Re: [PATCH] gpiolib: make legacy interfaces optional

[Alexander Sverdlin <alexander.sverdlin@gmail.com>]

On Tue, 2025-07-22 at 17:35 +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The traditional interfaces are only used on a small number of ancient
> boards. Make these optional now so they can be disabled by default.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>

> ---
> This is the first patch of a series to turn off the legacy interfaces
> by default. If we can still have this one in linux-6.17, we can more
> easily merge the other patches for 6.18.
> 
> See for the longer series:
> https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=config-gpio-legacy
> 
> I'm sure there are still problems in the other patches, but it
> does pass my randconfig build tests on the three architectures
> I'm testing on. I plan to post them after some more testing
> once -rc1 is out.
> 
>  drivers/gpio/Kconfig  |  3 +++
>  drivers/gpio/Makefile |  2 +-
>  include/linux/gpio.h  | 10 ++++++----
>  3 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 12bdf6e965f1..8bda3c9d47b4 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -14,6 +14,9 @@ menuconfig GPIOLIB
>  
>  if GPIOLIB
>  
> +config GPIOLIB_LEGACY
> +	def_bool y
> +
>  config GPIOLIB_FASTPATH_LIMIT
>  	int "Maximum number of GPIOs for fast path"
>  	range 32 512
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 88dedd298256..b01ff2b68bf6 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -5,7 +5,7 @@ ccflags-$(CONFIG_DEBUG_GPIO)	+= -DDEBUG
>  
>  obj-$(CONFIG_GPIOLIB)		+= gpiolib.o
>  obj-$(CONFIG_GPIOLIB)		+= gpiolib-devres.o
> -obj-$(CONFIG_GPIOLIB)		+= gpiolib-legacy.o
> +obj-$(CONFIG_GPIOLIB_LEGACY)	+= gpiolib-legacy.o
>  obj-$(CONFIG_OF_GPIO)		+= gpiolib-of.o
>  obj-$(CONFIG_GPIO_CDEV)		+= gpiolib-cdev.o
>  obj-$(CONFIG_GPIO_SYSFS)	+= gpiolib-sysfs.o
> diff --git a/include/linux/gpio.h b/include/linux/gpio.h
> index ff99ed76fdc3..8f85ddb26429 100644
> --- a/include/linux/gpio.h
> +++ b/include/linux/gpio.h
> @@ -13,6 +13,11 @@
>  #define __LINUX_GPIO_H
>  
>  #include <linux/types.h>
> +#ifdef CONFIG_GPIOLIB
> +#include <linux/gpio/consumer.h>
> +#endif
> +
> +#ifdef CONFIG_GPIOLIB_LEGACY
>  
>  struct device;
>  
> @@ -22,9 +27,6 @@ struct device;
>  #define GPIOF_OUT_INIT_HIGH	((0 << 0) | (1 << 1))
>  
>  #ifdef CONFIG_GPIOLIB
> -
> -#include <linux/gpio/consumer.h>
> -
>  /*
>   * "valid" GPIO numbers are nonnegative and may be passed to
>   * setup routines like gpio_request().  Only some valid numbers
> @@ -170,5 +172,5 @@ static inline int devm_gpio_request_one(struct device *dev, unsigned gpio,
>  }
>  
>  #endif /* ! CONFIG_GPIOLIB */
> -
> +#endif /* CONFIG_GPIOLIB_LEGACY */
>  #endif /* __LINUX_GPIO_H */

-- 
Alexander Sverdlin.