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authorIsaac Scott <isaac.scott@ideasonboard.com>2025-10-29 18:03:18 +0000
committerHans Verkuil <hverkuil+cisco@kernel.org>2025-11-13 10:57:52 +0100
commitfd3f646e1c9d783d1f4ef30e5376ccf315a8ae30 (patch)
treee2dd234e17621c9f5aa8659b3b35f4cd2d6f7b3a /include/media
parentca042de64800a0bcc3e0866e4efaa4a657e8ddc9 (diff)
media: v4l: Add helper to get number of active lanes via a pad
Sometimes, users will not use all of the MIPI CSI 2 lanes available when connecting to the MIPI CSI receiver of their device. Add a helper function that checks the mbus_config for the device driver to allow users to define the number of active data lanes through the get_mbus_config op. If the driver does not implement this op, fall back to using the maximum number of lanes available. Reviewed-by: Frank Li <Frank.Li@nxp.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Isaac Scott <isaac.scott@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Diffstat (limited to 'include/media')
-rw-r--r--include/media/v4l2-common.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 5c0a7f6b5bb6..f8b1faced79c 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -581,6 +581,26 @@ int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat,
#ifdef CONFIG_MEDIA_CONTROLLER
s64 v4l2_get_link_freq(const struct media_pad *pad, unsigned int mul,
unsigned int div);
+
+/**
+ * v4l2_get_active_data_lanes - Get number of active data lanes from driver
+ *
+ * @pad: The transmitter's media pad.
+ * @max_data_lanes: The maximum number of active data lanes supported by
+ * the MIPI CSI link in hardware.
+ *
+ * This function is intended for obtaining the number of data lanes that are
+ * actively being used by the driver for a MIPI CSI-2 device on a given media pad.
+ * This information is derived from a mbus_config fetched from a device driver
+ * using the get_mbus_config v4l2_subdev pad op.
+ *
+ * Return:
+ * * >0: Number of active data lanes
+ * * %-EINVAL: Number of active data lanes is invalid, as it exceeds the maximum
+ * supported data lanes.
+ */
+int v4l2_get_active_data_lanes(const struct media_pad *pad,
+ unsigned int max_data_lanes);
#endif
void v4l2_simplify_fraction(u32 *numerator, u32 *denominator,