media: Prefer designated initializers over memset for subdev pad ops

Structures passed to subdev pad operations are all zero-initialized, but
not always with the same kind of code constructs. While most drivers
used designated initializers, which zero all the fields that are not
specified, when declaring variables, some use memset(). Those two
methods lead to the same end result, and, depending on compiler
optimizations, may even be completely equivalent, but they're not
consistent.

Improve coding style consistency by using designated initializers
instead of calling memset(). Where applicable, also move the variables
to inner scopes of for loops to ensure correct initialization in all
iterations.

Signed-off-by: Laurent Pinchart <[e-mail]>
Reviewed-by: Lad Prabhakar <[e-mail]> # For am437x
Acked-by: Sakari Ailus <[e-mail]>
Reviewed-by: Tomi Valkeinen <[e-mail]>
Reviewed-by: Kieran Bingham <[e-mail]>
Reviewed-by: Philipp Zabel <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/platform/renesas/vsp1/vsp1_drm.c

···
 			      struct vsp1_entity *prev, unsigned int prev_pad,
 			      struct vsp1_entity *next, unsigned int next_pad)
 {
-	struct v4l2_subdev_format format;
+	struct v4l2_subdev_format format = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	int ret;
 
 	if (!uif) {
···
 	prev->sink = uif;
 	prev->sink_pad = UIF_PAD_SINK;
 
-	memset(&format, 0, sizeof(format));
-	format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	format.pad = prev_pad;
 
 	ret = v4l2_subdev_call(&prev->subdev, pad, get_fmt, NULL, &format);
···
 				      struct vsp1_entity *uif,
 				      unsigned int brx_input)
 {
-	struct v4l2_subdev_selection sel;
-	struct v4l2_subdev_format format;
+	struct v4l2_subdev_selection sel = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
+	struct v4l2_subdev_format format = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	const struct v4l2_rect *crop;
 	int ret;
 
···
 	 */
 	crop = &vsp1->drm->inputs[rpf->entity.index].crop;
 
-	memset(&format, 0, sizeof(format));
-	format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	format.pad = RWPF_PAD_SINK;
 	format.format.width = crop->width + crop->left;
 	format.format.height = crop->height + crop->top;
···
 		__func__, format.format.width, format.format.height,
 		format.format.code, rpf->entity.index);
 
-	memset(&sel, 0, sizeof(sel));
-	sel.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	sel.pad = RWPF_PAD_SINK;
 	sel.target = V4L2_SEL_TGT_CROP;
 	sel.r = *crop;

drivers/media/platform/renesas/vsp1/vsp1_entity.c

···
 int vsp1_entity_init_cfg(struct v4l2_subdev *subdev,
 			 struct v4l2_subdev_state *sd_state)
 {
-	struct v4l2_subdev_format format;
 	unsigned int pad;
 
 	for (pad = 0; pad < subdev->entity.num_pads - 1; ++pad) {
-		memset(&format, 0, sizeof(format));
-
-		format.pad = pad;
-		format.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY
-			     : V4L2_SUBDEV_FORMAT_ACTIVE;
+		struct v4l2_subdev_format format = {
+			.pad = pad,
+			.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY
+			       : V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
 
 		v4l2_subdev_call(subdev, pad, set_fmt, sd_state, &format);
 	}

drivers/media/platform/samsung/exynos4-is/fimc-capture.c

···
 	struct fimc_dev *fimc = ctx->fimc_dev;
 	struct fimc_pipeline *p = to_fimc_pipeline(fimc->vid_cap.ve.pipe);
 	struct v4l2_subdev *sd = p->subdevs[IDX_SENSOR];
-	struct v4l2_subdev_format sfmt;
+	struct v4l2_subdev_format sfmt = {
+		.which = set ? V4L2_SUBDEV_FORMAT_ACTIVE
+		       : V4L2_SUBDEV_FORMAT_TRY,
+	};
 	struct v4l2_mbus_framefmt *mf = &sfmt.format;
 	struct media_entity *me;
 	struct fimc_fmt *ffmt;
···
 	if (WARN_ON(!sd || !tfmt))
 		return -EINVAL;
 
-	memset(&sfmt, 0, sizeof(sfmt));
 	sfmt.format = *tfmt;
-	sfmt.which = set ? V4L2_SUBDEV_FORMAT_ACTIVE : V4L2_SUBDEV_FORMAT_TRY;
 
 	me = fimc_pipeline_get_head(&sd->entity);
 

drivers/media/platform/ti/am437x/am437x-vpfe.c

···
 			  struct v4l2_frmsizeenum *fsize)
 {
 	struct vpfe_device *vpfe = video_drvdata(file);
-	struct v4l2_subdev_frame_size_enum fse;
+	struct v4l2_subdev_frame_size_enum fse = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	struct v4l2_subdev *sd = vpfe->current_subdev->sd;
 	struct vpfe_fmt *fmt;
 	int ret;
···
 
 	memset(fsize->reserved, 0x0, sizeof(fsize->reserved));
 
