Merge tag 'irqchip-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier:

 - A new driver for the FSL MU widget that provides platform MSI

 - An update for the Realtek RTL irqchip to use a DT binding that
   actually describes the hardware

 - A handful of DT updates, as well as minor code and spelling fixes

Link: https://lore.kernel.org/r/20221002125554.3902840-1-maz@kernel.org

6 files changed, 532 insertions, 75 deletions

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 296ea673d661..12b044151298 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -138,6 +138,7 @@ struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
 
 	return domain;
 }
+EXPORT_SYMBOL_GPL(platform_msi_create_irq_domain);
 
 static int platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
 					irq_write_msi_msg_t write_msi_msg)
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 66b9fa408bf2..4d85a1870c43 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -3,7 +3,7 @@ menu "IRQ chip support"
 
 config IRQCHIP
 	def_bool y
-	depends on OF_IRQ
+	depends on (OF_IRQ || ACPI_GENERIC_GSI)
 
 config ARM_GIC
 	bool
@@ -481,6 +481,20 @@ config IMX_INTMUX
 	help
 	  Support for the i.MX INTMUX interrupt multiplexer.
 
+config IMX_MU_MSI
+	tristate "i.MX MU used as MSI controller"
+	depends on OF && HAS_IOMEM
+	default m if ARCH_MXC
+	select IRQ_DOMAIN
+	select IRQ_DOMAIN_HIERARCHY
+	select GENERIC_MSI_IRQ_DOMAIN
+	help
+	  Provide a driver for the MU block used as a CPU-to-CPU MSI
+	  controller. This requires a specially crafted DT to make use
+	  of this driver.
+
+	  If unsure, say N
+
 config LS1X_IRQ
 	bool "Loongson-1 Interrupt Controller"
 	depends on MACH_LOONGSON32
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b6acbca2248b..87b49a10962c 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -99,6 +99,7 @@ obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
 obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
+obj-$(CONFIG_IMX_MU_MSI)		+= irq-imx-mu-msi.o
 obj-$(CONFIG_MADERA_IRQ)		+= irq-madera.o
 obj-$(CONFIG_LS1X_IRQ)			+= irq-ls1x.o
 obj-$(CONFIG_TI_SCI_INTR_IRQCHIP)	+= irq-ti-sci-intr.o
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 262658fd5f9e..34d58567b78d 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -978,7 +978,7 @@ static int __gic_update_rdist_properties(struct redist_region *region,
 	u64 typer = gic_read_typer(ptr + GICR_TYPER);
 	u32 ctlr = readl_relaxed(ptr + GICR_CTLR);
 
-	/* Boot-time cleanip */
+	/* Boot-time cleanup */
 	if ((typer & GICR_TYPER_VLPIS) && (typer & GICR_TYPER_RVPEID)) {
 		u64 val;
 
