summaryrefslogtreecommitdiffstats
path: root/drivers/irqchip/irq-loongson-liointc.c
blob: 9ed1bc47366348b5b9066bc4873a317d82c011af (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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
 *  Loongson Local IO Interrupt Controller support
 */

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/irqchip.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/smp.h>
#include <linux/irqchip/chained_irq.h>

#include <boot_param.h>

#define LIOINTC_CHIP_IRQ	32
#define LIOINTC_NUM_PARENT 4

#define LIOINTC_INTC_CHIP_START	0x20

#define LIOINTC_REG_INTC_STATUS	(LIOINTC_INTC_CHIP_START + 0x20)
#define LIOINTC_REG_INTC_EN_STATUS	(LIOINTC_INTC_CHIP_START + 0x04)
#define LIOINTC_REG_INTC_ENABLE	(LIOINTC_INTC_CHIP_START + 0x08)
#define LIOINTC_REG_INTC_DISABLE	(LIOINTC_INTC_CHIP_START + 0x0c)
#define LIOINTC_REG_INTC_POL	(LIOINTC_INTC_CHIP_START + 0x10)
#define LIOINTC_REG_INTC_EDGE	(LIOINTC_INTC_CHIP_START + 0x14)

#define LIOINTC_SHIFT_INTx	4

#define LIOINTC_ERRATA_IRQ	10

struct liointc_handler_data {
	struct liointc_priv	*priv;
	u32			parent_int_map;
};

struct liointc_priv {
	struct irq_chip_generic		*gc;
	struct liointc_handler_data	handler[LIOINTC_NUM_PARENT];
	u8				map_cache[LIOINTC_CHIP_IRQ];
	bool				has_lpc_irq_errata;
};

static void liointc_chained_handle_irq(struct irq_desc *desc)
{
	struct liointc_handler_data *handler = irq_desc_get_handler_data(desc);
	struct irq_chip *chip = irq_desc_get_chip(desc);
	struct irq_chip_generic *gc = handler->priv->gc;
	u32 pending;

	chained_irq_enter(chip, desc);

	pending = readl(gc->reg_base + LIOINTC_REG_INTC_STATUS);

	if (!pending) {
		/* Always blame LPC IRQ if we have that bug */
		if (handler->priv->has_lpc_irq_errata &&
			(handler->parent_int_map & gc->mask_cache &
			BIT(LIOINTC_ERRATA_IRQ)))
			pending = BIT(LIOINTC_ERRATA_IRQ);
		else
			spurious_interrupt();
	}

	while (pending) {
		int bit = __ffs(pending);

		generic_handle_irq(irq_find_mapping(gc->domain, bit));
		pending &= ~BIT(bit);
	}

	chained_irq_exit(chip, desc);
}

static void liointc_set_bit(struct irq_chip_generic *gc,
				unsigned int offset,
				u32 mask, bool set)
{
	if (set)
		writel(readl(gc->reg_base + offset) | mask,
				gc->reg_base + offset);
	else
		writel(readl(gc->reg_base + offset) & ~mask,
				gc->reg_base + offset);
}

static int liointc_set_type(struct irq_data *data, unsigned int type)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
	u32 mask = data->mask;
	unsigned long flags;

	irq_gc_lock_irqsave(gc, flags);
	switch (type) {
	case IRQ_TYPE_LEVEL_HIGH:
		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
		break;
	case IRQ_TYPE_LEVEL_LOW:
		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
		break;
	case IRQ_TYPE_EDGE_RISING:
		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
		break;
	case IRQ_TYPE_EDGE_FALLING:
		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
		break;
	default:
		irq_gc_unlock_irqrestore(gc, flags);
		return -EINVAL;
	}
	irq_gc_unlock_irqrestore(gc, flags);

	irqd_set_trigger_type(data, type);
	return 0;
}

static void liointc_resume(struct irq_chip_generic *gc)
{
	struct liointc_priv *priv = gc->private;
	unsigned long flags;
	int i;

	irq_gc_lock_irqsave(gc, flags);
	/* Disable all at first */
	writel(0xffffffff, gc->reg_base + LIOINTC_REG_INTC_DISABLE);
	/* Restore map cache */
	for (i = 0; i < LIOINTC_CHIP_IRQ; i++)
		writeb(priv->map_cache[i], gc->reg_base + i);
	/* Restore mask cache */
	writel(gc->mask_cache, gc->reg_base + LIOINTC_REG_INTC_ENABLE);
	irq_gc_unlock_irqrestore(gc, flags);
}

