From 529ea36818112530791a2ec083a1a3066be6174c Mon Sep 17 00:00:00 2001
From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Date: Thu, 22 Apr 2021 16:53:28 +0200
Subject: [PATCH] irqchip: Add support for IDT 79rc3243x interrupt controller
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@alpha.franken.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210422145330.73452-1-tsbogend@alpha.franken.de
---
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 715eb4366e358..18b0d0b33b8b1 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -583,4 +583,9 @@ config WPCM450_AIC
help
Support for the interrupt controller in the Nuvoton WPCM450 BMC SoC.
+config IRQ_IDT3243X
+ bool
+ select GENERIC_IRQ_CHIP
+ select IRQ_DOMAIN
+
endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index bef57937e7296..18573602a939b 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -114,3 +114,4 @@ 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_WPCM450_AIC) += irq-wpcm450-aic.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 0000000000000..f0996820077a9
--- /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,32434-pic", idt_pic_init);
--
2.30.2