Thread (20 messages) 20 messages, 5 authors, 2024-11-22

Re: [PATCH v2 2/7] gpio: Add Nuvoton NCT6694 GPIO support

From: Bartosz Golaszewski <hidden>
Date: 2024-11-21 08:28:28
Also in: linux-can, linux-gpio, linux-hwmon, linux-i2c, linux-rtc, linux-watchdog, lkml

On Thu, Nov 21, 2024 at 7:41 AM Ming Yu [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 | 441 ++++++++++++++++++++++++++++++++++++
 4 files changed, 455 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..1776200b3a04
--- /dev/null
+++ b/drivers/gpio/gpio-nct6694.c
@@ -0,0 +1,441 @@
+// 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;
+
+       /* GPIO line names */
+       char **names;
You only use this in probe() and after assigning it to gc->names, you
never reference it again. You don't need this field here, it can be a
local variable in probe().
+};
+
+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;
+
+       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;
+
+       data->names = devm_kzalloc(dev, sizeof(char *) * NCT6694_NR_GPIO,
devm_kcalloc()?
+                                  GFP_KERNEL);
+       if (!data->names)
+               return -ENOMEM;
+
+       for (i = 0; i < NCT6694_NR_GPIO; i++) {
+               data->names[i] = devm_kasprintf(dev, GFP_KERNEL, "GPIO%X%d",
+                                               cell->id, i);
+               if (!data->names[i])
+                       return -ENOMEM;
+       }
+
+       data->nct6694 = nct6694;
+       data->group = cell->id;
+
+       data->gpio.names                = (const char * const*)data->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);
+
+       platform_set_drvdata(pdev, data);
There is no corresponding platform_get_drvdata() so you don't need this.
+
+       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 [off-list ref]");
+MODULE_LICENSE("GPL");
It's an MFD device, don't you need a MODULE_ALIAS() for this module to load?

Bart
--
2.34.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help