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From:   Jiaxun Yang <jiaxun.yang@flygoat.com>
To:     linux-mips@vger.kernel.org
Cc:     tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com,
        robh+dt@kernel.org, mark.rutland@arm.com,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        Jiaxun Yang <jiaxun.yang@flygoat.com>
Subject: [PATCH v3 1/2] irqchip: Add driver for Loongson-1 interrupt controller
Date:   Thu, 24 Jan 2019 11:27:29 +0800
Message-Id: <20190124032730.18237-2-jiaxun.yang@flygoat.com>
In-Reply-To: <20190124032730.18237-1-jiaxun.yang@flygoat.com>
References: <20190122154557.22689-1-jiaxun.yang@flygoat.com>
 <20190124032730.18237-1-jiaxun.yang@flygoat.com>
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This controller appeared on Loongson-1 family MCUs
including Loongson-1B and Loongson-1C.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 drivers/irqchip/Kconfig    |   9 ++
 drivers/irqchip/Makefile   |   1 +
 drivers/irqchip/irq-ls1x.c | 176 +++++++++++++++++++++++++++++++++++++
 3 files changed, 186 insertions(+)
 create mode 100644 drivers/irqchip/irq-ls1x.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3d1e60779078..5dcb5456cd14 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -406,6 +406,15 @@ config IMX_IRQSTEER
 	help
 	  Support for the i.MX IRQSTEER interrupt multiplexer/remapper.
 
+config LS1X_IRQ
+	bool "Loongson-1 Interrupt Controller"
+	depends on MACH_LOONGSON32
+	default y
+	select IRQ_DOMAIN
+	select GENERIC_IRQ_CHIP
+	help
+	  Support for the Loongson-1 platform Interrupt Controller.
+
 endmenu
 
 config SIFIVE_PLIC
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c93713d24b86..7acd0e36d0b4 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -94,3 +94,4 @@ obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
 obj-$(CONFIG_MADERA_IRQ)		+= irq-madera.o
+obj-$(CONFIG_LS1X_IRQ)			+= irq-ls1x.o
diff --git a/drivers/irqchip/irq-ls1x.c b/drivers/irqchip/irq-ls1x.c
new file mode 100644
index 000000000000..de92ca04cf9f
--- /dev/null
+++ b/drivers/irqchip/irq-ls1x.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2019, Jiaxun Yang <jiaxun.yang@flygoat.com>
+ *  Loongson-1 platform IRQ support
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/irqchip.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/irqchip/chained_irq.h>
+
+#include <asm/mach-loongson32/irq.h>
+
+
+#define MAX_CHIPS	5
+#define LS_REG_INTC_STATUS	0x00
+#define LS_REG_INTC_EN	0x04
+#define LS_REG_INTC_SET	0x08
+#define LS_REG_INTC_CLR	0x0c
+#define LS_REG_INTC_POL	0x10
+#define LS_REG_INTC_EDGE	0x14
+#define CHIP_SIZE	0x18
+
+static void ls_chained_handle_irq(struct irq_desc *desc)
+{
+	struct irq_chip_generic *gc = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 pending;
+
+	chained_irq_enter(chip, desc);
+	pending = readl(gc->reg_base + LS_REG_INTC_STATUS) &
+			readl(gc->reg_base + LS_REG_INTC_EN);
+
+	if (!pending) {
+		spurious_interrupt();
+		chained_irq_exit(chip, desc);
+		return;
+	}
+
+	while (pending) {
+		int bit = __ffs(pending);
+
+		generic_handle_irq(gc->irq_base + bit);
+		pending &= ~BIT(bit);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void ls_intc_set_bit(struct irq_chip_generic *gc,
+							unsigned int offset,
+							u32 mask, bool set)
+{
+	if (set)
+		writel(readl(gc->reg_base + offset) | mask,
+		gc->reg_base + offset);
+	else
+		writel(readl(gc->reg_base + offset) & ~mask,
+		gc->reg_base + offset);
+}
+
+static int ls_intc_set_type(struct irq_data *data, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+	u32 mask = data->mask;
+
+	switch (type) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, false);
+		ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, true);
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, false);
+		ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, false);
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, true);
+		ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, true);
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, true);
+		ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, false);
+		break;
+	case IRQ_TYPE_NONE:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+
+static int __init ls_intc_of_init(struct device_node *node,
+				       struct device_node *parent)
+{
+	struct irq_chip_generic *gc[MAX_CHIPS];
+	struct irq_chip_type *ct;
+	struct irq_domain *domain;
+	void __iomem *base;
+	int parent_irq[MAX_CHIPS], err = 0;
+	unsigned int i = 0;
+
+	unsigned int num_chips = of_irq_count(node);
+
+	base = of_iomap(node, 0);
+	if (!base)
+		return -ENODEV;
+
+	for (i = 0; i < num_chips; i++) {
+		/* Mask all irqs */
+		writel(0x0, base + (i * CHIP_SIZE) +
+		       LS_REG_INTC_EN);
+
+		/* Set all irqs to high level triggered */
+		writel(0xffffffff, base + (i * CHIP_SIZE) +
+		       LS_REG_INTC_POL);
+
+		parent_irq[i] = irq_of_parse_and_map(node, i);
+
+		if (!parent_irq[i]) {
+			pr_warn("unable to get parent irq for irqchip %u\n", i);
+			goto out_err;
+		}
+
+		gc[i] = irq_alloc_generic_chip("INTC", 1,
+					    LS1X_IRQ_BASE + (i * 32),
+					    base + (i * CHIP_SIZE),
+					    handle_level_irq);
+
+		ct = gc[i]->chip_types;
+		ct->regs.mask = LS_REG_INTC_EN;
+		ct->regs.ack = LS_REG_INTC_CLR;
+		ct->chip.irq_unmask = irq_gc_mask_set_bit;
+		ct->chip.irq_mask = irq_gc_mask_clr_bit;
+		ct->chip.irq_ack = irq_gc_ack_set_bit;
+		ct->chip.irq_set_type = ls_intc_set_type;
+
+		irq_setup_generic_chip(gc[i], IRQ_MSK(32), 0, 0,
+				       IRQ_NOPROBE | IRQ_LEVEL);
+	}
+
+	domain = irq_domain_add_legacy(node, num_chips * 32, LS1X_IRQ_BASE, 0,
+		&irq_domain_simple_ops, NULL);
+	if (!domain) {
+		pr_warn("unable to register IRQ domain\n");
+		err = -EINVAL;
+		goto out_err;
+	}
+
+	for (i = 0; i < num_chips; i++)
+		irq_set_chained_handler_and_data(parent_irq[i],
+		ls_chained_handle_irq, gc[i]);
+
+	pr_info("ls1x-irq: %u chips registered\n", num_chips);
+
+	return 0;
+
+out_err:
+	for (i = 0; i < MAX_CHIPS; i++) {
+		if (gc[i])
+			irq_destroy_generic_chip(gc[i], IRQ_MSK(32),
+				       IRQ_NOPROBE | IRQ_LEVEL, 0);
+		if (parent_irq[i])
+			irq_dispose_mapping(parent_irq[i]);
+	}
+	return err;
+}
+
+IRQCHIP_DECLARE(ls1x_intc, "loongson,ls1x-intc", ls_intc_of_init);
-- 
2.20.1