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Florian Fainelli7f646e92014-05-23 17:40:53 -07001/*
2 * Generic Broadcom Set Top Box Level 2 Interrupt controller driver
3 *
4 * Copyright (C) 2014 Broadcom Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/init.h>
19#include <linux/slab.h>
20#include <linux/module.h>
Kevin Cernekee1abbdba2014-11-06 22:44:29 -080021#include <linux/kconfig.h>
Florian Fainelli7f646e92014-05-23 17:40:53 -070022#include <linux/platform_device.h>
Kevin Cernekee05f12752014-11-06 22:44:20 -080023#include <linux/spinlock.h>
Florian Fainelli7f646e92014-05-23 17:40:53 -070024#include <linux/of.h>
25#include <linux/of_irq.h>
26#include <linux/of_address.h>
27#include <linux/of_platform.h>
28#include <linux/interrupt.h>
29#include <linux/irq.h>
30#include <linux/io.h>
31#include <linux/irqdomain.h>
32#include <linux/irqchip.h>
33#include <linux/irqchip/chained_irq.h>
34
Florian Fainelli7f646e92014-05-23 17:40:53 -070035/* Register offsets in the L2 interrupt controller */
36#define CPU_STATUS 0x00
37#define CPU_SET 0x04
38#define CPU_CLEAR 0x08
39#define CPU_MASK_STATUS 0x0c
40#define CPU_MASK_SET 0x10
41#define CPU_MASK_CLEAR 0x14
42
43/* L2 intc private data structure */
44struct brcmstb_l2_intc_data {
45 int parent_irq;
46 void __iomem *base;
47 struct irq_domain *domain;
48 bool can_wake;
49 u32 saved_mask; /* for suspend/resume */
50};
51
Thomas Gleixnerbd0b9ac2015-09-14 10:42:37 +020052static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)
Florian Fainelli7f646e92014-05-23 17:40:53 -070053{
54 struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
Kevin Cernekee1abbdba2014-11-06 22:44:29 -080055 struct irq_chip_generic *gc = irq_get_domain_generic_chip(b->domain, 0);
Florian Fainelli7f646e92014-05-23 17:40:53 -070056 struct irq_chip *chip = irq_desc_get_chip(desc);
Thomas Gleixnerbd0b9ac2015-09-14 10:42:37 +020057 unsigned int irq;
Florian Fainelli7f646e92014-05-23 17:40:53 -070058 u32 status;
59
60 chained_irq_enter(chip, desc);
61
Kevin Cernekee1abbdba2014-11-06 22:44:29 -080062 status = irq_reg_readl(gc, CPU_STATUS) &
63 ~(irq_reg_readl(gc, CPU_MASK_STATUS));
Florian Fainelli7f646e92014-05-23 17:40:53 -070064
65 if (status == 0) {
Kevin Cernekee05f12752014-11-06 22:44:20 -080066 raw_spin_lock(&desc->lock);
Thomas Gleixnerbd0b9ac2015-09-14 10:42:37 +020067 handle_bad_irq(desc);
Kevin Cernekee05f12752014-11-06 22:44:20 -080068 raw_spin_unlock(&desc->lock);
Florian Fainelli7f646e92014-05-23 17:40:53 -070069 goto out;
70 }
71
72 do {
73 irq = ffs(status) - 1;
74 /* ack at our level */
Kevin Cernekee1abbdba2014-11-06 22:44:29 -080075 irq_reg_writel(gc, 1 << irq, CPU_CLEAR);
Florian Fainelli7f646e92014-05-23 17:40:53 -070076 status &= ~(1 << irq);
77 generic_handle_irq(irq_find_mapping(b->domain, irq));
78 } while (status);
79out:
80 chained_irq_exit(chip, desc);
81}
82
83static void brcmstb_l2_intc_suspend(struct irq_data *d)
84{
85 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
86 struct brcmstb_l2_intc_data *b = gc->private;
87
88 irq_gc_lock(gc);
89 /* Save the current mask */
Kevin Cernekee1abbdba2014-11-06 22:44:29 -080090 b->saved_mask = irq_reg_readl(gc, CPU_MASK_STATUS);
Florian Fainelli7f646e92014-05-23 17:40:53 -070091
92 if (b->can_wake) {
93 /* Program the wakeup mask */
Kevin Cernekee1abbdba2014-11-06 22:44:29 -080094 irq_reg_writel(gc, ~gc->wake_active, CPU_MASK_SET);
95 irq_reg_writel(gc, gc->wake_active, CPU_MASK_CLEAR);
Florian Fainelli7f646e92014-05-23 17:40:53 -070096 }
97 irq_gc_unlock(gc);
98}
99
100static void brcmstb_l2_intc_resume(struct irq_data *d)
101{
102 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
103 struct brcmstb_l2_intc_data *b = gc->private;
104
105 irq_gc_lock(gc);
106 /* Clear unmasked non-wakeup interrupts */
Kevin Cernekee1abbdba2014-11-06 22:44:29 -0800107 irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active, CPU_CLEAR);
Florian Fainelli7f646e92014-05-23 17:40:53 -0700108
