/*
* Driver for Socionext External Interrupt Unit (EXIU)
*
* Copyright (c) 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
*
* Based on irq-tegra.c:
* Copyright (C) 2011 Google, Inc.
* Copyright (C) 2010,2013, NVIDIA 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.
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <dt-bindings/interrupt-controller/arm-gic.h>
#define NUM_IRQS 32
#define EIMASK 0x00
#define EISRCSEL 0x04
#define EIREQSTA 0x08
#define EIRAWREQSTA 0x0C
#define EIREQCLR 0x10
#define EILVL 0x14
#define EIEDG 0x18
#define EISIR 0x1C
struct exiu_irq_data {
void __iomem *base;
u32 spi_base;
};
static void exiu_irq_eoi(struct irq_data *d)
{
struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
writel(BIT(d->hwirq), data->base + EIREQCLR);
irq_chip_eoi_parent(d);
}
static void exiu_irq_mask(struct irq_data *d)
{
struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
u32 val;
val = readl_relaxed(data->base + EIMASK) | BIT(d->hwirq);
writel_relaxed(val, data->base + EIMASK);
irq_chip_mask_parent(d);
}
static void exiu_irq_unmask(struct irq_data *d)
{
struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
u32 val;
val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
writel_relaxed(val, data->base + EIMASK);
irq_chip_unmask_parent(d);
}
static void exiu_irq_enable(struct irq_data *d)
{
struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
u32 val;
/* clear interrupts that were latched while disabled */
writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
val = readl_relaxed(data->base + EIMASK) & ~BIT(d->hwirq);
writel_relaxed(val, data->base + EIMASK);
irq_chip_enable_parent(d);
}
static int exiu_irq_set_type(struct irq_data *d, unsigned int type)
{
struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
u32 val;
val = readl_relaxed(data->base + EILVL);
if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
val |= BIT(d->hwirq);
else
val &= ~BIT(d->hwirq);
writel_relaxed(val, data->base + EILVL);
val = readl_relaxed(data->base + EIEDG);
if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
val &= ~BIT(d->hwirq);
else
val |= BIT(d->hwirq);
writel_relaxed(val, data->base + EIEDG);
writel_relaxed(BIT(d->hwirq), data->base + EIREQCLR);
return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
}
static struct irq_chip exiu_irq_chip = {
.name = "EXIU",
.irq_eoi = exiu_irq_eoi,
.irq_enable = exiu_irq_enable,
.irq_mask = exiu_irq_mask,
.irq_unmask = exiu_irq_unmask,
.irq_set_type = exiu_irq_set_type,
.irq_set_affinity = irq_chip_set_affinity_parent,
.flags = IRQCHIP_SET_TYPE_MASKED |
IRQCHIP_SKIP_SET_WAKE |
IRQCHIP_EOI_THREADED |
IRQCHIP_MASK_ON_SUSPEND,
};
static int exiu_domain_translate(struct irq_domain *domain,
struct irq_fwspec *fwspec,
unsigned long *hwirq,
unsigned int *type)
{
struct exiu_irq_data *info = domain->host_data;
if (is_of_node(fwspec->fwnode)) {
if (fwspec->param_count != 3)
return -EINVAL;
if (fwspec->param[0] != GIC_SPI)
return -EINVAL; /* No PPI should point to this domain */
*hwirq = fwspec->param[1] - info->spi_base;
*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
return 0;
}
return -EINVAL;
}
static int exiu_domain_alloc(struct irq_domain *dom, unsigned int virq,
unsigned int nr_irqs, void *data)
{
struct irq_fwspec *fwspec = data;
struct irq_fwspec parent_fwspec;
struct exiu_irq_data *info = dom->host_data;
irq_hw_number_t hwirq;
if (fwspec->param_count != 3)
return -EINVAL; /* Not GIC compliant */
if (fwspec->param[0] != GIC_SPI)
return -EINVAL; /* No PPI should point to this domain */
WARN_ON(nr_irqs != 1);
hwirq = fwspec->param[1] - info->spi_base;
irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &exiu_irq_chip, info);
parent_fwspec = *fwspec;
parent_fwspec.fwnode = dom->parent->fwnode;
return irq_domain_alloc_irqs_parent(dom, virq, nr_irqs, &parent_fwspec);
}
static const struct irq_domain_ops exiu_domain_ops = {
.translate = exiu_domain_translate,
.alloc = exiu_domain_alloc,
.free = irq_domain_free_irqs_common,
};
static int __init exiu_init(struct device_node *node,
struct device_node *parent)
{
struct irq_domain *parent_domain, *domain;
struct exiu_irq_data *data;
int err;
if (!parent) {
pr_err("%pOF: no parent, giving up\n", node);
return -ENODEV;
}
parent_domain = irq_find_host(parent);
if (!parent_domain) {
pr_err("%pOF: unable to obtain parent domain\n", node);
return -ENXIO;
}
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
if (of_property_read_u32(node, "socionext,spi-base", &data->spi_base)) {
pr_err("%pOF: failed to parse 'spi-base' property\n", node);
err = -ENODEV;
goto out_free;
}
data->base = of_iomap(node, 0);
if (IS_ERR(data->base)) {
err = PTR_ERR(data->base);
goto out_free;
}
/* clear and mask all interrupts */
writel_relaxed(0xFFFFFFFF, data->base + EIREQCLR);
writel_relaxed(0xFFFFFFFF, data->base + EIMASK);
domain = irq_domain_add_hierarchy(parent_domain, 0, NUM_IRQS, node,
&exiu_domain_ops, data);
if (!domain) {
pr_err("%pOF: failed to allocate domain\n", node);
err = -ENOMEM;
goto out_unmap;
}
pr_info("%pOF: %d interrupts forwarded to %pOF\n", node, NUM_IRQS,
parent);
return 0;
out_unmap:
iounmap(data->base);
out_free:
kfree(data);
return err;
}
IRQCHIP_DECLARE(exiu, "socionext,synquacer-exiu", exiu_init);
