aboutsummaryrefslogtreecommitdiff
path: root/drivers/irqchip/irq-ts4800.c
blob: 2325fb3c482b8714d9041eed94ea8c91095f2beb (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
/*
 * Multiplexed-IRQs driver for TS-4800's FPGA
 *
 * Copyright (c) 2015 - Savoir-faire Linux
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.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/platform_device.h>

#define IRQ_MASK        0x4
#define IRQ_STATUS      0x8

struct ts4800_irq_data {
	void __iomem            *base;
	struct irq_domain       *domain;
	struct irq_chip         irq_chip;
};

static void ts4800_irq_mask(struct irq_data *d)
{
	struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
	u16 reg = readw(data->base + IRQ_MASK);
	u16 mask = 1 << d->hwirq;

	writew(reg | mask, data->base + IRQ_MASK);
}

static void ts4800_irq_unmask(struct irq_data *d)
{
	struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
	u16 reg = readw(data->base + IRQ_MASK);
	u16 mask = 1 << d->hwirq;

	writew(reg & ~mask, data->base + IRQ_MASK);
}

static int ts4800_irqdomain_map(struct irq_domain *d, unsigned int irq,
				irq_hw_number_t hwirq)
{
	struct ts4800_irq_data *data = d->host_data;

	irq_set_chip_and_handler(irq, &data->irq_chip, handle_simple_irq);
	irq_set_chip_data(irq, data);
	irq_set_noprobe(irq);

	return 0;
}

static const struct irq_domain_ops ts4800_ic_ops = {
	.map = ts4800_irqdomain_map,
	.xlate = irq_domain_xlate_onecell,
};

static void ts4800_ic_chained_handle_irq(struct irq_desc *desc)
{
	struct ts4800_irq_data *data = irq_desc_get_handler_data(desc);
	struct irq_chip *chip = irq_desc_get_chip(desc);
	u16 status = readw(data->base + IRQ_STATUS);

	chained_irq_enter(chip, desc);

	if (unlikely(status == 0)) {
		handle_bad_irq(desc);
		goto out;
	}

	do {
		unsigned int bit = __ffs(status);
		int irq = irq_find_mapping(data->domain, bit);

		status &= ~(1 << bit);
		generic_handle_irq(irq);
	} while (status);

out:
	chained_irq_exit(chip, desc);
}

static int ts4800_ic_probe(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	struct ts4800_irq_data *data;
	struct irq_chip *irq_chip;
	struct resource *res;
	int parent_irq;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	data->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(data->base))
		return PTR_ERR(data->base);

	writew(0xFFFF, data->base + IRQ_MASK);

	parent_irq = irq_of_parse_and_map(node, 0);
	if (!parent_irq) {
		dev_err(&pdev->dev, "failed to get parent IRQ\n");
		return -EINVAL;
	}

	irq_chip = &data->irq_chip;
	irq_chip->name = dev_name(&pdev->dev);
	irq_chip->irq_mask = ts4800_irq_mask;
	irq_chip->irq_unmask = ts4800_irq_unmask;

	data->domain = irq_domain_add_linear(node, 8, &ts4800_ic_ops, data);
	if (!data->domain) {
		dev_err(&pdev->dev, "cannot add IRQ domain\n");
		return -ENOMEM;
	}

	irq_set_chained_handler_and_data(parent_irq,
					 ts4800_ic_chained_handle_irq, data);

	platform_set_drvdata(pdev, data);

	return 0;
}

static int ts4800_ic_remove(struct platform_device *pdev)
{
	struct ts4800_irq_data *data = platform_get_drvdata(pdev);

	irq_domain_remove(data->domain);

	return 0;
}

static const struct of_device_id ts4800_ic_of_match[] = {
	{ .compatible = "technologic,ts4800-irqc", },
	{},
};
MODULE_DEVICE_TABLE(of, ts4800_ic_of_match);

static struct platform_driver ts4800_ic_driver = {
	.probe  = ts4800_ic_probe,
	.remove = ts4800_ic_remove,
	.driver = {
		.name = "ts4800-irqc",
		.of_match_table = ts4800_ic_of_match,
	},
};
module_platform_driver(ts4800_ic_driver);

MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:ts4800_irqc");