1/*
2 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
3 *  JZ4740 platform IRQ support
4 *
5 *  This program is free software; you can redistribute it and/or modify it
6 *  under  the terms of the GNU General	 Public License as published by the
7 *  Free Software Foundation;  either version 2 of the License, or (at your
8 *  option) any later version.
9 *
10 *  You should have received a copy of the GNU General Public License along
11 *  with this program; if not, write to the Free Software Foundation, Inc.,
12 *  675 Mass Ave, Cambridge, MA 02139, USA.
13 *
14 */
15
16#include <linux/errno.h>
17#include <linux/init.h>
18#include <linux/types.h>
19#include <linux/interrupt.h>
20#include <linux/ioport.h>
21#include <linux/timex.h>
22#include <linux/slab.h>
23#include <linux/delay.h>
24
25#include <linux/debugfs.h>
26#include <linux/seq_file.h>
27
28#include <asm/io.h>
29#include <asm/mipsregs.h>
30#include <asm/irq_cpu.h>
31
32#include <asm/mach-jz4740/base.h>
33#include <asm/mach-jz4740/irq.h>
34
35#include "irq.h"
36
37static void __iomem *jz_intc_base;
38
39#define JZ_REG_INTC_STATUS	0x00
40#define JZ_REG_INTC_MASK	0x04
41#define JZ_REG_INTC_SET_MASK	0x08
42#define JZ_REG_INTC_CLEAR_MASK	0x0c
43#define JZ_REG_INTC_PENDING	0x10
44
45static irqreturn_t jz4740_cascade(int irq, void *data)
46{
47	uint32_t irq_reg;
48
49	irq_reg = readl(jz_intc_base + JZ_REG_INTC_PENDING);
50
51	if (irq_reg)
52		generic_handle_irq(__fls(irq_reg) + JZ4740_IRQ_BASE);
53
54	return IRQ_HANDLED;
55}
56
57static void jz4740_irq_set_mask(struct irq_chip_generic *gc, uint32_t mask)
58{
59	struct irq_chip_regs *regs = &gc->chip_types->regs;
60
61	writel(mask, gc->reg_base + regs->enable);
62	writel(~mask, gc->reg_base + regs->disable);
63}
64
65void jz4740_irq_suspend(struct irq_data *data)
66{
67	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
68	jz4740_irq_set_mask(gc, gc->wake_active);
69}
70
71void jz4740_irq_resume(struct irq_data *data)
72{
73	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
74	jz4740_irq_set_mask(gc, gc->mask_cache);
75}
76
77static struct irqaction jz4740_cascade_action = {
78	.handler = jz4740_cascade,
79	.name = "JZ4740 cascade interrupt",
80};
81
82void __init arch_init_irq(void)
83{
84	struct irq_chip_generic *gc;
85	struct irq_chip_type *ct;
86
87	mips_cpu_irq_init();
88
89	jz_intc_base = ioremap(JZ4740_INTC_BASE_ADDR, 0x14);
90
91	/* Mask all irqs */
92	writel(0xffffffff, jz_intc_base + JZ_REG_INTC_SET_MASK);
93
94	gc = irq_alloc_generic_chip("INTC", 1, JZ4740_IRQ_BASE, jz_intc_base,
95		handle_level_irq);
96
97	gc->wake_enabled = IRQ_MSK(32);
98
99	ct = gc->chip_types;
100	ct->regs.enable = JZ_REG_INTC_CLEAR_MASK;
101	ct->regs.disable = JZ_REG_INTC_SET_MASK;
102	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
103	ct->chip.irq_mask = irq_gc_mask_disable_reg;
104	ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
105	ct->chip.irq_set_wake = irq_gc_set_wake;
106	ct->chip.irq_suspend = jz4740_irq_suspend;
107	ct->chip.irq_resume = jz4740_irq_resume;
108
109	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, 0, IRQ_NOPROBE | IRQ_LEVEL);
110
111	setup_irq(2, &jz4740_cascade_action);
112}
113
114asmlinkage void plat_irq_dispatch(void)
115{
116	unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
117	if (pending & STATUSF_IP2)
118		do_IRQ(2);
119	else if (pending & STATUSF_IP3)
120		do_IRQ(3);
121	else
122		spurious_interrupt();
123}
124
125#ifdef CONFIG_DEBUG_FS
126
127static inline void intc_seq_reg(struct seq_file *s, const char *name,
128	unsigned int reg)
129{
130	seq_printf(s, "%s:\t\t%08x\n", name, readl(jz_intc_base + reg));
131}
132
133static int intc_regs_show(struct seq_file *s, void *unused)
134{
135	intc_seq_reg(s, "Status", JZ_REG_INTC_STATUS);
136	intc_seq_reg(s, "Mask", JZ_REG_INTC_MASK);
137	intc_seq_reg(s, "Pending", JZ_REG_INTC_PENDING);
138
139	return 0;
140}
141
142static int intc_regs_open(struct inode *inode, struct file *file)
143{
144	return single_open(file, intc_regs_show, NULL);
145}
146
147static const struct file_operations intc_regs_operations = {
148	.open		= intc_regs_open,
149	.read		= seq_read,
150	.llseek		= seq_lseek,
151	.release	= single_release,
152};
153
154static int __init intc_debugfs_init(void)
155{
156	(void) debugfs_create_file("jz_regs_intc", S_IFREG | S_IRUGO,
157				NULL, NULL, &intc_regs_operations);
158	return 0;
159}
160subsys_initcall(intc_debugfs_init);
161
162#endif
163