */
37 #define ESR_OFFSET(irq)		(REG_OFFSET(irq, 2))	/* 0x20 */
38 #define SEC_ESR_OFFSET		(SEC_REG_OFFSET(2))	/* 0x90 */
39 #define ECR_OFFSET(irq)		(REG_OFFSET(irq, 3))	/* 0x30 */
40 #define SEC_ECR_OFFSET		(SEC_REG_OFFSET(3))	/* 0x98 */
41 #define PIR_OFFSET		(0x40)
42 #define MSR_OFFSET		(0x44)
43 #define PM_OFFSET(irq)		(REG_OFFSET(irq, 5))	/* 0x50 */
44 #define TM_OFFSET(irq)		(REG_OFFSET(irq, 6))	/* 0x60 */
45 
46 #define REG(addr) ((u32 *)(KSEG1ADDR(AR7_REGS_IRQ) + addr))
47 
48 #define CHNL_OFFSET(chnl) (CHNLS_OFFSET + (chnl * 4))
49 
50 static int ar7_irq_base;
51 
52 static void ar7_unmask_irq(struct irq_data *d)
53 {
54 	writel(1 << ((d->irq - ar7_irq_base) % 32),
55 	       REG(ESR_OFFSET(d->irq - ar7_irq_base)));
56 }
57 
58 static void ar7_mask_irq(struct irq_data *d)
59 {
60 	writel(1 << ((d->irq - ar7_irq_base) % 32),
61 	       REG(ECR_OFFSET(d->irq - ar7_irq_base)));
62 }
63 
64 static void ar7_ack_irq(struct irq_data *d)
65 {
66 	writel(1 << ((d->irq - ar7_irq_base) % 32),
67 	       REG(CR_OFFSET(d->irq - ar7_irq_base)));
68 }
69 
70 static void ar7_unmask_sec_irq(struct irq_data *d)
71 {
72 	writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_ESR_OFFSET));
73 }
74 
75 static void ar7_mask_sec_irq(struct irq_data *d)
76 {
77 	writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_ECR_OFFSET));
78 }
79 
80 static void ar7_ack_sec_irq(struct irq_data *d)
81 {
82 	writel(1 << (d->irq - ar7_irq_base - 40), REG(SEC_CR_OFFSET));
83 }
84 
85 static struct irq_chip ar7_irq_type = {
86 	.name = "AR7",
87 	.irq_unmask = ar7_unmask_irq,
88 	.irq_mask = ar7_mask_irq,
89 	.irq_ack = ar7_ack_irq
90 };
91 
92 static struct irq_chip ar7_sec_irq_type = {
93 	.name = "AR7",
94 	.irq_unmask = ar7_unmask_sec_irq,
95 	.irq_mask = ar7_mask_sec_irq,
96 	.irq_ack = ar7_ack_sec_irq,
97 };
98 
99 static struct irqaction ar7_cascade_action = {
100 	.handler = no_action,
101 	.name = "AR7 cascade interrupt",
102 	.flags = IRQF_NO_THREAD,
103 };
104 
105 static void __init ar7_irq_init(int base)
106 {
107 	int i;
108 	/*
109 	 * Disable interrupts and clear pending
110 	 */
111 	writel(0xffffffff, REG(ECR_OFFSET(0)));
112 	writel(0xff, REG(ECR_OFFSET(32)));
113 	writel(0xffffffff, REG(SEC_ECR_OFFSET));
114 	writel(0xffffffff, REG(CR_OFFSET(0)));
115 	writel(0xff, REG(CR_OFFSET(32)));
116 	writel(0xffffffff, REG(SEC_CR_OFFSET));
117 
118 	ar7_irq_base = base;
119 
120 	for (i = 0; i < 40; i++) {
121 		writel(i, REG(CHNL_OFFSET(i)));
122 		/* Primary IRQ's */
123 		irq_set_chip_and_handler(base + i, &ar7_irq_type,
124 					 handle_level_irq);
125 		/* Secondary IRQ's */
126 		if (i < 32)
127 			irq_set_chip_and_handler(base + i + 40,
128 						 &ar7_sec_irq_type,
129 						 handle_level_irq);
130 	}
131 
132 	setup_irq(2, &ar7_cascade_action);
133 	setup_irq(ar7_irq_base, &ar7_cascade_action);
134 	set_c0_status(IE_IRQ0);
135 }
136 
137 void __init arch_init_irq(void)
138 {
139 	mips_cpu_irq_init();
140 	ar7_irq_init(8);
141 }
142 
143 static void ar7_cascade(void)
144 {
145 	u32 status;
146 	int i, irq;
147 
148 	/* Primary IRQ's */
149 	irq = readl(REG(PIR_OFFSET)) & 0x3f;
150 	if (irq) {
151 		do_IRQ(ar7_irq_base + irq);
152 		return;
153 	}
154 
155 	/* Secondary IRQ's are cascaded through primary '0' */
156 	writel(1, REG(CR_OFFSET(irq)));
157 	status = readl(REG(SEC_SR_OFFSET));
158 	for (i = 0; i < 32; i++) {
159 		if (status & 1) {
160 			do_IRQ(ar7_irq_base + i + 40);
161 			return;
162 		}
163 		status >>= 1;
164 	}
165 
166 	spurious_interrupt();
167 }
168 
169 asmlinkage void plat_irq_dispatch(void)
170 {
171 	unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
172 	if (pending & STATUSF_IP7)		/* cpu timer */
173 		do_IRQ(7);
174 	else if (pending & STATUSF_IP2)		/* int0 hardware line */
175 		ar7_cascade();
176 	else
177 		spurious_interrupt();
178 }
179