diff --git a/drivers/irqchip/irq-imx-mu-msi.c b/drivers/irqchip/irq-imx-mu-msi.c
new file mode 100644
index 000000000000..b62139dc36e8
--- /dev/null
+++ b/drivers/irqchip/irq-imx-mu-msi.c
@@ -0,0 +1,453 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Freescale MU used as MSI controller
+ *
+ * Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de>
+ * Copyright 2022 NXP
+ *	Frank Li <Frank.Li@nxp.com>
+ *	Peng Fan <peng.fan@nxp.com>
+ *
+ * Based on drivers/mailbox/imx-mailbox.c
+ */
+
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/spinlock.h>
+
+#define IMX_MU_CHANS            4
+
+enum imx_mu_xcr {
+	IMX_MU_GIER,
+	IMX_MU_GCR,
+	IMX_MU_TCR,
+	IMX_MU_RCR,
+	IMX_MU_xCR_MAX,
+};
+
+enum imx_mu_xsr {
+	IMX_MU_SR,
+	IMX_MU_GSR,
+	IMX_MU_TSR,
+	IMX_MU_RSR,
+	IMX_MU_xSR_MAX
+};
+
+enum imx_mu_type {
+	IMX_MU_V2 = BIT(1),
+};
+
+/* Receive Interrupt Enable */
+#define IMX_MU_xCR_RIEn(data, x) ((data->cfg->type) & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
+#define IMX_MU_xSR_RFn(data, x) ((data->cfg->type) & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
+
+struct imx_mu_dcfg {
+	enum imx_mu_type type;
+	u32     xTR;            /* Transmit Register0 */
+	u32     xRR;            /* Receive Register0 */
+	u32     xSR[IMX_MU_xSR_MAX];         /* Status Registers */
+	u32     xCR[IMX_MU_xCR_MAX];         /* Control Registers */
+};
+
+struct imx_mu_msi {
+	raw_spinlock_t			lock;
+	struct irq_domain		*msi_domain;
+	void __iomem			*regs;
+	phys_addr_t			msiir_addr;
+	const struct imx_mu_dcfg	*cfg;
+	unsigned long			used;
+	struct clk			*clk;
+};
+
+static void imx_mu_write(struct imx_mu_msi *msi_data, u32 val, u32 offs)
+{
+	iowrite32(val, msi_data->regs + offs);
+}
+
+static u32 imx_mu_read(struct imx_mu_msi *msi_data, u32 offs)
+{
+	return ioread32(msi_data->regs + offs);
+}
+
+static u32 imx_mu_xcr_rmw(struct imx_mu_msi *msi_data, enum imx_mu_xcr type, u32 set, u32 clr)
+{
+	unsigned long flags;
+	u32 val;
+
+	raw_spin_lock_irqsave(&msi_data->lock, flags);
+	val = imx_mu_read(msi_data, msi_data->cfg->xCR[type]);
+	val &= ~clr;
+	val |= set;
+	imx_mu_write(msi_data, val, msi_data->cfg->xCR[type]);
+	raw_spin_unlock_irqrestore(&msi_data->lock, flags);
+
+	return val;
+}
+
+static void imx_mu_msi_parent_mask_irq(struct irq_data *data)
+{
+	struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+
+	imx_mu_xcr_rmw(msi_data, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(msi_data, data->hwirq));
+}
+
+static void imx_mu_msi_parent_unmask_irq(struct irq_data *data)
+{
+	struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+
+	imx_mu_xcr_rmw(msi_data, IMX_MU_RCR, IMX_MU_xCR_RIEn(msi_data, data->hwirq), 0);
+}
+
+static void imx_mu_msi_parent_ack_irq(struct irq_data *data)
+{
+	struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+
+	imx_mu_read(msi_data, msi_data->cfg->xRR + data->hwirq * 4);
+}
+
+static struct irq_chip imx_mu_msi_irq_chip = {
+	.name = "MU-MSI",
+	.irq_ack = irq_chip_ack_parent,
+};
+
+static struct msi_domain_ops imx_mu_msi_irq_ops = {
+};
+
+static struct msi_domain_info imx_mu_msi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+	.ops	= &imx_mu_msi_irq_ops,
+	.chip	= &imx_mu_msi_irq_chip,
+};
+
+static void imx_mu_msi_parent_compose_msg(struct irq_data *data,
+					  struct msi_msg *msg)
+{
+	struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+	u64 addr = msi_data->msiir_addr + 4 * data->hwirq;
+
+	msg->address_hi = upper_32_bits(addr);
+	msg->address_lo = lower_32_bits(addr);
+	msg->data = data->hwirq;
+}
+
+static int imx_mu_msi_parent_set_affinity(struct irq_data *irq_data,
+				   const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
+}
+
+static struct irq_chip imx_mu_msi_parent_chip = {
+	.name		= "MU",
+	.irq_mask	= imx_mu_msi_parent_mask_irq,
