diff mbox series

[v1,2/9] gpio: Add Nuvoton NCT6694 GPIO support

Message ID 20241024085922.133071-3-tmyu0@nuvoton.com (mailing list archive)
State Changes Requested
Headers show
Series Add Nuvoton NCT6694 MFD devices | expand

Commit Message

Ming Yu Oct. 24, 2024, 8:59 a.m. UTC
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 | 489 ++++++++++++++++++++++++++++++++++++
 4 files changed, 503 insertions(+)
 create mode 100644 drivers/gpio/gpio-nct6694.c

Comments

Bartosz Golaszewski Oct. 24, 2024, 9:47 a.m. UTC | #1
On Thu, Oct 24, 2024 at 10:59 AM Ming Yu <a0282524688@gmail.com> wrote:
>
> 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 | 489 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 503 insertions(+)
>  create mode 100644 drivers/gpio/gpio-nct6694.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 30157ca95cf3..2c86d5dab3f1 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16438,6 +16438,7 @@ 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 d93cd4f722b4..aa78ad9ff4ac 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1450,6 +1450,18 @@ 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 1429e8c0229b..02c94aa28017 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -121,6 +121,7 @@ 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..42c0e6e76730
> --- /dev/null
> +++ b/drivers/gpio/gpio-nct6694.c
> @@ -0,0 +1,489 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Nuvoton NCT6694 GPIO controller driver based on USB interface.
> + *
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + */
> +
> +#include <linux/gpio.h>

Don't include this header. It's documented as obsolete.

> +#include <linux/gpio/driver.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/nct6694.h>
> +

You only use it once, drop it.

> +#define DRVNAME "nct6694-gpio"
> +
> +/* Host interface */
> +#define REQUEST_GPIO_MOD               0xFF
> +#define REQUEST_GPIO_LEN               0x01
> +
> +/* Report Channel */
> +#define GPIO_VER_REG                   0x90
> +#define GPIO_VALID_REG                 0x110
> +#define GPI_DATA_REG                   0x120
> +#define GPO_DIR_REG                    0x170
> +#define GPO_TYPE_REG                   0x180
> +#define GPO_DATA_REG                   0x190
> +
> +#define GPI_STS_REG                    0x130
> +#define GPI_CLR_REG                    0x140
> +#define GPI_FALLING_REG                        0x150
> +#define GPI_RISING_REG                 0x160
> +

Please use the NCT6694 prefix for these defines, otherwise it's not
clear whether they come from the driver or from GPIO core.

[]

> +
> +static const char * const nct6694_gpio_name[] = {
> +       "NCT6694-GPIO0",
> +       "NCT6694-GPIO1",
> +       "NCT6694-GPIO2",
> +       "NCT6694-GPIO3",
> +       "NCT6694-GPIO4",
> +       "NCT6694-GPIO5",
> +       "NCT6694-GPIO6",
> +       "NCT6694-GPIO7",
> +       "NCT6694-GPIO8",
> +       "NCT6694-GPIO9",
> +       "NCT6694-GPIOA",
> +       "NCT6694-GPIOB",
> +       "NCT6694-GPIOC",
> +       "NCT6694-GPIOD",
> +       "NCT6694-GPIOE",
> +       "NCT6694-GPIOF",
> +};

This looks like it corresponds with the MFD cells and makes me wonder:
am I getting that wrong or do you want to register 0xf GPIO chips? Or
a single GPIO chip with 0xf lines? What is the topology?

> +
> +static int nct6694_gpio_probe(struct platform_device *pdev)
> +{
> +       const struct mfd_cell *cell = mfd_get_cell(pdev);
> +       struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> +       struct nct6694_gpio_data *data;
> +       struct gpio_irq_chip *girq;
> +       int ret;
> +
> +       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +       if (!data)
> +               return -ENOMEM;
> +
> +       data->nct6694 = nct6694;
> +       data->group = cell->id;
> +
> +       data->gpio.label                = nct6694_gpio_name[cell->id];
> +       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                = 8;
> +
> +       INIT_WORK(&data->irq_work, nct6694_irq);
> +       INIT_WORK(&data->irq_trig_work, nct6694_irq_trig);
> +       mutex_init(&data->irq_lock);
> +
> +       ret = nct6694_register_handler(nct6694, GPIO_IRQ_STATUS,
> +                                      nct6694_gpio_handler, data);
> +       if (ret) {
> +               dev_err(&pdev->dev, "%s:  Failed to register handler: %pe\n",
> +                       __func__, ERR_PTR(ret));
> +               return ret;
> +       }
> +
> +       platform_set_drvdata(pdev, data);
> +
> +       ret = nct6694_get_irq_trig(data);
> +       if (ret)
> +               return ret;
> +
> +       /* 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 = gpiochip_add_data(&data->gpio, data);
> +       if (ret) {
> +               dev_err(&pdev->dev, "%s: Failed to register GPIO chip: %pe",
> +                       __func__, ERR_PTR(ret));
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static void nct6694_gpio_remove(struct platform_device *pdev)
> +{
> +       struct nct6694_gpio_data *data = platform_get_drvdata(pdev);
> +
> +       gpiochip_remove(&data->gpio);

This should be dropped in favor of using devm_gpiochip_add_data().
Especially since you probably want to cancel the irq_work before
removing the chip.

