File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/irqchip/irq-renesas-irqc.c b/drivers/irqchip/irq-renesas-irqc.c
new file mode 100644
index 0000000..52304b1
--- /dev/null
+++ b/drivers/irqchip/irq-renesas-irqc.c
@@ -0,0 +1,308 @@
+/*
+ * Renesas IRQC Driver
+ *
+ *  Copyright (C) 2013 Magnus Damm
+ *
+ * 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
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+
+#define IRQC_IRQ_MAX	32	/* maximum 32 interrupts per driver instance */
+
+#define IRQC_REQ_STS	0x00	/* Interrupt Request Status Register */
+#define IRQC_EN_STS	0x04	/* Interrupt Enable Status Register */
+#define IRQC_EN_SET	0x08	/* Interrupt Enable Set Register */
+#define IRQC_INT_CPU_BASE(n) (0x000 + ((n) * 0x10))
+				/* SYS-CPU vs. RT-CPU */
+#define DETECT_STATUS	0x100	/* IRQn Detect Status Register */
+#define MONITOR		0x104	/* IRQn Signal Level Monitor Register */
+#define HLVL_STS	0x108	/* IRQn High Level Detect Status Register */
+#define LLVL_STS	0x10c	/* IRQn Low Level Detect Status Register */
+#define S_R_EDGE_STS	0x110	/* IRQn Sync Rising Edge Detect Status Reg. */
+#define S_F_EDGE_STS	0x114	/* IRQn Sync Falling Edge Detect Status Reg. */
+#define A_R_EDGE_STS	0x118	/* IRQn Async Rising Edge Detect Status Reg. */
+#define A_F_EDGE_STS	0x11c	/* IRQn Async Falling Edge Detect Status Reg. */
+#define CHTEN_STS	0x120	/* Chattering Reduction Status Register */
+#define IRQC_CONFIG(n) (0x180 + ((n) * 0x04))
+				/* IRQn Configuration Register */
+
+struct irqc_irq {
+	int hw_irq;
+	int requested_irq;
+	struct irqc_priv *p;
+};
+
+struct irqc_priv {
+	void __iomem *iomem;
+	void __iomem *cpu_int_base;
+	struct irqc_irq irq[IRQC_IRQ_MAX];
+	unsigned int number_of_irqs;
+	struct platform_device *pdev;
+	struct irq_chip_generic *gc;
+	struct irq_domain *irq_domain;
+	struct clk *clk;
+};
+
+static struct irqc_priv *irq_data_to_priv(struct irq_data *data)
+{
+	return data->domain->host_data;
+}
+
+static void irqc_dbg(struct irqc_irq *i, char *str)
+{
+	dev_dbg(&i->p->pdev->dev, "%s (%d:%d)\n",
+		str, i->requested_irq, i->hw_irq);
+}
+
+static unsigned char irqc_sense[IRQ_TYPE_SENSE_MASK + 1] = {
+	[IRQ_TYPE_LEVEL_LOW]	= 0x01,
+	[IRQ_TYPE_LEVEL_HIGH]	= 0x02,
+	[IRQ_TYPE_EDGE_FALLING]	= 0x04,	/* Synchronous */
+	[IRQ_TYPE_EDGE_RISING]	= 0x08,	/* Synchronous */
+	[IRQ_TYPE_EDGE_BOTH]	= 0x0c,	/* Synchronous */
+};
+
+static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct irqc_priv *p = irq_data_to_priv(d);
+	int hw_irq = irqd_to_hwirq(d);
+	unsigned char value = irqc_sense[type & IRQ_TYPE_SENSE_MASK];
+	u32 tmp;
+
+	irqc_dbg(&p->irq[hw_irq], "sense");
+
+	if (!value)
+		return -EINVAL;
+
+	tmp = ioread32(p->iomem + IRQC_CONFIG(hw_irq));
+	tmp &= ~0x3f;
+	tmp |= value;
+	iowrite32(tmp, p->iomem + IRQC_CONFIG(hw_irq));
+	return 0;
+}
+
+static int irqc_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+	struct irqc_priv *p = irq_data_to_priv(d);
+	int hw_irq = irqd_to_hwirq(d);
+
+	irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);
+
+	if (!p->clk)
+		return 0;
+
+	if (on)
+		clk_enable(p->clk);
+	else
+		clk_disable(p->clk);
+
+	return 0;
+}
+
+static irqreturn_t irqc_irq_handler(int irq, void *dev_id)
+{
+	struct irqc_irq *i = dev_id;
+	struct irqc_priv *p = i->p;
+	u32 bit = BIT(i->hw_irq);
+
+	irqc_dbg(i, "demux1");
+
+	if (ioread32(p->iomem + DETECT_STATUS) & bit) {
+		iowrite32(bit, p->iomem + DETECT_STATUS);
+		irqc_dbg(i, "demux2");
+		generic_handle_irq(irq_find_mapping(p->irq_domain, i->hw_irq));
+		return IRQ_HANDLED;
+	}
+	return IRQ_NONE;
+}
+
+static int irqc_probe(struct platform_device *pdev)
+{
+	struct irqc_priv *p;
+	struct resource *io;
+	struct resource *irq;
+	const char *name = dev_name(&pdev->dev);
+	int ret;
+	int k;
+
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p) {
+		dev_err(&pdev->dev, "failed to allocate driver data\n");