-	memset(&fse, 0x0, sizeof(fse));
 	fse.index = fsize->index;
 	fse.pad = 0;
 	fse.code = fmt->code;
-	fse.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	ret = v4l2_subdev_call(sd, pad, enum_frame_size, NULL, &fse);
 	if (ret)
 		return ret;
···
 {
 	struct vpfe_device *vpfe = container_of(notifier->v4l2_dev,
 					       struct vpfe_device, v4l2_dev);
-	struct v4l2_subdev_mbus_code_enum mbus_code;
 	struct vpfe_subdev_info *sdinfo;
 	struct vpfe_fmt *fmt;
 	int ret = 0;
···
 
 	vpfe->num_active_fmt = 0;
 	for (j = 0, i = 0; (ret != -EINVAL); ++j) {
-		memset(&mbus_code, 0, sizeof(mbus_code));
-		mbus_code.index = j;
-		mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
+		struct v4l2_subdev_mbus_code_enum mbus_code = {
+			.index = j,
+			.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
+
 		ret = v4l2_subdev_call(subdev, pad, enum_mbus_code,
 				       NULL, &mbus_code);
 		if (ret)

drivers/media/platform/ti/cal/cal-video.c

···
 
 static int cal_ctx_v4l2_init_formats(struct cal_ctx *ctx)
 {
-	struct v4l2_subdev_mbus_code_enum mbus_code;
 	struct v4l2_mbus_framefmt mbus_fmt;
 	const struct cal_format_info *fmtinfo;
 	unsigned int i, j, k;
···
 	ctx->num_active_fmt = 0;
 
 	for (j = 0, i = 0; ; ++j) {
+		struct v4l2_subdev_mbus_code_enum mbus_code = {
+			.index = j,
+			.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
 
-		memset(&mbus_code, 0, sizeof(mbus_code));
-		mbus_code.index = j;
-		mbus_code.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 		ret = v4l2_subdev_call(ctx->phy->source, pad, enum_mbus_code,
 				       NULL, &mbus_code);
 		if (ret == -EINVAL)

drivers/media/usb/dvb-usb/cxusb-analog.c

···
 {
 	struct dvb_usb_device *dvbdev = video_drvdata(file);
 	struct cxusb_medion_dev *cxdev = dvbdev->priv;
-	struct v4l2_subdev_format subfmt;
+	struct v4l2_subdev_format subfmt = {
+		.which = isset ? V4L2_SUBDEV_FORMAT_ACTIVE :
+			 V4L2_SUBDEV_FORMAT_TRY,
+	};
 	u32 field;
 	int ret;
 
···
 	field = vb2_start_streaming_called(&cxdev->videoqueue) ?
 		cxdev->field_order : cxusb_medion_field_order(cxdev);
 
-	memset(&subfmt, 0, sizeof(subfmt));
-	subfmt.which = isset ? V4L2_SUBDEV_FORMAT_ACTIVE :
-		V4L2_SUBDEV_FORMAT_TRY;
 	subfmt.format.width = f->fmt.pix.width & ~1;
 	subfmt.format.height = f->fmt.pix.height & ~1;
 	subfmt.format.code = MEDIA_BUS_FMT_FIXED;
···
 					    .buf = tuner_analog_msg_data,
 					    .len =
 					    sizeof(tuner_analog_msg_data) };
-	struct v4l2_subdev_format subfmt;
+	struct v4l2_subdev_format subfmt = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	int ret;
 
 	/* switch tuner to analog mode so IF demod will become accessible */
···
 	v4l2_subdev_call(cxdev->tuner, video, s_std, cxdev->norm);
 	v4l2_subdev_call(cxdev->cx25840, video, s_std, cxdev->norm);
 
-	memset(&subfmt, 0, sizeof(subfmt));
-	subfmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 	subfmt.format.width = cxdev->width;
 	subfmt.format.height = cxdev->height;
 	subfmt.format.code = MEDIA_BUS_FMT_FIXED;

drivers/staging/media/imx/imx-media-capture.c

···
 				 struct v4l2_streamparm *a)
 {
 	struct capture_priv *priv = video_drvdata(file);
-	struct v4l2_subdev_frame_interval fi;
+	struct v4l2_subdev_frame_interval fi = {
+		.pad = priv->src_sd_pad,
+	};
 	int ret;
 
 	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		return -EINVAL;
 
-	memset(&fi, 0, sizeof(fi));
-	fi.pad = priv->src_sd_pad;
 	ret = v4l2_subdev_call(priv->src_sd, video, g_frame_interval, &fi);
 	if (ret < 0)
 		return ret;
···
 				 struct v4l2_streamparm *a)
 {
 	struct capture_priv *priv = video_drvdata(file);
-	struct v4l2_subdev_frame_interval fi;
+	struct v4l2_subdev_frame_interval fi = {
+		.pad = priv->src_sd_pad,
+	};
 	int ret;
 
 	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		return -EINVAL;
 
-	memset(&fi, 0, sizeof(fi));
-	fi.pad = priv->src_sd_pad;
 	fi.interval = a->parm.capture.timeperframe;
 	ret = v4l2_subdev_call(priv->src_sd, video, s_frame_interval, &fi);
 	if (ret < 0)

drivers/staging/media/imx/imx-media-utils.c

···
 		       struct v4l2_subdev_state *sd_state)
 {
 	struct v4l2_mbus_framefmt *mf_try;
-	struct v4l2_subdev_format format;
 	unsigned int pad;
 	int ret;
 
 	for (pad = 0; pad < sd->entity.num_pads; pad++) {
-		memset(&format, 0, sizeof(format));
+		struct v4l2_subdev_format format = {
+			.pad = pad,
+			.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+		};
 
-		format.pad = pad;
-		format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 		ret = v4l2_subdev_call(sd, pad, get_fmt, NULL, &format);
 		if (ret)
 			continue;

drivers/staging/media/omap4iss/iss_video.c

···
 __iss_video_get_format(struct iss_video *video,
 		       struct v4l2_mbus_framefmt *format)
 {
-	struct v4l2_subdev_format fmt;
+	struct v4l2_subdev_format fmt = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
 	struct v4l2_subdev *subdev;
 	u32 pad;
 	int ret;
···
 	if (!subdev)
 		return -EINVAL;
 
-	memset(&fmt, 0, sizeof(fmt));
 	fmt.pad = pad;
-	fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
 
 	mutex_lock(&video->mutex);
 	ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);