1// SPDX-License-Identifier: (GPL-2.0 OR MIT)
2/*
3 * Microsemi Ocelot IRQ controller driver
4 *
5 * Copyright (c) 2017 Microsemi Corporation
6 */
7#include <linux/bitops.h>
8#include <linux/irq.h>
9#include <linux/of_address.h>
10#include <linux/of_irq.h>
11#include <linux/irqchip.h>
12#include <linux/irqchip/chained_irq.h>
13#include <linux/interrupt.h>
14
15#define ICPU_CFG_INTR_INTR_STICKY	0x10
16#define ICPU_CFG_INTR_INTR_ENA		0x18
17#define ICPU_CFG_INTR_INTR_ENA_CLR	0x1c
18#define ICPU_CFG_INTR_INTR_ENA_SET	0x20
19#define ICPU_CFG_INTR_DST_INTR_IDENT(x)	(0x38 + 0x4 * (x))
20#define ICPU_CFG_INTR_INTR_TRIGGER(x)	(0x5c + 0x4 * (x))
21
22#define OCELOT_NR_IRQ 24
23
24static void ocelot_irq_unmask(struct irq_data *data)
25{
26	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
27	struct irq_chip_type *ct = irq_data_get_chip_type(data);
28	unsigned int mask = data->mask;
29	u32 val;
30
31	irq_gc_lock(gc);
32	val = irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(0)) |
33	      irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(1));
34	if (!(val & mask))
35		irq_reg_writel(gc, mask, ICPU_CFG_INTR_INTR_STICKY);
36
37	*ct->mask_cache &= ~mask;
38	irq_reg_writel(gc, mask, ICPU_CFG_INTR_INTR_ENA_SET);
39	irq_gc_unlock(gc);
40}
41
42static void ocelot_irq_handler(struct irq_desc *desc)
43{
44	struct irq_chip *chip = irq_desc_get_chip(desc);
45	struct irq_domain *d = irq_desc_get_handler_data(desc);
46	struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, 0);
47	u32 reg = irq_reg_readl(gc, ICPU_CFG_INTR_DST_INTR_IDENT(0));
48
49	chained_irq_enter(chip, desc);
50
51	while (reg) {
52		u32 hwirq = __fls(reg);
53
54		generic_handle_irq(irq_find_mapping(d, hwirq));
55		reg &= ~(BIT(hwirq));
56	}
57
58	chained_irq_exit(chip, desc);
59}
60
61static int __init ocelot_irq_init(struct device_node *node,
62				  struct device_node *parent)
63{
64	struct irq_domain *domain;
65	struct irq_chip_generic *gc;
66	int parent_irq, ret;
67
68	parent_irq = irq_of_parse_and_map(node, 0);
69	if (!parent_irq)
70		return -EINVAL;
71
72	domain = irq_domain_add_linear(node, OCELOT_NR_IRQ,
73				       &irq_generic_chip_ops, NULL);
74	if (!domain) {
75		pr_err("%pOFn: unable to add irq domain\n", node);
76		return -ENOMEM;
77	}
78
79	ret = irq_alloc_domain_generic_chips(domain, OCELOT_NR_IRQ, 1,
80					     "icpu", handle_level_irq,
81					     0, 0, 0);
82	if (ret) {
83		pr_err("%pOFn: unable to alloc irq domain gc\n", node);
84		goto err_domain_remove;
85	}
86
87	gc = irq_get_domain_generic_chip(domain, 0);
88	gc->reg_base = of_iomap(node, 0);
89	if (!gc->reg_base) {
90		pr_err("%pOFn: unable to map resource\n", node);
91		ret = -ENOMEM;
92		goto err_gc_free;
93	}
94
95	gc->chip_types[0].regs.ack = ICPU_CFG_INTR_INTR_STICKY;
96	gc->chip_types[0].regs.mask = ICPU_CFG_INTR_INTR_ENA_CLR;
97	gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
98	gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
99	gc->chip_types[0].chip.irq_unmask = ocelot_irq_unmask;
100
101	/* Mask and ack all interrupts */
102	irq_reg_writel(gc, 0, ICPU_CFG_INTR_INTR_ENA);
103	irq_reg_writel(gc, 0xffffffff, ICPU_CFG_INTR_INTR_STICKY);
104
105	irq_set_chained_handler_and_data(parent_irq, ocelot_irq_handler,
106					 domain);
107
108	return 0;
109
110err_gc_free:
111	irq_free_generic_chip(gc);
112
113err_domain_remove:
114	irq_domain_remove(domain);
115
116	return ret;
117}
118IRQCHIP_DECLARE(ocelot_icpu, "mscc,ocelot-icpu-intr", ocelot_irq_init);
119