aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/irqchip/irq-loongson-htvec.c
blob: 1ece9337c78dcee49df65c43aae285ce476cbe66 (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
 *  Loongson HyperTransport Interrupt Vector support
 */

#define pr_fmt(fmt) "htvec: " fmt

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>

/* Registers */
#define HTVEC_EN_OFF		0x20
#define HTVEC_MAX_PARENT_IRQ	4

#define VEC_COUNT_PER_REG	32
#define VEC_REG_COUNT		4
#define VEC_COUNT		(VEC_COUNT_PER_REG * VEC_REG_COUNT)
#define VEC_REG_IDX(irq_id)	((irq_id) / VEC_COUNT_PER_REG)
#define VEC_REG_BIT(irq_id)	((irq_id) % VEC_COUNT_PER_REG)

struct htvec {
	void __iomem		*base;
	struct irq_domain	*htvec_domain;
	raw_spinlock_t		htvec_lock;
};

static void htvec_irq_dispatch(struct irq_desc *desc)
{
	int i;
	u32 pending;
	bool handled = false;
	struct irq_chip *chip = irq_desc_get_chip(desc);
	struct htvec *priv = irq_desc_get_handler_data(desc);

	chained_irq_enter(chip, desc);

	for (i = 0; i < VEC_REG_COUNT; i++) {
		pending = readl(priv->base + 4 * i);
		while (pending) {
			int bit = __ffs(pending);

			generic_handle_irq(irq_linear_revmap(priv->htvec_domain, bit +
							     VEC_COUNT_PER_REG * i));
			pending &= ~BIT(bit);
			handled = true;
		}
	}

	if (!handled)
		spurious_interrupt();

	chained_irq_exit(chip, desc);
}

static void htvec_ack_irq(struct irq_data *d)
{
	struct htvec *priv = irq_data_get_irq_chip_data(d);

	writel(BIT(VEC_REG_BIT(d->hwirq)),
	       priv->base + VEC_REG_IDX(d->hwirq) * 4);
}

static void htvec_mask_irq(struct irq_data *d)
{
	u32 reg;
	void __iomem *addr;
	struct htvec *priv = irq_data_get_irq_chip_data(d);

	raw_spin_lock(&priv->htvec_lock);
	addr = priv->base + HTVEC_EN_OFF;
	addr += VEC_REG_IDX(d->hwirq) * 4;
	reg = readl(addr);
	reg &= ~BIT(VEC_REG_BIT(d->hwirq));
	writel(reg, addr);
	raw_spin_unlock(&priv->htvec_lock);
}

static void htvec_unmask_irq(struct irq_data *d)
{
	u32 reg;
	void __iomem *addr;
	struct htvec *priv = irq_data_get_irq_chip_data(d);

	raw_spin_lock(&priv->htvec_lock);
	addr = priv->base + HTVEC_EN_OFF;
	addr += VEC_REG_IDX(d->hwirq) * 4;
	reg = readl(addr);
	reg |= BIT(VEC_REG_BIT(d->hwirq));
	writel(reg, addr);
	raw_spin_unlock(&priv->htvec_lock);
}

static struct irq_chip htvec_irq_chip = {
	.name			= "LOONGSON_HTVEC",
	.irq_mask		= htvec_mask_irq,
	.irq_unmask		= htvec_unmask_irq,
	.irq_ack		= htvec_ack_irq,
};

static int htvec_domain_alloc(struct irq_domain *domain, unsigned int virq,
			      unsigned int nr_irqs, void *arg)
{
	unsigned long hwirq;
	unsigned int type, i;
	struct htvec *priv = domain->host_data;

	irq_domain_translate_onecell(domain, arg, &hwirq, &type);

	for (i = 0; i < nr_irqs; i++) {
		irq_domain_set_info(domain, virq + i, hwirq + i, &htvec_irq_chip,
				    priv, handle_edge_irq, NULL, NULL);
	}

	return 0;
}

static void htvec_domain_free(struct irq_domain *domain, unsigned int virq,
				  unsigned int nr_irqs)
{
	int i;

	for (i = 0; i < nr_irqs; i++) {
		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);

		irq_set_handler(virq + i, NULL);
		irq_domain_reset_irq_data(d);
	}
}

static const struct irq_domain_ops htvec_domain_ops = {
	.translate	= irq_domain_translate_onecell,
	.alloc		= htvec_domain_alloc,
	.free		= htvec_domain_free,
};

static void htvec_reset(struct htvec *priv)
{
	u32 idx;

	/* Clear IRQ cause registers, mask all interrupts */
	for (idx = 0; idx < VEC_REG_COUNT; idx++) {
		writel_relaxed(0x0, priv->base + HTVEC_EN_OFF + 4 * idx);
		writel_relaxed(0xFFFFFFFF, priv->base);
	}
}

static int htvec_of_init(struct device_node *node,
				struct device_node *parent)
{
	struct htvec *priv;
	int err, parent_irq[4], num_parents = 0, i;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	raw_spin_lock_init(&priv->htvec_lock);
	priv->base = of_iomap(node, 0);
	if (!priv->base) {
		err = -ENOMEM;
		goto free_priv;
	}

	/* Interrupt may come from any of the 4 interrupt line */
	for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++) {
		parent_irq[i] = irq_of_parse_and_map(node, i);
		if (parent_irq[i] <= 0)
			break;

		num_parents++;
	}

	if (!num_parents) {
		pr_err("Failed to get parent irqs\n");
		err = -ENODEV;
		goto iounmap_base;
	}

	priv->htvec_domain = irq_domain_create_linear(of_node_to_fwnode(node),
						      VEC_COUNT,
						      &htvec_domain_ops,
						      priv);
	if (!priv->htvec_domain) {
		pr_err("Failed to create IRQ domain\n");
		err = -ENOMEM;
		goto iounmap_base;
	}

	htvec_reset(priv);

	for (i = 0; i < num_parents; i++)
		irq_set_chained_handler_and_data(parent_irq[i],
						 htvec_irq_dispatch, priv);

	return 0;

iounmap_base:
	iounmap(priv->base);
free_priv:
	kfree(priv);

	return err;
}

IRQCHIP_DECLARE(htvec, "loongson,htvec-1.0", htvec_of_init);