1// SPDX-License-Identifier: GPL-2.0
2/*
3 * irqchip for the Faraday Technology FTINTC010 Copyright (C) 2017 Linus
4 * Walleij <linus.walleij@linaro.org>
5 *
6 * Based on arch/arm/mach-gemini/irq.c
7 * Copyright (C) 2001-2006 Storlink, Corp.
8 * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@gmail.com>
9 */
10#include <linux/bitops.h>
11#include <linux/irq.h>
12#include <linux/io.h>
13#include <linux/irqchip.h>
14#include <linux/irqchip/versatile-fpga.h>
15#include <linux/irqdomain.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19#include <linux/of_irq.h>
20#include <linux/cpu.h>
21
22#include <asm/exception.h>
23#include <asm/mach/irq.h>
24
25#define FT010_NUM_IRQS 32
26
27#define FT010_IRQ_SOURCE(base_addr)	(base_addr + 0x00)
28#define FT010_IRQ_MASK(base_addr)	(base_addr + 0x04)
29#define FT010_IRQ_CLEAR(base_addr)	(base_addr + 0x08)
30/* Selects level- or edge-triggered */
31#define FT010_IRQ_MODE(base_addr)	(base_addr + 0x0C)
32/* Selects active low/high or falling/rising edge */
33#define FT010_IRQ_POLARITY(base_addr)	(base_addr + 0x10)
34#define FT010_IRQ_STATUS(base_addr)	(base_addr + 0x14)
35#define FT010_FIQ_SOURCE(base_addr)	(base_addr + 0x20)
36#define FT010_FIQ_MASK(base_addr)	(base_addr + 0x24)
37#define FT010_FIQ_CLEAR(base_addr)	(base_addr + 0x28)
38#define FT010_FIQ_MODE(base_addr)	(base_addr + 0x2C)
39#define FT010_FIQ_POLARITY(base_addr)	(base_addr + 0x30)
40#define FT010_FIQ_STATUS(base_addr)	(base_addr + 0x34)
41
42/**
43 * struct ft010_irq_data - irq data container for the Faraday IRQ controller
44 * @base: memory offset in virtual memory
45 * @chip: chip container for this instance
46 * @domain: IRQ domain for this instance
47 */
48struct ft010_irq_data {
49	void __iomem *base;
50	struct irq_chip chip;
51	struct irq_domain *domain;
52};
53
54static void ft010_irq_mask(struct irq_data *d)
55{
56	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
57	unsigned int mask;
58
59	mask = readl(FT010_IRQ_MASK(f->base));
60	mask &= ~BIT(irqd_to_hwirq(d));
61	writel(mask, FT010_IRQ_MASK(f->base));
62}
63
64static void ft010_irq_unmask(struct irq_data *d)
65{
66	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
67	unsigned int mask;
68
69	mask = readl(FT010_IRQ_MASK(f->base));
70	mask |= BIT(irqd_to_hwirq(d));
71	writel(mask, FT010_IRQ_MASK(f->base));
72}
73
74static void ft010_irq_ack(struct irq_data *d)
75{
76	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
77
78	writel(BIT(irqd_to_hwirq(d)), FT010_IRQ_CLEAR(f->base));
79}
80
81static int ft010_irq_set_type(struct irq_data *d, unsigned int trigger)
82{
83	struct ft010_irq_data *f = irq_data_get_irq_chip_data(d);
84	int offset = irqd_to_hwirq(d);
85	u32 mode, polarity;
86
87	mode = readl(FT010_IRQ_MODE(f->base));
88	polarity = readl(FT010_IRQ_POLARITY(f->base));
89
90	if (trigger & (IRQ_TYPE_LEVEL_LOW)) {
91		irq_set_handler_locked(d, handle_level_irq);
92		mode &= ~BIT(offset);
93		polarity |= BIT(offset);
94	} else if (trigger & (IRQ_TYPE_LEVEL_HIGH)) {
