1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/drivers/irqchip/irq-zevio.c
4 *
5 * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
6 */
7
8 #include <linux/io.h>
9 #include <linux/irq.h>
10 #include <linux/irqchip.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 #include <linux/of_irq.h>
14
15 #include <asm/mach/irq.h>
16 #include <asm/exception.h>
17
18 #define IO_STATUS 0x000
19 #define IO_RAW_STATUS 0x004
20 #define IO_ENABLE 0x008
21 #define IO_DISABLE 0x00C
22 #define IO_CURRENT 0x020
23 #define IO_RESET 0x028
24 #define IO_MAX_PRIOTY 0x02C
25
26 #define IO_IRQ_BASE 0x000
27 #define IO_FIQ_BASE 0x100
28
29 #define IO_INVERT_SEL 0x200
30 #define IO_STICKY_SEL 0x204
31 #define IO_PRIORITY_SEL 0x300
32
33 #define MAX_INTRS 32
34 #define FIQ_START MAX_INTRS
35
36 static struct irq_domain *zevio_irq_domain;
37 static void __iomem *zevio_irq_io;
38
zevio_irq_ack(struct irq_data * irqd)39 static void zevio_irq_ack(struct irq_data *irqd)
40 {
41 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(irqd);
42 struct irq_chip_regs *regs = &irq_data_get_chip_type(irqd)->regs;
43
44 readl(gc->reg_base + regs->ack);
45 }
46
zevio_handle_irq(struct pt_regs * regs)47 static void __exception_irq_entry zevio_handle_irq(struct pt_regs *regs)
48 {
49 int irqnr;
50
51 while (readl(zevio_irq_io + IO_STATUS)) {
52 irqnr = readl(zevio_irq_io + IO_CURRENT);
53 generic_handle_domain_irq(zevio_irq_domain, irqnr);
54 }
55 }
56
zevio_init_irq_base(void __iomem * base)57 static void __init zevio_init_irq_base(void __iomem *base)
58 {
59 /* Disable all interrupts */
60 writel(~0, base + IO_DISABLE);
61
62 /* Accept interrupts of all priorities */
63 writel(0xF, base + IO_MAX_PRIOTY);
64
65 /* Reset existing interrupts */
66 readl(base + IO_RESET);
67 }
68
zevio_of_init(struct device_node * node,struct device_node * parent)69 static int __init zevio_of_init(struct device_node *node,
70 struct device_node *parent)
71 {
72 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
73 struct irq_chip_generic *gc;
74 int ret;
75
76 if (WARN_ON(zevio_irq_io || zevio_irq_domain))
77 return -EBUSY;
78
79 zevio_irq_io = of_iomap(node, 0);
80 BUG_ON(!zevio_irq_io);
81
82 /* Do not invert interrupt status bits */
83 writel(~0, zevio_irq_io + IO_INVERT_SEL);
84
85 /* Disable sticky interrupts */
86 writel(0, zevio_irq_io + IO_STICKY_SEL);
87
88 /* We don't use IRQ priorities. Set each IRQ to highest priority. */
89 memset_io(zevio_irq_io + IO_PRIORITY_SEL, 0, MAX_INTRS * sizeof(u32));
90
91 /* Init IRQ and FIQ */
92 zevio_init_irq_base(zevio_irq_io + IO_IRQ_BASE);
93 zevio_init_irq_base(zevio_irq_io + IO_FIQ_BASE);
94
95 zevio_irq_domain = irq_domain_add_linear(node, MAX_INTRS,
96 &irq_generic_chip_ops, NULL);
97 BUG_ON(!zevio_irq_domain);
98
99 ret = irq_alloc_domain_generic_chips(zevio_irq_domain, MAX_INTRS, 1,
100 "zevio_intc", handle_level_irq,
101 clr, 0, IRQ_GC_INIT_MASK_CACHE);
102 BUG_ON(ret);
103
104 gc = irq_get_domain_generic_chip(zevio_irq_domain, 0);
105 gc->reg_base = zevio_irq_io;
106 gc->chip_types[0].chip.irq_ack = zevio_irq_ack;
107 gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
108 gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
109 gc->chip_types[0].regs.mask = IO_IRQ_BASE + IO_ENABLE;
110 gc->chip_types[0].regs.enable = IO_IRQ_BASE + IO_ENABLE;
111 gc->chip_types[0].regs.disable = IO_IRQ_BASE + IO_DISABLE;
112 gc->chip_types[0].regs.ack = IO_IRQ_BASE + IO_RESET;
113
114 set_handle_irq(zevio_handle_irq);
115
116 pr_info("TI-NSPIRE classic IRQ controller\n");
117 return 0;
118 }
119
120 IRQCHIP_DECLARE(zevio_irq, "lsi,zevio-intc", zevio_of_init);
121