[PATCH v3 2/7] gpio: Add Nuvoton NCT6694 GPIO support

Ming Yu
2024-12-10T10:46:03Z

This driver supports GPIO and IRQ functionality for NCT6694 MFD
device based on USB interface.

Signed-off-by: Ming Yu <tmyu0@nuvoton.com>
---
MAINTAINERS | 1 +
drivers/gpio/Kconfig | 12 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-nct6694.c | 438 ++++++++++++++++++++++++++++++++++++
4 files changed, 452 insertions(+)
create mode 100644 drivers/gpio/gpio-nct6694.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9c9a94ff8f98..6688c5c470b7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16545,6 +16545,7 @@ NUVOTON NCT6694 MFD DRIVER
M: Ming Yu <tmyu0@nuvoton.com>
L: linux-kernel@vger.kernel.org
S: Supported
+F: drivers/gpio/gpio-nct6694.c
F: drivers/mfd/nct6694.c
F: include/linux/mfd/nct6694.h

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 56fee58e281e..7773b5326e60 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1460,6 +1460,18 @@ config GPIO_MAX77650
GPIO driver for MAX77650/77651 PMIC from Maxim Semiconductor.
These chips have a single pin that can be configured as GPIO.

+config GPIO_NCT6694
+ tristate "Nuvoton NCT6694 GPIO controller support"
+ depends on MFD_NCT6694
+ select GENERIC_IRQ_CHIP
+ select GPIOLIB_IRQCHIP
+ help
+ This driver supports 8 GPIO pins per bank that can all be interrupt
+ sources.
+
+ This driver can also be built as a module. If so, the module will be
+ called gpio-nct6694.
+
config GPIO_PALMAS
bool "TI PALMAS series PMICs GPIO"
depends on MFD_PALMAS
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index af3ba4d81b58..ad80a078b27b 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -123,6 +123,7 @@ obj-$(CONFIG_GPIO_MXC) += gpio-mxc.o
obj-$(CONFIG_GPIO_MXS) += gpio-mxs.o
obj-$(CONFIG_GPIO_NOMADIK) += gpio-nomadik.o
obj-$(CONFIG_GPIO_NPCM_SGPIO) += gpio-npcm-sgpio.o
+obj-$(CONFIG_GPIO_NCT6694) += gpio-nct6694.o
obj-$(CONFIG_GPIO_OCTEON) += gpio-octeon.o
obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o
obj-$(CONFIG_GPIO_PALMAS) += gpio-palmas.o
diff --git a/drivers/gpio/gpio-nct6694.c b/drivers/gpio/gpio-nct6694.c
new file mode 100644
index 000000000000..8aac034e6d06
--- /dev/null
+++ b/drivers/gpio/gpio-nct6694.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 GPIO controller driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/* Host interface */
+#define NCT6694_GPIO_MOD 0xFF
+#define NCT6694_GPIO_LEN 0x01
+
+/* Report Channel */
+#define NCT6694_GPIO_VER 0x90
+#define NCT6694_GPIO_VALID 0x110
+#define NCT6694_GPI_DATA 0x120
+#define NCT6694_GPO_DIR 0x170
+#define NCT6694_GPO_TYPE 0x180
+#define NCT6694_GPO_DATA 0x190
+
+#define NCT6694_GPI_STS 0x130
+#define NCT6694_GPI_CLR 0x140
+#define NCT6694_GPI_FALLING 0x150
+#define NCT6694_GPI_RISING 0x160
+
+#define NCT6694_NR_GPIO 8
+
+struct nct6694_gpio_data {
+ struct nct6694 *nct6694;
+ struct gpio_chip gpio;
+ struct mutex lock;
+ /* Protect irq operation */
+ struct mutex irq_lock;
+
+ unsigned char xmit_buf;
+ unsigned char irq_trig_falling;
+ unsigned char irq_trig_rising;
+
+ /* Current gpio group */
+ unsigned char group;
+};
+
+static int nct6694_get_direction(struct gpio_chip *gpio, unsigned int offset)
+{
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DIR + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ return !(BIT(offset) & data->xmit_buf);
+}
+
+static int nct6694_direction_input(struct gpio_chip *gpio, unsigned int offset)
+{
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DIR + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ data->xmit_buf &= ~(1 << offset);
+
+ return nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DIR + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+}
+
+static int nct6694_direction_output(struct gpio_chip *gpio,
+ unsigned int offset, int val)
+{
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ /* Set direction to output */