> +       cancel_work(&data->irq_work);
> +       cancel_work(&data->irq_trig_work);
> +}
> +
> +static struct platform_driver nct6694_gpio_driver = {
> +       .driver = {
> +               .name   = DRVNAME,
> +       },
> +       .probe          = nct6694_gpio_probe,
> +       .remove         = nct6694_gpio_remove,
> +};
> +
> +static int __init nct6694_init(void)
> +{
> +       int err;
> +
> +       err = platform_driver_register(&nct6694_gpio_driver);
> +       if (!err) {
> +               if (err)

If err is equal to 0, check if it's not equal to zero?

> +                       platform_driver_unregister(&nct6694_gpio_driver);

If platform_driver_register() failed, then the device was never registered.

> +       }
> +
> +       return err;
> +}
> +subsys_initcall(nct6694_init);

Any reason why this must be initialized earlier? It's a USB driver after all.

> +
> +static void __exit nct6694_exit(void)
> +{
> +       platform_driver_unregister(&nct6694_gpio_driver);
> +}
> +module_exit(nct6694_exit);
> +
> +MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
> +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> +MODULE_LICENSE("GPL");
> --
> 2.34.1
>

Bart
Bartosz Golaszewski Oct. 25, 2024, 7:12 a.m. UTC | #2
On Fri, Oct 25, 2024 at 4:53 AM 游子民 <a0282524688@gmail.com> wrote:
>
> Dear Bart,
>
> Thank you for your comments.
>

I'm not going to read HTML email. Please resend as plain text.

Bart
Ming Yu Oct. 25, 2024, 7:38 a.m. UTC | #3
Sorry, resending this email in plain text format.

Dear Bart,

Thank you for your comments.

Bartosz Golaszewski <brgl@bgdev.pl> 於 2024年10月24日 週四 下午5:47寫道:
>
> On Thu, Oct 24, 2024 at 10:59 AM Ming Yu <a0282524688@gmail.com> wrote:
> >
> > 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 | 489 ++++++++++++++++++++++++++++++++++++
> >  4 files changed, 503 insertions(+)
> >  create mode 100644 drivers/gpio/gpio-nct6694.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 30157ca95cf3..2c86d5dab3f1 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -16438,6 +16438,7 @@ 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 d93cd4f722b4..aa78ad9ff4ac 100644
> > --- a/drivers/gpio/Kconfig
> > +++ b/drivers/gpio/Kconfig
> > @@ -1450,6 +1450,18 @@ 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 1429e8c0229b..02c94aa28017 100644
> > --- a/drivers/gpio/Makefile
> > +++ b/drivers/gpio/Makefile
> > @@ -121,6 +121,7 @@ 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..42c0e6e76730
> > --- /dev/null
> > +++ b/drivers/gpio/gpio-nct6694.c
> > @@ -0,0 +1,489 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Nuvoton NCT6694 GPIO controller driver based on USB interface.
> > + *
> > + * Copyright (C) 2024 Nuvoton Technology Corp.
> > + */
> > +
> > +#include <linux/gpio.h>
>
> Don't include this header. It's documented as obsolete.

[Ming] Okay! I'll drop it in the next patch.

>
> > +#include <linux/gpio/driver.h>
> > +#include <linux/module.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/mfd/core.h>
> > +#include <linux/mfd/nct6694.h>
> > +
>
> You only use it once, drop it.

[Ming] That line is blank, did you mean #include <linux/gpio.h>?

>
> > +#define DRVNAME "nct6694-gpio"
> > +
> > +/* Host interface */
> > +#define REQUEST_GPIO_MOD               0xFF
> > +#define REQUEST_GPIO_LEN               0x01
> > +
> > +/* Report Channel */
> > +#define GPIO_VER_REG                   0x90
> > +#define GPIO_VALID_REG                 0x110
> > +#define GPI_DATA_REG                   0x120
> > +#define GPO_DIR_REG                    0x170
> > +#define GPO_TYPE_REG                   0x180
> > +#define GPO_DATA_REG                   0x190
> > +
> > +#define GPI_STS_REG                    0x130
> > +#define GPI_CLR_REG                    0x140
> > +#define GPI_FALLING_REG                        0x150
> > +#define GPI_RISING_REG                 0x160
> > +
>
> Please use the NCT6694 prefix for these defines, otherwise it's not
> clear whether they come from the driver or from GPIO core.
>
> []

[Ming] Okay! I'll add the prefix to the defines in the next patch.

>
> > +
> > +static const char * const nct6694_gpio_name[] = {
> > +       "NCT6694-GPIO0",
> > +       "NCT6694-GPIO1",
> > +       "NCT6694-GPIO2",
> > +       "NCT6694-GPIO3",
> > +       "NCT6694-GPIO4",
> > +       "NCT6694-GPIO5",
> > +       "NCT6694-GPIO6",
> > +       "NCT6694-GPIO7",
> > +       "NCT6694-GPIO8",
> > +       "NCT6694-GPIO9",
> > +       "NCT6694-GPIOA",
> > +       "NCT6694-GPIOB",
> > +       "NCT6694-GPIOC",
> > +       "NCT6694-GPIOD",
> > +       "NCT6694-GPIOE",
> > +       "NCT6694-GPIOF",
> > +};
>
> This looks like it corresponds with the MFD cells and makes me wonder:
> am I getting that wrong or do you want to register 0xf GPIO chips? Or
> a single GPIO chip with 0xf lines? What is the topology?

[Ming] Yes, it corresponds to the MFD cells.
I would like to register 16 GPIO chips, each with 8 lines.
The chip has 128 pins totally, the core can check if the pin is valid through
the init_valid_mask() callback.

