[PATCH v5 1/2] gpio: gpio-mlxbf3: Add gpio driver support

Asmaa Mnebhi
2023-03-14T22:19:07Z

Add support for the BlueField-3 SoC GPIO driver.
This driver configures and handles GPIO interrupts. It also enables a user
to manipulate certain GPIO pins via libgpiod tools or other kernel drivers.
The usables pins are defined via the "gpio-reserved-ranges" property.

Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
---
drivers/gpio/Kconfig | 13 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-mlxbf3.c | 245 +++++++++++++++++++++++++++++++++++++
3 files changed, 259 insertions(+)
create mode 100644 drivers/gpio/gpio-mlxbf3.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index ec7cfd4f52b1..3b67e1591519 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1534,6 +1534,19 @@ config GPIO_MLXBF2
help
Say Y here if you want GPIO support on Mellanox BlueField 2 SoC.

+config GPIO_MLXBF3
+ tristate "Mellanox BlueField 3 SoC GPIO"
+ depends on (MELLANOX_PLATFORM && ARM64) || COMPILE_TEST
+ select GPIO_GENERIC
+ select GPIOLIB_IRQCHIP
+ help
+ Say Y if you want GPIO support on Mellanox BlueField 3 SoC.
+ This GPIO controller supports interrupt handling and enables the
+ manipulation of certain GPIO pins.
+ This controller should be used in parallel with pinctrl-mlxbf to
+ control the desired gpios.
+ This driver can also be built as a module called mlxbf3-gpio.
+
config GPIO_ML_IOH
tristate "OKI SEMICONDUCTOR ML7213 IOH GPIO support"
depends on X86 || COMPILE_TEST
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 010587025fc8..76545ca31457 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -101,6 +101,7 @@ obj-$(CONFIG_GPIO_MERRIFIELD) += gpio-merrifield.o
obj-$(CONFIG_GPIO_ML_IOH) += gpio-ml-ioh.o
obj-$(CONFIG_GPIO_MLXBF) += gpio-mlxbf.o
obj-$(CONFIG_GPIO_MLXBF2) += gpio-mlxbf2.o
+obj-$(CONFIG_GPIO_MLXBF3) += gpio-mlxbf3.o
obj-$(CONFIG_GPIO_MM_LANTIQ) += gpio-mm-lantiq.o
obj-$(CONFIG_GPIO_MOCKUP) += gpio-mockup.o
obj-$(CONFIG_GPIO_MOXTET) += gpio-moxtet.o
diff --git a/drivers/gpio/gpio-mlxbf3.c b/drivers/gpio/gpio-mlxbf3.c
new file mode 100644
index 000000000000..4225f6d38db3
--- /dev/null
+++ b/drivers/gpio/gpio-mlxbf3.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0-only or BSD-3-Clause
+/* Copyright (C) 2022 NVIDIA CORPORATION & AFFILIATES */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+/*
+ * There are 2 YU GPIO blocks:
+ * gpio[0]: HOST_GPIO0->HOST_GPIO31
+ * gpio[1]: HOST_GPIO32->HOST_GPIO55
+ */
+#define MLXBF3_GPIO_MAX_PINS_PER_BLOCK 32
+
+/*
+ * fw_gpio[x] block registers and their offset
+ */
+#define MLXBF_GPIO_FW_OUTPUT_ENABLE_SET 0x00
+#define MLXBF_GPIO_FW_DATA_OUT_SET 0x04
+
+#define MLXBF_GPIO_FW_OUTPUT_ENABLE_CLEAR 0x00
+#define MLXBF_GPIO_FW_DATA_OUT_CLEAR 0x04
+
+#define MLXBF_GPIO_CAUSE_RISE_EN 0x00
+#define MLXBF_GPIO_CAUSE_FALL_EN 0x04
+#define MLXBF_GPIO_READ_DATA_IN 0x08
+
+#define MLXBF_GPIO_CAUSE_OR_CAUSE_EVTEN0 0x00
+#define MLXBF_GPIO_CAUSE_OR_EVTEN0 0x14
+#define MLXBF_GPIO_CAUSE_OR_CLRCAUSE 0x18
+
+struct mlxbf3_gpio_context {
+ struct gpio_chip gc;
+
+ /* YU GPIO block address */
+ void __iomem *gpio_set_io;
+ void __iomem *gpio_clr_io;
+ void __iomem *gpio_io;
+
+ /* YU GPIO cause block address */
+ void __iomem *gpio_cause_io;
+};
+
+static void mlxbf3_gpio_irq_enable(struct irq_data *irqd)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+ struct mlxbf3_gpio_context *gs = gpiochip_get_data(gc);
+ irq_hw_number_t offset = irqd_to_hwirq(irqd);
+ unsigned long flags;
+ u32 val;
+
+ raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+ gpiochip_enable_irq(gc, offset);
+ writel(BIT(offset), gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_CLRCAUSE);
+
+ val = readl(gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);
+ val |= BIT(offset);
+ writel(val, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);
+ raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+}
+
+static void mlxbf3_gpio_irq_disable(struct irq_data *irqd)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+ struct mlxbf3_gpio_context *gs = gpiochip_get_data(gc);
+ irq_hw_number_t offset = irqd_to_hwirq(irqd);
+ unsigned long flags;
+ u32 val;
+
+ raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+ val = readl(gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);
+ val &= ~BIT(offset);
+ writel(val, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);
+ gpiochip_disable_irq(gc, offset);
+ raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+}
+
+static irqreturn_t mlxbf3_gpio_irq_handler(int irq, void *ptr)
+{
+ struct mlxbf3_gpio_context *gs = ptr;
+ struct gpio_chip *gc = &gs->gc;
