On the Renesas RZ/N1 SoC, GPIOs can generate interruptions. Those
interruption lines are multiplexed by the GPIO Interrupt Multiplexer in
order to map 32 * 3 GPIO interrupt lines to 8 GIC interrupt lines.
The GPIO interrupt multiplexer IP does nothing but select 8 GPIO
IRQ lines out of the 96 available to wire them to the GIC input lines.
Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
---
drivers/soc/renesas/Kconfig | 4 +
drivers/soc/renesas/Makefile | 1 +
drivers/soc/renesas/rzn1_irqmux.c | 169 ++++++++++++++++++++++++++++++
3 files changed, 174 insertions(+)
create mode 100644 drivers/soc/renesas/rzn1_irqmux.c
diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
index fbc3b69d21a7..9e8ac33052fb 100644
--- a/drivers/soc/renesas/Kconfig
+++ b/drivers/soc/renesas/Kconfig
@@ -58,6 +58,7 @@ config ARCH_RZN1
select PM
select PM_GENERIC_DOMAINS
select ARM_AMBA
+ select RZN1_IRQMUX
if ARM && ARCH_RENESAS
@@ -435,6 +436,9 @@ config PWC_RZV2M
config RST_RCAR
bool "Reset Controller support for R-Car" if COMPILE_TEST
+config RZN1_IRQMUX
+ bool "Renesas RZ/N1 GPIO IRQ multiplexer support" if COMPILE_TEST
+
config SYSC_RZ
bool "System controller for RZ SoCs" if COMPILE_TEST
diff --git a/drivers/soc/renesas/Makefile b/drivers/soc/renesas/Makefile
index 3bdcc6a395d5..daa932c7698d 100644
--- a/drivers/soc/renesas/Makefile
+++ b/drivers/soc/renesas/Makefile
@@ -14,4 +14,5 @@ obj-$(CONFIG_SYS_R9A09G057) += r9a09g057-sys.o
# Family
obj-$(CONFIG_PWC_RZV2M) += pwc-rzv2m.o
obj-$(CONFIG_RST_RCAR) += rcar-rst.o
+obj-$(CONFIG_RZN1_IRQMUX) += rzn1_irqmux.o
obj-$(CONFIG_SYSC_RZ) += rz-sysc.o
diff --git a/drivers/soc/renesas/rzn1_irqmux.c b/drivers/soc/renesas/rzn1_irqmux.c
new file mode 100644
index 000000000000..37e41c2b9104
--- /dev/null
+++ b/drivers/soc/renesas/rzn1_irqmux.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RZ/N1 GPIO Interrupt Multiplexer
+ *
+ * Copyright 2025 Schneider Electric
+ * Author: Herve Codina <herve.codina@xxxxxxxxxxx>
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+#define IRQMUX_MAX_IRQS 8
+
+static int irqmux_is_phandle_args_equal(const struct of_phandle_args *a,
+ const struct of_phandle_args *b)
+{
+ int i;
+
+ if (a->np != b->np)
+ return false;
+
+ if (a->args_count != b->args_count)
+ return false;
+
+ for (i = 0; i < a->args_count; i++) {
+ if (a->args[i] != b->args[i])
+ return false;
+ }
+
+ return true;
+}
+
+static int irqmux_find_interrupt_index(struct device *dev, struct device_node *np,
+ const struct of_phandle_args *expected_irq)
+{
+ struct of_phandle_args out_irq;
+ bool is_equal;
+ int ret;
+ int i;
+
+ for (i = 0; i < IRQMUX_MAX_IRQS; i++) {
+ ret = of_irq_parse_one(np, i, &out_irq);
+ if (ret)
+ return ret;
+
+ is_equal = irqmux_is_phandle_args_equal(expected_irq, &out_irq);
+ of_node_put(out_irq.np);
+ if (is_equal)
+ return i;
+ }
+
+ return -ENOENT;
+}
+
+struct irqmux_cb_data {
+ struct device_node *np;
+ struct device *dev;
+ u32 __iomem *regs;
+};
+
+static int irqmux_imap_cb(void *data, const __be32 *imap,
+ const struct of_phandle_args *parent_args)
+{
+ struct irqmux_cb_data *priv = data;
+ u32 src_hwirq;
+ int index;
+
+ /*
+ * The child #address-cells is 0. Already checked in irqmux_setup().
+ * The first value in imap is the src_hwirq
+ */
+ src_hwirq = be32_to_cpu(*imap);
+
+ /*
+ * Get the index in our interrupt array that matches the parent in the
+ * interrupt-map
+ */
+ index = irqmux_find_interrupt_index(priv->dev, priv->np, parent_args);
+ if (index < 0)
+ return dev_err_probe(priv->dev, index, "output interrupt not found\n");
+
+ dev_info(priv->dev, "interrupt %u mapped to output interrupt[%u]\n",
+ src_hwirq, index);
+
+ /*
+ * Our interrupt array items matches 1:1 the interrupt lines that could
+ * be configured by registers (same order, same number).
+ * Configure the related register with the src hwirq retrieved from the
+ * interrupt-map.
+ */
+ writel(src_hwirq, priv->regs + index);
+
+ return 0;
+}
+
+static int irqmux_setup(struct device *dev, struct device_node *np, u32 __iomem *regs)
+{
+ struct irqmux_cb_data cb_data;
+ u32 tmp;
+ int ret;
+
+ /* We support only #interrupt-cells = <1> and #address-cells = <0> */
+ ret = of_property_read_u32(np, "#interrupt-cells", &tmp);
+ if (ret)
+ return ret;
+ if (tmp != 1)
+ return -EINVAL;
+
+ ret = of_property_read_u32(np, "#address-cells", &tmp);
+ if (ret)
+ return ret;
+ if (tmp != 0)
+ return -EINVAL;
+
+ cb_data.dev = dev;
+ cb_data.regs = regs;
+ cb_data.np = np;
+ return of_irq_foreach_imap(np, irqmux_imap_cb, &cb_data);
+}
+
+static int irqmux_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ u32 __iomem *regs;
+ int nr_irqs;
+ int ret;
+
+ regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ nr_irqs = of_irq_count(np);
+ if (nr_irqs < 0)
+ return nr_irqs;
+
+ if (nr_irqs > IRQMUX_MAX_IRQS) {
+ dev_err(dev, "too many output interrupts\n");
+ return -ENOENT;
+ }
+
+ ret = irqmux_setup(dev, np, regs);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to setup mux\n");
+
+ return 0;
+}
+
+static const struct of_device_id irqmux_of_match[] = {
+ { .compatible = "renesas,rzn1-gpioirqmux", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, irq_mux_of_match);
+
+static struct platform_driver irqmux_driver = {
+ .probe = irqmux_probe,
+ .driver = {
+ .name = "rzn1_irqmux",
+ .of_match_table = irqmux_of_match,
+ },
+};
+module_platform_driver(irqmux_driver);
+
+MODULE_AUTHOR("Herve Codina <herve.codina@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Renesas RZ/N1 GPIO IRQ Multiplexer Driver");
+MODULE_LICENSE("GPL");
--
2.50.1
