Re: [PATCH 1/3] drivers/gpio: devres.c: allow gpio array requests for managed devices

[Rob Jones]

On 18/06/14 14:24, Heiko Stübner wrote:
> Am Dienstag, 10. Juni 2014, 15:41:46 schrieb Rob Jones:
> > Add functions devm_gpio_request_array() and devm_gpio_free_array()
> > which are exactly analogous to the equivalent non-managed device
> > functions gpio_request_array() and gpio_free_array(), which can be
> > found in module gpiolib.c.
> >
> > Note that if devm_gpio_request_array() fails, no gpios are obtained.
> > No indication is provided as to which particular request failed.
> >
> > Reviewed-by: Ian Molton <ian.molton@xxxxxxxxxxxxxxx>
> > Signed-off-by: Rob Jones <rob.jones@xxxxxxxxxxxxxxx>
> apart from the doc issue below this looks ok to me
>
>
> > ---
> >   drivers/gpio/devres.c |   57
> > +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/gpio.h  |
> >   4 ++++
> >   2 files changed, 61 insertions(+)
> >
> > diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
> > index 307464f..fd95240d 100644
> > --- a/drivers/gpio/devres.c
> > +++ b/drivers/gpio/devres.c
> > @@ -186,6 +186,63 @@ int devm_gpio_request_one(struct device *dev, unsigned
> > gpio, EXPORT_SYMBOL(devm_gpio_request_one);
> >
> >   /**
> > + * devm_gpio_request_array - request multiple GPIOs in a single call
> > + *			     for a managed device
> > + * @dev:	device requesting the gpio
> > + * @array:      array of the 'struct gpio'
> > + * @num:        how many GPIOs in the array
> @dev uses a tab as spacing, while @array and @num use spaces, might be nice to
> have this consistent.

I'm not sure how that happened. I'll rework it before re-submitting the 
series.

> > + *
> > + * Except for the extra @dev argument, this function takes the
> > + * same arguments and performs the same function as
> > + * gpio_request().  GPIOs requested with this function will be
> > + * automatically freed on driver detach.
> > + *
> > + * If GPIOs allocated with this function need to be freed separately,
> > + * devm_gpio_free_array() or devm_gpio_free() must be used.
> > + */
> > +int devm_gpio_request_array(struct device *dev,
> > +			    const struct gpio *array,
> > +			    size_t num)
> > +{
> > +	int i, err = 0;
> > +
> > +	for (i = 0; i < num; i++, array++) {
> > +		err = devm_gpio_request_one(dev,
> > +					    array->gpio,
> > +					    array->flags,
> > +					    array->label);
> > +		if (err) {
> > +			while (i--)
> > +				devm_gpio_free(dev, (--array)->gpio);
> > +		}
> > +	}
> > +
> > +	return err;
> > +}
> > +EXPORT_SYMBOL(devm_gpio_request_array);
> > +
> > +/**
> > + * devm_gpio_free_array - release multiple GPIOs in a single call
> > + *			  for a managed device
> > + * @dev:	device requesting the gpio
> > + * @array:      array of the 'struct gpio'
> > + * @num:        how many GPIOs in the array
> same here
>
> > + *
> > + * Except for the extra @dev argument, this function takes the
> > + * same arguments and performs the same function as gpio_free_array().
> > + * This function instead of gpio_free_array() should be used to
> > + * manually free GPIOs allocated with devm_gpio_request().
> > + */
> > +void devm_gpio_free_array(struct device *dev,
> > +			  const struct gpio *array,
> > +			  size_t num)
> > +{
> > +	while (num--)
> > +		devm_gpio_free(dev, (array++)->gpio);
> > +}
> > +EXPORT_SYMBOL(devm_gpio_free_array);
> > +
> > +/**
> >    *      devm_gpio_free - free a GPIO
> >    *      @dev: device to free GPIO for
> >    *      @gpio: GPIO to free
> > diff --git a/include/linux/gpio.h b/include/linux/gpio.h
> > index 85aa5d0..12d5648 100644
> > --- a/include/linux/gpio.h
> > +++ b/include/linux/gpio.h
> > @@ -84,6 +84,10 @@ struct device;
> >   int devm_gpio_request(struct device *dev, unsigned gpio, const char
> > *label); int devm_gpio_request_one(struct device *dev, unsigned gpio,
> >   			  unsigned long flags, const char *label);
> > +int devm_gpio_request_array(struct device *dev, const struct gpio *array,
> > +			    size_t num);
> > +void devm_gpio_free_array(struct device *dev, const struct gpio *array,
> > +			 size_t num);
> >   void devm_gpio_free(struct device *dev, unsigned int gpio);
> >
> >   #else /* ! CONFIG_GPIOLIB */

--
Rob Jones
Project Manager
Codethink Ltd
mailto:rob.jones@xxxxxxxxxxxxxxx
tel:+44 161 236 5575

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