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1/*
2 * OpenRISC irq.c
3 *
4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
6 * declaration.
7 *
8 * Modifications for the OpenRISC architecture:
9 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
17#include <linux/ptrace.h>
18#include <linux/errno.h>
19#include <linux/interrupt.h>
20#include <linux/init.h>
21#include <linux/of.h>
22#include <linux/ftrace.h>
23#include <linux/irq.h>
24#include <linux/seq_file.h>
25#include <linux/kernel_stat.h>
26
27#include <linux/irqflags.h>
28
29/* read interrupt enabled status */
30unsigned long arch_local_save_flags(void)
31{
32 return mfspr(SPR_SR) & (SPR_SR_IEE|SPR_SR_TEE);
33}
34EXPORT_SYMBOL(arch_local_save_flags);
35
36/* set interrupt enabled status */
37void arch_local_irq_restore(unsigned long flags)
38{
39 mtspr(SPR_SR, ((mfspr(SPR_SR) & ~(SPR_SR_IEE|SPR_SR_TEE)) | flags));
40}
41EXPORT_SYMBOL(arch_local_irq_restore);
42
43
44/* OR1K PIC implementation */
45
46/* We're a couple of cycles faster than the generic implementations with
47 * these 'fast' versions.
48 */
49
50static void or1k_pic_mask(struct irq_data *data)
51{
52 mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->irq));
53}
54
55static void or1k_pic_unmask(struct irq_data *data)
56{
57 mtspr(SPR_PICMR, mfspr(SPR_PICMR) | (1UL << data->irq));
58}
59
60static void or1k_pic_ack(struct irq_data *data)
61{
62 /* EDGE-triggered interrupts need to be ack'ed in order to clear
63 * the latch.
64 * LEVER-triggered interrupts do not need to be ack'ed; however,
65 * ack'ing the interrupt has no ill-effect and is quicker than
66 * trying to figure out what type it is...
67 */
68
69 /* The OpenRISC 1000 spec says to write a 1 to the bit to ack the
70 * interrupt, but the OR1200 does this backwards and requires a 0
71 * to be written...
72 */
73
74#ifdef CONFIG_OR1K_1200
75 /* There are two oddities with the OR1200 PIC implementation:
76 * i) LEVEL-triggered interrupts are latched and need to be cleared
77 * ii) the interrupt latch is cleared by writing a 0 to the bit,
78 * as opposed to a 1 as mandated by the spec
79 */
80
81 mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->irq));
82#else
83 WARN(1, "Interrupt handling possibily broken\n");
84 mtspr(SPR_PICSR, (1UL << irq));
85#endif
86}
87
88static void or1k_pic_mask_ack(struct irq_data *data)
89{
90 /* Comments for pic_ack apply here, too */
91
92#ifdef CONFIG_OR1K_1200
93 mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->irq));
94#else
95 WARN(1, "Interrupt handling possibily broken\n");
96 mtspr(SPR_PICSR, (1UL << irq));
97#endif
98}
99
100static int or1k_pic_set_type(struct irq_data *data, unsigned int flow_type)
101{
102 /* There's nothing to do in the PIC configuration when changing
103 * flow type. Level and edge-triggered interrupts are both
104 * supported, but it's PIC-implementation specific which type
105 * is handled. */
106
107 return irq_setup_alt_chip(data, flow_type);
108}
109
110static inline int pic_get_irq(int first)
111{
112 int irq;
113
114 irq = ffs(mfspr(SPR_PICSR) >> first);
115
116 return irq ? irq + first - 1 : NO_IRQ;
117}
118
119static void __init or1k_irq_init(void)
120{
121 struct irq_chip_generic *gc;
122 struct irq_chip_type *ct;
123
124 /* Disable all interrupts until explicitly requested */
125 mtspr(SPR_PICMR, (0UL));
126
127 gc = irq_alloc_generic_chip("or1k-PIC", 1, 0, 0, handle_level_irq);
128 ct = gc->chip_types;
129
130 ct->chip.irq_unmask = or1k_pic_unmask;
131 ct->chip.irq_mask = or1k_pic_mask;
132 ct->chip.irq_ack = or1k_pic_ack;
133 ct->chip.irq_mask_ack = or1k_pic_mask_ack;
134 ct->chip.irq_set_type = or1k_pic_set_type;
135
136 /* The OR1K PIC can handle both level and edge trigged
137 * interrupts in roughly the same manner
138 */
139#if 0
140 /* FIXME: chip.type??? */
141 ct->chip.type = IRQ_TYPE_EDGE_BOTH | IRQ_TYPE_LEVEL_MASK;
142#endif
143
144 irq_setup_generic_chip(gc, IRQ_MSK(NR_IRQS), 0,
145 IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
146}
147
148void __init init_IRQ(void)
149{
150 or1k_irq_init();
151}
152
153void __irq_entry do_IRQ(struct pt_regs *regs)
154{
155 int irq = -1;
156 struct pt_regs *old_regs = set_irq_regs(regs);
157
158 irq_enter();
159
160 while ((irq = pic_get_irq(irq + 1)) != NO_IRQ)
161 generic_handle_irq(irq);
162
163 irq_exit();
164 set_irq_regs(old_regs);
165}
166
167unsigned int irq_create_of_mapping(struct device_node *controller,
168 const u32 *intspec, unsigned int intsize)
169{
170 return intspec[0];
171}
172EXPORT_SYMBOL_GPL(irq_create_of_mapping);
1/*
2 * OpenRISC irq.c
3 *
4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
6 * declaration.
7 *
8 * Modifications for the OpenRISC architecture:
9 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
17#include <linux/interrupt.h>
18#include <linux/init.h>
19#include <linux/ftrace.h>
20#include <linux/irq.h>
21#include <linux/irqchip.h>
22#include <linux/export.h>
23#include <linux/irqflags.h>
24
25/* read interrupt enabled status */
26unsigned long arch_local_save_flags(void)
27{
28 return mfspr(SPR_SR) & (SPR_SR_IEE|SPR_SR_TEE);
29}
30EXPORT_SYMBOL(arch_local_save_flags);
31
32/* set interrupt enabled status */
33void arch_local_irq_restore(unsigned long flags)
34{
35 mtspr(SPR_SR, ((mfspr(SPR_SR) & ~(SPR_SR_IEE|SPR_SR_TEE)) | flags));
36}
37EXPORT_SYMBOL(arch_local_irq_restore);
38
39void __init init_IRQ(void)
40{
41 irqchip_init();
42}
43
44static void (*handle_arch_irq)(struct pt_regs *);
45
46void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
47{
48 handle_arch_irq = handle_irq;
49}
50
51void __irq_entry do_IRQ(struct pt_regs *regs)
52{
53 handle_arch_irq(regs);
54}