summaryrefslogtreecommitdiffstats
path: root/drivers/irqchip/irq-brcmstb-l2.c
blob: 5e4ca139e4eacaa70eb5cba5b7ce4124aed93381 (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
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
/*
 * Generic Broadcom Set Top Box Level 2 Interrupt controller driver
 *
 * Copyright (C) 2014-2017 Broadcom
 *
 * 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/spinlock.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>

struct brcmstb_intc_init_params {
	irq_flow_handler_t handler;
	int cpu_status;
	int cpu_clear;
	int cpu_mask_status;
	int cpu_mask_set;
	int cpu_mask_clear;
};

/* Register offsets in the L2 latched interrupt controller */
static const struct brcmstb_intc_init_params l2_edge_intc_init = {
	.handler		= handle_edge_irq,
	.cpu_status		= 0x00,
	.cpu_clear		= 0x08,
	.cpu_mask_status	= 0x0c,
	.cpu_mask_set		= 0x10,
	.cpu_mask_clear		= 0x14
};

/* Register offsets in the L2 level interrupt controller */
static const struct brcmstb_intc_init_params l2_lvl_intc_init = {
	.handler		= handle_level_irq,
	.cpu_status		= 0x00,
	.cpu_clear		= -1, /* Register not present */
	.cpu_mask_status	= 0x04,
	.cpu_mask_set		= 0x08,
	.cpu_mask_clear		= 0x0C
};

/* L2 intc private data structure */
struct brcmstb_l2_intc_data {
	struct irq_domain *domain;
	struct irq_chip_generic *gc;
	int status_offset;
	int mask_offset;
	bool can_wake;
	u32 saved_mask; /* for suspend/resume */
};

/**
 * brcmstb_l2_mask_and_ack - Mask and ack pending interrupt
 * @d: irq_data
 *
 * Chip has separate enable/disable registers instead of a single mask
 * register and pending interrupt is acknowledged by setting a bit.
 *
 * Note: This function is generic and could easily be added to the
 * generic irqchip implementation if there ever becomes a will to do so.
 * Perhaps with a name like irq_gc_mask_disable_and_ack_set().
 *
 * e.g.: https://patchwork.kernel.org/patch/9831047/
 */
static void brcmstb_l2_mask_and_ack(struct irq_data *d)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	struct irq_chip_type *ct = irq_data_get_chip_type(d);
	u32 mask = d->mask;

	irq_gc_lock(gc);
	irq_reg_writel(gc, mask, ct->regs.disable);
	*ct->mask_cache &= ~mask;
	irq_reg_writel(gc, mask, ct->regs.ack);
	irq_gc_unlock(gc);
}

static void brcmstb_l2_intc_irq_handle(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);
	unsigned int irq;
	u32 status;

	chained_irq_enter(chip, desc);

	status = irq_reg_readl(b->gc, b->status_offset) &
		~(irq_reg_readl(b->gc, b->mask_offset));

	if (status == 0) {
		raw_spin_lock(&desc->lock);
		handle_bad_irq(desc);
		raw_spin_unlock(&desc->lock);
		goto out;
	}

	do {
		irq = ffs(status) - 1;
		status &= ~(1 << irq);
		generic_handle_irq(irq_linear_revmap(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 irq_chip_type *ct = irq_data_get_chip_type(d);
	struct brcmstb_l2_intc_data *b = gc->private;
	unsigned long flags;

	irq_gc_lock_irqsave(gc, flags);
	/* Save the current mask */
	b->saved_mask = irq_reg_readl(gc, ct->regs.mask);

	if (b->can_wake) {
		/* Program the wakeup mask */
		irq_reg_writel(gc, ~gc->wake_active, ct->regs.disable);
		irq_reg_writel(gc, gc->wake_active, ct->regs.enable);
	}
	irq_gc_unlock_irqrestore(gc, flags);
}

static void brcmstb_l2_intc_resume(struct irq_data *d)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	struct irq_chip_type *ct = irq_data_get_chip_type(d);
	struct brcmstb_l2_intc_data *b = gc->private;
	unsigned long flags;

	irq_gc_lock_irqsave(gc, flags);
	if (ct->chip.irq_ack) {
		/* Clear unmasked non-wakeup interrupts */
		irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active,
				ct->regs.ack);
	}

	/* Restore the saved mask */
	irq_reg_writel(gc, b->saved_mask, ct->regs.disable);
	irq_reg_writel(gc, ~b->saved_mask, ct->regs.enable);
	irq_gc_unlock_irqrestore(gc, flags);
}

static int __init brcmstb_l2_intc_of_init(struct device_node *np,
					  struct device_node *parent,
					  const struct brcmstb_intc_init_params
					  *init_params)
{
	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
	struct brcmstb_l2_intc_data *data;
	struct irq_chip_type *ct;
	int ret;
	unsigned int flags;
	int parent_irq;
	void __iomem *base;

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

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

	/* Disable all interrupts by default */
	writel(0xffffffff, base + init_params->cpu_mask_set);

	/* Wakeup interrupts may be retained from S5 (cold boot) */
	data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
	if (!data->can_wake && (init_params->cpu_clear >= 0))
		writel(0xffffffff, base + init_params->cpu_clear);

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

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

	/* MIPS chips strapped for BE will automagically configure the
	 * peripheral registers for CPU-native byte order.
	 */
	flags = 0;
	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
		flags |= IRQ_GC_BE_IO;

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

	/* Set the IRQ chaining logic */
	irq_set_chained_handler_and_data(parent_irq,
					 brcmstb_l2_intc_irq_handle, data);

	data->gc = irq_get_domain_generic_chip(data->domain, 0);
	data->gc->reg_base = base;
	data->gc->private = data;
	data->status_offset = init_params->cpu_status;
	data->mask_offset = init_params->cpu_mask_status;

	ct = data->gc->chip_types;

	if (init_params->cpu_clear >= 0) {
		ct->regs.ack = init_params->cpu_clear;
		ct->chip.irq_ack = irq_gc_ack_set_bit;
		ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack;
	} else {
		/* No Ack - but still slightly more efficient to define this */
		ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
	}

	ct->chip.irq_mask = irq_gc_mask_disable_reg;
	ct->regs.disable = init_params->cpu_mask_set;
	ct->regs.mask = init_params->cpu_mask_status;

	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
	ct->regs.enable = init_params->cpu_mask_clear;

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

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

	return 0;

out_free_domain:
	irq_domain_remove(data->domain);
out_unmap:
	iounmap(base);
out_free:
	kfree(data);
	return ret;
}

static int __init brcmstb_l2_edge_intc_of_init(struct device_node *np,
	struct device_node *parent)
{
	return brcmstb_l2_intc_of_init(np, parent, &l2_edge_intc_init);
}
IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_edge_intc_of_init);

static int __init brcmstb_l2_lvl_intc_of_init(struct device_node *np,
	struct device_node *parent)
{
	return brcmstb_l2_intc_of_init(np, parent, &l2_lvl_intc_init);
}
IRQCHIP_DECLARE(bcm7271_l2_intc, "brcm,bcm7271-l2-intc",
	brcmstb_l2_lvl_intc_of_init);