gpio: visconti: Add Toshiba Visconti GPIO support

Add the GPIO driver for Toshiba Visconti ARM SoCs.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

3 files changed, 229 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 6addc923fa70..520fdf2bda30 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -648,6 +648,16 @@ config GPIO_VF610
 	help
 	  Say yes here to support Vybrid vf610 GPIOs.
 
+config GPIO_VISCONTI
+	tristate "Toshiba Visconti GPIO support"
+	depends on ARCH_VISCONTI || COMPILE_TEST
+	depends on OF_GPIO
+	select GPIOLIB_IRQCHIP
+	select GPIO_GENERIC
+	select IRQ_DOMAIN_HIERARCHY
+	help
+	  Say yes here to support GPIO on Tohisba Visconti.
+
 config GPIO_VR41XX
 	tristate "NEC VR4100 series General-purpose I/O Uint support"
 	depends on CPU_VR41XX
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 35e3b6026665..2c2a705766f3 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -164,6 +164,7 @@ 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-$(CONFIG_GPIO_VISCONTI)		+= gpio-visconti.o
 obj-$(CONFIG_GPIO_VR41XX)		+= gpio-vr41xx.o
 obj-$(CONFIG_GPIO_VX855)		+= gpio-vx855.o
 obj-$(CONFIG_GPIO_WCD934X)		+= gpio-wcd934x.o
diff --git a/drivers/gpio/gpio-visconti.c b/drivers/gpio/gpio-visconti.c
new file mode 100644
index 000000000000..0e3d19828eb1
--- /dev/null
+++ b/drivers/gpio/gpio-visconti.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Toshiba Visconti GPIO Support
+ *
+ * (C) Copyright 2020 Toshiba Electronic Devices & Storage Corporation
+ * (C) Copyright 2020 TOSHIBA CORPORATION
+ *
+ * Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+
+/* register offset */
+#define GPIO_DIR	0x00
+#define GPIO_IDATA	0x08
+#define GPIO_ODATA	0x10
+#define GPIO_OSET	0x18
+#define GPIO_OCLR	0x20
+#define GPIO_INTMODE	0x30
+
+#define BASE_HW_IRQ 24
+
+struct visconti_gpio {
+	void __iomem *base;
+	spinlock_t lock; /* protect gpio register */
+	struct gpio_chip gpio_chip;
+	struct irq_chip irq_chip;
+};
+
+static int visconti_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct visconti_gpio *priv = gpiochip_get_data(gc);
+	u32 offset = irqd_to_hwirq(d);
+	u32 bit = BIT(offset);
+	u32 intc_type = IRQ_TYPE_EDGE_RISING;
+	u32 intmode, odata;
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	odata = readl(priv->base + GPIO_ODATA);
+	intmode = readl(priv->base + GPIO_INTMODE);
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		odata &= ~bit;
+		intmode &= ~bit;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		odata |= bit;
+		intmode &= ~bit;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		intmode |= bit;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		intc_type = IRQ_TYPE_LEVEL_HIGH;
+		odata &= ~bit;
+		intmode &= ~bit;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		intc_type = IRQ_TYPE_LEVEL_HIGH;
+		odata |= bit;
+		intmode &= ~bit;
+		break;
+	default:
+		ret = -EINVAL;
+		goto err;
+	}
+
+	writel(odata, priv->base + GPIO_ODATA);
+	writel(intmode, priv->base + GPIO_INTMODE);
+	irq_set_irq_type(offset, intc_type);
+
+	ret = irq_chip_set_type_parent(d, type);
+err:
+	spin_unlock_irqrestore(&priv->lock, flags);
+	return ret;
+}
+
+static int visconti_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
+					       unsigned int child,
+					       unsigned int child_type,
+					       unsigned int *parent,
+					       unsigned int *parent_type)
+{
+	/* Interrupts 0..15 mapped to interrupts 24..39 on the GIC */
+	if (child < 16) {
+		/* All these interrupts are level high in the CPU */
+		*parent_type = IRQ_TYPE_LEVEL_HIGH;
+		*parent = child + BASE_HW_IRQ;
+		return 0;
+	}
+	return -EINVAL;
+}
+
+static void *visconti_gpio_populate_parent_fwspec(struct gpio_chip *chip,
+						  unsigned int parent_hwirq,
+						  unsigned int parent_type)
+{
+	struct irq_fwspec *fwspec;
+
+	fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
+	if (!fwspec)
+		return NULL;
+
+	fwspec->fwnode = chip->irq.parent_domain->fwnode;
+	fwspec->param_count = 3;
+	fwspec->param[0] = 0;
+	fwspec->param[1] = parent_hwirq;
+	fwspec->param[2] = parent_type;
+
+	return fwspec;
+}
+
+static int visconti_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct visconti_gpio *priv;
+	struct irq_chip *irq_chip;
+	struct gpio_irq_chip *girq;
+	struct irq_domain *parent;
+	struct device_node *irq_parent;
+	struct fwnode_handle *fwnode;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->lock);
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	irq_parent = of_irq_find_parent(dev->of_node);
+	if (!irq_parent) {
+		dev_err(dev, "No IRQ parent node\n");
+		return -ENODEV;
+	}
+
+	parent = irq_find_host(irq_parent);
+	if (!parent) {
+		dev_err(dev, "No IRQ parent domain\n");
+		return -ENODEV;
+	}
+
+	fwnode = of_node_to_fwnode(irq_parent);
+	of_node_put(irq_parent);
+
+	ret = bgpio_init(&priv->gpio_chip, dev, 4,
+			 priv->base + GPIO_IDATA,
+			 priv->base + GPIO_OSET,
+			 priv->base + GPIO_OCLR,
+			 priv->base + GPIO_DIR,
+			 NULL,
+			 0);
+	if (ret) {
+		dev_err(dev, "unable to init generic GPIO\n");
+		return ret;
+	}
+
+	irq_chip = &priv->irq_chip;
+	irq_chip->name = dev_name(dev);
+	irq_chip->irq_mask = irq_chip_mask_parent;
+	irq_chip->irq_unmask = irq_chip_unmask_parent;
+	irq_chip->irq_eoi = irq_chip_eoi_parent;
+	irq_chip->irq_set_type = visconti_gpio_irq_set_type;
+	irq_chip->flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND;
+
+	girq = &priv->gpio_chip.irq;
+	girq->chip = irq_chip;
+	girq->fwnode = fwnode;
+	girq->parent_domain = parent;
+	girq->child_to_parent_hwirq = visconti_gpio_child_to_parent_hwirq;
+	girq->populate_parent_alloc_arg = visconti_gpio_populate_parent_fwspec;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_level_irq;
+
+	ret = devm_gpiochip_add_data(dev, &priv->gpio_chip, priv);
+	if (ret) {
+		dev_err(dev, "failed to add GPIO chip\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return ret;
+}
+
+static const struct of_device_id visconti_gpio_of_match[] = {
+	{ .compatible = "toshiba,gpio-tmpv7708", },
+	{ /* end of table */ }
+};
+MODULE_DEVICE_TABLE(of, visconti_gpio_of_match);
+
+static struct platform_driver visconti_gpio_driver = {
+	.probe		= visconti_gpio_probe,
+	.driver		= {
+		.name	= "visconti_gpio",
+		.of_match_table = of_match_ptr(visconti_gpio_of_match),
+	}
+};
+module_platform_driver(visconti_gpio_driver);
+
+MODULE_AUTHOR("Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>");
+MODULE_DESCRIPTION("Toshiba Visconti GPIO Driver");
+MODULE_LICENSE("GPL v2");