[v5,3/3] gpio: uniphier: add UniPhier GPIO controller driver

diff --git a/MAINTAINERS b/MAINTAINERS
index f46a322..f7c9cfa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2013,6 +2013,7 @@  F:	arch/arm/mm/cache-uniphier.c
 F:	arch/arm64/boot/dts/socionext/
 F:	drivers/bus/uniphier-system-bus.c
 F:	drivers/clk/uniphier/
+F:	drivers/gpio/gpio-uniphier.c
 F:	drivers/i2c/busses/i2c-uniphier*
 F:	drivers/irqchip/irq-uniphier-aidet.c
 F:	drivers/pinctrl/uniphier/
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 3f80f16..25c0f308 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -475,6 +475,14 @@  config GPIO_TZ1090_PDC
 	help
 	  Say yes here to support Toumaz Xenif TZ1090 PDC GPIOs.
 
+config GPIO_UNIPHIER
+	tristate "UniPhier GPIO support"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF_GPIO
+	select IRQ_DOMAIN_HIERARCHY
+	help
+	  Say yes here to support UniPhier GPIOs.
+
 config GPIO_VF610
 	def_bool y
 	depends on ARCH_MXC && SOC_VF610
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index aeb70e9d..472f675 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -131,6 +131,7 @@  obj-$(CONFIG_GPIO_TWL6040)	+= gpio-twl6040.o
 obj-$(CONFIG_GPIO_TZ1090)	+= gpio-tz1090.o
 obj-$(CONFIG_GPIO_TZ1090_PDC)	+= gpio-tz1090-pdc.o
 obj-$(CONFIG_GPIO_UCB1400)	+= gpio-ucb1400.o
+obj-$(CONFIG_GPIO_UNIPHIER)	+= gpio-uniphier.o
 obj-$(CONFIG_GPIO_VF610)	+= gpio-vf610.o
 obj-$(CONFIG_GPIO_VIPERBOARD)	+= gpio-viperboard.o
 obj-$(CONFIG_GPIO_VR41XX)	+= gpio-vr41xx.o
diff --git a/drivers/gpio/gpio-uniphier.c b/drivers/gpio/gpio-uniphier.c
new file mode 100644
index 0000000..450474d
--- /dev/null
+++ b/drivers/gpio/gpio-uniphier.c
@@ -0,0 +1,504 @@ 
+/*
+ * Copyright (C) 2017 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.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.
+ *
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio/driver.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <dt-bindings/gpio/uniphier-gpio.h>
+
+#define UNIPHIER_GPIO_BANK_MASK		\
+				GENMASK((UNIPHIER_GPIO_LINES_PER_BANK) - 1, 0)
+
+#define UNIPHIER_GPIO_IRQ_MAX_NUM	24
+
+#define UNIPHIER_GPIO_PORT_DATA		0x0	/* data */
+#define UNIPHIER_GPIO_PORT_DIR		0x4	/* direction (1:in, 0:out) */
+#define UNIPHIER_GPIO_IRQ_EN		0x90	/* irq enable */
+#define UNIPHIER_GPIO_IRQ_MODE		0x94	/* irq mode (1: both edge) */
+#define UNIPHIER_GPIO_IRQ_FLT_EN	0x98	/* noise filter enable */
+#define UNIPHIER_GPIO_IRQ_FLT_CYC	0x9c	/* noise filter clock cycle */
+
+struct uniphier_gpio_priv {
+	struct gpio_chip chip;
+	struct irq_chip irq_chip;
+	struct irq_domain *domain;
+	void __iomem *regs;
+	spinlock_t lock;
+	u32 saved_vals[0];
+};
+
+static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
+{
+	unsigned int reg;
+
+	reg = (bank + 1) * 8;
+
+	/*
+	 * Unfortunately, the GPIO port registers are not contiguous because
+	 * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
+	 */
+	if (reg >= UNIPHIER_GPIO_IRQ_EN)
+		reg += 0x10;
+
+	return reg;
+}
+
+static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
+					    unsigned int *bank, u32 *mask)
+{
+	*bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
+	*mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
+}
+
+static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
+				     unsigned int reg, u32 mask, u32 val)
+{
+	unsigned long flags;
+	u32 tmp;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	tmp = readl(priv->regs + reg);
+	tmp &= ~mask;
+	tmp |= mask & val;
+	writel(tmp, priv->regs + reg);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static void uniphier_gpio_bank_write(struct gpio_chip *chip, unsigned int bank,
+				     unsigned int reg, u32 mask, u32 val)
+{
+	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
+
+	if (!mask)
+		return;
+
+	uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
+				 mask, val);
+}
+
+static void uniphier_gpio_offset_write(struct gpio_chip *chip,
+				       unsigned int offset, unsigned int reg,
+				       int val)
+{
+	unsigned int bank;
+	u32 mask;
+
+	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
+
+	uniphier_gpio_bank_write(chip, bank, reg, mask, val ? mask : 0);
+}
+
+static int uniphier_gpio_offset_read(struct gpio_chip *chip,
+				     unsigned int offset, unsigned int reg)
+{
+	struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
+	unsigned int bank, reg_offset;
