[PATCH v2 1/2] irqchip: add lpc18xx gpio pin interrupt driver

[Joachim Eastwood <manabian@gmail.com>]

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
---
 drivers/irqchip/Kconfig                 |   5 +
 drivers/irqchip/Makefile                |   1 +
 drivers/irqchip/irq-lpc18xx-gpio-pint.c | 219 ++++++++++++++++++++++++++++++++
 3 files changed, 225 insertions(+)
 create mode 100644 drivers/irqchip/irq-lpc18xx-gpio-pint.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3e12479..0278837e 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -211,6 +211,11 @@ config KEYSTONE_IRQ
 		Support for Texas Instruments Keystone 2 IRQ controller IP which
 		is part of the Keystone 2 IPC mechanism
 
+config LPC18XX_GPIO_PINT
+	bool
+	select IRQ_DOMAIN
+	select GENERIC_IRQ_CHIP
+
 config MIPS_GIC
 	bool
 	select GENERIC_IRQ_IPI
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b03cfcb..bf60e0c 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_BCM7038_L1_IRQ)		+= irq-bcm7038-l1.o
 obj-$(CONFIG_BCM7120_L2_IRQ)		+= irq-bcm7120-l2.o
 obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o
 obj-$(CONFIG_KEYSTONE_IRQ)		+= irq-keystone.o
+obj-$(CONFIG_LPC18XX_GPIO_PINT)		+= irq-lpc18xx-gpio-pint.o
 obj-$(CONFIG_MIPS_GIC)			+= irq-mips-gic.o
 obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mtk-sysirq.o
 obj-$(CONFIG_ARCH_DIGICOLOR)		+= irq-digicolor.o
diff --git a/drivers/irqchip/irq-lpc18xx-gpio-pint.c b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
new file mode 100644
index 0000000..d53e99b
--- /dev/null
+++ b/drivers/irqchip/irq-lpc18xx-gpio-pint.c
@@ -0,0 +1,219 @@
+/*
+ * Irqchip driver for GPIO Pin Interrupt (PINT) on NXP LPC18xx/43xx.
+ *
+ * Copyright (C) 2016 Joachim Eastwood <manabian@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+/* LPC18xx GPIO pin interrupt register offsets */
+#define LPC18XX_GPIO_PINT_ISEL		0x000
+#define LPC18XX_GPIO_PINT_SIENR		0x008
+#define LPC18XX_GPIO_PINT_CIENR		0x00c
+#define LPC18XX_GPIO_PINT_SIENF		0x014
+#define LPC18XX_GPIO_PINT_CIENF		0x018
+#define LPC18XX_GPIO_PINT_IST		0x024
+
+#define PINT_MAX_IRQS			32
+
+struct lpc18xx_gpio_pint_chip {
+	struct irq_domain *domain;
+	void __iomem	  *base;
+	struct clk	  *clk;
+	unsigned int	  revmap[];
+};
+
+static void lpc18xx_gpio_pint_handler(struct irq_desc *desc)
+{
+	struct lpc18xx_gpio_pint_chip *pint = irq_desc_get_handler_data(desc);
+	unsigned int irq = irq_desc_get_irq(desc);
+	unsigned int hwirq = pint->revmap[irq];
+	unsigned int virq;
+
+	virq = irq_find_mapping(pint->domain, hwirq);
+	generic_handle_irq(virq);
+}
+
+static void lpc18xx_gpio_pint_edge_mask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 mask = d->mask;
+
+	irq_gc_lock(gc);
+	irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_CIENR);
+	irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_CIENF);
+	irq_gc_unlock(gc);
+}
+
+static void lpc18xx_gpio_pint_edge_unmask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	u32 type, mask = d->mask;
+
+	irq_gc_lock(gc);
+	type = irqd_get_trigger_type(d);
+	if (type & IRQ_TYPE_EDGE_RISING)
+		irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_SIENR);
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_SIENF);
+	irq_gc_unlock(gc);
+}
+
+static int lpc18xx_gpio_pint_type(struct irq_data *data, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+	u32 mask = data->mask;
+
+	irq_gc_lock(gc);
+	if (type & IRQ_TYPE_LEVEL_MASK)
+		gc->type_cache |= mask;
+	else
+		gc->type_cache &= ~mask;
+	irq_reg_writel(gc, gc->type_cache, LPC18XX_GPIO_PINT_ISEL);
+
+	switch (type) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_SIENF);