static const char * const parent_names[] = {"int0", "int1", "int2", "int3"};

int __init liointc_of_init(struct device_node *node,
				struct device_node *parent)
{
	struct irq_chip_generic *gc;
	struct irq_domain *domain;
	struct irq_chip_type *ct;
	struct liointc_priv *priv;
	void __iomem *base;
	u32 of_parent_int_map[LIOINTC_NUM_PARENT];
	int parent_irq[LIOINTC_NUM_PARENT];
	bool have_parent = FALSE;
	int sz, i, err = 0;

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

	base = of_iomap(node, 0);
	if (!base) {
		err = -ENODEV;
		goto out_free_priv;
	}

	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
		parent_irq[i] = of_irq_get_byname(node, parent_names[i]);
		if (parent_irq[i] > 0)
			have_parent = TRUE;
	}
	if (!have_parent) {
		err = -ENODEV;
		goto out_iounmap;
	}

	sz = of_property_read_variable_u32_array(node,
						"loongson,parent_int_map",
						&of_parent_int_map[0],
						LIOINTC_NUM_PARENT,
						LIOINTC_NUM_PARENT);
	if (sz < 4) {
		pr_err("loongson-liointc: No parent_int_map\n");
		err = -ENODEV;
		goto out_iounmap;
	}

	for (i = 0; i < LIOINTC_NUM_PARENT; i++)
		priv->handler[i].parent_int_map = of_parent_int_map[i];

	/* Setup IRQ domain */
	domain = irq_domain_add_linear(node, 32,
					&irq_generic_chip_ops, priv);
	if (!domain) {
		pr_err("loongson-liointc: cannot add IRQ domain\n");
		err = -EINVAL;
		goto out_iounmap;
	}

	err = irq_alloc_domain_generic_chips(domain, 32, 1,
					node->full_name, handle_level_irq,
					IRQ_NOPROBE, 0, 0);
	if (err) {
		pr_err("loongson-liointc: unable to register IRQ domain\n");
		goto out_free_domain;
	}


	/* Disable all IRQs */
	writel(0xffffffff, base + LIOINTC_REG_INTC_DISABLE);
	/* Set to level triggered */
	writel(0x0, base + LIOINTC_REG_INTC_EDGE);

	/* Generate parent INT part of map cache */
	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
		u32 pending = priv->handler[i].parent_int_map;

		while (pending) {
			int bit = __ffs(pending);

			priv->map_cache[bit] = BIT(i) << LIOINTC_SHIFT_INTx;
			pending &= ~BIT(bit);
		}
	}

	for (i = 0; i < LIOINTC_CHIP_IRQ; i++) {
		/* Generate core part of map cache */
		priv->map_cache[i] |= BIT(loongson_sysconf.boot_cpu_id);
		writeb(priv->map_cache[i], base + i);
	}

	gc = irq_get_domain_generic_chip(domain, 0);
	gc->private = priv;
	gc->reg_base = base;
	gc->domain = domain;
	gc->resume = liointc_resume;

	ct = gc->chip_types;
	ct->regs.enable = LIOINTC_REG_INTC_ENABLE;
	ct->regs.disable = LIOINTC_REG_INTC_DISABLE;
	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
	ct->chip.irq_mask = irq_gc_mask_disable_reg;
	ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
	ct->chip.irq_set_type = liointc_set_type;

	gc->mask_cache = 0;
	priv->gc = gc;

	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
		if (parent_irq[i] <= 0)
			continue;

		priv->handler[i].priv = priv;
		irq_set_chained_handler_and_data(parent_irq[i],
				liointc_chained_handle_irq, &priv->handler[i]);
	}

	return 0;

out_free_domain:
	irq_domain_remove(domain);
out_iounmap:
	iounmap(base);
out_free_priv:
	kfree(priv);

	return err;
}

IRQCHIP_DECLARE(loongson_liointc_1_0, "loongson,liointc-1.0", liointc_of_init);
IRQCHIP_DECLARE(loongson_liointc_1_0a, "loongson,liointc-1.0a", liointc_of_init);