[RFC PATCH v2 16/31] irqchip: Add irq-kvx-itgen driver

[Yann Sionneau <ysionneau@kalray.eu>]

From: Jules Maselbas <jmaselbas@kalray.eu>

The Kalray Core Interrupt Controller is tightly integrated in each kv3
core present in the Coolidge SoC.

It provides the following features:
 - 32 independent interrupt sources
 - 2-bit configurable priority level
 - 2-bit configurable ownership level

Co-developed-by: Clement Leger <clement@clement-leger.fr>
Signed-off-by: Clement Leger <clement@clement-leger.fr>
Co-developed-by: Julian Vetter <jvetter@kalray.eu>
Signed-off-by: Julian Vetter <jvetter@kalray.eu>
Co-developed-by: Vincent Chardon <vincent.chardon@elsys-design.com>
Signed-off-by: Vincent Chardon <vincent.chardon@elsys-design.com>
Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
---

Notes:
    V1 -> V2: new patch
     - removed header include/linux/irqchip/irq-kvx-apic-gic.h
     - header moved to drivers/irqchip/ but in another patch
     - removed print on probe success

 drivers/irqchip/Kconfig         |   8 ++
 drivers/irqchip/Makefile        |   1 +
 drivers/irqchip/irq-kvx-itgen.c | 236 ++++++++++++++++++++++++++++++++
 3 files changed, 245 insertions(+)
 create mode 100644 drivers/irqchip/irq-kvx-itgen.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 2433e4ba0759..546bc611f3f3 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -340,6 +340,14 @@ config KVX_APIC_GIC
 	select IRQ_DOMAIN
 	select IRQ_DOMAIN_HIERARCHY
 
