Re: [RFC 2/5] gpiolib: export descriptor-based GPIO interface

From: Stephen Warren
Date: Wed Sep 04 2013 - 15:58:23 EST


On 09/04/2013 05:29 AM, Alexandre Courbot wrote:
> This patch exports the gpiod_* family of API functions, a safer
> alternative to the legacy gpio interface. Differences between the gpiod
> and gpio APIs are:
>
> - gpio works with integers, whereas gpiod operates on opaque handlers
> which cannot be forged or used before proper acquisition
> - gpiod get/set functions are aware of the active low state of a GPIO
> - gpio consumers should now include <linux/gpio/consumer.h> to access
> the new interface, whereas chips drivers will use
> <linux/gpio/driver.h>
>
> The legacy gpio API is now built as inline functions on top of gpiod.
>

> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h

> +struct gpio_chip {

> + int (*get_direction)(struct gpio_chip *chip,
> + unsigned offset);
> + int (*direction_input)(struct gpio_chip *chip,
> + unsigned offset);
> + int (*get)(struct gpio_chip *chip,
> + unsigned offset);
> + int (*direction_output)(struct gpio_chip *chip,
> + unsigned offset, int value);
> + int (*set_debounce)(struct gpio_chip *chip,
> + unsigned offset,
> + unsigned debounce);
> +
> + void (*set)(struct gpio_chip *chip,
> + unsigned offset, int value);
> +

Minor nit: It might be nice to sort/group these entries more cohesively,
i.e. get_direction, direction_input, direction_output, get, set,
set_debounce?
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