/*
* 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;
irq_gc_lock(gc);
/* 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(gc);
}
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;
irq_gc_lock(gc);
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(gc);
}
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;
}
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);
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);