>
> > +
> > +static int nct6694_gpio_probe(struct platform_device *pdev)
> > +{
> > +       const struct mfd_cell *cell = mfd_get_cell(pdev);
> > +       struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> > +       struct nct6694_gpio_data *data;
> > +       struct gpio_irq_chip *girq;
> > +       int ret;
> > +
> > +       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> > +       if (!data)
> > +               return -ENOMEM;
> > +
> > +       data->nct6694 = nct6694;
> > +       data->group = cell->id;
> > +
> > +       data->gpio.label                = nct6694_gpio_name[cell->id];
> > +       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                = 8;
> > +
> > +       INIT_WORK(&data->irq_work, nct6694_irq);
> > +       INIT_WORK(&data->irq_trig_work, nct6694_irq_trig);
> > +       mutex_init(&data->irq_lock);
> > +
> > +       ret = nct6694_register_handler(nct6694, GPIO_IRQ_STATUS,
> > +                                      nct6694_gpio_handler, data);
> > +       if (ret) {
> > +               dev_err(&pdev->dev, "%s:  Failed to register handler: %pe\n",
> > +                       __func__, ERR_PTR(ret));
> > +               return ret;
> > +       }
> > +
> > +       platform_set_drvdata(pdev, data);
> > +
> > +       ret = nct6694_get_irq_trig(data);
> > +       if (ret)
> > +               return ret;
> > +
> > +       /* 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 = gpiochip_add_data(&data->gpio, data);
> > +       if (ret) {
> > +               dev_err(&pdev->dev, "%s: Failed to register GPIO chip: %pe",
> > +                       __func__, ERR_PTR(ret));
> > +               return ret;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static void nct6694_gpio_remove(struct platform_device *pdev)
> > +{
> > +       struct nct6694_gpio_data *data = platform_get_drvdata(pdev);
> > +
> > +       gpiochip_remove(&data->gpio);
>
> This should be dropped in favor of using devm_gpiochip_add_data().
> Especially since you probably want to cancel the irq_work before
> removing the chip.

[Ming] Okay! I'll change it in the next patch.

>
> > +       cancel_work(&data->irq_work);
> > +       cancel_work(&data->irq_trig_work);
> > +}
> > +
> > +static struct platform_driver nct6694_gpio_driver = {
> > +       .driver = {
> > +               .name   = DRVNAME,
> > +       },
> > +       .probe          = nct6694_gpio_probe,
> > +       .remove         = nct6694_gpio_remove,
> > +};
> > +
> > +static int __init nct6694_init(void)
> > +{
> > +       int err;
> > +
> > +       err = platform_driver_register(&nct6694_gpio_driver);
> > +       if (!err) {
> > +               if (err)
>
> If err is equal to 0, check if it's not equal to zero?
>
> > +                       platform_driver_unregister(&nct6694_gpio_driver);
>
> If platform_driver_register() failed, then the device was never registered.
>
> > +       }
> > +
> > +       return err;
> > +}
> > +subsys_initcall(nct6694_init);
>
> Any reason why this must be initialized earlier? It's a USB driver after all.

[Ming] For platform driver registration, I'll change it to
module_platform_driver()
in the next patch.

>
> > +
> > +static void __exit nct6694_exit(void)
> > +{
> > +       platform_driver_unregister(&nct6694_gpio_driver);
> > +}
> > +module_exit(nct6694_exit);
> > +
> > +MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
> > +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.34.1
> >
>
> Bart
Bartosz Golaszewski Oct. 25, 2024, 7:46 a.m. UTC | #4
On Fri, Oct 25, 2024 at 9:39 AM 游子民 <a0282524688@gmail.com> wrote:
>
> Sorry, resending this email in plain text format.
>
> Dear Bart,
>
> Thank you for your comments.
>
> Bartosz Golaszewski <brgl@bgdev.pl> 於 2024年10月24日 週四 下午5:47寫道:
> >
> > On Thu, Oct 24, 2024 at 10:59 AM Ming Yu <a0282524688@gmail.com> wrote:
> > >
> > > 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 | 489 ++++++++++++++++++++++++++++++++++++
> > >  4 files changed, 503 insertions(+)
> > >  create mode 100644 drivers/gpio/gpio-nct6694.c
> > >
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 30157ca95cf3..2c86d5dab3f1 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -16438,6 +16438,7 @@ 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 d93cd4f722b4..aa78ad9ff4ac 100644
> > > --- a/drivers/gpio/Kconfig
> > > +++ b/drivers/gpio/Kconfig
> > > @@ -1450,6 +1450,18 @@ 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 1429e8c0229b..02c94aa28017 100644
> > > --- a/drivers/gpio/Makefile
> > > +++ b/drivers/gpio/Makefile
> > > @@ -121,6 +121,7 @@ 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..42c0e6e76730
> > > --- /dev/null
> > > +++ b/drivers/gpio/gpio-nct6694.c
> > > @@ -0,0 +1,489 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Nuvoton NCT6694 GPIO controller driver based on USB interface.
> > > + *
> > > + * Copyright (C) 2024 Nuvoton Technology Corp.
> > > + */
> > > +
> > > +#include <linux/gpio.h>
> >
> > Don't include this header. It's documented as obsolete.
>
> [Ming] Okay! I'll drop it in the next patch.
>
> >
> > > +#include <linux/gpio/driver.h>
> > > +#include <linux/module.h>
> > > +#include <linux/interrupt.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/mfd/core.h>
> > > +#include <linux/mfd/nct6694.h>
> > > +
> >
> > You only use it once, drop it.
>
> [Ming] That line is blank, did you mean #include <linux/gpio.h>?
>
> >
> > > +#define DRVNAME "nct6694-gpio"

I meant this line. Just put the driver name in the driver struct
definition directly.

