INTx: phytium: Add Phytium INTx driver support

Driver for Phytium PCIe legacy INTx interrupt controller.

Signed-off-by: Chen Baozi <[email protected]>
Signed-off-by: Wang Yinfeng <[email protected]>
Signed-off-by: Tian Wei <[email protected]>

Documentation/devicetree/bindings/interrupt-controller/phytium,ixic.yaml

@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/phytium,ixic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Phytium INTx interrupt controller (IXIC)
+
+description: |
+  This is a pseudo interrupt controller to handle PCI legacy interrupt on
+  some Phytium SoCs, which sits between the PCI INTx devices and the GIC
+  and forwards the 4 INTx input signals to 4 adjacent GICv3 SPIs.
+
+
+maintainers:
+  - Chen Baozi <[email protected]>
+
+allOf:
+  - $ref: /schemas/interrupt-controller.yaml#
+
+properties:
+  compatible:
+    const: phytium,ixic
+
+  reg:
+    description: |
+      Specifies two regions of the register set, which are called
+      'ctr' and 'hpb'
+    minItems: 2
+    maxItems: 2
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    description: |
+      Specifies the number of cells needed to encode an interrupt source.
+    const: 3
+
+  intx-spi-base:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      The SPI number of the first SPI of the 4 adjacent ones the IXIC
+      forwards its interrupts to.
+
+required:
+  - compatible
+  - reg
+  - interrupt-controller
+  - '#interrupt-cells'
+  - intx-spi-base
+
+additionalProperties: false
+
+examples:
+  - |
+    ixic: interrupt-controller@29000000 {
+      compatible = "phytium,ixic";
+      reg-names = "ctr", "hpb";
+      reg = <0x0 0x29000000 0x0 0x00060000>,
+            <0x0 0x29100000 0x0 0x00002000>;
+      interrupt-controller;
+      interrupt-parent = <&gic>;
+      #interrupt-cells = <3>;
+      intx-spi-base = <28>;
+    };

drivers/irqchip/Kconfig

@@ -679,4 +679,12 @@ config SUNPLUS_SP7021_INTC
 	  chained controller, routing all interrupt source in P-Chip to
 	  the primary controller on C-Chip.
 
+config PHYTIUM_IXIC
+	bool "Phytium SoC PCI Legacy Interrupt Controller"
+	depends on ARCH_PHYTIUM
+	select IRQ_DOMAIN
+	select IRQ_DOMAIN_HIERARCHY
+	help
+	  This enables support PCI Legacy Interrupt on Phytium SoC.
+
 endmenu

drivers/irqchip/Makefile

@@ -120,3 +120,4 @@ 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_SUNPLUS_SP7021_INTC)	+= irq-sp7021-intc.o
+obj-$(CONFIG_PHYTIUM_IXIC)		+= irq-phytium-ixic.o