+	.irq_unmask	= imx_mu_msi_parent_unmask_irq,
+	.irq_ack	= imx_mu_msi_parent_ack_irq,
+	.irq_compose_msi_msg	= imx_mu_msi_parent_compose_msg,
+	.irq_set_affinity = imx_mu_msi_parent_set_affinity,
+};
+
+static int imx_mu_msi_domain_irq_alloc(struct irq_domain *domain,
+					unsigned int virq,
+					unsigned int nr_irqs,
+					void *args)
+{
+	struct imx_mu_msi *msi_data = domain->host_data;
+	unsigned long flags;
+	int pos, err = 0;
+
+	WARN_ON(nr_irqs != 1);
+
+	raw_spin_lock_irqsave(&msi_data->lock, flags);
+	pos = find_first_zero_bit(&msi_data->used, IMX_MU_CHANS);
+	if (pos < IMX_MU_CHANS)
+		__set_bit(pos, &msi_data->used);
+	else
+		err = -ENOSPC;
+	raw_spin_unlock_irqrestore(&msi_data->lock, flags);
+
+	if (err)
+		return err;
+
+	irq_domain_set_info(domain, virq, pos,
+			    &imx_mu_msi_parent_chip, msi_data,
+			    handle_edge_irq, NULL, NULL);
+	return 0;
+}
+
+static void imx_mu_msi_domain_irq_free(struct irq_domain *domain,
+				       unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+	struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(d);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&msi_data->lock, flags);
+	__clear_bit(d->hwirq, &msi_data->used);
+	raw_spin_unlock_irqrestore(&msi_data->lock, flags);
+}
+
+static const struct irq_domain_ops imx_mu_msi_domain_ops = {
+	.alloc	= imx_mu_msi_domain_irq_alloc,
+	.free	= imx_mu_msi_domain_irq_free,
+};
+
+static void imx_mu_msi_irq_handler(struct irq_desc *desc)
+{
+	struct imx_mu_msi *msi_data = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 status;
+	int i;
+
+	status = imx_mu_read(msi_data, msi_data->cfg->xSR[IMX_MU_RSR]);
+
+	chained_irq_enter(chip, desc);
+	for (i = 0; i < IMX_MU_CHANS; i++) {
+		if (status & IMX_MU_xSR_RFn(msi_data, i))
+			generic_handle_domain_irq(msi_data->msi_domain, i);
+	}
+	chained_irq_exit(chip, desc);
+}
+
+static int imx_mu_msi_domains_init(struct imx_mu_msi *msi_data, struct device *dev)
+{
+	struct fwnode_handle *fwnodes = dev_fwnode(dev);
+	struct irq_domain *parent;
+
+	/* Initialize MSI domain parent */
+	parent = irq_domain_create_linear(fwnodes,
+					    IMX_MU_CHANS,
+					    &imx_mu_msi_domain_ops,
+					    msi_data);
+	if (!parent) {
+		dev_err(dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
+
+	msi_data->msi_domain = platform_msi_create_irq_domain(fwnodes,
+					&imx_mu_msi_domain_info,
+					parent);
+
+	if (!msi_data->msi_domain) {
+		dev_err(dev, "failed to create MSI domain\n");
+		irq_domain_remove(parent);
+		return -ENOMEM;
+	}
+
+	irq_domain_set_pm_device(msi_data->msi_domain, dev);
+
+	return 0;
+}
+
+/* Register offset of different version MU IP */
+static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
+	.type	= 0,
+	.xTR    = 0x0,
+	.xRR    = 0x10,
+	.xSR    = {
+			[IMX_MU_SR]  = 0x20,
+			[IMX_MU_GSR] = 0x20,
+			[IMX_MU_TSR] = 0x20,
+			[IMX_MU_RSR] = 0x20,
+		  },
+	.xCR    = {
+			[IMX_MU_GIER] = 0x24,
+			[IMX_MU_GCR]  = 0x24,
+			[IMX_MU_TCR]  = 0x24,
+			[IMX_MU_RCR]  = 0x24,
+		  },
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
+	.type	= 0,
+	.xTR    = 0x20,
+	.xRR    = 0x40,
+	.xSR    = {
+			[IMX_MU_SR]  = 0x60,
+			[IMX_MU_GSR] = 0x60,
+			[IMX_MU_TSR] = 0x60,
+			[IMX_MU_RSR] = 0x60,
+		  },
+	.xCR    = {
+			[IMX_MU_GIER] = 0x64,
+			[IMX_MU_GCR]  = 0x64,
+			[IMX_MU_TCR]  = 0x64,
+			[IMX_MU_RCR]  = 0x64,
+		  },
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
+	.type   = IMX_MU_V2,
+	.xTR    = 0x200,
+	.xRR    = 0x280,
+	.xSR    = {
+			[IMX_MU_SR]  = 0xC,
+			[IMX_MU_GSR] = 0x118,
+			[IMX_MU_GSR] = 0x124,
+			[IMX_MU_RSR] = 0x12C,
+		  },
+	.xCR    = {
+			[IMX_MU_GIER] = 0x110,
+			[IMX_MU_GCR]  = 0x114,
+			[IMX_MU_TCR]  = 0x120,
+			[IMX_MU_RCR]  = 0x128
+		  },
+};
+
+static int __init imx_mu_of_init(struct device_node *dn,
+				 struct device_node *parent,