> > > +
> > > +/* Host interface */
> > > +#define REQUEST_GPIO_MOD               0xFF
> > > +#define REQUEST_GPIO_LEN               0x01
> > > +
> > > +/* Report Channel */
> > > +#define GPIO_VER_REG                   0x90
> > > +#define GPIO_VALID_REG                 0x110
> > > +#define GPI_DATA_REG                   0x120
> > > +#define GPO_DIR_REG                    0x170
> > > +#define GPO_TYPE_REG                   0x180
> > > +#define GPO_DATA_REG                   0x190
> > > +
> > > +#define GPI_STS_REG                    0x130
> > > +#define GPI_CLR_REG                    0x140
> > > +#define GPI_FALLING_REG                        0x150
> > > +#define GPI_RISING_REG                 0x160
> > > +
> >
> > Please use the NCT6694 prefix for these defines, otherwise it's not
> > clear whether they come from the driver or from GPIO core.
> >
> > []
>
> [Ming] Okay! I'll add the prefix to the defines in the next patch.
>
> >
> > > +
> > > +static const char * const nct6694_gpio_name[] = {
> > > +       "NCT6694-GPIO0",
> > > +       "NCT6694-GPIO1",
> > > +       "NCT6694-GPIO2",
> > > +       "NCT6694-GPIO3",
> > > +       "NCT6694-GPIO4",
> > > +       "NCT6694-GPIO5",
> > > +       "NCT6694-GPIO6",
> > > +       "NCT6694-GPIO7",
> > > +       "NCT6694-GPIO8",
> > > +       "NCT6694-GPIO9",
> > > +       "NCT6694-GPIOA",
> > > +       "NCT6694-GPIOB",
> > > +       "NCT6694-GPIOC",
> > > +       "NCT6694-GPIOD",
> > > +       "NCT6694-GPIOE",
> > > +       "NCT6694-GPIOF",
> > > +};
> >
> > This looks like it corresponds with the MFD cells and makes me wonder:
> > am I getting that wrong or do you want to register 0xf GPIO chips? Or
> > a single GPIO chip with 0xf lines? What is the topology?
>
> [Ming] Yes, it corresponds to the MFD cells.
> I would like to register 16 GPIO chips, each with 8 lines.
> The chip has 128 pins totally, the core can check if the pin is valid through
> the init_valid_mask() callback.
>

Ok, that's fine but the GPIO chip names should be in the MFD driver
only, it doesn't make sense to have them here. It's the MFD core that
will register the GPIO platform devices.

No for line names - as this is a dynamic USB expander, I'd suggest to
have them in the driver and assign to gc->names.

> >
> > > +
> > > +static int nct6694_gpio_probe(struct platform_device *pdev)
> > > +{
> > > +       const struct mfd_cell *cell = mfd_get_cell(pdev);
> > > +       struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> > > +       struct nct6694_gpio_data *data;
> > > +       struct gpio_irq_chip *girq;
> > > +       int ret;
> > > +
> > > +       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> > > +       if (!data)
> > > +               return -ENOMEM;
> > > +
> > > +       data->nct6694 = nct6694;
> > > +       data->group = cell->id;
> > > +
> > > +       data->gpio.label                = nct6694_gpio_name[cell->id];
> > > +       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                = 8;
> > > +
> > > +       INIT_WORK(&data->irq_work, nct6694_irq);
> > > +       INIT_WORK(&data->irq_trig_work, nct6694_irq_trig);
> > > +       mutex_init(&data->irq_lock);
> > > +
> > > +       ret = nct6694_register_handler(nct6694, GPIO_IRQ_STATUS,
> > > +                                      nct6694_gpio_handler, data);
> > > +       if (ret) {
> > > +               dev_err(&pdev->dev, "%s:  Failed to register handler: %pe\n",
> > > +                       __func__, ERR_PTR(ret));
> > > +               return ret;
> > > +       }
> > > +
> > > +       platform_set_drvdata(pdev, data);
> > > +
> > > +       ret = nct6694_get_irq_trig(data);
> > > +       if (ret)
> > > +               return ret;
> > > +
> > > +       /* 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 = gpiochip_add_data(&data->gpio, data);
> > > +       if (ret) {
> > > +               dev_err(&pdev->dev, "%s: Failed to register GPIO chip: %pe",
> > > +                       __func__, ERR_PTR(ret));
> > > +               return ret;
> > > +       }
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +static void nct6694_gpio_remove(struct platform_device *pdev)
> > > +{
> > > +       struct nct6694_gpio_data *data = platform_get_drvdata(pdev);
> > > +
> > > +       gpiochip_remove(&data->gpio);
> >
> > This should be dropped in favor of using devm_gpiochip_add_data().
> > Especially since you probably want to cancel the irq_work before
> > removing the chip.
>
> [Ming] Okay! I'll change it in the next patch.
>
> >
> > > +       cancel_work(&data->irq_work);
> > > +       cancel_work(&data->irq_trig_work);
> > > +}
> > > +
> > > +static struct platform_driver nct6694_gpio_driver = {
> > > +       .driver = {
> > > +               .name   = DRVNAME,
> > > +       },
> > > +       .probe          = nct6694_gpio_probe,
> > > +       .remove         = nct6694_gpio_remove,
> > > +};
> > > +
> > > +static int __init nct6694_init(void)
> > > +{
> > > +       int err;
> > > +
> > > +       err = platform_driver_register(&nct6694_gpio_driver);
> > > +       if (!err) {
> > > +               if (err)
> >
> > If err is equal to 0, check if it's not equal to zero?
> >
> > > +                       platform_driver_unregister(&nct6694_gpio_driver);
> >
> > If platform_driver_register() failed, then the device was never registered.
> >
> > > +       }
> > > +
> > > +       return err;
> > > +}
> > > +subsys_initcall(nct6694_init);
> >
> > Any reason why this must be initialized earlier? It's a USB driver after all.
>
> [Ming] For platform driver registration, I'll change it to
> module_platform_driver()
> in the next patch.
>

