From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:40371 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752853Ab3EOLce (ORCPT ); Wed, 15 May 2013 07:32:34 -0400 From: Laurent Pinchart To: Andrzej Hajda Cc: linux-media@vger.kernel.org, Sylwester Nawrocki , Sakari Ailus , Kyungmin Park , hj210.choi@samsung.com, sw0312.kim@samsung.com Subject: Re: [PATCH RFC v2 2/3] media: added managed v4l2 control initialization Date: Wed, 15 May 2013 13:32:54 +0200 Message-ID: <1820945.rcN45v55i8@avalon> In-Reply-To: <1368434086-9027-3-git-send-email-a.hajda@samsung.com> References: <1368434086-9027-1-git-send-email-a.hajda@samsung.com> <1368434086-9027-3-git-send-email-a.hajda@samsung.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Andrzej, Thank you for the patch. On Monday 13 May 2013 10:34:45 Andrzej Hajda wrote: > This patch adds managed versions of initialization > and cleanup functions for v4l2 control handler. > > Signed-off-by: Andrzej Hajda > Reviewed-by: Sylwester Nawrocki > Signed-off-by: Kyungmin Park > --- > v2: > - added missing struct device forward declaration, > - corrected few comments > --- > drivers/media/v4l2-core/v4l2-ctrls.c | 48 +++++++++++++++++++++++++++++++ > include/media/v4l2-ctrls.h | 31 ++++++++++++++++++++++ > 2 files changed, 79 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c > b/drivers/media/v4l2-core/v4l2-ctrls.c index ebb8e48..69c9b95 100644 > --- a/drivers/media/v4l2-core/v4l2-ctrls.c > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c > @@ -1421,6 +1421,54 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler > *hdl) } > EXPORT_SYMBOL(v4l2_ctrl_handler_free); > > +static void devm_v4l2_ctrl_handler_release(struct device *dev, void *res) > +{ > + struct v4l2_ctrl_handler **hdl = res; > + > + v4l2_ctrl_handler_free(*hdl); > +} > + > +int devm_v4l2_ctrl_handler_init(struct device *dev, > + struct v4l2_ctrl_handler *hdl, > + unsigned nr_of_controls_hint) > +{ > + struct v4l2_ctrl_handler **dr; > + int rc; > + > + dr = devres_alloc(devm_v4l2_ctrl_handler_release, sizeof(*dr), > + GFP_KERNEL); > + if (!dr) > + return -ENOMEM; > + > + rc = v4l2_ctrl_handler_init(hdl, nr_of_controls_hint); > + if (rc) { > + devres_free(dr); > + return rc; > + } > + > + *dr = hdl; > + devres_add(dev, dr); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(devm_v4l2_ctrl_handler_init); > + > +static int devm_v4l2_ctrl_handler_match(struct device *dev, void *res, > + void *data) > +{ > + struct v4l2_ctrl_handler **this = res, **hdl = data; > + > + return *this == *hdl; > +} > + > +void devm_v4l2_ctrl_handler_free(struct device *dev, > + struct v4l2_ctrl_handler *hdl) > +{ > + WARN_ON(devres_release(dev, devm_v4l2_ctrl_handler_release, > + devm_v4l2_ctrl_handler_match, &hdl)); > +} > +EXPORT_SYMBOL_GPL(devm_v4l2_ctrl_handler_free); I expect very few drivers to actually need devm_v4l2_ctrl_handler_free(), if any at all. Do you have a use case for that function at the moment ? If not, what about removing it for now and adding it later when (if) needed ? > + > /* For backwards compatibility: V4L2_CID_PRIVATE_BASE should no longer > be used except in G_CTRL, S_CTRL, QUERYCTRL and QUERYMENU when dealing > with applications that do not use the NEXT_CTRL flag. > diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h > index 7343a27..1986b90 100644 > --- a/include/media/v4l2-ctrls.h > +++ b/include/media/v4l2-ctrls.h > @@ -25,6 +25,7 @@ > #include > > /* forward references */ > +struct device; > struct file; > struct v4l2_ctrl_handler; > struct v4l2_ctrl_helper; > @@ -306,6 +307,36 @@ int v4l2_ctrl_handler_init_class(struct > v4l2_ctrl_handler *hdl, */ > void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl); > > +/* > + * devm_v4l2_ctrl_handler_init - managed control handler initialization > + * > + * @dev: Device the @hdl belongs to. > + * @hdl: The control handler. > + * @nr_of_controls_hint: A hint of how many controls this handler is > + * expected to refer to. > + * > + * This is a managed version of v4l2_ctrl_handler_init. Handler initialized > with + * this function will be automatically cleaned up on driver detach. + > * > + * If an handler initialized with this function needs to be cleaned up > + * separately, devm_v4l2_ctrl_handler_free() must be used. > + */ > +int devm_v4l2_ctrl_handler_init(struct device *dev, > + struct v4l2_ctrl_handler *hdl, > + unsigned nr_of_controls_hint); > + > +/** > + * devm_v4l2_ctrl_handler_free - managed control handler free > + * > + * @dev: Device the @hdl belongs to. > + * @hdl: Handler to be cleaned up. > + * > + * This function should be used to manual free of an control handler > + * initialized with devm_v4l2_ctrl_handler_init(). > + */ > +void devm_v4l2_ctrl_handler_free(struct device *dev, > + struct v4l2_ctrl_handler *hdl); > + > /** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls > belonging * to the handler to initialize the hardware to the current > control values. * @hdl: The control handler. -- Regards, Laurent Pinchart