+				 const struct imx_mu_dcfg *cfg)
+{
+	struct platform_device *pdev = of_find_device_by_node(dn);
+	struct device_link *pd_link_a;
+	struct device_link *pd_link_b;
+	struct imx_mu_msi *msi_data;
+	struct resource *res;
+	struct device *pd_a;
+	struct device *pd_b;
+	struct device *dev;
+	int ret;
+	int irq;
+
+	dev = &pdev->dev;
+
+	msi_data = devm_kzalloc(&pdev->dev, sizeof(*msi_data), GFP_KERNEL);
+	if (!msi_data)
+		return -ENOMEM;
+
+	msi_data->cfg = cfg;
+
+	msi_data->regs = devm_platform_ioremap_resource_byname(pdev, "processor-a-side");
+	if (IS_ERR(msi_data->regs)) {
+		dev_err(&pdev->dev, "failed to initialize 'regs'\n");
+		return PTR_ERR(msi_data->regs);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "processor-b-side");
+	if (!res)
+		return -EIO;
+
+	msi_data->msiir_addr = res->start + msi_data->cfg->xTR;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0)
+		return -ENODEV;
+
+	platform_set_drvdata(pdev, msi_data);
+
+	msi_data->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(msi_data->clk))
+		return PTR_ERR(msi_data->clk);
+
+	pd_a = dev_pm_domain_attach_by_name(dev, "processor-a-side");
+	if (IS_ERR(pd_a))
+		return PTR_ERR(pd_a);
+
+	pd_b = dev_pm_domain_attach_by_name(dev, "processor-b-side");
+	if (IS_ERR(pd_b))
+		return PTR_ERR(pd_b);
+
+	pd_link_a = device_link_add(dev, pd_a,
+			DL_FLAG_STATELESS |
+			DL_FLAG_PM_RUNTIME |
+			DL_FLAG_RPM_ACTIVE);
+
+	if (!pd_link_a) {
+		dev_err(dev, "Failed to add device_link to mu a.\n");
+		goto err_pd_a;
+	}
+
+	pd_link_b = device_link_add(dev, pd_b,
+			DL_FLAG_STATELESS |
+			DL_FLAG_PM_RUNTIME |
+			DL_FLAG_RPM_ACTIVE);
+
+
+	if (!pd_link_b) {
+		dev_err(dev, "Failed to add device_link to mu a.\n");
+		goto err_pd_b;
+	}
+
+	ret = imx_mu_msi_domains_init(msi_data, dev);
+	if (ret)
+		goto err_dm_init;
+
+	pm_runtime_enable(dev);
+
+	irq_set_chained_handler_and_data(irq,
+					 imx_mu_msi_irq_handler,
+					 msi_data);
+
+	return 0;
+
+err_dm_init:
+	device_link_remove(dev,	pd_b);
+err_pd_b:
+	device_link_remove(dev, pd_a);
+err_pd_a:
+	return -EINVAL;
+}
+
+static int __maybe_unused imx_mu_runtime_suspend(struct device *dev)
+{
+	struct imx_mu_msi *priv = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int __maybe_unused imx_mu_runtime_resume(struct device *dev)
+{
+	struct imx_mu_msi *priv = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		dev_err(dev, "failed to enable clock\n");
+
+	return ret;
+}
+
+static const struct dev_pm_ops imx_mu_pm_ops = {
+	SET_RUNTIME_PM_OPS(imx_mu_runtime_suspend,
+			   imx_mu_runtime_resume, NULL)
+};
+
+static int __init imx_mu_imx7ulp_of_init(struct device_node *dn,
+					 struct device_node *parent)
+{
+	return imx_mu_of_init(dn, parent, &imx_mu_cfg_imx7ulp);
+}
+
+static int __init imx_mu_imx6sx_of_init(struct device_node *dn,
+					struct device_node *parent)
+{
+	return imx_mu_of_init(dn, parent, &imx_mu_cfg_imx6sx);
+}
+
+static int __init imx_mu_imx8ulp_of_init(struct device_node *dn,
+					 struct device_node *parent)
+{
+	return imx_mu_of_init(dn, parent, &imx_mu_cfg_imx8ulp);
+}
+
+IRQCHIP_PLATFORM_DRIVER_BEGIN(imx_mu_msi)
+IRQCHIP_MATCH("fsl,imx7ulp-mu-msi", imx_mu_imx7ulp_of_init)
+IRQCHIP_MATCH("fsl,imx6sx-mu-msi", imx_mu_imx6sx_of_init)
+IRQCHIP_MATCH("fsl,imx8ulp-mu-msi", imx_mu_imx8ulp_of_init)
+IRQCHIP_PLATFORM_DRIVER_END(imx_mu_msi, .pm = &imx_mu_pm_ops)
+
+
+MODULE_AUTHOR("Frank Li <Frank.Li@nxp.com>");
+MODULE_DESCRIPTION("Freescale MU MSI controller driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/irqchip/irq-realtek-rtl.c b/drivers/irqchip/irq-realtek-rtl.c
index 56bf502d9c67..2a349082af81 100644
--- a/drivers/irqchip/irq-realtek-rtl.c
+++ b/drivers/irqchip/irq-realtek-rtl.c
@@ -21,11 +21,33 @@
 #define RTL_ICTL_IRR2		0x10
 #define RTL_ICTL_IRR3		0x14
 
