lkml.org 
[lkml]   [2017]   [Aug]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4 4/8] irqchip/irq-goldfish-pic: Add Goldfish PIC driver
Date
From: Miodrag Dinic <miodrag.dinic@imgtec.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@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
---
MAINTAINERS | 1 +
drivers/irqchip/Kconfig | 8 ++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-goldfish-pic.c | 145 +++++++++++++++++++++++++++++++++++++
4 files changed, 155 insertions(+)
create mode 100644 drivers/irqchip/irq-goldfish-pic.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 013da1d..6426875 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -844,6 +844,7 @@ ANDROID GOLDFISH PIC DRIVER
M: Miodrag Dinic <miodrag.dinic@imgtec.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@imgtec.com>
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index f1fd5f4..21fab14 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -306,3 +306,11 @@ config QCOM_IRQ_COMBINER
help
Say yes here to add support for the IRQ combiner devices embedded
in Qualcomm Technologies chips.
+
+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.
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e88d856..ade04a1 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -78,3 +78,4 @@ obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o
obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.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..948c35e
--- /dev/null
+++ b/drivers/irqchip/irq-goldfish-pic.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2017 Imagination Technologies Ltd. All rights reserved
+ * Author: Miodrag Dinic <miodrag.dinic@imgtec.com>
+ *
+ * This file implements interrupt controller driver for MIPS Goldfish PIC.
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <asm/setup.h>
+
+/* 0..7 MIPS CPU interrupts */
+#define GF_CPU_IRQ_PIC (MIPS_CPU_IRQ_BASE + 2)
+#define GF_CPU_IRQ_COMPARE (MIPS_CPU_IRQ_BASE + 7)
+
+#define GF_NR_IRQS 40
+/* 8..39 Cascaded Goldfish PIC interrupts */
+#define GF_IRQ_OFFSET 8
+
+#define GF_PIC_NUMBER 0x04
+#define GF_PIC_DISABLE_ALL 0x08
+#define GF_PIC_DISABLE 0x0c
+#define GF_PIC_ENABLE 0x10
+
+static struct irq_domain *irq_domain;
+static void __iomem *gf_pic_base;
+
+static inline void unmask_goldfish_irq(struct irq_data *d)
+{
+ writel(d->hwirq - GF_IRQ_OFFSET,
+ gf_pic_base + GF_PIC_ENABLE);
+ irq_enable_hazard();
+}
+
+static inline void mask_goldfish_irq(struct irq_data *d)
+{
+ writel(d->hwirq - GF_IRQ_OFFSET,
+ gf_pic_base + GF_PIC_DISABLE);
+ irq_disable_hazard();
+}
+
+static struct irq_chip goldfish_irq_controller = {
+ .name = "Goldfish PIC",
+ .irq_ack = mask_goldfish_irq,
+ .irq_mask = mask_goldfish_irq,
+ .irq_mask_ack = mask_goldfish_irq,
+ .irq_unmask = unmask_goldfish_irq,
+ .irq_eoi = unmask_goldfish_irq,
+ .irq_disable = mask_goldfish_irq,
+ .irq_enable = unmask_goldfish_irq,
+};
+
+static void goldfish_irq_dispatch(void)
+{
+ u32 irq;
+ u32 virq;
+
+ irq = readl(gf_pic_base + GF_PIC_NUMBER);
+ if (irq == 0) {
+ /* Timer interrupt */
+ do_IRQ(GF_CPU_IRQ_COMPARE);
+ return;
+ }
+
+ virq = irq_linear_revmap(irq_domain, irq);
+ virq += GF_IRQ_OFFSET;
+ do_IRQ(virq);
+}
+
+static void goldfish_ip2_irq_dispatch(struct irq_desc *desc)
+{
+ unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM;
+
+ if (pending & CAUSEF_IP2)
+ goldfish_irq_dispatch();
+ else
+ spurious_interrupt();
+}
+
+static int goldfish_pic_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ if (cpu_has_vint)
+ set_vi_handler(hw, goldfish_irq_dispatch);
+
+ irq_set_chip_and_handler(irq, &goldfish_irq_controller,
+ handle_level_irq);
+
+ return 0;
+}
+
+static const struct irq_domain_ops gf_pic_irq_domain_ops = {
+ .map = goldfish_pic_map,
+ .xlate = irq_domain_xlate_onetwocell,
+};
+
+static struct irqaction cascade = {
+ .handler = no_action,
+ .flags = IRQF_PROBE_SHARED,
+ .name = "cascade",
+};
+
+static void __init __goldfish_pic_init(struct device_node *of_node)
+{
+ gf_pic_base = of_iomap(of_node, 0);
+ if (!gf_pic_base)
+ panic("Failed to map Goldfish PIC base : No such device!");
+
+ /* Mask interrupts. */
+ writel(1, gf_pic_base + GF_PIC_DISABLE_ALL);
+
+ if (!cpu_has_vint)
+ irq_set_chained_handler(GF_CPU_IRQ_PIC,
+ goldfish_ip2_irq_dispatch);
+
+ setup_irq(GF_CPU_IRQ_PIC, &cascade);
+
+ irq_domain = irq_domain_add_legacy(of_node, GF_NR_IRQS,
+ GF_IRQ_OFFSET, 0,
+ &gf_pic_irq_domain_ops, NULL);
+ if (!irq_domain)
+ panic("Failed to add irqdomain for Goldfish PIC");
+}
+
+int __init goldfish_pic_of_init(struct device_node *of_node,
+ struct device_node *parent)
+{
+ __goldfish_pic_init(of_node);
+ return 0;
+}
+
+IRQCHIP_DECLARE(google_gf_pic, "google,goldfish-pic", goldfish_pic_of_init);
+
--
2.7.4
\
 
 \ /
  Last update: 2017-08-18 15:13    [W:0.057 / U:91.292 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site