aboutsummaryrefslogtreecommitdiff
path: root/drivers/irqchip/irq-keystone.c
blob: 54a5e870a8f56d627f9622a4a9fb03e07347aa0a (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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/*
 * Texas Instruments Keystone IRQ controller IP driver
 *
 * Copyright (C) 2014 Texas Instruments, Inc.
 * Author: Sajesh Kumar Saran <sajesh@ti.com>
 *	   Grygorii Strashko <grygorii.strashko@ti.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/irq.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/irqdomain.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

/* The source ID bits start from 4 to 31 (total 28 bits)*/
#define BIT_OFS			4
#define KEYSTONE_N_IRQ		(32 - BIT_OFS)

struct keystone_irq_device {
	struct device		*dev;
	struct irq_chip		 chip;
	u32			 mask;
	int			 irq;
	struct irq_domain	*irqd;
	struct regmap		*devctrl_regs;
	u32			devctrl_offset;
};

static inline u32 keystone_irq_readl(struct keystone_irq_device *kirq)
{
	int ret;
	u32 val = 0;

	ret = regmap_read(kirq->devctrl_regs, kirq->devctrl_offset, &val);
	if (ret < 0)
		dev_dbg(kirq->dev, "irq read failed ret(%d)\n", ret);
	return val;
}

static inline void
keystone_irq_writel(struct keystone_irq_device *kirq, u32 value)
{
	int ret;

	ret = regmap_write(kirq->devctrl_regs, kirq->devctrl_offset, value);
	if (ret < 0)
		dev_dbg(kirq->dev, "irq write failed ret(%d)\n", ret);
}

static void keystone_irq_setmask(struct irq_data *d)
{
	struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);

	kirq->mask |= BIT(d->hwirq);
	dev_dbg(kirq->dev, "mask %lu [%x]\n", d->hwirq, kirq->mask);
}

static void keystone_irq_unmask(struct irq_data *d)
{
	struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d);

	kirq->mask &= ~BIT(d->hwirq);
	dev_dbg(kirq->dev, "unmask %lu [%x]\n", d->hwirq, kirq->mask);
}

static void keystone_irq_ack(struct irq_data *d)
{
	/* nothing to do here */
}

static void keystone_irq_handler(struct irq_desc *desc)
{
	unsigned int irq = irq_desc_get_irq(desc);
	struct keystone_irq_device *kirq = irq_desc_get_handler_data(desc);
	unsigned long pending;
	int src, virq;

	dev_dbg(kirq->dev, "start irq %d\n", irq);

	chained_irq_enter(irq_desc_get_chip(desc), desc);

	pending = keystone_irq_readl(kirq);
	keystone_irq_writel(kirq, pending);

	dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask);

	pending = (pending >> BIT_OFS) & ~kirq->mask;

	dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending);

	for (src = 0; src < KEYSTONE_N_IRQ; src++) {
		if (BIT(src) & pending) {
			virq = irq_find_mapping(kirq->irqd, src);
			dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n",
				src, virq);
			if (!virq)
				dev_warn(kirq->dev, "spurious irq detected hwirq %d, virq %d\n",
					 src, virq);
			generic_handle_irq(virq);
		}
	}

	chained_irq_exit(irq_desc_get_chip(desc), desc);

	dev_dbg(kirq->dev, "end irq %d\n", irq);
}

static int keystone_irq_map(struct irq_domain *h, unsigned int virq,
				irq_hw_number_t hw)
{
	struct keystone_irq_device *kirq = h->host_data;

	irq_set_chip_data(virq, kirq);
	irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq);
	irq_set_probe(virq);
	return 0;
}

static const struct irq_domain_ops keystone_irq_ops = {
	.map	= keystone_irq_map,
	.xlate	= irq_domain_xlate_onecell,
};

static int keystone_irq_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct keystone_irq_device *kirq;
	int ret;

	if (np == NULL)
		return -EINVAL;

	kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL);
	if (!kirq)
		return -ENOMEM;

	kirq->devctrl_regs =
		syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
	if (IS_ERR(kirq->devctrl_regs))
		return PTR_ERR(kirq->devctrl_regs);

	ret = of_property_read_u32_index(np, "ti,syscon-dev", 1,
					 &kirq->devctrl_offset);
	if (ret) {
		dev_err(dev, "couldn't read the devctrl_offset offset!\n");
		return ret;
	}

	kirq->irq = platform_get_irq(pdev, 0);
	if (kirq->irq < 0) {
		dev_err(dev, "no irq resource %d\n", kirq->irq);
		return kirq->irq;
	}

	kirq->dev = dev;
	kirq->mask = ~0x0;
	kirq->chip.name		= "keystone-irq";
	kirq->chip.irq_ack	= keystone_irq_ack;
	kirq->chip.irq_mask	= keystone_irq_setmask;
	kirq->chip.irq_unmask	= keystone_irq_unmask;

	kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ,
					   &keystone_irq_ops, kirq);
	if (!kirq->irqd) {
		dev_err(dev, "IRQ domain registration failed\n");
		return -ENODEV;
	}

	platform_set_drvdata(pdev, kirq);

	irq_set_chained_handler_and_data(kirq->irq, keystone_irq_handler, kirq);

	/* clear all source bits */
	keystone_irq_writel(kirq, ~0x0);

	dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ);

	return 0;
}

static int keystone_irq_remove(struct platform_device *pdev)
{
	struct keystone_irq_device *kirq = platform_get_drvdata(pdev);
	int hwirq;

	for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++)
		irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq));

	irq_domain_remove(kirq->irqd);
	return 0;
}

static const struct of_device_id keystone_irq_dt_ids[] = {
	{ .compatible = "ti,keystone-irq", },
	{},
};
MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids);

static struct platform_driver keystone_irq_device_driver = {
	.probe		= keystone_irq_probe,
	.remove		= keystone_irq_remove,
	.driver		= {
		.name	= "keystone_irq",
		.of_match_table	= of_match_ptr(keystone_irq_dt_ids),
	}
};

module_platform_driver(keystone_irq_device_driver);

MODULE_AUTHOR("Texas Instruments");
MODULE_AUTHOR("Sajesh Kumar Saran");
MODULE_AUTHOR("Grygorii Strashko");
MODULE_DESCRIPTION("Keystone IRQ chip");
MODULE_LICENSE("GPL v2");