Thanks,
Bartosz

> >
> > > +
> > > +static void __exit nct6694_exit(void)
> > > +{
> > > +       platform_driver_unregister(&nct6694_gpio_driver);
> > > +}
> > > +module_exit(nct6694_exit);
> > > +
> > > +MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
> > > +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> > > +MODULE_LICENSE("GPL");
> > > --
> > > 2.34.1
> > >
> >
> > Bart
Ming Yu Oct. 28, 2024, 8:56 a.m. UTC | #5
Dear Bartosz,

Thank you for your comments,

Bartosz Golaszewski <brgl@bgdev.pl> 於 2024年10月25日 週五 下午3:47寫道:
>
> On Fri, Oct 25, 2024 at 9:39 AM 游子民 <a0282524688@gmail.com> wrote:
> >
> > Sorry, resending this email in plain text format.
> >
> > Dear Bart,
> >
> > Thank you for your comments.
> >
> > Bartosz Golaszewski <brgl@bgdev.pl> 於 2024年10月24日 週四 下午5:47寫道:
> > >
> > > On Thu, Oct 24, 2024 at 10:59 AM Ming Yu <a0282524688@gmail.com> wrote:
> > > >
> > > > 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 | 489 ++++++++++++++++++++++++++++++++++++
> > > >  4 files changed, 503 insertions(+)
> > > >  create mode 100644 drivers/gpio/gpio-nct6694.c
> > > >
> > > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > > index 30157ca95cf3..2c86d5dab3f1 100644
> > > > --- a/MAINTAINERS
> > > > +++ b/MAINTAINERS
> > > > @@ -16438,6 +16438,7 @@ 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 d93cd4f722b4..aa78ad9ff4ac 100644
> > > > --- a/drivers/gpio/Kconfig
> > > > +++ b/drivers/gpio/Kconfig
> > > > @@ -1450,6 +1450,18 @@ 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 1429e8c0229b..02c94aa28017 100644
> > > > --- a/drivers/gpio/Makefile
> > > > +++ b/drivers/gpio/Makefile
> > > > @@ -121,6 +121,7 @@ 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..42c0e6e76730
> > > > --- /dev/null
> > > > +++ b/drivers/gpio/gpio-nct6694.c
> > > > @@ -0,0 +1,489 @@
> > > > +// SPDX-License-Identifier: GPL-2.0
> > > > +/*
> > > > + * Nuvoton NCT6694 GPIO controller driver based on USB interface.
> > > > + *
> > > > + * Copyright (C) 2024 Nuvoton Technology Corp.
> > > > + */
> > > > +
> > > > +#include <linux/gpio.h>
> > >
> > > Don't include this header. It's documented as obsolete.
> >
> > [Ming] Okay! I'll drop it in the next patch.
> >
> > >
> > > > +#include <linux/gpio/driver.h>
> > > > +#include <linux/module.h>
> > > > +#include <linux/interrupt.h>
> > > > +#include <linux/platform_device.h>
> > > > +#include <linux/mfd/core.h>
> > > > +#include <linux/mfd/nct6694.h>
> > > > +
> > >
> > > You only use it once, drop it.
> >
> > [Ming] That line is blank, did you mean #include <linux/gpio.h>?
> >
> > >
> > > > +#define DRVNAME "nct6694-gpio"
>
> I meant this line. Just put the driver name in the driver struct
> definition directly.
>
> > > > +
> > > > +/* Host interface */
> > > > +#define REQUEST_GPIO_MOD               0xFF
> > > > +#define REQUEST_GPIO_LEN               0x01
> > > > +
> > > > +/* Report Channel */
> > > > +#define GPIO_VER_REG                   0x90
> > > > +#define GPIO_VALID_REG                 0x110
> > > > +#define GPI_DATA_REG                   0x120
> > > > +#define GPO_DIR_REG                    0x170
> > > > +#define GPO_TYPE_REG                   0x180
> > > > +#define GPO_DATA_REG                   0x190
> > > > +
> > > > +#define GPI_STS_REG                    0x130
> > > > +#define GPI_CLR_REG                    0x140
> > > > +#define GPI_FALLING_REG                        0x150
> > > > +#define GPI_RISING_REG                 0x160
> > > > +
> > >
> > > Please use the NCT6694 prefix for these defines, otherwise it's not
> > > clear whether they come from the driver or from GPIO core.
> > >
> > > []
> >
> > [Ming] Okay! I'll add the prefix to the defines in the next patch.
> >
> > >
> > > > +
> > > > +static const char * const nct6694_gpio_name[] = {
> > > > +       "NCT6694-GPIO0",
> > > > +       "NCT6694-GPIO1",
> > > > +       "NCT6694-GPIO2",
> > > > +       "NCT6694-GPIO3",
> > > > +       "NCT6694-GPIO4",
> > > > +       "NCT6694-GPIO5",
> > > > +       "NCT6694-GPIO6",
> > > > +       "NCT6694-GPIO7",
> > > > +       "NCT6694-GPIO8",
> > > > +       "NCT6694-GPIO9",
> > > > +       "NCT6694-GPIOA",
> > > > +       "NCT6694-GPIOB",
> > > > +       "NCT6694-GPIOC",
> > > > +       "NCT6694-GPIOD",
> > > > +       "NCT6694-GPIOE",
> > > > +       "NCT6694-GPIOF",
> > > > +};
> > >
> > > This looks like it corresponds with the MFD cells and makes me wonder:
> > > am I getting that wrong or do you want to register 0xf GPIO chips? Or
> > > a single GPIO chip with 0xf lines? What is the topology?
> >
> > [Ming] Yes, it corresponds to the MFD cells.
> > I would like to register 16 GPIO chips, each with 8 lines.
> > The chip has 128 pins totally, the core can check if the pin is valid through
> > the init_valid_mask() callback.
> >
>
> Ok, that's fine but the GPIO chip names should be in the MFD driver
> only, it doesn't make sense to have them here. It's the MFD core that
> will register the GPIO platform devices.

