1 /*
2 * linux/arch/arm/mach-at91/irq.c
3 *
4 * Copyright (C) 2004 SAN People
5 * Copyright (C) 2004 ATMEL
6 * Copyright (C) Rick Bronson
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #include <linux/init.h>
24 #include <linux/module.h>
25 #include <linux/mm.h>
26 #include <linux/types.h>
27
28 #include <mach/hardware.h>
29 #include <asm/irq.h>
30 #include <asm/setup.h>
31
32 #include <asm/mach/arch.h>
33 #include <asm/mach/irq.h>
34 #include <asm/mach/map.h>
35
36 void __iomem *at91_aic_base;
37
at91_aic_mask_irq(struct irq_data * d)38 static void at91_aic_mask_irq(struct irq_data *d)
39 {
40 /* Disable interrupt on AIC */
41 at91_aic_write(AT91_AIC_IDCR, 1 << d->irq);
42 }
43
at91_aic_unmask_irq(struct irq_data * d)44 static void at91_aic_unmask_irq(struct irq_data *d)
45 {
46 /* Enable interrupt on AIC */
47 at91_aic_write(AT91_AIC_IECR, 1 << d->irq);
48 }
49
50 unsigned int at91_extern_irq;
51
52 #define is_extern_irq(irq) ((1 << (irq)) & at91_extern_irq)
53
at91_aic_set_type(struct irq_data * d,unsigned type)54 static int at91_aic_set_type(struct irq_data *d, unsigned type)
55 {
56 unsigned int smr, srctype;
57
58 switch (type) {
59 case IRQ_TYPE_LEVEL_HIGH:
60 srctype = AT91_AIC_SRCTYPE_HIGH;
61 break;
62 case IRQ_TYPE_EDGE_RISING:
63 srctype = AT91_AIC_SRCTYPE_RISING;
64 break;
65 case IRQ_TYPE_LEVEL_LOW:
66 if ((d->irq == AT91_ID_FIQ) || is_extern_irq(d->irq)) /* only supported on external interrupts */
67 srctype = AT91_AIC_SRCTYPE_LOW;
68 else
69 return -EINVAL;
70 break;
71 case IRQ_TYPE_EDGE_FALLING:
72 if ((d->irq == AT91_ID_FIQ) || is_extern_irq(d->irq)) /* only supported on external interrupts */
73 srctype = AT91_AIC_SRCTYPE_FALLING;
74 else
75 return -EINVAL;
76 break;
77 default:
78 return -EINVAL;
79 }
80
81 smr = at91_aic_read(AT91_AIC_SMR(d->irq)) & ~AT91_AIC_SRCTYPE;
82 at91_aic_write(AT91_AIC_SMR(d->irq), smr | srctype);
83 return 0;
84 }
85
86 #ifdef CONFIG_PM
87
88 static u32 wakeups;
89 static u32 backups;
90
at91_aic_set_wake(struct irq_data * d,unsigned value)91 static int at91_aic_set_wake(struct irq_data *d, unsigned value)
92 {
93 if (unlikely(d->irq >= 32))
94 return -EINVAL;
95
96 if (value)
97 wakeups |= (1 << d->irq);
98 else
99 wakeups &= ~(1 << d->irq);
100
101 return 0;
102 }
103
at91_irq_suspend(void)104 void at91_irq_suspend(void)
105 {
106 backups = at91_aic_read(AT91_AIC_IMR);
107 at91_aic_write(AT91_AIC_IDCR, backups);
108 at91_aic_write(AT91_AIC_IECR, wakeups);
109 }
110
at91_irq_resume(void)111 void at91_irq_resume(void)
112 {
113 at91_aic_write(AT91_AIC_IDCR, wakeups);
114 at91_aic_write(AT91_AIC_IECR, backups);
115 }
116
117 #else
118 #define at91_aic_set_wake NULL
119 #endif
120
121 static struct irq_chip at91_aic_chip = {
122 .name = "AIC",
123 .irq_ack = at91_aic_mask_irq,
124 .irq_mask = at91_aic_mask_irq,
125 .irq_unmask = at91_aic_unmask_irq,
126 .irq_set_type = at91_aic_set_type,
127 .irq_set_wake = at91_aic_set_wake,
128 };
129
130 /*
131 * Initialize the AIC interrupt controller.
132 */
at91_aic_init(unsigned int priority[NR_AIC_IRQS])133 void __init at91_aic_init(unsigned int priority[NR_AIC_IRQS])
134 {
135 unsigned int i;
136
137 at91_aic_base = ioremap(AT91_AIC, 512);
138
139 if (!at91_aic_base)
140 panic("Impossible to ioremap AT91_AIC\n");
141
142 /*
143 * The IVR is used by macro get_irqnr_and_base to read and verify.
144 * The irq number is NR_AIC_IRQS when a spurious interrupt has occurred.
145 */
146 for (i = 0; i < NR_AIC_IRQS; i++) {
147 /* Put irq number in Source Vector Register: */
148 at91_aic_write(AT91_AIC_SVR(i), i);
149 /* Active Low interrupt, with the specified priority */
150 at91_aic_write(AT91_AIC_SMR(i), AT91_AIC_SRCTYPE_LOW | priority[i]);
151
152 irq_set_chip_and_handler(i, &at91_aic_chip, handle_level_irq);
153 set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
154
155 /* Perform 8 End Of Interrupt Command to make sure AIC will not Lock out nIRQ */
156 if (i < 8)
157 at91_aic_write(AT91_AIC_EOICR, 0);
158 }
159
160 /*
161 * Spurious Interrupt ID in Spurious Vector Register is NR_AIC_IRQS
162 * When there is no current interrupt, the IRQ Vector Register reads the value stored in AIC_SPU
163 */
164 at91_aic_write(AT91_AIC_SPU, NR_AIC_IRQS);
165
166 /* No debugging in AIC: Debug (Protect) Control Register */
167 at91_aic_write(AT91_AIC_DCR, 0);
168
169 /* Disable and clear all interrupts initially */
170 at91_aic_write(AT91_AIC_IDCR, 0xFFFFFFFF);
171 at91_aic_write(AT91_AIC_ICCR, 0xFFFFFFFF);
172 }
173