From 39d491761956b9c0e8c01ba5fc0a27558b90016e Mon Sep 17 00:00:00 2001
From: Jacopo Mondi <jacopo@jmondi.org>
Date: Wed, 30 Mar 2022 11:08:43 +0200
Subject: libcamera: v4l2_subdevice: Collect subdev capabilities
Collect subdev capabilities at open() time.
Model the V4L2SubdevCapabilties as V4L2Capability from the video
device class.
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
---
src/libcamera/v4l2_subdevice.cpp | 50 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
(limited to 'src')
diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
index 37960b76..a1672b23 100644
--- a/src/libcamera/v4l2_subdevice.cpp
+++ b/src/libcamera/v4l2_subdevice.cpp
@@ -133,6 +133,30 @@ const std::map<uint32_t, V4L2SubdeviceFormatInfo> formatInfoMap = {
} /* namespace */
+/**
+ * \struct V4L2SubdeviceCapability
+ * \brief struct v4l2_subdev_capability object wrapper and helpers
+ *
+ * The V4L2SubdeviceCapability structure manages the information returned by the
+ * VIDIOC_SUBDEV_QUERYCAP ioctl.
+ */
+
+/**
+ * \fn V4L2SubdeviceCapability::isReadOnly()
+ * \brief Retrieve if a subdevice is registered as read-only
+ *
+ * A V4L2 subdevice is registered as read-only if V4L2_SUBDEV_CAP_RO_SUBDEV
+ * is listed as part of its capabilities.
+ *
+ * \return True if the subdevice is registered as read-only, false otherwise
+ */
+
+/**
+ * \fn V4L2SubdeviceCapability::hasStreams()
+ * \brief Retrieve if a subdevice supports the V4L2 streams API
+ * \return True if the subdevice supports the streams API, false otherwise
+ */
+
/**
* \struct V4L2SubdeviceFormat
* \brief The V4L2 sub-device image format and sizes
@@ -284,7 +308,25 @@ V4L2Subdevice::~V4L2Subdevice()
*/
int V4L2Subdevice::open()
{
- return V4L2Device::open(O_RDWR);
+ int ret = V4L2Device::open(O_RDWR);
+ if (ret)
+ return ret;
+
+ /*
+ * Try to query the subdev capabilities. The VIDIOC_SUBDEV_QUERYCAP API
+ * was introduced in kernel v5.8, ENOTTY errors must be ignored to
+ * support older kernels.
+ */
+ caps_ = {};
+ ret = ioctl(VIDIOC_SUBDEV_QUERYCAP, &caps_);
+ if (ret < 0 && errno != ENOTTY) {
+ ret = -errno;
+ LOG(V4L2, Error)
+ << "Unable to query capabilities: " << strerror(-ret);
+ return ret;
+ }
+
+ return 0;
}
/**
@@ -527,6 +569,12 @@ const std::string &V4L2Subdevice::model()
return model_;
}
+/**
+ * \fn V4L2Subdevice::caps()
+ * \brief Retrieve the subdevice V4L2 capabilities
+ * \return The subdevice V4L2 capabilities
+ */
+
/**
* \brief Create a new video subdevice instance from \a entity in media device
* \a media
--
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