+	u32 mask;
+
+	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
+	reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
+
+	return !!(readl(priv->regs + reg_offset) & mask);
+}
+
+static int uniphier_gpio_get_direction(struct gpio_chip *chip,
+				       unsigned int offset)
+{
+	return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DIR);
+}
+
+static int uniphier_gpio_direction_input(struct gpio_chip *chip,
+					 unsigned int offset)
+{
+	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 1);
+
+	return 0;
+}
+
+static int uniphier_gpio_direction_output(struct gpio_chip *chip,
+					  unsigned int offset, int val)
+{
+	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
+	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 0);
+
+	return 0;
+}
+
+static int uniphier_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DATA);
+}
+
+static void uniphier_gpio_set(struct gpio_chip *chip,
+			      unsigned int offset, int val)
+{
+	uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
+}
+
+static void uniphier_gpio_set_multiple(struct gpio_chip *chip,
+				       unsigned long *mask, unsigned long *bits)
+{
+	unsigned int bank, shift, bank_mask, bank_bits;
+	int i;
+
+	for (i = 0; i < chip->ngpio; i += UNIPHIER_GPIO_LINES_PER_BANK) {
+		bank = i / UNIPHIER_GPIO_LINES_PER_BANK;
+		shift = i % BITS_PER_LONG;
+		bank_mask = (mask[BIT_WORD(i)] >> shift) &
+						UNIPHIER_GPIO_BANK_MASK;
+		bank_bits = bits[BIT_WORD(i)] >> shift;
+
+		uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_PORT_DATA,
+					 bank_mask, bank_bits);
+	}
+}
+
+static int uniphier_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	struct irq_fwspec fwspec;
+
+	if (offset < UNIPHIER_GPIO_IRQ_OFFSET)
+		return -ENXIO;
+
+	fwspec.fwnode = of_node_to_fwnode(chip->parent->of_node);
+	fwspec.param_count = 2;
+	fwspec.param[0] = offset - UNIPHIER_GPIO_IRQ_OFFSET;
+	fwspec.param[1] = IRQ_TYPE_NONE;
+
+	return irq_create_fwspec_mapping(&fwspec);
+}
+
+static void uniphier_gpio_irq_mask(struct irq_data *data)
+{
+	struct uniphier_gpio_priv *priv = data->chip_data;
+	u32 mask = BIT(data->hwirq);
+
+	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, 0);
+
+	return irq_chip_mask_parent(data);
+}
+
+static void uniphier_gpio_irq_unmask(struct irq_data *data)
+{
+	struct uniphier_gpio_priv *priv = data->chip_data;
+	u32 mask = BIT(data->hwirq);
+
+	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, mask);
+
+	return irq_chip_unmask_parent(data);
+}
+
+static int uniphier_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+	struct uniphier_gpio_priv *priv = data->chip_data;
+	u32 mask = BIT(data->hwirq);
+	u32 val = 0;
+
+	if (type == IRQ_TYPE_EDGE_BOTH) {
+		val = mask;
+		type = IRQ_TYPE_EDGE_FALLING;
+	}
+
+	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_MODE, mask, val);
+	/* To enable both edge detection, the noise filter must be enabled. */
+	uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_FLT_EN, mask, val);
+
+	return irq_chip_set_type_parent(data, type);
+}
+
+static int uniphier_gpio_irq_domain_translate(struct irq_domain *domain,
+					      struct irq_fwspec *fwspec,
+					      unsigned long *out_hwirq,
+					      unsigned int *out_type)
+{
+	if (WARN_ON(fwspec->param_count < 2))
+		return -EINVAL;
+
+	*out_hwirq = fwspec->param[0];
+	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+
+	return 0;
+}
+
+static int uniphier_gpio_irq_domain_alloc(struct irq_domain *domain,
+					  unsigned int virq,
+					  unsigned int nr_irqs, void *arg)
+{
+	struct uniphier_gpio_priv *priv = domain->host_data;
+	struct irq_domain *parent_domain = domain->parent;
+	struct of_phandle_args parent_irq;
+	struct irq_fwspec parent_fwspec;
+	irq_hw_number_t hwirq, parent_hwirq;
+	unsigned int type, parent_virq;
+	int ret;
+
+	if (WARN_ON(nr_irqs != 1))
+		return -EINVAL;
+
+	ret = uniphier_gpio_irq_domain_translate(domain, arg, &hwirq, &type);
+	if (ret)
+		return ret;
+
+	ret = of_irq_parse_one(priv->chip.parent->of_node, hwirq, &parent_irq);
+	if (ret)
+		return ret;
+
+	of_phandle_args_to_fwspec(&parent_irq, &parent_fwspec);
+
+	if (WARN_ON(!parent_domain))
+		return -EINVAL;
+
+	if (WARN_ON(parent_domain->fwnode != parent_fwspec.fwnode))
+		return -EINVAL;
+
+	parent_hwirq = parent_fwspec.param[0];
+
+	/*
+	 * of_platform_populate() may allocate IRQ resources statically.
