summaryrefslogtreecommitdiff
path: root/drivers/irqchip/irq-gemini.c
blob: 495224c743ee7c63ef2e209a928a120f78303376 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/*
 * irqchip for the Cortina Systems Gemini Copyright (C) 2017 Linus
 * Walleij <linus.walleij@linaro.org>
 *
 * Based on arch/arm/mach-gemini/irq.c
 * Copyright (C) 2001-2006 Storlink, Corp.
 * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
 */
#include <linux/bitops.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/irqchip/versatile-fpga.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/cpu.h>

#include <asm/exception.h>
#include <asm/mach/irq.h>

#define GEMINI_NUM_IRQS 32

#define GEMINI_IRQ_SOURCE(base_addr)	(base_addr + 0x00)
#define GEMINI_IRQ_MASK(base_addr)	(base_addr + 0x04)
#define GEMINI_IRQ_CLEAR(base_addr)	(base_addr + 0x08)
#define GEMINI_IRQ_MODE(base_addr)	(base_addr + 0x0C)
#define GEMINI_IRQ_POLARITY(base_addr)	(base_addr + 0x10)
#define GEMINI_IRQ_STATUS(base_addr)	(base_addr + 0x14)
#define GEMINI_FIQ_SOURCE(base_addr)	(base_addr + 0x20)
#define GEMINI_FIQ_MASK(base_addr)	(base_addr + 0x24)
#define GEMINI_FIQ_CLEAR(base_addr)	(base_addr + 0x28)
#define GEMINI_FIQ_MODE(base_addr)	(base_addr + 0x2C)
#define GEMINI_FIQ_POLARITY(base_addr)	(base_addr + 0x30)
#define GEMINI_FIQ_STATUS(base_addr)	(base_addr + 0x34)

/**
 * struct gemini_irq_data - irq data container for the Gemini IRQ controller
 * @base: memory offset in virtual memory
 * @chip: chip container for this instance
 * @domain: IRQ domain for this instance
 */
struct gemini_irq_data {
	void __iomem *base;
	struct irq_chip chip;
	struct irq_domain *domain;
};

static void gemini_irq_mask(struct irq_data *d)
{
	struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);
	unsigned int mask;

	mask = readl(GEMINI_IRQ_MASK(g->base));
	mask &= ~BIT(irqd_to_hwirq(d));
	writel(mask, GEMINI_IRQ_MASK(g->base));
}

static void gemini_irq_unmask(struct irq_data *d)
{
	struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);
	unsigned int mask;

	mask = readl(GEMINI_IRQ_MASK(g->base));
	mask |= BIT(irqd_to_hwirq(d));
	writel(mask, GEMINI_IRQ_MASK(g->base));
}

static void gemini_irq_ack(struct irq_data *d)
{
	struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);

	writel(BIT(irqd_to_hwirq(d)), GEMINI_IRQ_CLEAR(g->base));
}

static int gemini_irq_set_type(struct irq_data *d, unsigned int trigger)
{
	struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);
	int offset = irqd_to_hwirq(d);
	u32 mode, polarity;

	mode = readl(GEMINI_IRQ_MODE(g->base));
	polarity = readl(GEMINI_IRQ_POLARITY(g->base));

	if (trigger & (IRQ_TYPE_LEVEL_HIGH)) {
		irq_set_handler_locked(d, handle_level_irq);
		/* Disable edge detection */
		mode &= ~BIT(offset);
		polarity &= ~BIT(offset);
	} else if (trigger & IRQ_TYPE_EDGE_RISING) {
		irq_set_handler_locked(d, handle_edge_irq);
		mode |= BIT(offset);
		polarity |= BIT(offset);
	} else if (trigger & IRQ_TYPE_EDGE_FALLING) {
		irq_set_handler_locked(d, handle_edge_irq);
		mode |= BIT(offset);
		polarity &= ~BIT(offset);
	} else {
		irq_set_handler_locked(d, handle_bad_irq);
		pr_warn("GEMINI IRQ: no supported trigger selected for line %d\n",
			offset);
	}

	writel(mode, GEMINI_IRQ_MODE(g->base));
	writel(polarity, GEMINI_IRQ_POLARITY(g->base));

	return 0;
}

static struct irq_chip gemini_irq_chip = {
	.name		= "GEMINI",
	.irq_ack	= gemini_irq_ack,
	.irq_mask	= gemini_irq_mask,
	.irq_unmask	= gemini_irq_unmask,
	.irq_set_type	= gemini_irq_set_type,
};

/* Local static for the IRQ entry call */
static struct gemini_irq_data girq;

asmlinkage void __exception_irq_entry gemini_irqchip_handle_irq(struct pt_regs *regs)
{
	struct gemini_irq_data *g = &girq;
	int irq;
	u32 status;

	while ((status = readl(GEMINI_IRQ_STATUS(g->base)))) {
		irq = ffs(status) - 1;
		handle_domain_irq(g->domain, irq, regs);
	}
}

static int gemini_irqdomain_map(struct irq_domain *d, unsigned int irq,
				irq_hw_number_t hwirq)
{
	struct gemini_irq_data *g = d->host_data;

	irq_set_chip_data(irq, g);
	/* All IRQs should set up their type, flags as bad by default */
	irq_set_chip_and_handler(irq, &gemini_irq_chip, handle_bad_irq);
	irq_set_probe(irq);

	return 0;
}

static void gemini_irqdomain_unmap(struct irq_domain *d, unsigned int irq)
{
	irq_set_chip_and_handler(irq, NULL, NULL);
	irq_set_chip_data(irq, NULL);
}

static const struct irq_domain_ops gemini_irqdomain_ops = {
	.map = gemini_irqdomain_map,
	.unmap = gemini_irqdomain_unmap,
	.xlate = irq_domain_xlate_onetwocell,
};

int __init gemini_of_init_irq(struct device_node *node,
			      struct device_node *parent)
{
	struct gemini_irq_data *g = &girq;

	/*
	 * Disable the idle handler by default since it is buggy
	 * For more info see arch/arm/mach-gemini/idle.c
	 */
	cpu_idle_poll_ctrl(true);

	g->base = of_iomap(node, 0);
	WARN(!g->base, "unable to map gemini irq registers\n");

	/* Disable all interrupts */
	writel(0, GEMINI_IRQ_MASK(g->base));
	writel(0, GEMINI_FIQ_MASK(g->base));

	g->domain = irq_domain_add_simple(node, GEMINI_NUM_IRQS, 0,
					  &gemini_irqdomain_ops, g);
	set_handle_irq(gemini_irqchip_handle_irq);

	return 0;
}
IRQCHIP_DECLARE(gemini, "cortina,gemini-interrupt-controller",
		gemini_of_init_irq);