drivers/irqchip/irq-phytium-ixic.c

@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Phytium PCIe legacy INTx interrupt controller
+ *
+ * Copyright (c) 2020-2023, Phytium Technology Co., Ltd.
+ */
+
+#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		4
+
+#define CTR_BANK_NUM		6
+#define CTR_BANK_SIZE		0x10000
+#define CTR_BANK_ISTATUS_LOCAL	0x184
+
+#define HPB_INTX_STATUS_0	0x0
+#define HPB_INTX_STATUS_1	0x1000
+
+struct ixic_irq_data {
+	void __iomem *ctr;
+	void __iomem *hpb;
+	u32 spi_base;
+};
+
+static void phytium_ixic_irq_eoi(struct irq_data *d)
+{
+	struct ixic_irq_data *data = irq_data_get_irq_chip_data(d);
+	unsigned int intx = irqd_to_hwirq(d);
+	u32 gstatus = readl(data->hpb) | (readl(data->hpb + HPB_INTX_STATUS_1) << 12);
+	u32 imask, istatus;
+	int i;
+
+	WARN_ON(intx >= NUM_IRQS);
+	imask = 1 << (3 - intx);
+	istatus = (1 << intx) << 24;
+	for (i = 0; i < CTR_BANK_NUM; i++, gstatus >>= 4) {
+		if (gstatus & imask)
+			writel(istatus, data->ctr + CTR_BANK_SIZE*i + CTR_BANK_ISTATUS_LOCAL);
+	}
+
+	irq_chip_eoi_parent(d);
+}
+
+static struct irq_chip phytium_ixic_irq_chip = {
+	.name = "IXIU",
+	.irq_eoi = phytium_ixic_irq_eoi,
+	.irq_mask = irq_chip_mask_parent,
+	.irq_unmask = irq_chip_unmask_parent,
+	.irq_set_type = irq_chip_set_type_parent,
+	.irq_set_affinity = irq_chip_set_affinity_parent,
+	.flags = IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int phytium_ixic_translate(struct irq_domain *domain,
+				  struct irq_fwspec *fwspec,
+				  unsigned long *hwirq,
+				  unsigned int *type)
+{
+	struct ixic_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] - info->spi_base;
+		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+	}
+
+	return 0;
+}
+
+static int phytium_ixic_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 ixic_irq_data *info = dom->host_data;
+	irq_hw_number_t hwirq;
+
+	/* We assume the device use the parent's format directly */
+	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 */
+
+		/* Get the local hwirq of IXIC */
+		hwirq = fwspec->param[1] - info->spi_base;
+	} else {
+		hwirq = fwspec->param[0] - info->spi_base;
+	}
+	WARN_ON(nr_irqs != 1);
+	irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &phytium_ixic_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 ixic_domain_ops = {
+	.translate = phytium_ixic_translate,
+	.alloc	= phytium_ixic_alloc,
+	.free	= irq_domain_free_irqs_common,
+};
+
+static struct ixic_irq_data *phytium_ixic_init(const struct fwnode_handle *fwnode,
+					      struct resource *ctr, struct resource *hpb)
+{
+	struct ixic_irq_data *data;
+	int err;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+
+	if (fwnode_property_read_u32_array(fwnode, "intx-spi-base",
+					   &data->spi_base, 1)) {
+		err = -ENODEV;
+		goto out_free;
+	}
+
+	data->ctr = ioremap(ctr->start, resource_size(ctr));
+	if (!data->ctr) {
+		err = -ENODEV;
+		goto out_free;
+	}
+
+	data->hpb = ioremap(hpb->start, resource_size(hpb));
+	if (!data->hpb) {
+		err = -ENODEV;
+		goto out_free;
+	}
+
+	return data;
+
+out_free:
+	kfree(data);
+	return ERR_PTR(err);
+}
+
+static int __init phytium_ixic_dt_init(struct device_node *node,
+				   struct device_node *parent)
+{
+	struct irq_domain *pd, *d;
+	struct ixic_irq_data *data;
+	struct resource ctr, hpb;
+
+	if (!parent) {
+		pr_err("%pOF: no parent, giving up\n", node);
+		return -ENODEV;
+	}
+
+	pd = irq_find_host(parent);
+	if (!pd) {
+		pr_err("%pOF: unable to obtain parent domain\n", node);
+		return -ENXIO;
+	}
+
+	if (of_address_to_resource(node, 0, &ctr)) {
+		pr_err("%pOF: failed to parse 'ctr' memory resource\n", node);
+		return -ENXIO;
+	}
+
+	if (of_address_to_resource(node, 1, &hpb)) {
+		pr_err("%pOF: failed to parse 'hpb' memory resource\n", node);
+		return -ENXIO;
+	}
+
+	data = phytium_ixic_init(of_node_to_fwnode(node), &ctr, &hpb);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	d = irq_domain_add_hierarchy(pd, 0, NUM_IRQS, node, &ixic_domain_ops, data);
+	if (!d) {
+		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->ctr);
+	iounmap(data->hpb);
+	kfree(data);
+	return -ENOMEM;
+}
+IRQCHIP_DECLARE(ixic, "phytium,ixic", phytium_ixic_dt_init);
+
+#ifdef CONFIG_ACPI
+static int phytium_ixic_acpi_probe(struct platform_device *pdev)
+{
+	struct irq_domain *domain;
+	struct ixic_irq_data *data;
+	struct resource *ctr, *hpb;
+
+	ctr = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!ctr) {
+		dev_err(&pdev->dev, "failed to parse 'ctr' memory resource\n");
+		return -ENXIO;
+	}
+
+	hpb = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!hpb) {
+		dev_err(&pdev->dev, "failed to parse 'hpb' memory resource\n");
+		return -ENXIO;
+	}
+
+	data = phytium_ixic_init(dev_fwnode(&pdev->dev), ctr, hpb);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	domain = acpi_irq_create_hierarchy(0, NUM_IRQS, dev_fwnode(&pdev->dev),
+					   &ixic_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->ctr);
+	iounmap(data->hpb);
+	kfree(data);
+	return -ENOMEM;
+}
+
+static const struct acpi_device_id phytium_ixic_acpi_ids[] = {
+	{ "PHYT0013" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, phytium_ixic_acpi_ids);
+
+static struct platform_driver phytium_ixic_driver = {
+	.driver = {
+		.name = "phytium-ixic",
+		.acpi_match_table = phytium_ixic_acpi_ids,
+	},
+	.probe = phytium_ixic_acpi_probe,
+};
+builtin_platform_driver(phytium_ixic_driver);
+#endif