1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-sni-exiu.c b/drivers/irqchip/irq-sni-exiu.c
new file mode 100644
index 000000000..c7db617e1
--- /dev/null
+++ b/drivers/irqchip/irq-sni-exiu.c
@@ -0,0 +1,323 @@
+// 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