[PATCH v2 2/3] gpio: Enable Blaize BLZP1600 GPIO support

[Nikolaos Pasaloukos]

Blaize BLZP1600 GPIO controller is provided by VeriSilicon
Microelectronics based on the GPIO APB v0.2 design. It has 32
input/output ports which can be configured as edge or level
triggered interrupts. It also provides a de-bounce feature.
This controller is used on the Blaize BLZP1600 SoC.

Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Nikolaos Pasaloukos <nikolaos.pasaloukos@xxxxxxxxxx>
---
 MAINTAINERS                  |  10 ++
 drivers/gpio/Kconfig         |  11 ++
 drivers/gpio/Makefile        |   1 +
 drivers/gpio/gpio-blzp1600.c | 283 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 305 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index eb75c95f6c455516f7b1c8b3a39ddded5b38e0a9..7890586c9f1a6ff4afe368b91924038e2433939f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4104,6 +4104,16 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.gi
 F:	include/net/bluetooth/
 F:	net/bluetooth/
 
+BLZP1600 GPIO DRIVER
+M:	James Cowgill <james.cowgill@xxxxxxxxxx>
+M:	Matt Redfearn <matt.redfearn@xxxxxxxxxx>
+M:	Neil Jones <neil.jones@xxxxxxxxxx>
+M:	Nikolaos Pasaloukos <nikolaos.pasaloukos@xxxxxxxxxx>
+L:	linux-gpio@xxxxxxxxxxxxxxx
+S:	Maintained
+F:	Documentation/devicetree/bindings/gpio/blaize,blzp1600-gpio.yaml
+F:	drivers/gpio/gpio-blzp1600.c
+
 BONDING DRIVER
 M:	Jay Vosburgh <jv@xxxxxxxxxxxxx>
 L:	netdev@xxxxxxxxxxxxxxx
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index add5ad29a673c09082a913cb2404073b2034af48..b893b071a8d2dc5df5e0cb15b1a41ad8e6cb2b23 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -213,6 +213,17 @@ config GPIO_BCM_XGS_IPROC
 	help
 	  Say yes here to enable GPIO support for Broadcom XGS iProc SoCs.
 
