From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
To: Kent Gibson <warthog618@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
linux-gpio <linux-gpio@vger.kernel.org>,
Linus Walleij <linus.walleij@linaro.org>
Subject: Re: [PATCH 14/22] gpiolib: make cdev a build option
Date: Mon, 29 Jun 2020 16:25:22 +0200 [thread overview]
Message-ID: <CAMpxmJVQmo2S6AQgcPACHH8ziSQNUvAhkUJ3eW_YsLkbyGzm=Q@mail.gmail.com> (raw)
In-Reply-To: <20200623040107.22270-15-warthog618@gmail.com>
On Tue, Jun 23, 2020 at 6:02 AM Kent Gibson <warthog618@gmail.com> wrote:
>
> Make the gpiolib-cdev module a build option. This allows the CDEV
> interface to be removed from the kernel to reduce kernel size in
> applications where is it not required, and provides the parent for
> other other CDEV interface specific build options to follow.
>
> Suggested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> Signed-off-by: Kent Gibson <warthog618@gmail.com>
>
> ---
> drivers/gpio/Kconfig | 16 ++++++++++++++--
> drivers/gpio/Makefile | 2 +-
> drivers/gpio/gpiolib-cdev.h | 15 +++++++++++++++
> 3 files changed, 30 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index c6b5c65c8405..affc1524bc2c 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -66,8 +66,20 @@ config GPIO_SYSFS
>
> This ABI is deprecated. If you want to use GPIO from userspace,
> use the character device /dev/gpiochipN with the appropriate
> - ioctl() operations instead. The character device is always
> - available.
> + ioctl() operations instead.
> +
> +config GPIO_CDEV
> + bool "/dev/gpiochipN (character device interface)"
> + default y
> + help
> + Say Y here to add the character device /dev/gpiochipN interface
> + for GPIOs. The character device allows userspace to control GPIOs
> + using ioctl() operations.
> +
> + Only say N is you are sure that the GPIO character device is not
> + required.
> +
> + If unsure, say Y.
>
> config GPIO_GENERIC
> depends on HAS_IOMEM # Only for IOMEM drivers
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index ef666cfef9d0..45eb09808d12 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -7,8 +7,8 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o
> obj-$(CONFIG_GPIOLIB) += gpiolib-devres.o
> obj-$(CONFIG_GPIOLIB) += gpiolib-legacy.o
> obj-$(CONFIG_GPIOLIB) += gpiolib-devprop.o
> -obj-$(CONFIG_GPIOLIB) += gpiolib-cdev.o
> obj-$(CONFIG_OF_GPIO) += gpiolib-of.o
> +obj-$(CONFIG_GPIO_CDEV) += gpiolib-cdev.o
> obj-$(CONFIG_GPIO_SYSFS) += gpiolib-sysfs.o
> obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o
>
> diff --git a/drivers/gpio/gpiolib-cdev.h b/drivers/gpio/gpiolib-cdev.h
> index 973578e7ad10..19a4e3d57120 100644
> --- a/drivers/gpio/gpiolib-cdev.h
> +++ b/drivers/gpio/gpiolib-cdev.h
> @@ -5,7 +5,22 @@
>
> #include <linux/device.h>
>
> +#ifdef CONFIG_GPIO_CDEV
> +
> int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt);
> void gpiolib_cdev_unregister(struct gpio_device *gdev);
>
> +#else
> +
> +static inline int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
> +{
> + return 0;
> +}
> +
> +static inline void gpiolib_cdev_unregister(struct gpio_device *gdev)
> +{
> +}
> +
> +#endif /* CONFIG_GPIO_CDEV */
> +
> #endif /* GPIOLIB_CDEV_H */
> --
> 2.27.0
>
I know Linus doesn't like this, but I'm personally in favor of adding
this as long as it's enabled by default.