+#define RTL_ICTL_NUM_INPUTS	32
+
 #define REG(x)		(realtek_ictl_base + x)
 
 static DEFINE_RAW_SPINLOCK(irq_lock);
 static void __iomem *realtek_ictl_base;
 
+/*
+ * IRR0-IRR3 store 4 bits per interrupt, but Realtek uses inverted numbering,
+ * placing IRQ 31 in the first four bits. A routing value of '0' means the
+ * interrupt is left disconnected. Routing values {1..15} connect to output
+ * lines {0..14}.
+ */
+#define IRR_OFFSET(idx)		(4 * (3 - (idx * 4) / 32))
+#define IRR_SHIFT(idx)		((idx * 4) % 32)
+
+static void write_irr(void __iomem *irr0, int idx, u32 value)
+{
+	unsigned int offset = IRR_OFFSET(idx);
+	unsigned int shift = IRR_SHIFT(idx);
+	u32 irr;
+
+	irr = readl(irr0 + offset) & ~(0xf << shift);
+	irr |= (value & 0xf) << shift;
+	writel(irr, irr0 + offset);
+}
+
 static void realtek_ictl_unmask_irq(struct irq_data *i)
 {
 	unsigned long flags;
@@ -62,8 +84,14 @@ static struct irq_chip realtek_ictl_irq = {
 
 static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
 {
+	unsigned long flags;
+
 	irq_set_chip_and_handler(irq, &realtek_ictl_irq, handle_level_irq);
 
+	raw_spin_lock_irqsave(&irq_lock, flags);
+	write_irr(REG(RTL_ICTL_IRR0), hw, 1);
+	raw_spin_unlock_irqrestore(&irq_lock, flags);
+
 	return 0;
 }
 
