2 * Generic Broadcom Set Top Box Level 2 Interrupt controller driver
4 * Copyright (C) 2014 Broadcom Corporation
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.
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.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/kconfig.h>
22 #include <linux/platform_device.h>
23 #include <linux/spinlock.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>
31 #include <linux/irqdomain.h>
32 #include <linux/irqchip.h>
33 #include <linux/irqchip/chained_irq.h>
35 /* Register offsets in the L2 interrupt controller */
36 #define CPU_STATUS 0x00
38 #define CPU_CLEAR 0x08
39 #define CPU_MASK_STATUS 0x0c
40 #define CPU_MASK_SET 0x10
41 #define CPU_MASK_CLEAR 0x14
43 /* L2 intc private data structure */
44 struct brcmstb_l2_intc_data {
47 struct irq_domain *domain;
49 u32 saved_mask; /* for suspend/resume */
52 static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)
54 struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
55 struct irq_chip_generic *gc = irq_get_domain_generic_chip(b->domain, 0);
56 struct irq_chip *chip = irq_desc_get_chip(desc);
60 chained_irq_enter(chip, desc);
62 status = irq_reg_readl(gc, CPU_STATUS) &
63 ~(irq_reg_readl(gc, CPU_MASK_STATUS));
66 raw_spin_lock(&desc->lock);
68 raw_spin_unlock(&desc->lock);
73 irq = ffs(status) - 1;
74 /* ack at our level */
75 irq_reg_writel(gc, 1 << irq, CPU_CLEAR);
76 status &= ~(1 << irq);
77 generic_handle_irq(irq_find_mapping(b->domain, irq));
80 chained_irq_exit(chip, desc);
83 static void brcmstb_l2_intc_suspend(struct irq_data *d)
85 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
86 struct brcmstb_l2_intc_data *b = gc->private;
89 /* Save the current mask */
90 b->saved_mask = irq_reg_readl(gc, CPU_MASK_STATUS);
93 /* Program the wakeup mask */
94 irq_reg_writel(gc, ~gc->wake_active, CPU_MASK_SET);
95 irq_reg_writel(gc, gc->wake_active, CPU_MASK_CLEAR);
100 static void brcmstb_l2_intc_resume(struct irq_data *d)
102 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
103 struct brcmstb_l2_intc_data *b = gc->private;
106 /* Clear unmasked non-wakeup interrupts */
107 irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active, CPU_CLEAR);
109 /* Restore the saved mask */
110 irq_reg_writel(gc, b->saved_mask, CPU_MASK_SET);
111 irq_reg_writel(gc, ~b->saved_mask, CPU_MASK_CLEAR);
115 int __init brcmstb_l2_intc_of_init(struct device_node *np,
116 struct device_node *parent)
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;
125 data = kzalloc(sizeof(*data), GFP_KERNEL);
129 data->base = of_iomap(np, 0);
131 pr_err("failed to remap intc L2 registers\n");
136 /* Disable all interrupts by default */
137 writel(0xffffffff, data->base + CPU_MASK_SET);
139 /* Wakeup interrupts may be retained from S5 (cold boot) */
140 data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
142 writel(0xffffffff, data->base + CPU_CLEAR);
144 data->parent_irq = irq_of_parse_and_map(np, 0);
145 if (!data->parent_irq) {
146 pr_err("failed to find parent interrupt\n");
151 data->domain = irq_domain_add_linear(np, 32,
152 &irq_generic_chip_ops, NULL);
158 /* MIPS chips strapped for BE will automagically configure the
159 * peripheral registers for CPU-native byte order.
162 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
163 flags |= IRQ_GC_BE_IO;
165 /* Allocate a single Generic IRQ chip for this node */
166 ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
167 np->full_name, handle_edge_irq, clr, 0, flags);
169 pr_err("failed to allocate generic irq chip\n");
170 goto out_free_domain;
173 /* Set the IRQ chaining logic */
174 irq_set_chained_handler_and_data(data->parent_irq,
175 brcmstb_l2_intc_irq_handle, data);
177 gc = irq_get_domain_generic_chip(data->domain, 0);
178 gc->reg_base = data->base;
182 ct->chip.irq_ack = irq_gc_ack_set_bit;
183 ct->regs.ack = CPU_CLEAR;
185 ct->chip.irq_mask = irq_gc_mask_disable_reg;
186 ct->regs.disable = CPU_MASK_SET;
188 ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
189 ct->regs.enable = CPU_MASK_CLEAR;
191 ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
192 ct->chip.irq_resume = brcmstb_l2_intc_resume;
194 if (data->can_wake) {
195 /* This IRQ chip can wake the system, set all child interrupts
196 * in wake_enabled mask
198 gc->wake_enabled = 0xffffffff;
199 ct->chip.irq_set_wake = irq_gc_set_wake;
202 pr_info("registered L2 intc (mem: 0x%p, parent irq: %d)\n",
203 data->base, data->parent_irq);
208 irq_domain_remove(data->domain);
215 IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_intc_of_init);