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/*
* 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/kconfig.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>
/* 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(struct irq_desc *desc)
{
struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
struct irq_chip_generic *gc = irq_get_domain_generic_chip(b->domain, 0);
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned int irq;
u32 status;
chained_irq_enter(chip, desc);
status = irq_reg_readl(gc, CPU_STATUS) &
~(irq_reg_readl(gc, CPU_MASK_STATUS));
if (status == 0) {
raw_spin_lock(&desc->lock);
handle_bad_irq(desc);
raw_spin_unlock(&desc->lock);
goto out;
}
do {
irq = ffs(status) - 1;
/* ack at our level */
irq_reg_writel(gc, 1 << irq, 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 = irq_reg_readl(gc, CPU_MASK_STATUS);
if (b->can_wake) {
/* Program the wakeup mask */
irq_reg_writel(gc, ~gc->wake_active, CPU_MASK_SET);
irq_reg_writel(gc, gc->wake_active, 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 */
irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active, CPU_CLEAR);
/* Restore the saved mask */
irq_reg_writel(gc, b->saved_mask, CPU_MASK_SET);
irq_reg_writel(gc, ~b->saved_mask, CPU_MASK_CLEAR);
irq_gc_unlock(gc);
}
static 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;
unsigned int flags;
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 */
writel(0xffffffff, data->base + 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)
writel(0xffffffff, data->base + CPU_CLEAR);
data->parent_irq = irq_of_parse_and_map(np, 0);
if (!data->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, handle_edge_irq, 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(data->parent_irq,
brcmstb_l2_intc_irq_handle, data);
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 (data->can_wake) {
/* 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);
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