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DIR + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ data->xmit_buf |= (1 << offset);
+ ret = nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DIR + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ /* Then set output level */
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DATA + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ if (val)
+ data->xmit_buf |= (1 << offset);
+ else
+ data->xmit_buf &= ~(1 << offset);
+
+ return nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DATA + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+}
+
+static int nct6694_get_value(struct gpio_chip *gpio, unsigned int offset)
+{
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DIR + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ if (BIT(offset) & data->xmit_buf) {
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DATA + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ return !!(BIT(offset) & data->xmit_buf);
+ }
+
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPI_DATA + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ return !!(BIT(offset) & data->xmit_buf);
+}
+
+static void nct6694_set_value(struct gpio_chip *gpio, unsigned int offset,
+ int val)
+{
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+
+ guard(mutex)(&data->lock);
+
+ nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DATA + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+
+ if (val)
+ data->xmit_buf |= (1 << offset);
+ else
+ data->xmit_buf &= ~(1 << offset);
+
+ nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_DATA + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+}
+
+static int nct6694_set_config(struct gpio_chip *gpio, unsigned int offset,
+ unsigned long config)
+{
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_TYPE + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ switch (pinconf_to_config_param(config)) {
+ case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+ data->xmit_buf |= (1 << offset);
+ break;
+ case PIN_CONFIG_DRIVE_PUSH_PULL:
+ data->xmit_buf &= ~(1 << offset);
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+
+ return nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPO_TYPE + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+}
+
+static int nct6694_init_valid_mask(struct gpio_chip *gpio,
+ unsigned long *valid_mask,
+ unsigned int ngpios)
+{
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPIO_VALID + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ if (ret < 0)
+ return ret;
+
+ *valid_mask = data->xmit_buf;
+
+ return ret;
+}
+
+static irqreturn_t nct6694_irq_handler(int irq, void *priv)
+{
+ struct nct6694_gpio_data *data = priv;
+ unsigned char status;
+
+ guard(mutex)(&data->lock);
+
+ nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPI_STS + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+
+ status = data->xmit_buf;
+
+ while (status) {
+ int bit = __ffs(status);
+
+ data->xmit_buf = BIT(bit);
+ handle_nested_irq(irq_find_mapping(data->gpio.irq.domain, bit));
+ status &= ~(1 << bit);
+ nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPI_CLR + data->group,
+ NCT6694_GPIO_LEN, &data->xmit_buf);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int nct6694_get_irq_trig(struct nct6694_gpio_data *data)
+{
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPI_FALLING + data->group,
+ NCT6694_GPIO_LEN, &data->irq_trig_falling);
+ if (ret)
+ return ret;
+
+ return nct6694_read_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPI_RISING + data->group,
+ NCT6694_GPIO_LEN, &data->irq_trig_rising);
+}
+
+static void nct6694_irq_mask(struct irq_data *d)
+{
+ struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+ irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+ gpiochip_disable_irq(gpio, hwirq);
+}
+
+static void nct6694_irq_unmask(struct irq_data *d)
+{
+ struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+ irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+ gpiochip_enable_irq(gpio, hwirq);
