śr., 27 lis 2019 o 14:59 Marco Felsch <m.felsch@xxxxxxxxxxxxxx> napisał(a):
>
> Sometimes consumers needs to know the gpio-chip local gpio number of a
> 'struct gpio_desc' for further configuration. This is often the case for
> mfd devices.
>
We already have this support. It's just a matter of exporting it, so
maybe adjust the commit message to not be confusing.
That being said: I'm not really a fan of this - the whole idea of gpio
descriptors was to make them opaque and their hardware offsets
irrelevant. :(
> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> ---
> drivers/gpio/gpiolib.c | 6 ++++++
> include/linux/gpio/consumer.h | 10 ++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 104ed299d5ea..7709648313fc 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -4377,6 +4377,12 @@ int gpiod_count(struct device *dev, const char *con_id)
> }
> EXPORT_SYMBOL_GPL(gpiod_count);
>
> +int gpiod_to_offset(struct gpio_desc *desc)
Maybe call it: gpiod_desc_to_offset()?
> +{
> + return gpio_chip_hwgpio(desc);
> +}
> +EXPORT_SYMBOL_GPL(gpiod_to_offset);
> +
> /**
> * gpiod_get - obtain a GPIO for a given GPIO function
> * @dev: GPIO consumer, can be NULL for system-global GPIOs
> diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
> index b70af921c614..e2178c3bf7fd 100644
> --- a/include/linux/gpio/consumer.h
> +++ b/include/linux/gpio/consumer.h
> @@ -60,6 +60,9 @@ enum gpiod_flags {
> /* Return the number of GPIOs associated with a device / function */
> int gpiod_count(struct device *dev, const char *con_id);
>
> +/* Get the local chip offset from a global desc */
> +int gpiod_to_offset(struct gpio_desc *desc);
> +
> /* Acquire and dispose GPIOs */
> struct gpio_desc *__must_check gpiod_get(struct device *dev,
> const char *con_id,
> @@ -189,6 +192,13 @@ static inline int gpiod_count(struct device *dev, const char *con_id)
> return 0;
> }
>
> +static inline int gpiod_to_offset(struct gpio_desc *desc)
> +{
> + /* GPIO can never have been requested */
> + WARN_ON(desc);
> + return 0;
> +}
> +
> static inline struct gpio_desc *__must_check gpiod_get(struct device *dev,
> const char *con_id,
> enum gpiod_flags flags)
> --
> 2.20.1
>
