[PATCH v4 2/2] irqchip: Add Renesas RZ/A1 Interrupt Controller driver

[Geert Uytterhoeven]

Add a driver for the Renesas RZ/A1 Interrupt Controller.

This supports using up to 8 external interrupts on RZ/A1, with
configurable sense select.

NMI edge select is not yet supported.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: Chris Brandt <chris.brandt@xxxxxxxxxxx>
Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
---
For simplicity, interrupt-map-mask is not parsed, but ignored.

I also considered extracting the parsing code in of_irq_parse_raw() in a
new public helper function:

    int of_irq_parse_map(struct device_node **ipar, u32 *addrsize,
			 u32 *intsize, const __be32 **match_array,
			 struct of_phandle_args *out_irq);

However, that API is a bit ugly due to many output parameters
(of_irq_parse_raw() needs to iterate the interrupt hierarchy).
In addition, it's less efficient for irq-renesas-rza1.c, as the
interrupt-map must be parsed 8 times.

v4:
  - Add Reviewed-by,

v3:
  - Add Tested-by,
  - Replace renesas,gic-spi-base in DT by interrupt-map in DT,

v2:
  - Use u16 for register values,
  - Use relaxed I/O accessors,
  - Use "rza1-irqc" as irq_chip class name,
  - Replace gic_spi_base in OF match data by renesas,gic-spi-base in DT.
---
 drivers/irqchip/Kconfig            |   4 +
 drivers/irqchip/Makefile           |   1 +
 drivers/irqchip/irq-renesas-rza1.c | 283 +++++++++++++++++++++++++++++
 3 files changed, 288 insertions(+)
 create mode 100644 drivers/irqchip/irq-renesas-rza1.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 1c1f3f66dfd3c4d0..cab02070b519b4de 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -224,6 +224,10 @@ config RENESAS_IRQC
 	select GENERIC_IRQ_CHIP
 	select IRQ_DOMAIN
 