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
next prev parent reply other threads:[~2020-06-29 20:41 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 4:00 [PATCH 00/22] gpio: cdev: add uAPI V2 Kent Gibson
2020-06-23 4:00 ` [PATCH 01/22] gpiolib: move gpiolib-sysfs function declarations into their own header Kent Gibson
2020-06-24 13:34 ` Bartosz Golaszewski
2020-06-24 13:38 ` Kent Gibson
2020-06-23 4:00 ` [PATCH 02/22] gpiolib: cdev: sort includes Kent Gibson
2020-06-24 13:34 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 03/22] gpiolib: cdev: minor indentation fixes Kent Gibson
2020-06-24 13:35 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 04/22] gpiolib: cdev: refactor gpiohandle_flags_to_desc_flags Kent Gibson
2020-06-24 13:51 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 05/22] gpiolib: cdev: rename 'filep' and 'filp' to 'file' to be consistent with other use Kent Gibson
2020-06-24 13:52 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 06/22] gpiolib: cdev: rename numdescs to num_descs Kent Gibson
2020-06-24 13:53 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 07/22] gpiolib: cdev: remove pointless decrement of i Kent Gibson
2020-06-24 13:53 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 08/22] gpiolib: cdev: complete the irq/thread timestamp handshake Kent Gibson
2020-06-24 14:00 ` Bartosz Golaszewski
2020-06-24 14:08 ` Kent Gibson
2020-06-25 9:44 ` Bartosz Golaszewski
2020-06-25 10:01 ` Kent Gibson
2020-06-30 9:08 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 09/22] gpiolib: cdev: rename priv to gcdev Kent Gibson
2020-06-24 14:04 ` Bartosz Golaszewski
2020-06-24 14:19 ` Kent Gibson
2020-06-24 14:20 ` Bartosz Golaszewski
2020-06-24 23:16 ` Kent Gibson
2020-06-25 10:26 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 10/22] gpiolib: cdev: fix minor race in GET_LINEINFO_WATCH Kent Gibson
2020-06-24 14:05 ` Bartosz Golaszewski
2020-06-24 14:46 ` Andy Shevchenko
2020-06-24 15:57 ` Kent Gibson
2020-06-24 22:58 ` Kent Gibson
2020-06-25 8:44 ` Andy Shevchenko
2020-06-25 9:13 ` Kent Gibson
2020-06-25 9:23 ` Andy Shevchenko
2020-06-25 9:36 ` Kent Gibson
2020-06-23 4:00 ` [PATCH 11/22] gpiolib: cdev: remove recalculation of offset Kent Gibson
2020-06-30 8:56 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 12/22] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes Kent Gibson
2020-06-24 14:13 ` Bartosz Golaszewski
2020-06-23 4:00 ` [PATCH 13/22] gpio: uapi: define uAPI V2 Kent Gibson
2020-06-24 14:33 ` Andy Shevchenko
2020-06-24 15:40 ` Kent Gibson
2020-06-26 14:02 ` Kent Gibson
2020-06-24 14:36 ` Bartosz Golaszewski
2020-06-24 23:58 ` Kent Gibson
2020-06-23 4:00 ` [PATCH 14/22] gpiolib: make cdev a build option Kent Gibson
2020-06-29 14:25 ` Bartosz Golaszewski [this message]
2020-06-23 4:01 ` [PATCH 15/22] gpiolib: add build option for CDEV V1 ABI Kent Gibson
2020-06-29 14:26 ` Bartosz Golaszewski
2020-06-23 4:01 ` [PATCH 16/22] gpiolib: cdev: add V2 uAPI implementation to parity with V1 Kent Gibson
2020-06-23 17:44 ` Dan Carpenter
2020-06-23 23:23 ` Kent Gibson
2020-06-23 4:01 ` [PATCH 17/22] gpiolib: cdev: report edge detection in lineinfo Kent Gibson
2020-06-23 4:01 ` [PATCH 18/22] gpiolib: cdev: support setting debounce Kent Gibson
2020-06-23 4:01 ` [PATCH 19/22] gpio: uapi: document uAPI V1 as deprecated Kent Gibson
2020-06-23 4:01 ` [PATCH 20/22] tools: gpio: switch tools to V2 uAPI Kent Gibson
2020-06-23 4:01 ` [PATCH 21/22] tools: gpio: add debounce support to gpio-event-mon Kent Gibson
2020-06-23 4:01 ` [PATCH 22/22] tools: gpio: support monitoring multiple lines Kent Gibson
2020-06-30 10:43 ` Bartosz Golaszewski
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