[PATCH] irqchip: Add support for IDT 79rc3243x interrupt controller

From: Thomas Bogendoerfer
Date: Tue Apr 20 2021 - 08:34:50 EST


IDT 79rc3243x SoCs have rather simple interrupt controllers connected
to the MIPS CPU interrupt lines. Each of them has room for up to
32 interrupts.

Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
---
drivers/irqchip/Kconfig | 5 ++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-idt3243x.c | 124 +++++++++++++++++++++++++++++++++
3 files changed, 130 insertions(+)
create mode 100644 drivers/irqchip/irq-idt3243x.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index e74fa206240a..55562b36bf3c 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -586,4 +586,9 @@ config MST_IRQ
help
Support MStar Interrupt Controller.

+config IRQ_IDT3243X
+ bool
+ select GENERIC_IRQ_CHIP
+ select IRQ_DOMAIN
+
endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c59b95a0532c..341891443eec 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -113,3 +113,4 @@ obj-$(CONFIG_LOONGSON_PCH_MSI) += irq-loongson-pch-msi.o
obj-$(CONFIG_MST_IRQ) += irq-mst-intc.o
obj-$(CONFIG_SL28CPLD_INTC) += irq-sl28cpld.o
obj-$(CONFIG_MACH_REALTEK_RTL) += irq-realtek-rtl.o
+obj-$(CONFIG_IRQ_IDT3243X) += irq-idt3243x.o
diff --git a/drivers/irqchip/irq-idt3243x.c b/drivers/irqchip/irq-idt3243x.c
new file mode 100644
index 000000000000..61caf21ef46c
--- /dev/null
+++ b/drivers/irqchip/irq-idt3243x.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for IDT/Renesas 79RC3243x Interrupt Controller.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define IDT_PIC_NR_IRQS 32
+
+#define IDT_PIC_IRQ_PEND 0x00
+#define IDT_PIC_IRQ_MASK 0x08
+
+struct idt_pic_data {
+ void __iomem *base;
+ struct irq_domain *irq_domain;
+ struct irq_chip_generic *gc;
+};
+
+static void idt_irq_dispatch(struct irq_desc *desc)
+{
+ struct idt_pic_data *idtpic = irq_desc_get_handler_data(desc);
+ struct irq_chip *host_chip = irq_desc_get_chip(desc);
+ u32 pending, hwirq, virq;
+
+ chained_irq_enter(host_chip, desc);
+
+ pending = irq_reg_readl(idtpic->gc, IDT_PIC_IRQ_PEND);
+ pending &= ~idtpic->gc->mask_cache;
+ while (pending) {
+ hwirq = __fls(pending);
+ virq = irq_linear_revmap(idtpic->irq_domain, hwirq);
+ if (virq)
+ generic_handle_irq(virq);
+ pending &= ~(1 << hwirq);
+ }
+
+ chained_irq_exit(host_chip, desc);
+}
+
+static int idt_pic_init(struct device_node *of_node, struct device_node *parent)
+{
+ struct irq_domain *domain;
+ struct idt_pic_data *idtpic;
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+ unsigned int parent_irq;
+ int ret = 0;
+
+ idtpic = kzalloc(sizeof(*idtpic), GFP_KERNEL);
+ if (!idtpic) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ parent_irq = irq_of_parse_and_map(of_node, 0);
+ if (!parent_irq) {
+ pr_err("Failed to map parent IRQ!\n");
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ idtpic->base = of_iomap(of_node, 0);
+ if (!idtpic->base) {
+ pr_err("Failed to map base address!\n");
+ ret = -ENOMEM;
+ goto out_unmap_irq;
+ }
+
+ domain = irq_domain_add_linear(of_node, IDT_PIC_NR_IRQS,
+ &irq_generic_chip_ops, NULL);
+ if (!domain) {
+ pr_err("Failed to add irqdomain!\n");
+ ret = -ENOMEM;
+ goto out_iounmap;
+ }
+ idtpic->irq_domain = domain;
+
+ ret = irq_alloc_domain_generic_chips(domain, 32, 1, "IDTPIC",
+ handle_level_irq, 0,
+ IRQ_NOPROBE | IRQ_LEVEL, 0);
+ if (ret)
+ goto out_domain_remove;
+
+ gc = irq_get_domain_generic_chip(domain, 0);
+ gc->reg_base = idtpic->base;
+ gc->private = idtpic;
+
+ ct = gc->chip_types;
+ ct->regs.mask = IDT_PIC_IRQ_MASK;
+ ct->chip.irq_mask = irq_gc_mask_set_bit;
+ ct->chip.irq_unmask = irq_gc_mask_clr_bit;
+ idtpic->gc = gc;
+
+ /* Mask interrupts. */
+ writel(0xffffffff, idtpic->base + IDT_PIC_IRQ_MASK);
+ gc->mask_cache = 0xffffffff;
+
+ irq_set_chained_handler_and_data(parent_irq,
+ idt_irq_dispatch, idtpic);
+
+ return 0;
+
+out_domain_remove:
+ irq_domain_remove(domain);
+out_iounmap:
+ iounmap(idtpic->base);
+out_unmap_irq:
+ irq_dispose_mapping(parent_irq);
+out_free:
+ kfree(idtpic);
+out_err:
+ pr_err("Failed to initialize! (errno = %d)\n", ret);
+ return ret;
+}
+
+IRQCHIP_DECLARE(idt_pic, "idt,3243x-pic", idt_pic_init);
--
2.29.2