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Daniel Tang397e7b52013-12-05 17:12:17 +11001/*
2 * linux/drivers/irqchip/irq-zevio.c
3 *
4 * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2, as
8 * published by the Free Software Foundation.
9 *
10 */
11
12#include <linux/io.h>
13#include <linux/irq.h>
14#include <linux/of.h>
15#include <linux/of_address.h>
16#include <linux/of_irq.h>
17
18#include <asm/mach/irq.h>
19#include <asm/exception.h>
20
21#include "irqchip.h"
22
23#define IO_STATUS 0x000
24#define IO_RAW_STATUS 0x004
25#define IO_ENABLE 0x008
26#define IO_DISABLE 0x00C
27#define IO_CURRENT 0x020
28#define IO_RESET 0x028
29#define IO_MAX_PRIOTY 0x02C
30
31#define IO_IRQ_BASE 0x000
32#define IO_FIQ_BASE 0x100
33
34#define IO_INVERT_SEL 0x200
35#define IO_STICKY_SEL 0x204
36#define IO_PRIORITY_SEL 0x300
37
38#define MAX_INTRS 32
39#define FIQ_START MAX_INTRS
40
41static struct irq_domain *zevio_irq_domain;
42static void __iomem *zevio_irq_io;
43
44static void zevio_irq_ack(struct irq_data *irqd)
45{
46 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(irqd);
47 struct irq_chip_regs *regs =
48 &container_of(irqd->chip, struct irq_chip_type, chip)->regs;
49
50 readl(gc->reg_base + regs->ack);
51}
52
Stephen Boyd8783dd32014-03-04 16:40:30 -080053static void __exception_irq_entry zevio_handle_irq(struct pt_regs *regs)
Daniel Tang397e7b52013-12-05 17:12:17 +110054{
55 int irqnr;
56
57 while (readl(zevio_irq_io + IO_STATUS)) {
58 irqnr = readl(zevio_irq_io + IO_CURRENT);
59 irqnr = irq_find_mapping(zevio_irq_domain, irqnr);
60 handle_IRQ(irqnr, regs);
61 };
62}
63
64static void __init zevio_init_irq_base(void __iomem *base)
65{
66 /* Disable all interrupts */
67 writel(~0, base + IO_DISABLE);
68
69 /* Accept interrupts of all priorities */
70 writel(0xF, base + IO_MAX_PRIOTY);
71
72 /* Reset existing interrupts */
73 readl(base + IO_RESET);
74}
75
76static int __init zevio_of_init(struct device_node *node,
77 struct device_node *parent)
78{
79 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
80 struct irq_chip_generic *gc;
81 int ret;
82
83 if (WARN_ON(zevio_irq_io || zevio_irq_domain))
84 return -EBUSY;
85
86 zevio_irq_io = of_iomap(node, 0);
87 BUG_ON(!zevio_irq_io);
88
89 /* Do not invert interrupt status bits */
90 writel(~0, zevio_irq_io + IO_INVERT_SEL);
91
92 /* Disable sticky interrupts */
93 writel(0, zevio_irq_io + IO_STICKY_SEL);
94
95 /* We don't use IRQ priorities. Set each IRQ to highest priority. */
96 memset_io(zevio_irq_io + IO_PRIORITY_SEL, 0, MAX_INTRS * sizeof(u32));
97
98 /* Init IRQ and FIQ */
99 zevio_init_irq_base(zevio_irq_io + IO_IRQ_BASE);
100 zevio_init_irq_base(zevio_irq_io + IO_FIQ_BASE);
101
102 zevio_irq_domain = irq_domain_add_linear(node, MAX_INTRS,
103 &irq_generic_chip_ops, NULL);
104 BUG_ON(!zevio_irq_domain);
105
106 ret = irq_alloc_domain_generic_chips(zevio_irq_domain, MAX_INTRS, 1,
107 "zevio_intc", handle_level_irq,
108 clr, 0, IRQ_GC_INIT_MASK_CACHE);
109 BUG_ON(ret);
110
111 gc = irq_get_domain_generic_chip(zevio_irq_domain, 0);
112 gc->reg_base = zevio_irq_io;
113 gc->chip_types[0].chip.irq_ack = zevio_irq_ack;
114 gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
115 gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
116 gc->chip_types[0].regs.mask = IO_IRQ_BASE + IO_ENABLE;
117 gc->chip_types[0].regs.enable = IO_IRQ_BASE + IO_ENABLE;
118 gc->chip_types[0].regs.disable = IO_IRQ_BASE + IO_DISABLE;
119 gc->chip_types[0].regs.ack = IO_IRQ_BASE + IO_RESET;
120
121 set_handle_irq(zevio_handle_irq);
122
123 pr_info("TI-NSPIRE classic IRQ controller\n");
124 return 0;
125}
126
127IRQCHIP_DECLARE(zevio_irq, "lsi,zevio-intc", zevio_of_init);