+ unsigned long pending;
+ u32 level;
+
+ pending = readl(gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_CAUSE_EVTEN0);
+ writel(pending, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_CLRCAUSE);
+
+ for_each_set_bit(level, &pending, gc->ngpio)
+ generic_handle_domain_irq(gc->irq.domain, level);
+
+ return IRQ_RETVAL(pending);
+}
+
+static int
+mlxbf3_gpio_irq_set_type(struct irq_data *irqd, unsigned int type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+ struct mlxbf3_gpio_context *gs = gpiochip_get_data(gc);
+ irq_hw_number_t offset = irqd_to_hwirq(irqd);
+ unsigned long flags;
+ u32 val;
+
+ raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+
+ switch (type & IRQ_TYPE_SENSE_MASK) {
+ case IRQ_TYPE_EDGE_BOTH:
+ val = readl(gs->gpio_io + MLXBF_GPIO_CAUSE_FALL_EN);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + MLXBF_GPIO_CAUSE_FALL_EN);
+ val = readl(gs->gpio_io + MLXBF_GPIO_CAUSE_RISE_EN);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + MLXBF_GPIO_CAUSE_RISE_EN);
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ val = readl(gs->gpio_io + MLXBF_GPIO_CAUSE_RISE_EN);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + MLXBF_GPIO_CAUSE_RISE_EN);
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ val = readl(gs->gpio_io + MLXBF_GPIO_CAUSE_FALL_EN);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + MLXBF_GPIO_CAUSE_FALL_EN);
+ break;
+ default:
+ raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+ return -EINVAL;
+ }
+
+ raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+
+ irq_set_handler_locked(irqd, handle_edge_irq);
+
+ return 0;
+}
+
+/* This function needs to be defined for handle_edge_irq */
+static void mlxbf3_gpio_irq_ack(struct irq_data *data)
+{
+}
+
+static const struct irq_chip gpio_mlxbf3_irqchip = {
+ .name = "MLNXBF33",
+ .irq_ack = mlxbf3_gpio_irq_ack,
+ .irq_set_type = mlxbf3_gpio_irq_set_type,
+ .irq_enable = mlxbf3_gpio_irq_enable,
+ .irq_disable = mlxbf3_gpio_irq_disable,
+ .flags = IRQCHIP_IMMUTABLE,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static int mlxbf3_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mlxbf3_gpio_context *gs;
+ struct gpio_irq_chip *girq;
+ struct gpio_chip *gc;
+ int ret, irq;
+
+ gs = devm_kzalloc(dev, sizeof(*gs), GFP_KERNEL);
+ if (!gs)
+ return -ENOMEM;
+
+ gs->gpio_io = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(gs->gpio_io))
+ return PTR_ERR(gs->gpio_io);
+
+ gs->gpio_cause_io = devm_platform_ioremap_resource(pdev, 1);
+ if (IS_ERR(gs->gpio_cause_io))
+ return PTR_ERR(gs->gpio_cause_io);
+
+ gs->gpio_set_io = devm_platform_ioremap_resource(pdev, 2);
+ if (IS_ERR(gs->gpio_set_io))
+ return PTR_ERR(gs->gpio_set_io);
+
+ gs->gpio_clr_io = devm_platform_ioremap_resource(pdev, 3);
+ if (IS_ERR(gs->gpio_clr_io))
+ return PTR_ERR(gs->gpio_clr_io);
+ gc = &gs->gc;
+
+ ret = bgpio_init(gc, dev, 4,
+ gs->gpio_io + MLXBF_GPIO_READ_DATA_IN,
+ gs->gpio_set_io + MLXBF_GPIO_FW_DATA_OUT_SET,
+ gs->gpio_clr_io + MLXBF_GPIO_FW_DATA_OUT_CLEAR,
+ gs->gpio_set_io + MLXBF_GPIO_FW_OUTPUT_ENABLE_SET,
+ gs->gpio_clr_io + MLXBF_GPIO_FW_OUTPUT_ENABLE_CLEAR, 0);
+
+ gc->request = gpiochip_generic_request;
+ gc->free = gpiochip_generic_free;
+ gc->owner = THIS_MODULE;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq >= 0) {
+ girq = &gs->gc.irq;
+ gpio_irq_chip_set_chip(girq, &gpio_mlxbf3_irqchip);
+ girq->default_type = IRQ_TYPE_NONE;
+ /* This will let us handle the parent IRQ in the driver */
+ girq->num_parents = 0;
+ girq->parents = NULL;
+ girq->parent_handler = NULL;
+ girq->handler = handle_bad_irq;
+
+ /*
+ * Directly request the irq here instead of passing
+ * a flow-handler because the irq is shared.
+ */
+ ret = devm_request_irq(dev, irq, mlxbf3_gpio_irq_handler,
+ IRQF_SHARED, dev_name(dev), gs);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to request IRQ");
+ }
+
+ platform_set_drvdata(pdev, gs);
+
+ ret = devm_gpiochip_add_data(dev, &gs->gc, gs);
+ if (ret)
+ dev_err_probe(dev, ret, "Failed adding memory mapped gpiochip\n");
+
+ return 0;
+}
+
+static const struct acpi_device_id __maybe_unused mlxbf3_gpio_acpi_match[] = {
+ { "MLNXBF33", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, mlxbf3_gpio_acpi_match);
+
+static struct platform_driver mlxbf3_gpio_driver = {
+ .driver = {
+ .name = "mlxbf3_gpio",
+ .acpi_match_table = mlxbf3_gpio_acpi_match,
+ },
+ .probe = mlxbf3_gpio_probe,
+};
+module_platform_driver(mlxbf3_gpio_driver);
+
+MODULE_DESCRIPTION("NVIDIA BlueField-3 GPIO Driver");
+MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>");
+MODULE_LICENSE("Dual BSD/GPL");
--
2.30.1