I understand. I will remove it.

>
> No for line names - as this is a dynamic USB expander, I'd suggest to
> have them in the driver and assign to gc->names.

Could I create an array to map each of the GPIO pins?

>
> > >
> > > > +
> > > > +static int nct6694_gpio_probe(struct platform_device *pdev)
> > > > +{
> > > > +       const struct mfd_cell *cell = mfd_get_cell(pdev);
> > > > +       struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> > > > +       struct nct6694_gpio_data *data;
> > > > +       struct gpio_irq_chip *girq;
> > > > +       int ret;
> > > > +
> > > > +       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> > > > +       if (!data)
> > > > +               return -ENOMEM;
> > > > +
> > > > +       data->nct6694 = nct6694;
> > > > +       data->group = cell->id;
> > > > +
> > > > +       data->gpio.label                = nct6694_gpio_name[cell->id];
> > > > +       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                = 8;
> > > > +
> > > > +       INIT_WORK(&data->irq_work, nct6694_irq);
> > > > +       INIT_WORK(&data->irq_trig_work, nct6694_irq_trig);
> > > > +       mutex_init(&data->irq_lock);
> > > > +
> > > > +       ret = nct6694_register_handler(nct6694, GPIO_IRQ_STATUS,
> > > > +                                      nct6694_gpio_handler, data);
> > > > +       if (ret) {
> > > > +               dev_err(&pdev->dev, "%s:  Failed to register handler: %pe\n",
> > > > +                       __func__, ERR_PTR(ret));
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       platform_set_drvdata(pdev, data);
> > > > +
> > > > +       ret = nct6694_get_irq_trig(data);
> > > > +       if (ret)
> > > > +               return ret;
> > > > +
> > > > +       /* 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 = gpiochip_add_data(&data->gpio, data);
> > > > +       if (ret) {
> > > > +               dev_err(&pdev->dev, "%s: Failed to register GPIO chip: %pe",
> > > > +                       __func__, ERR_PTR(ret));
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > > +static void nct6694_gpio_remove(struct platform_device *pdev)
> > > > +{
> > > > +       struct nct6694_gpio_data *data = platform_get_drvdata(pdev);
> > > > +
> > > > +       gpiochip_remove(&data->gpio);
> > >
> > > This should be dropped in favor of using devm_gpiochip_add_data().
> > > Especially since you probably want to cancel the irq_work before
> > > removing the chip.
> >
> > [Ming] Okay! I'll change it in the next patch.
> >
> > >
> > > > +       cancel_work(&data->irq_work);
> > > > +       cancel_work(&data->irq_trig_work);
> > > > +}
> > > > +
> > > > +static struct platform_driver nct6694_gpio_driver = {
> > > > +       .driver = {
> > > > +               .name   = DRVNAME,
> > > > +       },
> > > > +       .probe          = nct6694_gpio_probe,
> > > > +       .remove         = nct6694_gpio_remove,
> > > > +};
> > > > +
> > > > +static int __init nct6694_init(void)
> > > > +{
> > > > +       int err;
> > > > +
> > > > +       err = platform_driver_register(&nct6694_gpio_driver);
> > > > +       if (!err) {
> > > > +               if (err)
> > >
> > > If err is equal to 0, check if it's not equal to zero?
> > >
> > > > +                       platform_driver_unregister(&nct6694_gpio_driver);
> > >
> > > If platform_driver_register() failed, then the device was never registered.
> > >
> > > > +       }
> > > > +
> > > > +       return err;
> > > > +}
> > > > +subsys_initcall(nct6694_init);
> > >
> > > Any reason why this must be initialized earlier? It's a USB driver after all.
> >
> > [Ming] For platform driver registration, I'll change it to
> > module_platform_driver()
> > in the next patch.
> >
>
> Thanks,
> Bartosz
>
> > >
> > > > +
> > > > +static void __exit nct6694_exit(void)
> > > > +{
> > > > +       platform_driver_unregister(&nct6694_gpio_driver);
> > > > +}
> > > > +module_exit(nct6694_exit);
> > > > +
> > > > +MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
> > > > +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> > > > +MODULE_LICENSE("GPL");
> > > > --
> > > > 2.34.1
> > > >
> > >
> > > Bart

Best regards,
Ming
Bartosz Golaszewski Oct. 30, 2024, 7:32 p.m. UTC | #6
On Mon, Oct 28, 2024 at 9:57 AM Ming Yu <a0282524688@gmail.com> wrote:
>
> >
> > No for line names - as this is a dynamic USB expander, I'd suggest to
> > have them in the driver and assign to gc->names.
>
> Could I create an array to map each of the GPIO pins?
>

Please trim the quoted email to only the relevant parts.

