lkml.org 
[lkml]   [2022]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] drivers: irqchip: add irq-type-changer
Date
Irq type changer is a virtual irqchip useful to support boards that
change (e.g. invert) interrupt signal between producer and consumer.

Usage example, for Kingfisher extension board for Renesas Gen-3 Soc,
that has WiFi interrupt delivered over inverting level-shifter:

/ {
gpio1_25_inverted: inverter {
compatible = "linux,irq-type-changer";
interrupt-controller;
#interrupt-cells = <2>;
interrupt-parent = <&gpio1>;
interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
};
};

&wlcore {
interrupt-parent = <&gpio1_25_inverted>;
interrupts = <0 IRQ_TYPE_EDGE_RISING>;
};

Then, wlcore driver observes IRQ_TYPE_EDGE_RISING trigger type and
configures interrupt output as such. At the same time, gpio-rcar driver
gets interrupt configured for IRQ_TYPE_EDGE_FALLING.

This version uses hierarchical irq_domain API, and works only with
parent interrupt domains compatible with that API.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
---
v1: https://lore.kernel.org/lkml/20220119201741.717770-1-nikita.yoush@cogentembedded.com/
Changes from v1:
- fixed order of kzalloc() args, caught by kbuild robot

drivers/irqchip/Kconfig | 18 ++++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-type-changer.c | 162 +++++++++++++++++++++++++++++
3 files changed, 181 insertions(+)
create mode 100644 drivers/irqchip/irq-type-changer.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 7038957f4a77..7f348016e82c 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -617,4 +617,22 @@ config MCHP_EIC
help
Support for Microchip External Interrupt Controller.