+config KVX_ITGEN
+	bool
+	depends on KVX
+	select GENERIC_IRQ_IPI if SMP
+	select GENERIC_MSI_IRQ_DOMAIN
+	select IRQ_DOMAIN
+	select IRQ_DOMAIN_HIERARCHY
+
 config INGENIC_IRQ
 	bool
 	depends on MACH_INGENIC
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 8ac1dd880420..6b8f459d8a21 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o
 obj-$(CONFIG_KEYSTONE_IRQ)		+= irq-keystone.o
 obj-$(CONFIG_MIPS_GIC)			+= irq-mips-gic.o
 obj-$(CONFIG_KVX_APIC_GIC)		+= irq-kvx-apic-gic.o
+obj-$(CONFIG_KVX_ITGEN)			+= irq-kvx-itgen.o
 obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mtk-sysirq.o irq-mtk-cirq.o
 obj-$(CONFIG_ARCH_DIGICOLOR)		+= irq-digicolor.o
 obj-$(CONFIG_ARCH_SA1100)		+= irq-sa11x0.o
diff --git a/drivers/irqchip/irq-kvx-itgen.c b/drivers/irqchip/irq-kvx-itgen.c
new file mode 100644
index 000000000000..f6af023a689e
--- /dev/null
+++ b/drivers/irqchip/irq-kvx-itgen.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ *            Julian Vetter
+ *            Vincent Chardon
+ */
+
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+
+/* Parameters */
+#define KVX_ITGEN_PARAM_OFFSET			0x1100
+#define KVX_ITGEN_PARAM_IT_NUM_OFFSET		0x0
+
+/* Target configuration */
+#define KVX_ITGEN_CFG_ENABLE_OFFSET		0x8
+#define KVX_ITGEN_CFG_ELEM_SIZE		0x10
+#define KVX_ITGEN_CFG_TARGET_OFFSET		0x0
+#define KVX_ITGEN_CFG_TARGET_MAILBOX_SHIFT	0x0
+#define KVX_ITGEN_CFG_TARGET_MAILBOX_MASK	0x7FUL
+#define KVX_ITGEN_CFG_TARGET_CLUSTER_SHIFT	0x8
+#define KVX_ITGEN_CFG_TARGET_CLUSTER_MASK	0x700UL
+#define KVX_ITGEN_CFG_TARGET_SELECT_BIT_SHIFT	0x18
+#define KVX_ITGEN_CFG_TARGET_SELECT_BIT_MASK	0x3F000000UL
+
+#define MB_ADDR_CLUSTER_SHIFT	24
+#define MB_ADDR_MAILBOX_SHIFT	9
+
+/**
+ * struct kvx_itgen - kvx interrupt generator (MSI client)
+ * @base: base address of the itgen controller
+ * @domain: IRQ domain of the controller
+ * @pdev: Platform device associated to the controller
+ */
+struct kvx_itgen {
+	void __iomem *base;
+	struct irq_domain *domain;
+	struct platform_device *pdev;
+};
+
+static void __iomem *get_itgen_cfg_offset(struct kvx_itgen *itgen,
+						irq_hw_number_t hwirq)
+{
+	return itgen->base + KVX_ITGEN_CFG_TARGET_OFFSET +
+				hwirq * KVX_ITGEN_CFG_ELEM_SIZE;
+}
+
+void __iomem *get_itgen_param_offset(struct kvx_itgen *itgen)
+{
+	return itgen->base + KVX_ITGEN_PARAM_OFFSET;
+}
+
+static void kvx_itgen_enable(struct irq_data *data, u32 value)
+{
+	struct kvx_itgen *itgen = irq_data_get_irq_chip_data(data);
+	void __iomem *enable_reg =
+		get_itgen_cfg_offset(itgen, irqd_to_hwirq(data)) +
+		KVX_ITGEN_CFG_ENABLE_OFFSET;
+
+	dev_dbg(&itgen->pdev->dev, "%sabling hwirq %d, addr %p\n",
+		 value ? "En" : "Dis",
+		 (int) irqd_to_hwirq(data),
+		 enable_reg);
+	writel(value, enable_reg);
+}
+
+static void kvx_itgen_mask(struct irq_data *data)
+{
+	kvx_itgen_enable(data, 0x0);
+	irq_chip_mask_parent(data);
+}
+
+static void kvx_itgen_unmask(struct irq_data *data)
+{
+	kvx_itgen_enable(data, 0x1);
+	irq_chip_unmask_parent(data);
+}
+
+#ifdef CONFIG_SMP
+static int kvx_itgen_irq_set_affinity(struct irq_data *data,
+				      const struct cpumask *dest, bool force)
+{
+	return -ENOSYS;
+}
+#endif
+
+static struct irq_chip itgen_irq_chip = {
+	.name =			"kvx-itgen",
+	.irq_mask =		kvx_itgen_mask,
+	.irq_unmask =		kvx_itgen_unmask,
+#ifdef CONFIG_SMP
+	.irq_set_affinity =	kvx_itgen_irq_set_affinity,
+#endif
+};
+
+#define ITGEN_UNSUPPORTED_TYPES (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING)
+
+static int kvx_itgen_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				   unsigned int nr_irqs, void *args)
+{
+	int i, err;
+	struct irq_fwspec *fwspec = args;
+	int hwirq = fwspec->param[0];
+	int type = IRQ_TYPE_NONE;
+	struct kvx_itgen *itgen;
+
+	if (fwspec->param_count >= 2)
+		type = fwspec->param[1];
+
+	WARN_ON(type & ITGEN_UNSUPPORTED_TYPES);
+
+	err = platform_msi_device_domain_alloc(domain, virq, nr_irqs);
+	if (err)
+		return err;
+
+	itgen = platform_msi_get_host_data(domain);
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+				      &itgen_irq_chip, itgen);
+		if (type == IRQ_TYPE_LEVEL_HIGH)
+			irq_set_handler(virq + i, handle_level_irq);
+	}
+
+	return 0;
+}
+
+static const struct irq_domain_ops itgen_domain_ops = {
+	.alloc		= kvx_itgen_domain_alloc,
+	.free		= irq_domain_free_irqs_common,
+};
+
+static void kvx_itgen_write_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+	struct irq_data *d = irq_get_irq_data(desc->irq);
+	struct kvx_itgen *itgen = irq_data_get_irq_chip_data(d);
+	uint32_t cfg_val = 0;
+	uintptr_t dest_addr = ((uint64_t) msg->address_hi << 32) |
+							msg->address_lo;
+	void __iomem *cfg = get_itgen_cfg_offset(itgen, irqd_to_hwirq(d));
+
+	/*
+	 * Address in the msi data is the address of the targeted mailbox.
+	 * To save a few cells of hw, itgen configuration expects the target
+	 * of the write using mppa id, cluster id and mailbox id instead
+	 * of address.
+	 * We extract these informations from the mailbox address.
+	 */
+
+	cfg_val |= (((kvx_sfr_get(PCR) & KVX_SFR_PCR_CID_MASK) >>
+				 KVX_SFR_PCR_CID_SHIFT)
+				<< KVX_ITGEN_CFG_TARGET_CLUSTER_SHIFT);
+	cfg_val |= ((dest_addr >> MB_ADDR_MAILBOX_SHIFT) &
+		     KVX_ITGEN_CFG_TARGET_MAILBOX_MASK)
+		    << KVX_ITGEN_CFG_TARGET_MAILBOX_SHIFT;
+
+	/*
+	 * msg->data contains the bit number to be written and is included in
+	 * the itgen config
+	 */
+	cfg_val |= ((msg->data << KVX_ITGEN_CFG_TARGET_SELECT_BIT_SHIFT)
+		    & KVX_ITGEN_CFG_TARGET_SELECT_BIT_MASK);
+
+	dev_dbg(&itgen->pdev->dev,
+		"Writing dest_addr %lx, value %x to cfg %p\n",
+		dest_addr, cfg_val, cfg);
+
+	writel(cfg_val, cfg);
+}
+
+static int
+kvx_itgen_device_probe(struct platform_device *pdev)
+{
+	struct kvx_itgen *itgen;
+	u32 it_count;
+	struct resource *mem;
+
+	itgen = devm_kzalloc(&pdev->dev, sizeof(*itgen), GFP_KERNEL);
+	if (!itgen)
+		return -ENOMEM;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	itgen->base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(itgen->base)) {
+		dev_err(&pdev->dev, "Failed to ioremap itgen\n");
+		return PTR_ERR(itgen->base);
+	}
+
+	itgen->pdev = pdev;
+	it_count = readl(get_itgen_param_offset(itgen) +
+				KVX_ITGEN_PARAM_IT_NUM_OFFSET);
+
+	itgen->domain = platform_msi_create_device_domain(&pdev->dev,
+						   it_count,
+						   kvx_itgen_write_msg,
+						   &itgen_domain_ops,
+						   itgen);
+	if (!itgen->domain) {
+		dev_err(&pdev->dev, "Failed to create device domain\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, itgen);
+
+	return 0;
+}
+
+static const struct of_device_id itgen_of_match[] = {
+	{ .compatible = "kalray,kvx-itgen" },
+	{ /* END */ }
+};
+MODULE_DEVICE_TABLE(of, itgen_of_match);
+
+static struct platform_driver itgen_platform_driver = {
+	.driver = {
+		.name		= "kvx-itgen",
+		.of_match_table	= itgen_of_match,
+	},
+	.probe			= kvx_itgen_device_probe,
+};
+
+static int __init kvx_itgen_init(void)
+{
+	return platform_driver_register(&itgen_platform_driver);
+}
+
+arch_initcall(kvx_itgen_init);
-- 
2.37.2