I'm not sure what you mean by that. There's a field in struct
gpio_chip which you can use to set the line names from the driver
code.

Bart
Ming Yu Nov. 1, 2024, 6:15 a.m. UTC | #7
Bartosz Golaszewski <brgl@bgdev.pl> 於 2024年10月31日 週四 上午3:32寫道:
>
> > > No for line names - as this is a dynamic USB expander, I'd suggest to
> > > have them in the driver and assign to gc->names.
> >
> > Could I create an array to map each of the GPIO pins?
> >
>
> Please trim the quoted email to only the relevant parts.
>
> I'm not sure what you mean by that. There's a field in struct
> gpio_chip which you can use to set the line names from the driver
> code.
>

Understood, thank you very much.

Best regards
Ming
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 30157ca95cf3..2c86d5dab3f1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16438,6 +16438,7 @@  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 d93cd4f722b4..aa78ad9ff4ac 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1450,6 +1450,18 @@  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 1429e8c0229b..02c94aa28017 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -121,6 +121,7 @@  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..42c0e6e76730
--- /dev/null
+++ b/drivers/gpio/gpio-nct6694.c
@@ -0,0 +1,489 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 GPIO controller driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+
+#define DRVNAME "nct6694-gpio"
+
+/* Host interface */
+#define REQUEST_GPIO_MOD		0xFF
+#define REQUEST_GPIO_LEN		0x01
+
+/* Report Channel */
+#define GPIO_VER_REG			0x90
+#define GPIO_VALID_REG			0x110
+#define GPI_DATA_REG			0x120
+#define GPO_DIR_REG			0x170
+#define GPO_TYPE_REG			0x180
+#define GPO_DATA_REG			0x190
+
+#define GPI_STS_REG			0x130
+#define GPI_CLR_REG			0x140
+#define GPI_FALLING_REG			0x150
+#define GPI_RISING_REG			0x160
+
+struct nct6694_gpio_data {
+	struct nct6694 *nct6694;
+	struct gpio_chip gpio;
+	struct work_struct irq_work;
+	struct work_struct irq_trig_work;
+
+	/* Protect irq operation */
+	struct mutex irq_lock;
+
+	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);
+	unsigned char buf;
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPO_DIR_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	return !(BIT(offset) & buf);
+}
+
+static int nct6694_direction_input(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	unsigned char buf;
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPO_DIR_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	buf &= ~(1 << offset);
+
+	ret = nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+				GPO_DIR_REG + data->group,
+				REQUEST_GPIO_LEN, &buf);
+
+	return ret;
+}
+
+static int nct6694_direction_output(struct gpio_chip *gpio,
+				    unsigned int offset, int val)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	unsigned char buf;
+	int ret;
+
+	/* Set direction to output */
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPO_DIR_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	buf |= (1 << offset);
+	ret = nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+				GPO_DIR_REG + data->group,
+				REQUEST_GPIO_LEN, &buf);
+	if (ret < 0)
+		return ret;
+
+	/* Then set output level */
+	ret = nct6694_read_msg(data->nct6694, 0xFF,
+			       GPO_DATA_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	if (val)
+		buf |= (1 << offset);
+	else
+		buf &= ~(1 << offset);
+
+	ret = nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+				GPO_DATA_REG + data->group,
+				REQUEST_GPIO_LEN, &buf);
+
+	return ret;
+}
+
+static int nct6694_get_value(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	unsigned char buf;
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPO_DIR_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	if (BIT(offset) & buf) {
+		ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+				       GPO_DATA_REG + data->group,
+				       REQUEST_GPIO_LEN, 0, 1, &buf);
+		if (ret < 0)
+			return ret;
+
+		return !!(BIT(offset) & buf);
+	}
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPI_DATA_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	return !!(BIT(offset) & buf);
+}
+
+static void nct6694_set_value(struct gpio_chip *gpio, unsigned int offset,
+			      int val)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	unsigned char buf;
+
+	nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			 GPO_DATA_REG + data->group,
+			 REQUEST_GPIO_LEN, 0, 1, &buf);
+
+	if (val)
+		buf |= (1 << offset);
+	else
+		buf &= ~(1 << offset);
+
+	nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+			  GPO_DATA_REG + data->group,
+			  REQUEST_GPIO_LEN, &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);
+	unsigned char buf;
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPO_TYPE_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+		buf |= (1 << offset);
+		break;
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		buf &= ~(1 << offset);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	ret = nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+				GPO_TYPE_REG + data->group,
