On 06/04/16 11:31, Laxman Dewangan wrote:
> Some of kernel driver uses the IIO framework to get the sensor
> value via ADC or IIO HW driver. The client driver get iio channel
> by iio_channel_get() and release it by calling iio_channel_release().
>
> Add resource managed version (devm_*) of these APIs so that if client
> calls the devm_iio_channel_get() then it need not to release it explicitly,
> it can be done by managed device framework when driver get un-binded.
>
> This reduces the code in error path and also need of .remove callback in
> some cases.
>
> Signed-off-by: Laxman Dewangan <ldewan...@nvidia.com>
I'm fine with this - but would like it to sit for a few more days to see
if it gets any other feedback.
> ---
> drivers/iio/inkern.c | 48
> ++++++++++++++++++++++++++++++++++++++++++++
> include/linux/iio/consumer.h | 27 +++++++++++++++++++++++++
> 2 files changed, 75 insertions(+)
>
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index 734a004..18e623f 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -356,6 +356,54 @@ void iio_channel_release(struct iio_channel *channel)
> }
> EXPORT_SYMBOL_GPL(iio_channel_release);
>
> +static void devm_iio_channel_free(struct device *dev, void *res)
> +{
> + struct iio_channel *channel = *(struct iio_channel **)res;
> +
> + iio_channel_release(channel);
> +}
> +
> +static int devm_iio_channel_match(struct device *dev, void *res, void *data)
> +{
> + struct iio_channel **r = res;
> +
> + if (!r || !*r) {
> + WARN_ON(!r || !*r);
> + return 0;
> + }
> +
> + return *r == data;
> +}
> +
> +struct iio_channel *devm_iio_channel_get(struct device *dev,
> + const char *channel_name)
> +{
> + struct iio_channel **ptr, *channel;
> +
> + ptr = devres_alloc(devm_iio_channel_free, sizeof(*ptr), GFP_KERNEL);
> + if (!ptr)
> + return ERR_PTR(-ENOMEM);
> +
> + channel = iio_channel_get(dev, channel_name);
> + if (IS_ERR(channel)) {
> + devres_free(ptr);
> + return channel;
> + }
> +
> + *ptr = channel;
> + devres_add(dev, ptr);
> +
> + return channel;
> +}
> +EXPORT_SYMBOL_GPL(devm_iio_channel_get);
> +
> +void devm_iio_channel_release(struct device *dev, struct iio_channel
> *channel)
> +{
> + WARN_ON(devres_release(dev, devm_iio_channel_free,
> + devm_iio_channel_match, channel));
> +}
> +EXPORT_SYMBOL_GPL(devm_iio_channel_release);
> +
> struct iio_channel *iio_channel_get_all(struct device *dev)
> {
> const char *name;
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index fad5867..e1e033d 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -49,6 +49,33 @@ struct iio_channel *iio_channel_get(struct device *dev,
> void iio_channel_release(struct iio_channel *chan);
>
> /**
> + * devm_iio_channel_get() - Resource managed version of iio_channel_get().
> + * @dev: Pointer to consumer device. Device name must match
> + * the name of the device as provided in the iio_map
> + * with which the desired provider to consumer mapping
> + * was registered.
> + * @consumer_channel: Unique name to identify the channel on the
> consumer
> + * side. This typically describes the channels use within
> + * the consumer. E.g. 'battery_voltage'
> + *
> + * Returns a pointer to negative errno if it is not able to get the iio
> channel
> + * otherwise returns valid pointer for iio channel.
> + *
> + * The allocated iio channel is automatically released when the device is
> + * unbound.
> + */
> +struct iio_channel *devm_iio_channel_get(struct device *dev,
> + const char *consumer_channel);
> +/**
> + * devm_iio_channel_release() - Resource managed version of
> + * iio_channel_release().
> + * @dev: Pointer to consumer device for which resource
> + * is allocared.
> + * @chan: The channel to be released.
> + */
> +void devm_iio_channel_release(struct device *dev, struct iio_channel *chan);
> +
> +/**
> * iio_channel_get_all() - get all channels associated with a client
> * @dev: Pointer to consumer device.
> *
>
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