summaryrefslogtreecommitdiffstats
path: root/drivers/irqchip/irq-brcmstb-l2.c
blob: 8ee2a36d58405b03b9d9655338d4bc7664a72939 (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
/*
 * Generic Broadcom Set Top Box Level 2 Interrupt controller driver
 *
 * Copyright (C) 2014 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt)	KBUILD_MODNAME	": " fmt

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/irqdomain.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>

#include <asm/mach/irq.h>

#include "irqchip.h"

/* Register offsets in the L2 interrupt controller */
#define CPU_STATUS	0x00
#define CPU_SET		0x04
#define CPU_CLEAR	0x08
#define CPU_MASK_STATUS	0x0c
#define CPU_MASK_SET	0x10
#define CPU_MASK_CLEAR	0x14

/* L2 intc private data structure */
struct brcmstb_l2_intc_data {
	int parent_irq;
	void __iomem *base;
	struct irq_domain *domain;
	bool can_wake;
	u32 saved_mask; /* for suspend/resume */
};

static void brcmstb_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)
{
	struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
	struct irq_chip *chip = irq_desc_get_chip(desc);
	u32 status;

	chained_irq_enter(chip, desc);

	status = __raw_readl(b->base + CPU_STATUS) &
		~(__raw_readl(b->base + CPU_MASK_STATUS));

	if (status == 0) {
		do_bad_IRQ(irq, desc);
		goto out;
	}

	do {
		irq = ffs(status) - 1;
		/* ack at our level */
		__raw_writel(1 << irq, b->base + CPU_CLEAR);
		status &= ~(1 << irq);
		generic_handle_irq(irq_find_mapping(b->domain, irq));
	} while (status);
out:
	chained_irq_exit(chip, desc);
}

static void brcmstb_l2_intc_suspend(struct irq_data *d)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	struct brcmstb_l2_intc_data *b = gc->private;

	irq_gc_lock(gc);
	/* Save the current mask */
	b->saved_mask = __raw_readl(b->base + CPU_MASK_STATUS);

	if (b->can_wake) {
		/* Program the wakeup mask */
		__raw_writel(~gc->wake_active, b->base + CPU_MASK_SET);
		__raw_writel(gc->wake_active, b->base + CPU_MASK_CLEAR);
	}
	irq_gc_unlock(gc);
}

static void brcmstb_l2_intc_resume(struct irq_data *d)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	struct brcmstb_l2_intc_data *b = gc->private;

	irq_gc_lock(gc);
	/* Clear unmasked non-wakeup interrupts */
	__raw_writel(~b->saved_mask & ~gc->wake_active, b->base + CPU_CLEAR);

	/* Restore the saved mask */
	__raw_writel(b->saved_mask, b->base + CPU_MASK_SET);
	__raw_writel(~b->saved_mask, b->base + CPU_MASK_CLEAR);
	irq_gc_unlock(gc);
}

int __init brcmstb_l2_intc_of_init(struct device_node *np,
					struct device_node *parent)
{
	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
	struct brcmstb_l2_intc_data *data;
	struct irq_chip_generic *gc;
	struct irq_chip_type *ct;
	int ret;

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

	data->base = of_iomap(np, 0);
	if (!data->base) {
		pr_err("failed to remap intc L2 registers\n");
		ret = -ENOMEM;
		goto out_free;
	}

	/* Disable all interrupts by default */
	__raw_writel(0xffffffff, data->base + CPU_MASK_SET);
	__raw_writel(0xffffffff, data->base + CPU_CLEAR);

	data->parent_irq = irq_of_parse_and_map(np, 0);
	if (data->parent_irq < 0) {
		pr_err("failed to find parent interrupt\n");
		ret = data->parent_irq;
		goto out_unmap;
	}

	data->domain = irq_domain_add_linear(np, 32,
				&irq_generic_chip_ops, NULL);
	if (!data->domain) {
		ret = -ENOMEM;
		goto out_unmap;
	}

	/* Allocate a single Generic IRQ chip for this node */
	ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
				np->full_name, handle_level_irq, clr, 0, 0);
	if (ret) {
		pr_err("failed to allocate generic irq chip\n");
		goto out_free_domain;
	}

	/* Set the IRQ chaining logic */
	irq_set_handler_data(data->parent_irq, data);
	irq_set_chained_handler(data->parent_irq, brcmstb_l2_intc_irq_handle);

	gc = irq_get_domain_generic_chip(data->domain, 0);
	gc->reg_base = data->base;
	gc->private = data;
	ct = gc->chip_types;

	ct->chip.irq_ack = irq_gc_ack_set_bit;
	ct->regs.ack = CPU_CLEAR;

	ct->chip.irq_mask = irq_gc_mask_disable_reg;
	ct->regs.disable = CPU_MASK_SET;

	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
	ct->regs.enable = CPU_MASK_CLEAR;

	ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
	ct->chip.irq_resume = brcmstb_l2_intc_resume;

	if (of_property_read_bool(np, "brcm,irq-can-wake")) {
		data->can_wake = true;
		/* This IRQ chip can wake the system, set all child interrupts
		 * in wake_enabled mask
		 */
		gc->wake_enabled = 0xffffffff;
		ct->chip.irq_set_wake = irq_gc_set_wake;
	}

	pr_info("registered L2 intc (mem: 0x%p, parent irq: %d)\n",
			data->base, data->parent_irq);

	return 0;

out_free_domain:
	irq_domain_remove(data->domain);
out_unmap:
	iounmap(data->base);
out_free:
	kfree(data);
	return ret;
}
IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_intc_of_init);
OpenPOWER on IntegriCloud