+config RENESAS_RZA1_IRQC
+	bool
+	select IRQ_DOMAIN_HIERARCHY
+
 config ST_IRQCHIP
 	bool
 	select REGMAP
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 606a003a00002678..c629a8ab76b2d097 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_JCORE_AIC)			+= irq-jcore-aic.o
 obj-$(CONFIG_RDA_INTC)			+= irq-rda-intc.o
 obj-$(CONFIG_RENESAS_INTC_IRQPIN)	+= irq-renesas-intc-irqpin.o
 obj-$(CONFIG_RENESAS_IRQC)		+= irq-renesas-irqc.o
+obj-$(CONFIG_RENESAS_RZA1_IRQC)		+= irq-renesas-rza1.o
 obj-$(CONFIG_VERSATILE_FPGA_IRQ)	+= irq-versatile-fpga.o
 obj-$(CONFIG_ARCH_NSPIRE)		+= irq-zevio.o
 obj-$(CONFIG_ARCH_VT8500)		+= irq-vt8500.o
diff --git a/drivers/irqchip/irq-renesas-rza1.c b/drivers/irqchip/irq-renesas-rza1.c
new file mode 100644
index 0000000000000000..b1f19b210190184f
--- /dev/null
+++ b/drivers/irqchip/irq-renesas-rza1.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/A1 IRQC Driver
+ *
+ * Copyright (C) 2019 Glider bvba
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+#define IRQC_NUM_IRQ		8
+
+#define ICR0			0	/* Interrupt Control Register 0 */
+
+#define ICR0_NMIL		BIT(15)	/* NMI Input Level (0=low, 1=high) */
+#define ICR0_NMIE		BIT(8)	/* Edge Select (0=falling, 1=rising) */
+#define ICR0_NMIF		BIT(1)	/* NMI Interrupt Request */
+
+#define ICR1			2	/* Interrupt Control Register 1 */
+
+#define ICR1_IRQS(n, sense)	((sense) << ((n) * 2))	/* IRQ Sense Select */
+#define ICR1_IRQS_LEVEL_LOW	0
+#define ICR1_IRQS_EDGE_FALLING	1
+#define ICR1_IRQS_EDGE_RISING	2
+#define ICR1_IRQS_EDGE_BOTH	3
+#define ICR1_IRQS_MASK(n)	ICR1_IRQS((n), 3)
+
+#define IRQRR			4	/* IRQ Interrupt Request Register */
+
+
+struct rza1_irqc_priv {
+	struct device *dev;
+	void __iomem *base;
+	struct irq_chip chip;
+	struct irq_domain *irq_domain;
+	struct of_phandle_args map[IRQC_NUM_IRQ];
+};
+
+static struct rza1_irqc_priv *irq_data_to_priv(struct irq_data *data)
+{
+	return data->domain->host_data;
+}
+
+static void rza1_irqc_eoi(struct irq_data *d)
+{
+	struct rza1_irqc_priv *priv = irq_data_to_priv(d);
+	u16 bit = BIT(irqd_to_hwirq(d));
+	u16 tmp;
+
+	tmp = readw_relaxed(priv->base + IRQRR);
+	if (tmp & bit)
+		writew_relaxed(GENMASK(IRQC_NUM_IRQ - 1, 0) & ~bit,
+			       priv->base + IRQRR);
+
+	irq_chip_eoi_parent(d);
+}
+
+static int rza1_irqc_set_type(struct irq_data *d, unsigned int type)
+{
+	struct rza1_irqc_priv *priv = irq_data_to_priv(d);
+	unsigned int hw_irq = irqd_to_hwirq(d);
+	u16 sense, tmp;
+
+	switch (type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_LEVEL_LOW:
+		sense = ICR1_IRQS_LEVEL_LOW;
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		sense = ICR1_IRQS_EDGE_FALLING;
+		break;
+
+	case IRQ_TYPE_EDGE_RISING:
+		sense = ICR1_IRQS_EDGE_RISING;
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		sense = ICR1_IRQS_EDGE_BOTH;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	tmp = readw_relaxed(priv->base + ICR1);
+	tmp &= ~ICR1_IRQS_MASK(hw_irq);
+	tmp |= ICR1_IRQS(hw_irq, sense);
+	writew_relaxed(tmp, priv->base + ICR1);
+	return 0;
+}
+
+static int rza1_irqc_alloc(struct irq_domain *domain, unsigned int virq,
+			   unsigned int nr_irqs, void *arg)
+{
+	struct rza1_irqc_priv *priv = domain->host_data;
+	struct irq_fwspec *fwspec = arg;
+	unsigned int hwirq = fwspec->param[0];
+	struct irq_fwspec spec;
+	unsigned int i;
+	int ret;
+
+	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &priv->chip,
+					    priv);
+	if (ret)
+		return ret;
+
+	spec.fwnode = &priv->dev->of_node->fwnode;
+	spec.param_count = priv->map[hwirq].args_count;
+	for (i = 0; i < spec.param_count; i++)
+		spec.param[i] = priv->map[hwirq].args[i];
+
+	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &spec);
+}
+
