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Subject[PATCH v10 2/3] irqchip/irq-goldfish-pic: Add Goldfish PIC driver
Date
From: Miodrag Dinic <miodrag.dinic@mips.com>

Add device driver for a virtual programmable interrupt controller

The virtual PIC is designed as a device tree-based interrupt controller.

The compatible string used by OS for binding the driver is
"google,goldfish-pic".

Signed-off-by: Miodrag Dinic <miodrag.dinic@mips.com>
Signed-off-by: Goran Ferenc <goran.ferenc@mips.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
---
MAINTAINERS | 1 +
drivers/irqchip/Kconfig | 8 +++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-goldfish-pic.c | 139 +++++++++++++++++++++++++++++++++++++
4 files changed, 149 insertions(+)
create mode 100644 drivers/irqchip/irq-goldfish-pic.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 998e705..381c9c8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -876,6 +876,7 @@ ANDROID GOLDFISH PIC DRIVER
M: Miodrag Dinic <miodrag.dinic@mips.com>
S: Supported
F: Documentation/devicetree/bindings/interrupt-controller/google,goldfish-pic.txt
+F: drivers/irqchip/irq-goldfish-pic.c

ANDROID GOLDFISH RTC DRIVER
M: Miodrag Dinic <miodrag.dinic@mips.com>
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 53380bd..af810b6 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -336,4 +336,12 @@ config MESON_IRQ_GPIO
help
Support Meson SoC Family GPIO Interrupt Multiplexer

+config GOLDFISH_PIC
+ bool "Goldfish programmable interrupt controller"
+ depends on MIPS && (GOLDFISH || COMPILE_TEST)
+ select IRQ_DOMAIN
+ help
+ Say yes here to enable Goldfish interrupt controller driver used
+ for Goldfish based virtual platforms.
+
endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index dae7282..1f6fb9d 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -83,3 +83,4 @@ obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
obj-$(CONFIG_IRQ_UNIPHIER_AIDET) += irq-uniphier-aidet.o
obj-$(CONFIG_ARCH_SYNQUACER) += irq-sni-exiu.o
obj-$(CONFIG_MESON_IRQ_GPIO) += irq-meson-gpio.o
+obj-$(CONFIG_GOLDFISH_PIC) += irq-goldfish-pic.o
diff --git a/drivers/irqchip/irq-goldfish-pic.c b/drivers/irqchip/irq-goldfish-pic.c
new file mode 100644
index 0000000..2a92f03
--- /dev/null
+++ b/drivers/irqchip/irq-goldfish-pic.c
@@ -0,0 +1,139 @@
+/*
+ * Driver for MIPS Goldfish Programmable Interrupt Controller.
+ *
+ * Author: Miodrag Dinic <miodrag.dinic@mips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#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 GFPIC_NR_IRQS 32
+
+/* 8..39 Cascaded Goldfish PIC interrupts */
+#define GFPIC_IRQ_BASE 8
+
+#define GFPIC_REG_IRQ_PENDING 0x04
+#define GFPIC_REG_IRQ_DISABLE_ALL 0x08
+#define GFPIC_REG_IRQ_DISABLE 0x0c
+#define GFPIC_REG_IRQ_ENABLE 0x10
+
+struct goldfish_pic_data {
+ void __iomem *base;
+ struct irq_domain *irq_domain;
+};
+
+static void goldfish_pic_cascade(struct irq_desc *desc)
+{
+ struct goldfish_pic_data *gfpic = 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 = readl(gfpic->base + GFPIC_REG_IRQ_PENDING);
+ while (pending) {
+ hwirq = __fls(pending);
+ virq = irq_linear_revmap(gfpic->irq_domain, hwirq);
+ generic_handle_irq(virq);
+ pending &= ~(1 << hwirq);
+ }
+
+ chained_irq_exit(host_chip, desc);
+}
+
+static const struct irq_domain_ops goldfish_irq_domain_ops = {
+ .xlate = irq_domain_xlate_onecell,
+};
+
+static int __init goldfish_pic_of_init(struct device_node *of_node,
+ struct device_node *parent)
+{
+ struct goldfish_pic_data *gfpic;
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+ unsigned int parent_irq;
+ int ret = 0;
+
+ gfpic = kzalloc(sizeof(*gfpic), GFP_KERNEL);
+ if (!gfpic) {
+ 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;
+ }
+
+ gfpic->base = of_iomap(of_node, 0);
+ if (!gfpic->base) {
+ pr_err("Failed to map base address!\n");
+ ret = -ENOMEM;
+ goto out_unmap_irq;
+ }
+
+ /* Mask interrupts. */
+ writel(1, gfpic->base + GFPIC_REG_IRQ_DISABLE_ALL);
+
+ gc = irq_alloc_generic_chip("GFPIC", 1, GFPIC_IRQ_BASE, gfpic->base,
+ handle_level_irq);
+ if (!gc) {
+ pr_err("Failed to allocate chip structures!\n");
+ ret = -ENOMEM;
+ goto out_iounmap;
+ }
+
+ ct = gc->chip_types;
+ ct->regs.enable = GFPIC_REG_IRQ_ENABLE;
+ ct->regs.disable = GFPIC_REG_IRQ_DISABLE;
+ ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
+ ct->chip.irq_mask = irq_gc_mask_disable_reg;
+
+ irq_setup_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS), 0,
+ IRQ_NOPROBE | IRQ_LEVEL, 0);
+
+ gfpic->irq_domain = irq_domain_add_legacy(of_node, GFPIC_NR_IRQS,
+ GFPIC_IRQ_BASE, 0,
+ &goldfish_irq_domain_ops,
+ NULL);
+ if (!gfpic->irq_domain) {
+ pr_err("Failed to add irqdomain!\n");
+ ret = -ENOMEM;
+ goto out_destroy_generic_chip;
+ }
+
+ irq_set_chained_handler_and_data(parent_irq,
+ goldfish_pic_cascade, gfpic);
+
+ pr_info("Successfully registered.\n");
+ return 0;
+
+out_destroy_generic_chip:
+ irq_destroy_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS),
+ IRQ_NOPROBE | IRQ_LEVEL, 0);
+out_iounmap:
+ iounmap(gfpic->base);
+out_unmap_irq:
+ irq_dispose_mapping(parent_irq);
+out_free:
+ kfree(gfpic);
+out_err:
+ pr_err("Failed to initialize! (errno = %d)\n", ret);
+ return ret;
+}
+
+IRQCHIP_DECLARE(google_gf_pic, "google,goldfish-pic", goldfish_pic_of_init);
--
2.7.4
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