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		irq_reg_writel(gc, mask, LPC18XX_GPIO_PINT_CIENF);
+		break;
+
+	/* IRQ_TYPE_EDGE_* is set in lpc18xx_gpio_pint_edge_unmask */
+	}
+
+	irqd_set_trigger_type(data, type);
+	irq_setup_alt_chip(data, type);
+	irq_gc_unlock(gc);
+
+	return 0;
+}
+
+static int lpc18xx_gpio_pint_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct lpc18xx_gpio_pint_chip *pint;
+	struct irq_chip_generic *gc;
+	int irqs[PINT_MAX_IRQS];
+	unsigned int max_virqno;
+	struct resource *regs;
+	int nrirqs;
+	int i, ret;
+
+	nrirqs = of_irq_count(np);
+	if (nrirqs > PINT_MAX_IRQS)
+		return -EINVAL;
+
+	max_virqno = 0;
+	for (i = 0; i < nrirqs; i++) {
+		irqs[i] = platform_get_irq(pdev, i);
+		if (max_virqno < irqs[i])
+			max_virqno = irqs[i];
+	}
+
+	pint = devm_kzalloc(&pdev->dev,
+			    sizeof(*pint) + (sizeof(unsigned int) * max_virqno),
+			    GFP_KERNEL);
+	if (!pint)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pint->base = devm_ioremap_resource(&pdev->dev, regs);
+	if (IS_ERR(pint->base))
+		return PTR_ERR(pint->base);
+
+
+	pint->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(pint->clk)) {
+		dev_err(&pdev->dev, "input clock not found\n");
+		return PTR_ERR(pint->clk);
+	}
+
+	ret = clk_prepare_enable(pint->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable clock\n");
+		return ret;
+	}
+
+	pint->domain = irq_domain_add_linear(np, nrirqs, &irq_generic_chip_ops,
+					     pint);
+	if (!pint->domain) {
+		dev_err(&pdev->dev, "unable setup irq domain\n");
+		ret = -EINVAL;
+		goto err_domain_add;
+	}
+
+	ret = irq_alloc_domain_generic_chips(pint->domain, nrirqs, 2,
+					     "gpio_pint", handle_edge_irq,
+					     0, 0, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "unable alloc irq domain chips\n");
+		goto err_alloc_domain_gc;
+	}
+
+	gc = irq_get_domain_generic_chip(pint->domain, 0);
+	gc->reg_base = pint->base;
+
+	gc->chip_types[0].type		    = IRQ_TYPE_EDGE_BOTH;
+	gc->chip_types[0].handler	    = handle_edge_irq;
+	gc->chip_types[0].chip.irq_ack	    = irq_gc_ack_set_bit;
+	gc->chip_types[0].chip.irq_mask	    = lpc18xx_gpio_pint_edge_mask;
+	gc->chip_types[0].chip.irq_unmask   = lpc18xx_gpio_pint_edge_unmask;
+	gc->chip_types[0].chip.irq_set_type = lpc18xx_gpio_pint_type;
+	gc->chip_types[0].regs.ack	    = LPC18XX_GPIO_PINT_IST;
+
+	gc->chip_types[1].type		    = IRQ_TYPE_LEVEL_MASK;
+	gc->chip_types[1].handler	    = handle_level_irq;
+	gc->chip_types[1].chip.irq_mask	    = irq_gc_mask_disable_reg;
+	gc->chip_types[1].chip.irq_unmask   = irq_gc_unmask_enable_reg;
+	gc->chip_types[1].chip.irq_set_type = lpc18xx_gpio_pint_type;
+	gc->chip_types[1].regs.enable	    = LPC18XX_GPIO_PINT_SIENR;
+	gc->chip_types[1].regs.disable	    = LPC18XX_GPIO_PINT_CIENR;
+
+	/* Disable and clear all interrupts */
+	writel(~0, pint->base + LPC18XX_GPIO_PINT_CIENR);
+	writel(~0, pint->base + LPC18XX_GPIO_PINT_CIENF);
+	writel(0,  pint->base + LPC18XX_GPIO_PINT_ISEL);
+	writel(~0, pint->base + LPC18XX_GPIO_PINT_IST);
+
+	for (i = 0; i < nrirqs; i++) {
+		pint->revmap[irqs[i]] = i;
+		irq_set_chained_handler_and_data(irqs[i],
+						 lpc18xx_gpio_pint_handler,
+						 pint);
+	}
+
+	return 0;
+
+err_alloc_domain_gc:
+	irq_domain_remove(pint->domain);
+err_domain_add:
+	clk_disable_unprepare(pint->clk);
+	return ret;
+}
+
+static const struct of_device_id lpc18xx_gpio_pint_match[] = {
+	{ .compatible = "nxp,lpc1850-gpio-pint" },
+	{ }
+};
+
+static struct platform_driver lpc18xx_gpio_pint_driver = {
+	.probe	= lpc18xx_gpio_pint_probe,
+	.driver	= {
+		.name = "lpc18xx-gpio-pint",
+		.of_match_table = lpc18xx_gpio_pint_match,
+	},
+};
+builtin_platform_driver(lpc18xx_gpio_pint_driver);
-- 
2.8.0