95		irq_set_handler_locked(d, handle_level_irq);
96		mode &= ~BIT(offset);
97		polarity &= ~BIT(offset);
98	} else if (trigger & IRQ_TYPE_EDGE_FALLING) {
99		irq_set_handler_locked(d, handle_edge_irq);
100		mode |= BIT(offset);
101		polarity |= BIT(offset);
102	} else if (trigger & IRQ_TYPE_EDGE_RISING) {
103		irq_set_handler_locked(d, handle_edge_irq);
104		mode |= BIT(offset);
105		polarity &= ~BIT(offset);
106	} else {
107		irq_set_handler_locked(d, handle_bad_irq);
108		pr_warn("Faraday IRQ: no supported trigger selected for line %d\n",
109			offset);
110	}
111
112	writel(mode, FT010_IRQ_MODE(f->base));
113	writel(polarity, FT010_IRQ_POLARITY(f->base));
114
115	return 0;
116}
117
118static struct irq_chip ft010_irq_chip = {
119	.name		= "FTINTC010",
120	.irq_ack	= ft010_irq_ack,
121	.irq_mask	= ft010_irq_mask,
122	.irq_unmask	= ft010_irq_unmask,
123	.irq_set_type	= ft010_irq_set_type,
124};
125
126/* Local static for the IRQ entry call */
127static struct ft010_irq_data firq;
128
129asmlinkage void __exception_irq_entry ft010_irqchip_handle_irq(struct pt_regs *regs)
130{
131	struct ft010_irq_data *f = &firq;
132	int irq;
133	u32 status;
134
135	while ((status = readl(FT010_IRQ_STATUS(f->base)))) {
136		irq = ffs(status) - 1;
137		handle_domain_irq(f->domain, irq, regs);
138	}
139}
140
141static int ft010_irqdomain_map(struct irq_domain *d, unsigned int irq,
142				irq_hw_number_t hwirq)
143{
144	struct ft010_irq_data *f = d->host_data;
145
146	irq_set_chip_data(irq, f);
147	/* All IRQs should set up their type, flags as bad by default */
148	irq_set_chip_and_handler(irq, &ft010_irq_chip, handle_bad_irq);
149	irq_set_probe(irq);
150
151	return 0;
152}
153
154static void ft010_irqdomain_unmap(struct irq_domain *d, unsigned int irq)
155{
156	irq_set_chip_and_handler(irq, NULL, NULL);
157	irq_set_chip_data(irq, NULL);
158}
159
160static const struct irq_domain_ops ft010_irqdomain_ops = {
161	.map = ft010_irqdomain_map,
162	.unmap = ft010_irqdomain_unmap,
163	.xlate = irq_domain_xlate_onetwocell,
164};
165
166int __init ft010_of_init_irq(struct device_node *node,
167			      struct device_node *parent)
168{
169	struct ft010_irq_data *f = &firq;
170
171	/*
172	 * Disable the idle handler by default since it is buggy
173	 * For more info see arch/arm/mach-gemini/idle.c
174	 */
175	cpu_idle_poll_ctrl(true);
176
177	f->base = of_iomap(node, 0);
178	WARN(!f->base, "unable to map gemini irq registers\n");
179
180	/* Disable all interrupts */
181	writel(0, FT010_IRQ_MASK(f->base));
182	writel(0, FT010_FIQ_MASK(f->base));
183
184	f->domain = irq_domain_add_simple(node, FT010_NUM_IRQS, 0,
185					  &ft010_irqdomain_ops, f);
186	set_handle_irq(ft010_irqchip_handle_irq);
187
188	return 0;
189}
190IRQCHIP_DECLARE(faraday, "faraday,ftintc010",
191		ft010_of_init_irq);
192IRQCHIP_DECLARE(gemini, "cortina,gemini-interrupt-controller",
193		ft010_of_init_irq);
194IRQCHIP_DECLARE(moxa, "moxa,moxart-ic",
195		ft010_of_init_irq);
196