109 /* Restore the saved mask */
Kevin Cernekee1abbdba2014-11-06 22:44:29 -0800110 irq_reg_writel(gc, b->saved_mask, CPU_MASK_SET);
111 irq_reg_writel(gc, ~b->saved_mask, CPU_MASK_CLEAR);
Florian Fainelli7f646e92014-05-23 17:40:53 -0700112 irq_gc_unlock(gc);
113}
114
115int __init brcmstb_l2_intc_of_init(struct device_node *np,
116 struct device_node *parent)
117{
118 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
119 struct brcmstb_l2_intc_data *data;
120 struct irq_chip_generic *gc;
121 struct irq_chip_type *ct;
122 int ret;
Kevin Cernekee1abbdba2014-11-06 22:44:29 -0800123 unsigned int flags;
Florian Fainelli7f646e92014-05-23 17:40:53 -0700124
125 data = kzalloc(sizeof(*data), GFP_KERNEL);
126 if (!data)
127 return -ENOMEM;
128
129 data->base = of_iomap(np, 0);
130 if (!data->base) {
131 pr_err("failed to remap intc L2 registers\n");
132 ret = -ENOMEM;
133 goto out_free;
134 }
135
136 /* Disable all interrupts by default */
Kevin Cernekee1abbdba2014-11-06 22:44:29 -0800137 writel(0xffffffff, data->base + CPU_MASK_SET);
Brian Norrisc9ae71e2014-12-25 09:49:02 -0800138
139 /* Wakeup interrupts may be retained from S5 (cold boot) */
140 data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
141 if (!data->can_wake)
142 writel(0xffffffff, data->base + CPU_CLEAR);
Florian Fainelli7f646e92014-05-23 17:40:53 -0700143
144 data->parent_irq = irq_of_parse_and_map(np, 0);
Dmitry Torokhovd99ba442014-11-14 14:16:42 -0800145 if (!data->parent_irq) {
Florian Fainelli7f646e92014-05-23 17:40:53 -0700146 pr_err("failed to find parent interrupt\n");
Dmitry Torokhovd99ba442014-11-14 14:16:42 -0800147 ret = -EINVAL;
Florian Fainelli7f646e92014-05-23 17:40:53 -0700148 goto out_unmap;
149 }
150
151 data->domain = irq_domain_add_linear(np, 32,
152 &irq_generic_chip_ops, NULL);
153 if (!data->domain) {
154 ret = -ENOMEM;
155 goto out_unmap;
156 }
157
Kevin Cernekee1abbdba2014-11-06 22:44:29 -0800158 /* MIPS chips strapped for BE will automagically configure the
159 * peripheral registers for CPU-native byte order.
160 */
161 flags = 0;
162 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
163 flags |= IRQ_GC_BE_IO;
164
Florian Fainelli7f646e92014-05-23 17:40:53 -0700165 /* Allocate a single Generic IRQ chip for this node */
166 ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
Kevin Cernekee1abbdba2014-11-06 22:44:29 -0800167 np->full_name, handle_edge_irq, clr, 0, flags);
Florian Fainelli7f646e92014-05-23 17:40:53 -0700168 if (ret) {
169 pr_err("failed to allocate generic irq chip\n");
170 goto out_free_domain;
171 }
172
173 /* Set the IRQ chaining logic */
Thomas Gleixnerf286c172015-06-21 21:10:52 +0200174 irq_set_chained_handler_and_data(data->parent_irq,
175 brcmstb_l2_intc_irq_handle, data);
Florian Fainelli7f646e92014-05-23 17:40:53 -0700176
177 gc = irq_get_domain_generic_chip(data->domain, 0);
178 gc->reg_base = data->base;
179 gc->private = data;
180 ct = gc->chip_types;
181
182 ct->chip.irq_ack = irq_gc_ack_set_bit;
183 ct->regs.ack = CPU_CLEAR;
184
185 ct->chip.irq_mask = irq_gc_mask_disable_reg;
186 ct->regs.disable = CPU_MASK_SET;
187
188 ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
189 ct->regs.enable = CPU_MASK_CLEAR;
190
191 ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
192 ct->chip.irq_resume = brcmstb_l2_intc_resume;
193
Brian Norrisc9ae71e2014-12-25 09:49:02 -0800194 if (data->can_wake) {
Florian Fainelli7f646e92014-05-23 17:40:53 -0700195 /* This IRQ chip can wake the system, set all child interrupts
196 * in wake_enabled mask
197 */
198 gc->wake_enabled = 0xffffffff;
199 ct->chip.irq_set_wake = irq_gc_set_wake;
200 }
201
202 pr_info("registered L2 intc (mem: 0x%p, parent irq: %d)\n",
203 data->base, data->parent_irq);
204
205 return 0;
206
207out_free_domain:
208 irq_domain_remove(data->domain);
209out_unmap:
210 iounmap(data->base);
211out_free:
212 kfree(data);
213 return ret;
214}
215IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_intc_of_init);