@@ -95,90 +123,50 @@ out:
 	chained_irq_exit(chip, desc);
 }
 
-/*
- * SoC interrupts are cascaded to MIPS CPU interrupts according to the
- * interrupt-map in the device tree. Each SoC interrupt gets 4 bits for
- * the CPU interrupt in an Interrupt Routing Register. Max 32 SoC interrupts
- * thus go into 4 IRRs. A routing value of '0' means the interrupt is left
- * disconnected. Routing values {1..15} connect to output lines {0..14}.
- */
-static int __init map_interrupts(struct device_node *node, struct irq_domain *domain)
-{
-	struct device_node *cpu_ictl;
-	const __be32 *imap;
-	u32 imaplen, soc_int, cpu_int, tmp, regs[4];
-	int ret, i, irr_regs[] = {
-		RTL_ICTL_IRR3,
-		RTL_ICTL_IRR2,
-		RTL_ICTL_IRR1,
-		RTL_ICTL_IRR0,
-	};
-	u8 mips_irqs_set;
-
-	ret = of_property_read_u32(node, "#address-cells", &tmp);
-	if (ret || tmp)
-		return -EINVAL;
-
-	imap = of_get_property(node, "interrupt-map", &imaplen);
-	if (!imap || imaplen % 3)
-		return -EINVAL;
-
-	mips_irqs_set = 0;
-	memset(regs, 0, sizeof(regs));
-	for (i = 0; i < imaplen; i += 3 * sizeof(u32)) {
-		soc_int = be32_to_cpup(imap);
-		if (soc_int > 31)
-			return -EINVAL;
-
-		cpu_ictl = of_find_node_by_phandle(be32_to_cpup(imap + 1));
-		if (!cpu_ictl)
-			return -EINVAL;
-		ret = of_property_read_u32(cpu_ictl, "#interrupt-cells", &tmp);
-		of_node_put(cpu_ictl);
-		if (ret || tmp != 1)
-			return -EINVAL;
-
-		cpu_int = be32_to_cpup(imap + 2);
-		if (cpu_int > 7 || cpu_int < 2)
-			return -EINVAL;
-
-		if (!(mips_irqs_set & BIT(cpu_int))) {
-			irq_set_chained_handler_and_data(cpu_int, realtek_irq_dispatch,
-							 domain);
-			mips_irqs_set |= BIT(cpu_int);
-		}
-
-		/* Use routing values (1..6) for CPU interrupts (2..7) */
-		regs[(soc_int * 4) / 32] |= (cpu_int - 1) << (soc_int * 4) % 32;
-		imap += 3;
-	}
-
-	for (i = 0; i < 4; i++)
-		writel(regs[i], REG(irr_regs[i]));
-
-	return 0;
-}
-
 static int __init realtek_rtl_of_init(struct device_node *node, struct device_node *parent)
 {
+	struct of_phandle_args oirq;
 	struct irq_domain *domain;
-	int ret;
+	unsigned int soc_irq;
+	int parent_irq;
 
 	realtek_ictl_base = of_iomap(node, 0);
 	if (!realtek_ictl_base)
 		return -ENXIO;
 
-	/* Disable all cascaded interrupts */
+	/* Disable all cascaded interrupts and clear routing */
 	writel(0, REG(RTL_ICTL_GIMR));
+	for (soc_irq = 0; soc_irq < RTL_ICTL_NUM_INPUTS; soc_irq++)
+		write_irr(REG(RTL_ICTL_IRR0), soc_irq, 0);
+
+	if (WARN_ON(!of_irq_count(node))) {
+		/*
+		 * If DT contains no parent interrupts, assume MIPS CPU IRQ 2
+		 * (HW0) is connected to the first output. This is the case for
+		 * all known hardware anyway. "interrupt-map" is deprecated, so
+		 * don't bother trying to parse that.
+		 */
+		oirq.np = of_find_compatible_node(NULL, NULL, "mti,cpu-interrupt-controller");
+		oirq.args_count = 1;
+		oirq.args[0] = 2;
+
+		parent_irq = irq_create_of_mapping(&oirq);
+
+		of_node_put(oirq.np);
+	} else {
+		parent_irq = of_irq_get(node, 0);
+	}
 
-	domain = irq_domain_add_simple(node, 32, 0,
-				       &irq_domain_ops, NULL);
+	if (parent_irq < 0)
+		return parent_irq;
+	else if (!parent_irq)
+		return -ENODEV;
 
-	ret = map_interrupts(node, domain);
-	if (ret) {
-		pr_err("invalid interrupt map\n");
-		return ret;
-	}
+	domain = irq_domain_add_linear(node, RTL_ICTL_NUM_INPUTS, &irq_domain_ops, NULL);
+	if (!domain)
+		return -ENOMEM;
+
+	irq_set_chained_handler_and_data(parent_irq, realtek_irq_dispatch, domain);
 
 	return 0;
 }