+config GPIO_BLZP1600
+	tristate "Blaize BLZP1600 GPIO support"
+	default y if ARCH_BLAIZE
+	depends on OF_GPIO
+	select GPIO_GENERIC
+	select GPIOLIB_IRQCHIP
+	help
+	  Say Y or M here to add support for the Blaize BLZP1600 GPIO device.
+	  The controller is based on the Verisilicon Microelectronics GPIO APB v0.2
+	  IP block.
+
 config GPIO_BRCMSTB
 	tristate "BRCMSTB GPIO support"
 	default y if (ARCH_BRCMSTB || BMIPS_GENERIC)
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index af3ba4d81b583842893ea69e677fbe2abf31bc7b..a04de399af619921fff74b93820899960d1fe97f 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_GPIO_BCM_XGS_IPROC)	+= gpio-xgs-iproc.o
 obj-$(CONFIG_GPIO_BD71815)		+= gpio-bd71815.o
 obj-$(CONFIG_GPIO_BD71828)		+= gpio-bd71828.o
 obj-$(CONFIG_GPIO_BD9571MWV)		+= gpio-bd9571mwv.o
+obj-$(CONFIG_GPIO_BLZP1600)		+= gpio-blzp1600.o
 obj-$(CONFIG_GPIO_BRCMSTB)		+= gpio-brcmstb.o
 obj-$(CONFIG_GPIO_BT8XX)		+= gpio-bt8xx.o
 obj-$(CONFIG_GPIO_CADENCE)		+= gpio-cadence.o
diff --git a/drivers/gpio/gpio-blzp1600.c b/drivers/gpio/gpio-blzp1600.c
new file mode 100644
index 0000000000000000000000000000000000000000..77ad0e596f3ea838cfdd46918847d35b5d66fdf5
--- /dev/null
+++ b/drivers/gpio/gpio-blzp1600.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 VeriSilicon Limited.
+ * Copyright (C) 2025 Blaize, Inc.
+ */
+
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define GPIO_DIR_REG	0x00
+#define GPIO_CTRL_REG	0x04
+#define GPIO_SET_REG	0x08
+#define GPIO_CLR_REG	0x0C
+#define GPIO_ODATA_REG	0x10
+#define GPIO_IDATA_REG	0x14
+#define GPIO_IEN_REG	0x18
+#define GPIO_IS_REG	0x1C
+#define GPIO_IBE_REG	0x20
+#define GPIO_IEV_REG	0x24
+#define GPIO_RIS_REG	0x28
+#define GPIO_IM_REG	0x2C
+#define GPIO_MIS_REG	0x30
+#define GPIO_IC_REG	0x34
+#define GPIO_DB_REG	0x38
+#define GPIO_DFG_REG	0x3C
+
+#define DRIVER_NAME "blzp1600-gpio"
+
+struct blzp1600_gpio {
+	void __iomem *base;
+	struct gpio_chip gc;
+	int irq;
+};
+
+static inline struct blzp1600_gpio *get_blzp1600_gpio_from_irq_data(struct irq_data *d)
+{
+	return gpiochip_get_data(irq_data_get_irq_chip_data(d));
+}
+
+static inline struct blzp1600_gpio *get_blzp1600_gpio_from_irq_desc(struct irq_desc *d)
+{
+	return gpiochip_get_data(irq_desc_get_handler_data(d));
+}
+
+static inline u32 blzp1600_gpio_read(struct blzp1600_gpio *chip, unsigned int offset)
+{
+	return readl_relaxed(chip->base + offset);
+}
+
+static inline void blzp1600_gpio_write(struct blzp1600_gpio *chip, unsigned int offset, u32 val)
+{
+	writel_relaxed(val, chip->base + offset);
+}
+
+static inline void blzp1600_gpio_rmw(void __iomem *reg, u32 mask, bool set)
+{
+	u32 val = readl_relaxed(reg);
+
+	if (set)
+		val |= mask;
+	else
+		val &= ~mask;
+
+	writel_relaxed(val, reg);
+}
+
+static void blzp1600_gpio_irq_mask(struct irq_data *d)
+{
+	struct blzp1600_gpio *chip = get_blzp1600_gpio_from_irq_data(d);
+
+	guard(raw_spinlock_irqsave)(&chip->gc.bgpio_lock);
+	blzp1600_gpio_rmw(chip->base + GPIO_IM_REG, BIT(d->hwirq), 1);
+}
+
+static void blzp1600_gpio_irq_unmask(struct irq_data *d)
+{
+	struct blzp1600_gpio *chip = get_blzp1600_gpio_from_irq_data(d);
+
+	guard(raw_spinlock_irqsave)(&chip->gc.bgpio_lock);
+	blzp1600_gpio_rmw(chip->base + GPIO_IM_REG, BIT(d->hwirq), 0);
+}
+
+static void blzp1600_gpio_irq_ack(struct irq_data *d)
+{
+	struct blzp1600_gpio *chip = get_blzp1600_gpio_from_irq_data(d);
+
+	blzp1600_gpio_write(chip, GPIO_IC_REG, BIT(d->hwirq));
+}
+
+static void blzp1600_gpio_irq_enable(struct irq_data *d)
+{
+	struct blzp1600_gpio *chip = get_blzp1600_gpio_from_irq_data(d);
+
+	gpiochip_enable_irq(&chip->gc, irqd_to_hwirq(d));
+
+	guard(raw_spinlock_irqsave)(&chip->gc.bgpio_lock);
+	blzp1600_gpio_rmw(chip->base + GPIO_DIR_REG, BIT(d->hwirq), 0);
+	blzp1600_gpio_rmw(chip->base + GPIO_IEN_REG, BIT(d->hwirq), 1);
+}
+
+static void blzp1600_gpio_irq_disable(struct irq_data *d)
+{
+	struct blzp1600_gpio *chip = get_blzp1600_gpio_from_irq_data(d);
+
+	guard(raw_spinlock_irqsave)(&chip->gc.bgpio_lock);
+	blzp1600_gpio_rmw(chip->base + GPIO_IEN_REG, BIT(d->hwirq), 0);
+	gpiochip_disable_irq(&chip->gc, irqd_to_hwirq(d));
+}
+
+static int blzp1600_gpio_irq_set_type(struct irq_data *d, u32 type)
+{
+	struct blzp1600_gpio *chip = get_blzp1600_gpio_from_irq_data(d);
+	u32 edge_level, single_both, fall_rise;
+	int mask = BIT(d->hwirq);
+
+	guard(raw_spinlock_irqsave)(&chip->gc.bgpio_lock);
+	edge_level = blzp1600_gpio_read(chip, GPIO_IS_REG);
