From patchwork Mon May 6 17:52:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 13655871 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B98B158201; Mon, 6 May 2024 17:53:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715017994; cv=none; b=Dq3KKnPafkBBwPE5WMmWBu6YS/afXfjyaSHVJuH+Sh417+CRlFZ3nXhkTrjoCw6qCnstEY7BVfGiMrdOtqi4EiBLGAWeYttUGlkJns4LNroAlgQ3G9LBWQGpIY7ufreMGPgDXFBGDK59iFUeDN3bmEMuZOdyc0un3ATq81tO2Kk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715017994; c=relaxed/simple; bh=TnNuQX2g0PtHRgzNjj1qruspQOLkETZhXtGC/kAGMIs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fEjjYfQsTk+Kzq5RhwhI/qZuYFVBq95WpcLp5i291mqfc2R6W+EaeBorlhX3MR8cC/SQs1QAM+hs2UiX77o4YQ3YwCdOGtIIcYqiH6psZg4SzcNVtd/L8v4DO2jv+WeLYDHUt1i/Cv+24wEiLK68vMHXERFMVQfdRIyOt89/tks= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=py8S/sp6; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="py8S/sp6" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id BD5731211; Mon, 6 May 2024 19:53:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1715017984; bh=TnNuQX2g0PtHRgzNjj1qruspQOLkETZhXtGC/kAGMIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=py8S/sp6nYZTH20Bl4ddC+yS7WxqFIbyWpZb5SYybtwwagF8CuytwQotAY3haJkhl c+e1K+cuxTry+ZyT0dtPfagfEuU0j5f96pJk6wPEQKqyKFnANWNHFJ3c8euEQ64aWC 1eBoafLonz2up1HjC21DFKdAUJP0CR3HW0GNrc+s= From: Laurent Pinchart To: linux-media@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Sakari Ailus , Tomi Valkeinen , Hans Verkuil , Dafna Hirschfeld , linux-rockchip@lists.infradead.org Subject: [PATCH 1/2] media: v4l2-subdev: Provide const-aware subdev state accessors Date: Mon, 6 May 2024 20:52:54 +0300 Message-ID: <20240506175255.24394-2-laurent.pinchart+renesas@ideasonboard.com> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240506175255.24394-1-laurent.pinchart+renesas@ideasonboard.com> References: <20240506175255.24394-1-laurent.pinchart+renesas@ideasonboard.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 It would be useful to mark instances of v4l2_subdev_state structures as const when code needs to access them read-only. This isn't currently possible, as the v4l2_subdev_state_get_*() accessor functions take a non-const pointer to the state. Use _Generic() to provide two different versions of the accessors, for const and non-const states respectively. The former returns a const pointer to the requested format, rectangle or interval, implementing const-correctness. The latter returns a non-const pointer, preserving the current behaviour for drivers. Signed-off-by: Laurent Pinchart --- Bike-shedding about names and the 4 leading underscores is allowed (and expected). --- drivers/media/v4l2-core/v4l2-subdev.c | 24 +++++----- include/media/v4l2-subdev.h | 66 ++++++++++++++++++--------- 2 files changed, 57 insertions(+), 33 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index 83c6d1e36871..af1fbc28c8f0 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -1616,8 +1616,8 @@ void v4l2_subdev_cleanup(struct v4l2_subdev *sd) EXPORT_SYMBOL_GPL(v4l2_subdev_cleanup); struct v4l2_mbus_framefmt * -__v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, - unsigned int pad, u32 stream) +____v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream) { struct v4l2_subdev_stream_configs *stream_configs; unsigned int i; @@ -1647,11 +1647,11 @@ __v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, return NULL; } -EXPORT_SYMBOL_GPL(__v4l2_subdev_state_get_format); +EXPORT_SYMBOL_GPL(____v4l2_subdev_state_get_format); struct v4l2_rect * -__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, - u32 stream) +____v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, + u32 stream) { struct v4l2_subdev_stream_configs *stream_configs; unsigned int i; @@ -1681,11 +1681,11 @@ __v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, return NULL; } -EXPORT_SYMBOL_GPL(__v4l2_subdev_state_get_crop); +EXPORT_SYMBOL_GPL(____v4l2_subdev_state_get_crop); struct v4l2_rect * -__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, - unsigned int pad, u32 stream) +____v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream) { struct v4l2_subdev_stream_configs *stream_configs; unsigned int i; @@ -1715,11 +1715,11 @@ __v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, return NULL; } -EXPORT_SYMBOL_GPL(__v4l2_subdev_state_get_compose); +EXPORT_SYMBOL_GPL(____v4l2_subdev_state_get_compose); struct v4l2_fract * -__v4l2_subdev_state_get_interval(struct v4l2_subdev_state *state, - unsigned int pad, u32 stream) +____v4l2_subdev_state_get_interval(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream) { struct v4l2_subdev_stream_configs *stream_configs; unsigned int i; @@ -1751,7 +1751,7 @@ __v4l2_subdev_state_get_interval(struct v4l2_subdev_state *state, return NULL; } -EXPORT_SYMBOL_GPL(__v4l2_subdev_state_get_interval); +EXPORT_SYMBOL_GPL(____v4l2_subdev_state_get_interval); #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index e30c463d90e5..ba722ab501c1 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -1340,21 +1340,27 @@ void v4l2_subdev_cleanup(struct v4l2_subdev *sd); */ /* * Wrap v4l2_subdev_state_get_format(), allowing the function to be called with - * two or three arguments. The purpose of the __v4l2_subdev_state_get_format() + * two or three arguments. The purpose of the __v4l2_subdev_state_gen_call() * macro below is to come up with the name of the function or macro to call, * using the last two arguments (_stream and _pad). The selected function or * macro is then called using the arguments specified by the caller. A similar * arrangement is used for v4l2_subdev_state_crop() and * v4l2_subdev_state_compose() below. */ -#define v4l2_subdev_state_get_format(state, pad, ...) \ - __v4l2_subdev_state_gen_call(format, ##__VA_ARGS__, , _pad) \ +#define v4l2_subdev_state_get_format(state, pad, ...) \ + __v4l2_subdev_state_gen_call(format, ##__VA_ARGS__, , _pad) \ (state, pad, ##__VA_ARGS__) -#define __v4l2_subdev_state_get_format_pad(state, pad) \ +#define __v4l2_subdev_state_get_format_pad(state, pad) \ __v4l2_subdev_state_get_format(state, pad, 0) +#define __v4l2_subdev_state_get_format(state, pad, stream) \ + _Generic(state, \ + const struct v4l2_subdev_state *: ((const struct v4l2_mbus_framefmt *) \ + ____v4l2_subdev_state_get_format((struct v4l2_subdev_state *)state, pad, stream)), \ + default: ____v4l2_subdev_state_get_format((struct v4l2_subdev_state *)state, pad, stream) \ + ) struct v4l2_mbus_framefmt * -__v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, - unsigned int pad, u32 stream); +____v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream); /** * v4l2_subdev_state_get_crop() - Get pointer to a stream crop rectangle @@ -1368,14 +1374,20 @@ __v4l2_subdev_state_get_format(struct v4l2_subdev_state *state, * For stream-unaware drivers the crop rectangle for the corresponding pad is * returned. If the pad does not exist, NULL is returned. */ -#define v4l2_subdev_state_get_crop(state, pad, ...) \ - __v4l2_subdev_state_gen_call(crop, ##__VA_ARGS__, , _pad) \ +#define v4l2_subdev_state_get_crop(state, pad, ...) \ + __v4l2_subdev_state_gen_call(crop, ##__VA_ARGS__, , _pad) \ (state, pad, ##__VA_ARGS__) -#define __v4l2_subdev_state_get_crop_pad(state, pad) \ +#define __v4l2_subdev_state_get_crop_pad(state, pad) \ __v4l2_subdev_state_get_crop(state, pad, 0) +#define __v4l2_subdev_state_get_crop(state, pad, stream) \ + _Generic(state, \ + const struct v4l2_subdev_state *: ((const struct v4l2_rect *) \ + ____v4l2_subdev_state_get_crop((struct v4l2_subdev_state *)state, pad, stream)), \ + default: ____v4l2_subdev_state_get_crop((struct v4l2_subdev_state *)state, pad, stream) \ + ) struct v4l2_rect * -__v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, - u32 stream); +____v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, + u32 stream); /** * v4l2_subdev_state_get_compose() - Get pointer to a stream compose rectangle @@ -1389,14 +1401,20 @@ __v4l2_subdev_state_get_crop(struct v4l2_subdev_state *state, unsigned int pad, * For stream-unaware drivers the compose rectangle for the corresponding pad is * returned. If the pad does not exist, NULL is returned. */ -#define v4l2_subdev_state_get_compose(state, pad, ...) \ - __v4l2_subdev_state_gen_call(compose, ##__VA_ARGS__, , _pad) \ +#define v4l2_subdev_state_get_compose(state, pad, ...) \ + __v4l2_subdev_state_gen_call(compose, ##__VA_ARGS__, , _pad) \ (state, pad, ##__VA_ARGS__) -#define __v4l2_subdev_state_get_compose_pad(state, pad) \ +#define __v4l2_subdev_state_get_compose_pad(state, pad) \ __v4l2_subdev_state_get_compose(state, pad, 0) +#define __v4l2_subdev_state_get_compose(state, pad, stream) \ + _Generic(state, \ + const struct v4l2_subdev_state *: ((const struct v4l2_rect *) \ + ____v4l2_subdev_state_get_compose((struct v4l2_subdev_state *)state, pad, stream)), \ + default: ____v4l2_subdev_state_get_compose((struct v4l2_subdev_state *)state, pad, stream) \ + ) struct v4l2_rect * -__v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, - unsigned int pad, u32 stream); +____v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream); /** * v4l2_subdev_state_get_interval() - Get pointer to a stream frame interval @@ -1410,14 +1428,20 @@ __v4l2_subdev_state_get_compose(struct v4l2_subdev_state *state, * For stream-unaware drivers the frame interval for the corresponding pad is * returned. If the pad does not exist, NULL is returned. */ -#define v4l2_subdev_state_get_interval(state, pad, ...) \ - __v4l2_subdev_state_gen_call(interval, ##__VA_ARGS__, , _pad) \ +#define v4l2_subdev_state_get_interval(state, pad, ...) \ + __v4l2_subdev_state_gen_call(interval, ##__VA_ARGS__, , _pad) \ (state, pad, ##__VA_ARGS__) -#define __v4l2_subdev_state_get_interval_pad(state, pad) \ +#define __v4l2_subdev_state_get_interval_pad(state, pad) \ __v4l2_subdev_state_get_interval(state, pad, 0) +#define __v4l2_subdev_state_get_interval(state, pad, stream) \ + _Generic(state, \ + const struct v4l2_subdev_state *: ((const struct v4l2_frac *) \ + ____v4l2_subdev_state_get_interval((struct v4l2_subdev_state *)state, pad, stream)), \ + default: ____v4l2_subdev_state_get_interval((struct v4l2_subdev_state *)state, pad, stream) \ + ) struct v4l2_fract * -__v4l2_subdev_state_get_interval(struct v4l2_subdev_state *state, - unsigned int pad, u32 stream); +____v4l2_subdev_state_get_interval(struct v4l2_subdev_state *state, + unsigned int pad, u32 stream); #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)