Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753436AbcDFKmL (ORCPT ); Wed, 6 Apr 2016 06:42:11 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:2426 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750994AbcDFKmI (ORCPT ); Wed, 6 Apr 2016 06:42:08 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Wed, 06 Apr 2016 03:40:37 -0700 From: Laxman Dewangan To: , , , , CC: , , , Laxman Dewangan Subject: [PATCH 1/3] iio: core: Add devm_ APIs for iio_channel_{get,release} Date: Wed, 6 Apr 2016 16:01:06 +0530 Message-ID: <1459938668-9180-1-git-send-email-ldewangan@nvidia.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3689 Lines: 116 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 --- 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. * -- 2.1.4