+	single_both = blzp1600_gpio_read(chip, GPIO_IBE_REG);
+	fall_rise = blzp1600_gpio_read(chip, GPIO_IEV_REG);
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_BOTH:
+		edge_level &= ~mask;
+		single_both |= mask;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		edge_level &= ~mask;
+		single_both &= ~mask;
+		fall_rise |= mask;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		edge_level &= ~mask;
+		single_both &= ~mask;
+		fall_rise &= ~mask;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		edge_level |= mask;
+		fall_rise |= mask;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		edge_level |= mask;
+		fall_rise &= ~mask;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	blzp1600_gpio_write(chip, GPIO_IS_REG, edge_level);
+	blzp1600_gpio_write(chip, GPIO_IBE_REG, single_both);
+	blzp1600_gpio_write(chip, GPIO_IEV_REG, fall_rise);
+
+	if (type & IRQ_TYPE_LEVEL_MASK)
+		irq_set_handler_locked(d, handle_level_irq);
+	else
+		irq_set_handler_locked(d, handle_edge_irq);
+
+	return 0;
+}
+
+static const struct irq_chip blzp1600_gpio_irqchip = {
+	.name = DRIVER_NAME,
+	.irq_ack = blzp1600_gpio_irq_ack,
+	.irq_mask = blzp1600_gpio_irq_mask,
+	.irq_unmask = blzp1600_gpio_irq_unmask,
+	.irq_set_type = blzp1600_gpio_irq_set_type,
+	.irq_enable = blzp1600_gpio_irq_enable,
+	.irq_disable = blzp1600_gpio_irq_disable,
+	.flags = IRQCHIP_IMMUTABLE | IRQCHIP_MASK_ON_SUSPEND,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static void blzp1600_gpio_irqhandler(struct irq_desc *desc)
+{
+	struct blzp1600_gpio *gpio = get_blzp1600_gpio_from_irq_desc(desc);
+	struct irq_chip *irqchip = irq_desc_get_chip(desc);
+	unsigned long irq_status;
+	int hwirq = 0;
+
+	chained_irq_enter(irqchip, desc);
+	irq_status = blzp1600_gpio_read(gpio, GPIO_RIS_REG);
+	for_each_set_bit(hwirq, &irq_status, gpio->gc.ngpio)
+		generic_handle_domain_irq(gpio->gc.irq.domain, hwirq);
+
+	chained_irq_exit(irqchip, desc);
+}
+
+static int blzp1600_gpio_set_debounce(struct gpio_chip *gc, unsigned int offset,
+				      unsigned int debounce)
+{
+	struct blzp1600_gpio *chip = gpiochip_get_data(gc);
+
+	guard(raw_spinlock_irqsave)(&chip->gc.bgpio_lock);
+	blzp1600_gpio_rmw(chip->base + GPIO_DB_REG, BIT(offset), debounce);
+
+	return 0;
+}
+
+static int blzp1600_gpio_set_config(struct gpio_chip *gc, unsigned int offset, unsigned long config)
+{
+	u32 debounce;
+
+	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
+		return -ENOTSUPP;
+
+	debounce = pinconf_to_config_argument(config);
+	return blzp1600_gpio_set_debounce(gc, offset, debounce);
+}
+
+static int blzp1600_gpio_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct blzp1600_gpio *chip;
+	struct gpio_chip *gc;
+	int ret;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(chip->base))
+		return PTR_ERR(chip->base);
+
+	ret = bgpio_init(&chip->gc, &pdev->dev, 4, chip->base + GPIO_IDATA_REG,
+			 chip->base + GPIO_SET_REG, chip->base + GPIO_CLR_REG,
+			 chip->base + GPIO_DIR_REG, NULL, 0);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Failed to register generic gpio\n");
+
+	/* configure the gpio chip */
+	gc = &chip->gc;
+	gc->set_config = blzp1600_gpio_set_config;
+
+	if (of_property_read_bool(node, "interrupt-controller")) {
+		struct gpio_irq_chip *girq;
+
+		chip->irq = platform_get_irq(pdev, 0);
+		if (chip->irq < 0)
+			return chip->irq;
+
+		girq = &gc->irq;
+		gpio_irq_chip_set_chip(girq, &blzp1600_gpio_irqchip);
+		girq->parent_handler = blzp1600_gpio_irqhandler;
+		girq->num_parents = 1;
+		girq->parents = devm_kcalloc(&pdev->dev, 1, sizeof(*girq->parents), GFP_KERNEL);
+		if (!girq->parents)
+			return -ENOMEM;
+
+		girq->parents[0] = chip->irq;
+		girq->default_type = IRQ_TYPE_NONE;
+	}
+
+	return devm_gpiochip_add_data(&pdev->dev, gc, chip);
+}
+
+static const struct of_device_id blzp1600_gpio_of_match[] = {
+	{ .compatible = "blaize,blzp1600-gpio", },
+	{ /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, blzp1600_gpio_of_match);
+
+static struct platform_driver blzp1600_gpio_driver = {
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.of_match_table = of_match_ptr(blzp1600_gpio_of_match),
+	},
+	.probe		= blzp1600_gpio_probe,
+};
+
+module_platform_driver(blzp1600_gpio_driver);
+
+MODULE_AUTHOR("Nikolaos Pasaloukos <nikolaos.pasaloukos@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Blaize BLZP1600 GPIO driver");
+MODULE_LICENSE("GPL");

-- 
2.43.0