linux-stable/drivers/irqchip/irq-sni-exiu.c
Daniel Thompson 4efc851c36 irqchip/exiu: Fix acknowledgment of edge triggered interrupts
Currently the EXIU uses the fasteoi interrupt flow that is configured by
it's parent (irq-gic-v3.c). With this flow the only chance to clear the
interrupt request happens during .irq_eoi() and (obviously) this happens
after the interrupt handler has run. EXIU requires edge triggered
interrupts to be acked prior to interrupt handling. Without this we
risk incorrect interrupt dismissal when a new interrupt is delivered
after the handler reads and acknowledges the peripheral but before the
irq_eoi() takes place.

Fix this by clearing the interrupt request from .irq_ack() if we are
configured for edge triggered interrupts. This requires adopting the
fasteoi-ack flow instead of the fasteoi to ensure the ack gets called.

These changes have been tested using the power button on a
Developerbox/SC2A11 combined with some hackery in gpio-keys so I can
play with the different trigger mode [and an mdelay(500) so I can
can check what happens on a double click in both modes].

Fixes: 706cffc1b9 ("irqchip/exiu: Add support for Socionext Synquacer EXIU controller")
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503134541.2566457-1-daniel.thompson@linaro.org
2022-05-04 16:33:17 +01:00

323 lines
7.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for Socionext External Interrupt Unit (EXIU)
*
* Copyright (c) 2017-2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
*
* Based on irq-tegra.c:
* Copyright (C) 2011 Google, Inc.
* Copyright (C) 2010,2013, NVIDIA Corporation
*/
#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 <linux/platform_device.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_ack(struct irq_data *d)
{
struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
writel(BIT(d->hwirq), data->base + EIREQCLR);
}
static void exiu_irq_eoi(struct irq_data *d)
{
struct exiu_irq_data *data = irq_data_get_irq_chip_data(d);
/*
* Level triggered interrupts are latched and must be cleared during
* EOI or the interrupt will be jammed on. Of course if a level
* triggered interrupt is still asserted then the write will not clear
* the interrupt.
*/
if (irqd_is_level_type(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);
irq_set_handler_locked(d, handle_fasteoi_irq);
} else {
val |= BIT(d->hwirq);
irq_set_handler_locked(d, handle_fasteoi_ack_irq);
}
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_ack = exiu_irq_ack,
.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;
} else {
if (fwspec->param_count != 2)
return -EINVAL;
*hwirq = fwspec->param[0];
*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
}
return 0;
}
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;
parent_fwspec = *fwspec;
if (is_of_node(dom->parent->fwnode)) {
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 */
hwirq = fwspec->param[1] - info->spi_base;
} else {
hwirq = fwspec->param[0];
parent_fwspec.param[0] = hwirq + info->spi_base + 32;
}
WARN_ON(nr_irqs != 1);
irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &exiu_irq_chip, info);
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 struct exiu_irq_data *exiu_init(const struct fwnode_handle *fwnode,
struct resource *res)
{
struct exiu_irq_data *data;
int err;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return ERR_PTR(-ENOMEM);
if (fwnode_property_read_u32_array(fwnode, "socionext,spi-base",
&data->spi_base, 1)) {
err = -ENODEV;
goto out_free;
}
data->base = ioremap(res->start, resource_size(res));
if (!data->base) {
err = -ENODEV;
goto out_free;
}
/* clear and mask all interrupts */
writel_relaxed(0xFFFFFFFF, data->base + EIREQCLR);
writel_relaxed(0xFFFFFFFF, data->base + EIMASK);
return data;
out_free:
kfree(data);
return ERR_PTR(err);
}
static int __init exiu_dt_init(struct device_node *node,
struct device_node *parent)
{
struct irq_domain *parent_domain, *domain;
struct exiu_irq_data *data;
struct resource res;
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;
}
if (of_address_to_resource(node, 0, &res)) {
pr_err("%pOF: failed to parse memory resource\n", node);
return -ENXIO;
}
data = exiu_init(of_node_to_fwnode(node), &res);
if (IS_ERR(data))
return PTR_ERR(data);
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);
goto out_unmap;
}
pr_info("%pOF: %d interrupts forwarded to %pOF\n", node, NUM_IRQS,
parent);
return 0;
out_unmap:
iounmap(data->base);
kfree(data);
return -ENOMEM;
}
IRQCHIP_DECLARE(exiu, "socionext,synquacer-exiu", exiu_dt_init);
#ifdef CONFIG_ACPI
static int exiu_acpi_probe(struct platform_device *pdev)
{
struct irq_domain *domain;
struct exiu_irq_data *data;
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "failed to parse memory resource\n");
return -ENXIO;
}
data = exiu_init(dev_fwnode(&pdev->dev), res);
if (IS_ERR(data))
return PTR_ERR(data);
domain = acpi_irq_create_hierarchy(0, NUM_IRQS, dev_fwnode(&pdev->dev),
&exiu_domain_ops, data);
if (!domain) {
dev_err(&pdev->dev, "failed to create IRQ domain\n");
goto out_unmap;
}
dev_info(&pdev->dev, "%d interrupts forwarded\n", NUM_IRQS);
return 0;
out_unmap:
iounmap(data->base);
kfree(data);
return -ENOMEM;
}
static const struct acpi_device_id exiu_acpi_ids[] = {
{ "SCX0008" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(acpi, exiu_acpi_ids);
static struct platform_driver exiu_driver = {
.driver = {
.name = "exiu",
.acpi_match_table = exiu_acpi_ids,
},
.probe = exiu_acpi_probe,
};
builtin_platform_driver(exiu_driver);
#endif