+static int rza1_irqc_translate(struct irq_domain *domain,
+			       struct irq_fwspec *fwspec, unsigned long *hwirq,
+			       unsigned int *type)
+{
+	if (fwspec->param_count != 2 || fwspec->param[0] >= IRQC_NUM_IRQ)
+		return -EINVAL;
+
+	*hwirq = fwspec->param[0];
+	*type = fwspec->param[1];
+	return 0;
+}
+
+static const struct irq_domain_ops rza1_irqc_domain_ops = {
+	.alloc = rza1_irqc_alloc,
+	.translate = rza1_irqc_translate,
+};
+
+static int rza1_irqc_parse_map(struct rza1_irqc_priv *priv,
+			       struct device_node *gic_node)
+{
+	unsigned int imaplen, i, j, ret;
+	struct device *dev = priv->dev;
+	struct device_node *ipar;
+	const __be32 *imap;
+	u32 intsize;
+
+	imap = of_get_property(dev->of_node, "interrupt-map", &imaplen);
+	if (!imap)
+		return -EINVAL;
+
+	for (i = 0; i < IRQC_NUM_IRQ; i++) {
+		if (imaplen < 3)
+			return -EINVAL;
+
+		/* Check interrupt number, ignore sense */
+		if (be32_to_cpup(imap) != i)
+			return -EINVAL;
+
+		ipar = of_find_node_by_phandle(be32_to_cpup(imap + 2));
+		if (ipar != gic_node) {
+			of_node_put(ipar);
+			return -EINVAL;
+		}
+
+		imap += 3;
+		imaplen -= 3;
+
+		ret = of_property_read_u32(ipar, "#interrupt-cells", &intsize);
+		of_node_put(ipar);
+		if (ret)
+			return ret;
+
+		if (imaplen < intsize)
+			return -EINVAL;
+
+		priv->map[i].args_count = intsize;
+		for (j = 0; j < intsize; j++)
+			priv->map[i].args[j] = be32_to_cpup(imap++);
+
+		imaplen -= intsize;
+	}
+
+	return 0;
+}
+
+static int rza1_irqc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct irq_domain *parent = NULL;
+	struct device_node *gic_node;
+	struct rza1_irqc_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+	priv->dev = dev;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	gic_node = of_irq_find_parent(np);
+	if (gic_node) {
+		parent = irq_find_host(gic_node);
+		of_node_put(gic_node);
+	}
+
+	if (!parent) {
+		dev_err(dev, "cannot find parent domain\n");
+		return -ENODEV;
+	}
+
+	ret = rza1_irqc_parse_map(priv, gic_node);
+	if (ret) {
+		dev_err(dev, "cannot parse %s: %d\n", "interrupt-map", ret);
+		return ret;
+	}
+
+	priv->chip.name = "rza1-irqc",
+	priv->chip.irq_mask = irq_chip_mask_parent,
+	priv->chip.irq_unmask = irq_chip_unmask_parent,
+	priv->chip.irq_eoi = rza1_irqc_eoi,
+	priv->chip.irq_retrigger = irq_chip_retrigger_hierarchy,
+	priv->chip.irq_set_type = rza1_irqc_set_type,
+	priv->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
+
+	priv->irq_domain = irq_domain_add_hierarchy(parent, 0, IRQC_NUM_IRQ,
+						    np, &rza1_irqc_domain_ops,
+						    priv);
+	if (!priv->irq_domain) {
+		dev_err(dev, "cannot initialize irq domain\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int rza1_irqc_remove(struct platform_device *pdev)
+{
+	struct rza1_irqc_priv *priv = platform_get_drvdata(pdev);
+
+	irq_domain_remove(priv->irq_domain);
+	return 0;
+}
+
+static const struct of_device_id rza1_irqc_dt_ids[] = {
+	{ .compatible = "renesas,rza1-irqc" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rza1_irqc_dt_ids);
+
+static struct platform_driver rza1_irqc_device_driver = {
+	.probe		= rza1_irqc_probe,
+	.remove		= rza1_irqc_remove,
+	.driver		= {
+		.name	= "renesas_rza1_irqc",
+		.of_match_table	= rza1_irqc_dt_ids,
+	}
+};
+
+static int __init rza1_irqc_init(void)
+{
+	return platform_driver_register(&rza1_irqc_device_driver);
+}
+postcore_initcall(rza1_irqc_init);
+
+static void __exit rza1_irqc_exit(void)
+{
+	platform_driver_unregister(&rza1_irqc_device_driver);
+}
+module_exit(rza1_irqc_exit);
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@xxxxxxxxx>");
+MODULE_DESCRIPTION("Renesas RZ/A1 IRQC Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1