+	 * If the parent hwirq has been already mapped, we need to unmap it
+	 * because hierarchy irqdomain shares one virq among stacked irqchips.
+	 */
+	parent_virq = irq_find_mapping(parent_domain, parent_hwirq);
+	if (parent_virq) {
+		/* If someone has requested this irq, do not bother it */
+		if (irq_has_action(parent_virq))
+			return -EBUSY;
+		irq_dispose_mapping(parent_virq);
+	}
+
+	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
+					    &priv->irq_chip, priv);
+	if (ret)
+		return ret;
+
+	if (type == IRQ_TYPE_EDGE_BOTH)
+		parent_fwspec.param[1] = IRQ_TYPE_EDGE_FALLING;
+	else
+		parent_fwspec.param[1] = type;
+
+	return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
+}
+
+static void uniphier_gpio_irq_domain_activate(struct irq_domain *domain,
+					      struct irq_data *data)
+{
+	struct uniphier_gpio_priv *priv = domain->host_data;
+	struct gpio_chip *chip = &priv->chip;
+
+	gpiochip_lock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
+}
+
+static void uniphier_gpio_irq_domain_deactivate(struct irq_domain *domain,
+						struct irq_data *data)
+{
+	struct uniphier_gpio_priv *priv = domain->host_data;
+	struct gpio_chip *chip = &priv->chip;
+
+	gpiochip_unlock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
+}
+
+static const struct irq_domain_ops uniphier_gpio_irq_domain_ops = {
+	.alloc = uniphier_gpio_irq_domain_alloc,
+	.free = irq_domain_free_irqs_common,
+	.activate = uniphier_gpio_irq_domain_activate,
+	.deactivate = uniphier_gpio_irq_domain_deactivate,
+	.translate = uniphier_gpio_irq_domain_translate,
+};
+
+static void uniphier_gpio_hw_init(struct uniphier_gpio_priv *priv)
+{
+	/*
+	 * Due to the hardware design, the noise filter must be enabled to
+	 * detect both edge interrupts.  This filter is intended to remove the
+	 * noise from the irq lines.  It does not work for GPIO input, so GPIO
+	 * debounce is not supported.  Unfortunately, the filter period is
+	 * shared among all irq lines.  Just choose a sensible period here.
+	 */
+	writel(0xff, priv->regs + UNIPHIER_GPIO_IRQ_FLT_CYC);
+}
+
+static unsigned int uniphier_gpio_get_nbanks(unsigned int ngpio)
+{
+	return DIV_ROUND_UP(ngpio, UNIPHIER_GPIO_LINES_PER_BANK);
+}
+
+static int uniphier_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *parent_np;
+	struct irq_domain *parent_domain;
+	struct uniphier_gpio_priv *priv;
+	struct gpio_chip *chip;
+	struct irq_chip *irq_chip;
+	struct resource *regs;
+	unsigned int nregs;
+	u32 ngpios;
+	int ret;
+
+	parent_np = of_irq_find_parent(dev->of_node);
+	if (!parent_np)
+		return -ENXIO;
+
+	parent_domain = irq_find_host(parent_np);
+	of_node_put(parent_np);
+	if (!parent_domain)
+		return -EPROBE_DEFER;
+
+	ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
+	if (ret)
+		return ret;
+
+	nregs = uniphier_gpio_get_nbanks(ngpios) * 2 + 3;
+	priv = devm_kzalloc(dev,
+			    sizeof(*priv) + sizeof(priv->saved_vals[0]) * nregs,
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->regs = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(priv->regs))
+		return PTR_ERR(priv->regs);
+
+	spin_lock_init(&priv->lock);
+
+	chip = &priv->chip;
+	chip->label = dev_name(dev);
+	chip->parent = dev;
+	chip->request = gpiochip_generic_request;
+	chip->free = gpiochip_generic_free;
+	chip->get_direction = uniphier_gpio_get_direction;
+	chip->direction_input = uniphier_gpio_direction_input;
+	chip->direction_output = uniphier_gpio_direction_output;
+	chip->get = uniphier_gpio_get;
+	chip->set = uniphier_gpio_set;
+	chip->set_multiple = uniphier_gpio_set_multiple;
+	chip->to_irq = uniphier_gpio_to_irq;
+	chip->base = -1;
+	chip->ngpio = ngpios;
+