+config IRQ_TYPE_CHANGER
+ bool "Interrupt trigger type changer"
+ select IRQ_DOMAIN
+ select IRQ_DOMAIN_HIERARCHY
+ help
+ Interrupt trigger type changer is designed to support boards that
+ modify (e.g. invert) signal between interrupt source and interrupt
+ controller input. So trigger type configured by a driver for some
+ interrupt output pin does not match trigger type that shall be used
+ to configure interrupt controller's input where that pin is connected.
+
+ In this case, board device tree shall add an interrupt trigger
+ type changer node and use it as the interrupt parent for the node
+ representing interrupt source. Then, interrupt trigger type defined
+ in the interrupt source node will be visible for the interrupt source
+ driver, and (different) trigger type defined inside the changer node
+ will be used to configure the interrupt controller.
+
endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c1f611cbfbf8..57a664837857 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -117,3 +117,4 @@ obj-$(CONFIG_WPCM450_AIC) += irq-wpcm450-aic.o
obj-$(CONFIG_IRQ_IDT3243X) += irq-idt3243x.o
obj-$(CONFIG_APPLE_AIC) += irq-apple-aic.o
obj-$(CONFIG_MCHP_EIC) += irq-mchp-eic.o
+obj-$(CONFIG_IRQ_TYPE_CHANGER) += irq-type-changer.o
diff --git a/drivers/irqchip/irq-type-changer.c b/drivers/irqchip/irq-type-changer.c
new file mode 100644
index 000000000000..0f461fda6610
--- /dev/null
+++ b/drivers/irqchip/irq-type-changer.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/of_irq.h>
+
+struct changer {
+ unsigned long count;
+ struct {
+ struct irq_fwspec fwspec;
+ unsigned int type;
+ } out[0];
+};
+
+static int changer_set_type(struct irq_data *data, unsigned int type)
+{
+ struct changer *ch = data->domain->host_data;
+ struct irq_data *parent_data = data->parent_data;
+
+ return parent_data->chip->irq_set_type(parent_data,
+ ch->out[data->hwirq].type);
+}
+
+static struct irq_chip changer_chip = {
+ .name = "type-changer",
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_set_type = changer_set_type,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+ .irq_set_wake = irq_chip_set_wake_parent,
+};
+
+static int changer_domain_translate(struct irq_domain *domain,
+ struct irq_fwspec *fwspec,
+ unsigned long *hwirq,
+ unsigned int *type)
+{
+ struct changer *ch = domain->host_data;
+
+ if (fwspec->param_count != 2)
+ return -EINVAL;
+ if (fwspec->param[0] >= ch->count)
+ return -ENXIO;
+
+ *hwirq = fwspec->param[0];
+ *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+ return 0;
+}
+
+static int changer_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ struct changer *ch = domain->host_data;
+ struct irq_fwspec *fwspec = arg;
+ irq_hw_number_t hwirq;
+ unsigned int type;
+ int ret;
+
+ if (WARN_ON(nr_irqs != 1))
+ return -EINVAL;
+
+ ret = changer_domain_translate(domain, fwspec, &hwirq, &type);
+ if (ret)
+ return ret;
+
+ irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &changer_chip, ch);
+
+ return irq_domain_alloc_irqs_parent(domain, virq, 1,
+ &ch->out[hwirq].fwspec);
+}
+
+static const struct irq_domain_ops changer_domain_ops = {
+ .translate = changer_domain_translate,
+ .alloc = changer_domain_alloc,
+ .free = irq_domain_free_irqs_common,
+};
+
+static int __init changer_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct irq_domain *domain, *parent_domain;
+ int count, i, ret;
+ struct changer *ch;
+ struct of_phandle_args pargs;
+ irq_hw_number_t unused;
+
+ if (!parent) {
+ pr_err("%pOF: no parent node\n", node);
+ return -EINVAL;
+ }
+
+ parent_domain = irq_find_host(parent);
+ if (!parent_domain) {
+ pr_err("%pOF: no parent domain\n", node);
+ return -EINVAL;
+ }
+
+ if (WARN_ON(!parent_domain->ops->translate))
+ return -EINVAL;
+
+ count = of_irq_count(node);
+ if (count < 1) {
+ pr_err("%pOF: no interrupts defined\n", node);
+ return -EINVAL;
+ }
+
+ ch = kzalloc(sizeof(*ch) + count * sizeof(ch->out[0]), GFP_KERNEL);
+ if (!ch)
+ return -ENOMEM;
+ ch->count = count;
+
+ for (i = 0; i < count; i++) {
+ ret = of_irq_parse_one(node, i, &pargs);
+ if (ret) {
+ pr_err("%pOF: interrupt %d: error %d parsing\n",
+ node, i, ret);
+ goto out_free;
+ }
+ of_phandle_args_to_fwspec(pargs.np, pargs.args,
+ pargs.args_count,
+ &ch->out[i].fwspec);
+ ret = parent_domain->ops->translate(parent_domain,
+ &ch->out[i].fwspec,
+ &unused,
+ &ch->out[i].type);
+ if (ret) {
+ pr_err("%pOF: interrupt %d: error %d extracting type\n",
+ node, i, ret);
+ goto out_free;
+ }
+ if (ch->out[i].type == IRQ_TYPE_NONE) {
+ pr_err("%pOF: interrupt %d: no type\n", node, i);
+ ret = -ENXIO;
+ goto out_free;
+ }
+ }
+
+ domain = irq_domain_create_hierarchy(parent_domain, 0, count,
+ of_node_to_fwnode(node),
+ &changer_domain_ops, ch);
+ if (!domain) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+
+ return 0;
+
+out_free:
+ kfree(ch);
+ return ret;
+}
+
+IRQCHIP_PLATFORM_DRIVER_BEGIN(changer)
+IRQCHIP_MATCH("linux,irq-type-changer", changer_of_init)
+IRQCHIP_PLATFORM_DRIVER_END(changer)
+MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush.cogentembedded.com>");
+MODULE_DESCRIPTION("Virtual irqchip to support trigger type change in route");
+MODULE_LICENSE("GPL v2");
--
2.30.2
\
 
 \ /
  Last update: 2022-01-24 10:57    [W:0.093 / U:1.660 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site