+		ret = -ENOMEM;
+		goto err0;
+	}
+
+	p->pdev = pdev;
+	platform_set_drvdata(pdev, p);
+
+	p->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(p->clk)) {
+		dev_warn(&pdev->dev, "unable to get clock\n");
+		p->clk = NULL;
+	}
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	/* get hold of manadatory IOMEM */
+	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!io) {
+		dev_err(&pdev->dev, "not enough IOMEM resources\n");
+		ret = -EINVAL;
+		goto err1;
+	}
+
+	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
+	for (k = 0; k < IRQC_IRQ_MAX; k++) {
+		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
+		if (!irq)
+			break;
+
+		p->irq[k].p = p;
+		p->irq[k].hw_irq = k;
+		p->irq[k].requested_irq = irq->start;
+	}
+
+	p->number_of_irqs = k;
+	if (p->number_of_irqs < 1) {
+		dev_err(&pdev->dev, "not enough IRQ resources\n");
+		ret = -EINVAL;
+		goto err1;
+	}
+
+	/* ioremap IOMEM and setup read/write callbacks */
+	p->iomem = ioremap_nocache(io->start, resource_size(io));
+	if (!p->iomem) {
+		dev_err(&pdev->dev, "failed to remap IOMEM\n");
+		ret = -ENXIO;
+		goto err2;
+	}
+
+	p->cpu_int_base = p->iomem + IRQC_INT_CPU_BASE(0); /* SYS-SPI */
+
+	p->irq_domain = irq_domain_add_linear(pdev->dev.of_node,
+					      p->number_of_irqs,
+					      &irq_generic_chip_ops, p);
+	if (!p->irq_domain) {
+		ret = -ENXIO;
+		dev_err(&pdev->dev, "cannot initialize irq domain\n");
+		goto err2;
+	}
+
+	ret = irq_alloc_domain_generic_chips(p->irq_domain, p->number_of_irqs,
+					     1, name, handle_level_irq,
+					     0, 0, IRQ_GC_INIT_NESTED_LOCK);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot allocate generic chip\n");
+		goto err3;
+	}
+
+	p->gc = irq_get_domain_generic_chip(p->irq_domain, 0);
+	p->gc->reg_base = p->cpu_int_base;
+	p->gc->chip_types[0].regs.enable = IRQC_EN_SET;
+	p->gc->chip_types[0].regs.disable = IRQC_EN_STS;
+	p->gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
+	p->gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
+	p->gc->chip_types[0].chip.irq_set_type	= irqc_irq_set_type;
+	p->gc->chip_types[0].chip.irq_set_wake	= irqc_irq_set_wake;
+	p->gc->chip_types[0].chip.flags	= IRQCHIP_MASK_ON_SUSPEND;
+
+	/* request interrupts one by one */
+	for (k = 0; k < p->number_of_irqs; k++) {
+		if (request_irq(p->irq[k].requested_irq, irqc_irq_handler,
+				0, name, &p->irq[k])) {
+			dev_err(&pdev->dev, "failed to request IRQ\n");
+			ret = -ENOENT;
+			goto err4;
+		}
+	}
+
+	dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
+
+	return 0;
+err4:
+	while (--k >= 0)
+		free_irq(p->irq[k].requested_irq, &p->irq[k]);
+
+err3:
+	irq_domain_remove(p->irq_domain);
+err2:
+	iounmap(p->iomem);
+err1:
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	kfree(p);
+err0:
+	return ret;
+}
+
+static int irqc_remove(struct platform_device *pdev)
+{
+	struct irqc_priv *p = platform_get_drvdata(pdev);
+	int k;
+
+	for (k = 0; k < p->number_of_irqs; k++)
+		free_irq(p->irq[k].requested_irq, &p->irq[k]);
+
+	irq_domain_remove(p->irq_domain);
+	iounmap(p->iomem);
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	kfree(p);
+	return 0;
+}
+
+static const struct of_device_id irqc_dt_ids[] = {
+	{ .compatible = "renesas,irqc", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, irqc_dt_ids);
+
+static struct platform_driver irqc_device_driver = {
+	.probe		= irqc_probe,
+	.remove		= irqc_remove,
+	.driver		= {
+		.name	= "renesas_irqc",
+		.of_match_table	= irqc_dt_ids,
+	}
+};
+
+static int __init irqc_init(void)
+{
+	return platform_driver_register(&irqc_device_driver);
+}
+postcore_initcall(irqc_init);
+
+static void __exit irqc_exit(void)
+{
+	platform_driver_unregister(&irqc_device_driver);
+}
+module_exit(irqc_exit);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas IRQC Driver");
+MODULE_LICENSE("GPL v2");