irqchip: Add RDA8810PL interrupt driver

Add interrupt driver for RDA Micro RDA8810PL SoC.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/Kconfig

@@ -195,6 +195,10 @@ config JCORE_AIC
 	help
 	  Support for the J-Core integrated AIC.
 
+config RDA_INTC
+	bool
+	select IRQ_DOMAIN
+
 config RENESAS_INTC_IRQPIN
 	bool
 	select IRQ_DOMAIN

drivers/irqchip/Makefile

@@ -43,6 +43,7 @@ obj-$(CONFIG_IMGPDC_IRQ)		+= irq-imgpdc.o
 obj-$(CONFIG_IRQ_MIPS_CPU)		+= irq-mips-cpu.o
 obj-$(CONFIG_SIRF_IRQ)			+= irq-sirfsoc.o
 obj-$(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_VERSATILE_FPGA_IRQ)	+= irq-versatile-fpga.o

drivers/irqchip/irq-rda-intc.c

@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RDA8810PL SoC irqchip driver
+ *
+ * Copyright RDA Microelectronics Company Limited
+ * Copyright (c) 2017 Andreas Färber
+ * Copyright (c) 2018 Manivannan Sadhasivam
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+
+#include <asm/exception.h>
+
+#define RDA_INTC_FINALSTATUS	0x00
+#define RDA_INTC_MASK_SET	0x08
+#define RDA_INTC_MASK_CLR	0x0c
+
+#define RDA_IRQ_MASK_ALL	0xFFFFFFFF
+
+#define RDA_NR_IRQS 32
+
+static void __iomem *rda_intc_base;
+static struct irq_domain *rda_irq_domain;
+
+static void rda_intc_mask_irq(struct irq_data *d)
+{
+	writel_relaxed(BIT(d->hwirq), rda_intc_base + RDA_INTC_MASK_CLR);
+}
+
+static void rda_intc_unmask_irq(struct irq_data *d)
+{
+	writel_relaxed(BIT(d->hwirq), rda_intc_base + RDA_INTC_MASK_SET);
+}
+
+static int rda_intc_set_type(struct irq_data *data, unsigned int flow_type)
+{
+	/* Hardware supports only level triggered interrupts */
+	if ((flow_type & (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW)) == flow_type)
+		return 0;
+
+	return -EINVAL;
+}
+
+static void __exception_irq_entry rda_handle_irq(struct pt_regs *regs)
+{
+	u32 stat = readl_relaxed(rda_intc_base + RDA_INTC_FINALSTATUS);
+	u32 hwirq;
+
+	while (stat) {
+		hwirq = __fls(stat);
+		handle_domain_irq(rda_irq_domain, hwirq, regs);
+		stat &= ~BIT(hwirq);
+	}
+}
+
+static struct irq_chip rda_irq_chip = {
+	.name		= "rda-intc",
+	.irq_mask	= rda_intc_mask_irq,
+	.irq_unmask	= rda_intc_unmask_irq,
+	.irq_set_type	= rda_intc_set_type,
+};
+
+static int rda_irq_map(struct irq_domain *d,
+		       unsigned int virq, irq_hw_number_t hw)
+{
+	irq_set_status_flags(virq, IRQ_LEVEL);
+	irq_set_chip_and_handler(virq, &rda_irq_chip, handle_level_irq);
+	irq_set_chip_data(virq, d->host_data);
+	irq_set_probe(virq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops rda_irq_domain_ops = {
+	.map = rda_irq_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static int __init rda8810_intc_init(struct device_node *node,
+				    struct device_node *parent)
+{
+	rda_intc_base = of_io_request_and_map(node, 0, "rda-intc");
+	if (!rda_intc_base)
+		return -ENXIO;
+
+	/* Mask all interrupt sources */
+	writel_relaxed(RDA_IRQ_MASK_ALL, rda_intc_base + RDA_INTC_MASK_CLR);
+
+	rda_irq_domain = irq_domain_create_linear(&node->fwnode, RDA_NR_IRQS,
+						  &rda_irq_domain_ops,
+						  rda_intc_base);
+	if (!rda_irq_domain) {
+		iounmap(rda_intc_base);
+		return -ENOMEM;
+	}
+
+	set_handle_irq(rda_handle_irq);
+
+	return 0;
+}
+
+IRQCHIP_DECLARE(rda_intc, "rda,8810pl-intc", rda8810_intc_init);