+	irq_chip = &priv->irq_chip;
+	irq_chip->name = dev_name(dev);
+	irq_chip->irq_mask = uniphier_gpio_irq_mask;
+	irq_chip->irq_unmask = uniphier_gpio_irq_unmask;
+	irq_chip->irq_eoi = irq_chip_eoi_parent;
+	irq_chip->irq_set_affinity = irq_chip_set_affinity_parent;
+	irq_chip->irq_set_type = uniphier_gpio_irq_set_type;
+
+	uniphier_gpio_hw_init(priv);
+
+	ret = devm_gpiochip_add_data(dev, chip, priv);
+	if (ret)
+		return ret;
+
+	priv->domain = irq_domain_create_hierarchy(
+					parent_domain, 0,
+					UNIPHIER_GPIO_IRQ_MAX_NUM,
+					of_node_to_fwnode(dev->of_node),
+					&uniphier_gpio_irq_domain_ops, priv);
+	if (!priv->domain)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static int uniphier_gpio_remove(struct platform_device *pdev)
+{
+	struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
+
+	irq_domain_remove(priv->domain);
+
+	return 0;
+}
+
+static int __maybe_unused uniphier_gpio_suspend(struct device *dev)
+{
+	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
+	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
+	u32 *val = priv->saved_vals;
+	unsigned int reg;
+	int i;
+
+	for (i = 0; i < nbanks; i++) {
+		reg = uniphier_gpio_bank_to_reg(i);
+
+		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
+		*val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
+	}
+
+	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_EN);
+	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_MODE);
+	*val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
+
+	return 0;
+}
+
+static int __maybe_unused uniphier_gpio_resume(struct device *dev)
+{
+	struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
+	unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
+	const u32 *val = priv->saved_vals;
+	unsigned int reg;
+	int i;
+
+	for (i = 0; i < nbanks; i++) {
+		reg = uniphier_gpio_bank_to_reg(i);
+
+		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
+		writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
+	}
+
+	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_EN);
+	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_MODE);
+	writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
+
+	uniphier_gpio_hw_init(priv);
+
+	return 0;
+}
+
+static const struct dev_pm_ops uniphier_gpio_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(uniphier_gpio_suspend,
+				     uniphier_gpio_resume)
+};
+
+static const struct of_device_id uniphier_gpio_match[] = {
+	{ .compatible = "socionext,uniphier-gpio" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
+
+static struct platform_driver uniphier_gpio_driver = {
+	.probe = uniphier_gpio_probe,
+	.remove = uniphier_gpio_remove,
+	.driver = {
+		.name = "uniphier-gpio",
+		.of_match_table = uniphier_gpio_match,
+		.pm = &uniphier_gpio_pm_ops,
+	},
+};
+module_platform_driver(uniphier_gpio_driver);
+
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_DESCRIPTION("UniPhier GPIO driver");
+MODULE_LICENSE("GPL");
diff --git a/include/dt-bindings/gpio/uniphier-gpio.h b/include/dt-bindings/gpio/uniphier-gpio.h
new file mode 100644
index 0000000..9f0ad17
--- /dev/null
+++ b/include/dt-bindings/gpio/uniphier-gpio.h
@@ -0,0 +1,18 @@ 
+/*
+ * Copyright (C) 2017 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ */
+
+#ifndef _DT_BINDINGS_GPIO_UNIPHIER_H
+#define _DT_BINDINGS_GPIO_UNIPHIER_H
+
+#define UNIPHIER_GPIO_LINES_PER_BANK	8
+
+#define UNIPHIER_GPIO_IRQ_OFFSET	((UNIPHIER_GPIO_LINES_PER_BANK) * 15)
+
+#define UNIPHIER_GPIO_PORT(bank, line)	\
+			((UNIPHIER_GPIO_LINES_PER_BANK) * (bank) + (line))
+
+#define UNIPHIER_GPIO_IRQ(n)		((UNIPHIER_GPIO_IRQ_OFFSET) + (n))
+
+#endif /* _DT_BINDINGS_GPIO_UNIPHIER_H */