[libcamera-devel] [RFC PATCH 3/6] libcamera: v4l2_subdevice: Add methods to get/set frame interval

[Marian Cichy]

Add API-methods to get and set the frame interval on V4L2-subdevices.

Signed-off-by: Marian Cichy <m.cichy at pengutronix.de>
---
 include/libcamera/internal/v4l2_subdevice.h |  4 ++
 src/libcamera/v4l2_subdevice.cpp            | 43 +++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/include/libcamera/internal/v4l2_subdevice.h b/include/libcamera/internal/v4l2_subdevice.h
index d2b9ca55..310746d9 100644
--- a/include/libcamera/internal/v4l2_subdevice.h
+++ b/include/libcamera/internal/v4l2_subdevice.h
@@ -12,6 +12,7 @@
 #include <vector>
 
 #include <libcamera/class.h>
+#include <libcamera/fraction.h>
 #include <libcamera/geometry.h>
 
 #include "libcamera/internal/formats.h"
@@ -60,6 +61,9 @@ public:
 	int setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
 		      Whence whence = ActiveFormat);
 
+	int getFrameInterval(unsigned int pad, Fraction *frameInterval);
+	int setFrameInterval(unsigned int pad, Fraction *frameInterval);
+
 	static std::unique_ptr<V4L2Subdevice>
 	fromEntityName(const MediaDevice *media, const std::string &entity);
 
diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
index 721ff5a9..eac2d7d3 100644
--- a/src/libcamera/v4l2_subdevice.cpp
+++ b/src/libcamera/v4l2_subdevice.cpp
@@ -17,6 +17,7 @@
 #include <linux/media-bus-format.h>
 #include <linux/v4l2-subdev.h>
 
+#include <libcamera/fraction.h>
 #include <libcamera/geometry.h>
 
 #include "libcamera/internal/log.h"
@@ -440,6 +441,48 @@ int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
 	return 0;
 }
 
+int V4L2Subdevice::getFrameInterval(unsigned int pad, Fraction *frameInterval)
+{
+	struct v4l2_subdev_frame_interval subdevFrameInterval = {};
+	subdevFrameInterval.pad = pad;
+
+	int ret = ioctl(VIDIOC_SUBDEV_G_FRAME_INTERVAL, &subdevFrameInterval);
+	if (ret) {
+		LOG(V4L2, Debug)
+			<< "Unable to get frame interval on pad " << pad
+			<< ": " << strerror(-ret);
+		return ret;
+	}
+
+	frameInterval->numerator = subdevFrameInterval.interval.numerator;
+	frameInterval->denominator = subdevFrameInterval.interval.denominator;
+
+	return 0;
+}
+
+int V4L2Subdevice::setFrameInterval(unsigned int pad, Fraction *frameInterval)
+{
+	struct v4l2_subdev_frame_interval subdevFrameInterval = {};
+	struct v4l2_fract fract = { frameInterval->numerator,
+				    frameInterval->denominator };
+
+	subdevFrameInterval.pad = pad;
+	subdevFrameInterval.interval = fract;
+
+	int ret = ioctl(VIDIOC_SUBDEV_S_FRAME_INTERVAL, &subdevFrameInterval);
+	if (ret) {
+		LOG(V4L2, Debug)
+			<< "Unable to set frame interval on pad " << pad
+			<< ": " << strerror(-ret);
+		return ret;
+	}
+
+	frameInterval->numerator = subdevFrameInterval.interval.numerator;
+	frameInterval->denominator = subdevFrameInterval.interval.denominator;
+
+	return 0;
+}
+
 /**
  * \brief Create a new video subdevice instance from \a entity in media device
  * \a media
-- 
2.29.2