diff mbox series

[v8,05/20] gpiolib: make cdev a build option

Message ID 20200909102640.1657622-6-warthog618@gmail.com
State New
Headers show
Series gpio: cdev: add uAPI v2 | expand

Commit Message

Kent Gibson Sept. 9, 2020, 10:26 a.m. UTC
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        | 17 +++++++++++++++--
 drivers/gpio/Makefile       |  2 +-
 drivers/gpio/gpiolib-cdev.h | 15 +++++++++++++++
 3 files changed, 31 insertions(+), 3 deletions(-)

Comments

Andy Shevchenko Sept. 15, 2020, 10:12 a.m. UTC | #1
On Wed, Sep 9, 2020 at 1:30 PM 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.

In favour of tiny builds!
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Suggested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> Signed-off-by: Kent Gibson <warthog618@gmail.com>
> ---
>  drivers/gpio/Kconfig        | 17 +++++++++++++++--
>  drivers/gpio/Makefile       |  2 +-
>  drivers/gpio/gpiolib-cdev.h | 15 +++++++++++++++
>  3 files changed, 31 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 5cfdaf3b004d..e4debd66d71f 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -66,8 +66,21 @@ 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
> +       prompt "Character device (/dev/gpiochipN) support" if EXPERT
> +       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 if 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 4f9abff4f2dc..7c24c8d77068 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 */
> --
> 2.28.0
>
diff mbox series

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 5cfdaf3b004d..e4debd66d71f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -66,8 +66,21 @@  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
+	prompt "Character device (/dev/gpiochipN) support" if EXPERT
+	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 if 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 4f9abff4f2dc..7c24c8d77068 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 */