media: platform: rzg2l-cru: Use v4l2_get_link_freq()

The rzg2l_csi2_calc_mbps() function currently tries to calculate the
link frequency for a CSI2 bus using the V4L2_CID_PIXEL_RATE control
of the remote subdevice. Switch the function to v4l2_get_link_freq()
which correctly targets V4L2_CID_LINK_FREQ before falling back on
V4L2_CID_PIXEL_RATE if the former is unavailable.

Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Daniel Scally <dan.scally+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20250625-rzg2l-cru-v6-3-a9099ed26c14@ideasonboard.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

1 files changed, 20 insertions, 13 deletions

diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
index 9243306e2aa9..cec165551183 100644
--- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-csi2.c
@@ -282,15 +282,18 @@ static int rzg2l_csi2_calc_mbps(struct rzg2l_csi2 *csi2)
 	const struct rzg2l_csi2_format *format;
 	const struct v4l2_mbus_framefmt *fmt;
 	struct v4l2_subdev_state *state;
-	struct v4l2_ctrl *ctrl;
+	struct media_pad *remote_pad;
 	u64 mbps;
+	s64 ret;
 
-	/* Read the pixel rate control from remote. */
-	ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE);
-	if (!ctrl) {
-		dev_err(csi2->dev, "no pixel rate control in subdev %s\n",
-			source->name);
-		return -EINVAL;
+	if (!csi2->remote_source)
+		return -ENODEV;
+
+	remote_pad = media_pad_remote_pad_unique(&csi2->pads[RZG2L_CSI2_SINK]);
+	if (IS_ERR(remote_pad)) {
+		dev_err(csi2->dev, "can't get source pad of %s (%ld)\n",
+			csi2->remote_source->name, PTR_ERR(remote_pad));
+		return PTR_ERR(remote_pad);
 	}
 
 	state = v4l2_subdev_lock_and_get_active_state(&csi2->subdev);
@@ -298,12 +301,16 @@ static int rzg2l_csi2_calc_mbps(struct rzg2l_csi2 *csi2)
 	format = rzg2l_csi2_code_to_fmt(fmt->code);
 	v4l2_subdev_unlock_state(state);
 
-	/*
-	 * Calculate hsfreq in Mbps
-	 * hsfreq = (pixel_rate * bits_per_sample) / number_of_lanes
-	 */
-	mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * format->bpp;
-	do_div(mbps, csi2->lanes * 1000000);
+	/* Read the link frequency from remote subdevice. */
+	ret = v4l2_get_link_freq(remote_pad, format->bpp, csi2->lanes * 2);
+	if (ret < 0) {
+		dev_err(csi2->dev, "can't retrieve link freq from subdev %s\n",
+			source->name);
+		return -EINVAL;
+	}
+
+	mbps = ret * 2;
+	do_div(mbps, 1000000);
 
 	return mbps;
 }