+}
+
+static int nct6694_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+ irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+ guard(mutex)(&data->lock);
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_RISING:
+ data->irq_trig_rising |= BIT(hwirq);
+ break;
+
+ case IRQ_TYPE_EDGE_FALLING:
+ data->irq_trig_falling |= BIT(hwirq);
+ break;
+
+ case IRQ_TYPE_EDGE_BOTH:
+ data->irq_trig_rising |= BIT(hwirq);
+ data->irq_trig_falling |= BIT(hwirq);
+ break;
+
+ default:
+ return -ENOTSUPP;
+ }
+
+ return 0;
+}
+
+static void nct6694_irq_bus_lock(struct irq_data *d)
+{
+ struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+
+ mutex_lock(&data->irq_lock);
+}
+
+static void nct6694_irq_bus_sync_unlock(struct irq_data *d)
+{
+ struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+ struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+
+ scoped_guard(mutex, &data->lock) {
+ nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPI_FALLING + data->group,
+ NCT6694_GPIO_LEN, &data->irq_trig_falling);
+
+ nct6694_write_msg(data->nct6694, NCT6694_GPIO_MOD,
+ NCT6694_GPI_RISING + data->group,
+ NCT6694_GPIO_LEN, &data->irq_trig_rising);
+ }
+
+ mutex_unlock(&data->irq_lock);
+}
+
+static const struct irq_chip nct6694_irq_chip = {
+ .name = "nct6694-gpio",
+ .irq_mask = nct6694_irq_mask,
+ .irq_unmask = nct6694_irq_unmask,
+ .irq_set_type = nct6694_irq_set_type,
+ .irq_bus_lock = nct6694_irq_bus_lock,
+ .irq_bus_sync_unlock = nct6694_irq_bus_sync_unlock,
+ .flags = IRQCHIP_IMMUTABLE,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static int nct6694_gpio_probe(struct platform_device *pdev)
+{
+ const struct mfd_cell *cell = mfd_get_cell(pdev);
+ struct device *dev = &pdev->dev;
+ struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+ struct nct6694_gpio_data *data;
+ struct gpio_irq_chip *girq;
+ int ret, irq, i;
+ char **names;
+
+ irq = irq_create_mapping(nct6694->domain,
+ NCT6694_IRQ_GPIO0 + cell->id);
+ if (!irq)
+ return -EINVAL;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ names = devm_kcalloc(dev, NCT6694_NR_GPIO, sizeof(char *),
+ GFP_KERNEL);
+ if (!names)
+ return -ENOMEM;
+
+ for (i = 0; i < NCT6694_NR_GPIO; i++) {
+ names[i] = devm_kasprintf(dev, GFP_KERNEL, "GPIO%X%d",
+ cell->id, i);
+ if (!names[i])
+ return -ENOMEM;
+ }
+
+ data->nct6694 = nct6694;
+ data->group = cell->id;
+
+ data->gpio.names = (const char * const*)names;
+ data->gpio.label = pdev->name;
+ data->gpio.direction_input = nct6694_direction_input;
+ data->gpio.get = nct6694_get_value;
+ data->gpio.direction_output = nct6694_direction_output;
+ data->gpio.set = nct6694_set_value;
+ data->gpio.get_direction = nct6694_get_direction;
+ data->gpio.set_config = nct6694_set_config;
+ data->gpio.init_valid_mask = nct6694_init_valid_mask;
+ data->gpio.base = -1;
+ data->gpio.can_sleep = false;
+ data->gpio.owner = THIS_MODULE;
+ data->gpio.ngpio = NCT6694_NR_GPIO;
+
+ mutex_init(&data->irq_lock);
+
+ ret = nct6694_get_irq_trig(data);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to get irq trigger type\n");
+
+ /* Register gpio chip to GPIO framework */
+ girq = &data->gpio.irq;
+ gpio_irq_chip_set_chip(girq, &nct6694_irq_chip);
+ girq->parent_handler = NULL;
+ girq->num_parents = 0;
+ girq->parents = NULL;
+ girq->default_type = IRQ_TYPE_NONE;
+ girq->handler = handle_level_irq;
+ girq->threaded = true;
+
+ ret = devm_request_threaded_irq(dev, irq, NULL, nct6694_irq_handler,
+ IRQF_ONESHOT | IRQF_SHARED,
+ "nct6694-gpio", data);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to request irq\n");
+
+ return devm_gpiochip_add_data(dev, &data->gpio, data);
+}
+
+static struct platform_driver nct6694_gpio_driver = {
+ .driver = {
+ .name = "nct6694-gpio",
+ },
+ .probe = nct6694_gpio_probe,
+};
+
+module_platform_driver(nct6694_gpio_driver);
+
+MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-gpio");
--
2.34.1