Re: [RFC] gpiolib: import gpio_request_array() from linux 3.7

[Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>]

On 23:16 Sun 03 Feb     , Antony Pavlov wrote:
> Also import related functions gpio_request_one() and
> gpio_free_array().
> 
> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> ---
>  drivers/gpio/gpio.c |   66 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/gpio.h      |   43 +++++++++++++++++++++++++++++++++
>  2 files changed, 109 insertions(+)
> 
> diff --git a/drivers/gpio/gpio.c b/drivers/gpio/gpio.c
> index d37f5a0..631168d 100644
> --- a/drivers/gpio/gpio.c
> +++ b/drivers/gpio/gpio.c
> @@ -65,6 +65,72 @@ void gpio_free(unsigned gpio)
>  	free(gi->label);
>  }
>  
> +/**
> + * gpio_request_one - request a single GPIO with initial configuration
> + * @gpio:	the GPIO number
> + * @flags:	GPIO configuration as specified by GPIOF_*
> + * @label:	a literal description string of this GPIO
> + */
> +int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
> +{
> +	int err;
> +
> +	err = gpio_request(gpio, label);
> +	if (err)
> +		return err;
> +
> +	if (flags & GPIOF_DIR_IN)
> +		err = gpio_direction_input(gpio);
> +	else
> +		err = gpio_direction_output(gpio,
> +				(flags & GPIOF_INIT_HIGH) ? 1 : 0);
> +
> +	if (err)
> +		goto free_gpio;
> +
> +	return 0;
> +
> +free_gpio:
> +	gpio_free(gpio);
> +	return err;
> +}
> +EXPORT_SYMBOL(gpio_request_one);
> +
> +/**
> + * gpio_request_array - request multiple GPIOs in a single call
> + * @array:	array of the 'struct gpio'
> + * @num:	how many GPIOs in the array
> + */
> +int gpio_request_array(const struct gpio *array, size_t num)
> +{
> +	int i, err;
> +
> +	for (i = 0; i < num; i++, array++) {
> +		err = gpio_request_one(array->gpio, array->flags, array->label);
> +		if (err)
> +			goto err_free;
> +	}
> +	return 0;
> +
> +err_free:
> +	while (i--)
> +		gpio_free((--array)->gpio);
> +	return err;
> +}
> +EXPORT_SYMBOL(gpio_request_array);
> +
> +/**
> + * gpio_free_array - release multiple GPIOs in a single call
> + * @array:	array of the 'struct gpio'
> + * @num:	how many GPIOs in the array
> + */
> +void gpio_free_array(const struct gpio *array, size_t num)
> +{
> +	while (num--)
> +		gpio_free((array++)->gpio);
> +}
> +EXPORT_SYMBOL(gpio_free_array);
> +
>  void gpio_set_value(unsigned gpio, int value)
>  {
>  	struct gpio_info *gi = &gpio_desc[gpio];
> diff --git a/include/gpio.h b/include/gpio.h
> index eedb980..37c151d 100644
> --- a/include/gpio.h
> +++ b/include/gpio.h
> @@ -3,6 +3,29 @@
>  
>  #include <asm/gpio.h>
>  
> +/* make these flag values available regardless of GPIO kconfig options */
> +#define GPIOF_DIR_OUT	(0 << 0)
> +#define GPIOF_DIR_IN	(1 << 0)
> +
> +#define GPIOF_INIT_LOW	(0 << 1)
> +#define GPIOF_INIT_HIGH	(1 << 1)
> +
> +#define GPIOF_IN		(GPIOF_DIR_IN)
> +#define GPIOF_OUT_INIT_LOW	(GPIOF_DIR_OUT | GPIOF_INIT_LOW)
> +#define GPIOF_OUT_INIT_HIGH	(GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
> +
> +/**
> + * struct gpio - a structure describing a GPIO with configuration
> + * @gpio:	the GPIO number
> + * @flags:	GPIO configuration as specified by GPIOF_*
> + * @label:	a literal description string of this GPIO
> + */
> +struct gpio {
> +	unsigned	gpio;
> +	unsigned long	flags;
> +	const char	*label;
> +};
> +
>  #ifndef CONFIG_GPIOLIB
>  static inline int gpio_request(unsigned gpio, const char *label)
>  {
> @@ -12,9 +35,29 @@ static inline int gpio_request(unsigned gpio, const char *label)
>  static inline void gpio_free(unsigned gpio)
>  {
>  }
> +
> +static inline int gpio_request_one(unsigned gpio,
> +					unsigned long flags, const char *label)
> +{
> +	return 0;
> +}
> +
> +static inline int gpio_request_array(const struct gpio *array, size_t num)
> +{
> +	return 0;
> +}
you can not do this

as if we start to use this in generic driver where gpio_direction_input/output
work

we will endup with no configuration

so you need to provide working inline instead
> +
> +static inline void gpio_free_array(const struct gpio *array, size_t num)
> +{
> +	/* GPIO can never have been requested */
> +	WARN_ON(1);
> +}
>  #else
>  int gpio_request(unsigned gpio, const char *label);
>  void gpio_free(unsigned gpio);
> +int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
> +int gpio_request_array(const struct gpio *array, size_t num);
> +void gpio_free_array(const struct gpio *array, size_t num);
>  #endif
>  
>  struct gpio_chip;
> -- 
> 1.7.10.4
> 
> 
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