+				REQUEST_GPIO_LEN, &buf);
+
+	return ret;
+}
+
+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);
+	unsigned char buf;
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPIO_VALID_REG + data->group,
+			       REQUEST_GPIO_LEN, 0, 1, &buf);
+	if (ret < 0)
+		return ret;
+
+	*valid_mask = buf;
+
+	return ret;
+}
+
+static void nct6694_irq(struct work_struct *irq_work)
+{
+	struct nct6694_gpio_data *data;
+	unsigned char status;
+
+	data = container_of(irq_work, struct nct6694_gpio_data, irq_work);
+
+	nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			 GPI_STS_REG + data->group, 1,
+			 0, 1, &status);
+
+	while (status) {
+		int bit = __ffs(status);
+		unsigned char val = BIT(bit);
+
+		handle_nested_irq(irq_find_mapping(data->gpio.irq.domain, bit));
+		status &= ~(1 << bit);
+		nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+				  GPI_CLR_REG + data->group,
+				  REQUEST_GPIO_LEN, &val);
+	}
+}
+
+static void nct6694_gpio_handler(void *private_data)
+{
+	struct nct6694_gpio_data *data = private_data;
+	struct nct6694 *nct6694 = data->nct6694;
+
+	queue_work(nct6694->async_workqueue, &data->irq_work);
+}
+
+static int nct6694_get_irq_trig(struct nct6694_gpio_data *data)
+{
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPI_FALLING_REG + data->group,
+			       1, 0, 1, &data->irq_trig_falling);
+	if (ret)
+		return ret;
+
+	ret = nct6694_read_msg(data->nct6694, REQUEST_GPIO_MOD,
+			       GPI_RISING_REG + data->group,
+			       1, 0, 1, &data->irq_trig_rising);
+
+	return ret;
+}
+
+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 void nct6694_irq_trig(struct work_struct *irq_trig_work)
+{
+	struct nct6694_gpio_data *data;
+
+	data = container_of(irq_trig_work, struct nct6694_gpio_data,
+			    irq_trig_work);
+
+	nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+			  GPI_FALLING_REG + data->group,
+			  1, &data->irq_trig_falling);
+
+	nct6694_write_msg(data->nct6694, REQUEST_GPIO_MOD,
+			  GPI_RISING_REG + data->group,
+			  1, &data->irq_trig_rising);
+}
+
+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);
+	struct nct6694 *nct6694 = data->nct6694;
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+	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 -EOPNOTSUPP;
+	}
+
+	queue_work(nct6694->async_workqueue, &data->irq_trig_work);
+
+	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);
+
+	mutex_unlock(&data->irq_lock);
+}
+
+static const struct irq_chip nct6694_irq_chip = {
+	.name			= "nct6694",
+	.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 const char * const nct6694_gpio_name[] = {
+	"NCT6694-GPIO0",
+	"NCT6694-GPIO1",
+	"NCT6694-GPIO2",
+	"NCT6694-GPIO3",
+	"NCT6694-GPIO4",
+	"NCT6694-GPIO5",
+	"NCT6694-GPIO6",
+	"NCT6694-GPIO7",
+	"NCT6694-GPIO8",
+	"NCT6694-GPIO9",
+	"NCT6694-GPIOA",
+	"NCT6694-GPIOB",
+	"NCT6694-GPIOC",
+	"NCT6694-GPIOD",
+	"NCT6694-GPIOE",
+	"NCT6694-GPIOF",
+};
+
+static int nct6694_gpio_probe(struct platform_device *pdev)
+{
+	const struct mfd_cell *cell = mfd_get_cell(pdev);
+	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+	struct nct6694_gpio_data *data;
+	struct gpio_irq_chip *girq;
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->nct6694 = nct6694;
+	data->group = cell->id;
+
+	data->gpio.label		= nct6694_gpio_name[cell->id];
+	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		= 8;
+
+	INIT_WORK(&data->irq_work, nct6694_irq);
+	INIT_WORK(&data->irq_trig_work, nct6694_irq_trig);
+	mutex_init(&data->irq_lock);
+
+	ret = nct6694_register_handler(nct6694, GPIO_IRQ_STATUS,
+				       nct6694_gpio_handler, data);
+	if (ret) {
+		dev_err(&pdev->dev, "%s:  Failed to register handler: %pe\n",
+			__func__, ERR_PTR(ret));
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	ret = nct6694_get_irq_trig(data);
+	if (ret)
+		return ret;
+
+	/* 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 = gpiochip_add_data(&data->gpio, data);
+	if (ret) {
+		dev_err(&pdev->dev, "%s: Failed to register GPIO chip: %pe",
+			__func__, ERR_PTR(ret));
+		return ret;
+	}
+
+	return 0;
+}
+
+static void nct6694_gpio_remove(struct platform_device *pdev)
+{
+	struct nct6694_gpio_data *data = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&data->gpio);
+	cancel_work(&data->irq_work);
+	cancel_work(&data->irq_trig_work);
+}
+
+static struct platform_driver nct6694_gpio_driver = {
+	.driver = {
+		.name	= DRVNAME,
+	},
+	.probe		= nct6694_gpio_probe,
+	.remove		= nct6694_gpio_remove,
+};
+
+static int __init nct6694_init(void)
+{
+	int err;
+
+	err = platform_driver_register(&nct6694_gpio_driver);
+	if (!err) {
+		if (err)
+			platform_driver_unregister(&nct6694_gpio_driver);
+	}
+
+	return err;
+}
+subsys_initcall(nct6694_init);
+
+static void __exit nct6694_exit(void)
+{
+	platform_driver_unregister(&nct6694_gpio_driver);
+}
+module_exit(nct6694_exit);
+
+MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");