chore: vendor trimmed v4l2r capture crate

libs/v4l2r/src/ioctl/streamon.rs

@@ -0,0 +1,71 @@
+//! Safe wrapper for the `VIDIOC_STREAM(ON|OFF)` ioctls.
+use crate::QueueType;
+use nix::errno::Errno;
+use std::os::unix::io::AsRawFd;
+use thiserror::Error;
+
+#[doc(hidden)]
+mod ioctl {
+    nix::ioctl_write_ptr!(vidioc_streamon, b'V', 18, u32);
+    nix::ioctl_write_ptr!(vidioc_streamoff, b'V', 19, u32);
+}
+
+#[derive(Debug, Error)]
+pub enum StreamOnError {
+    #[error("queue type ({0}) not supported, or no buffers allocated or enqueued")]
+    InvalidQueue(QueueType),
+    #[error("invalid pad configuration")]
+    InvalidPadConfig,
+    #[error("invalid pipeline link configuration")]
+    InvalidPipelineConfig,
+    #[error("ioctl error: {0}")]
+    IoctlError(Errno),
+}
+
+impl From<StreamOnError> for Errno {
+    fn from(err: StreamOnError) -> Self {
+        match err {
+            StreamOnError::InvalidQueue(_) => Errno::EINVAL,
+            StreamOnError::InvalidPadConfig => Errno::EPIPE,
+            StreamOnError::InvalidPipelineConfig => Errno::ENOLINK,
+            StreamOnError::IoctlError(e) => e,
+        }
+    }
+}
+
+/// Safe wrapper around the `VIDIOC_STREAMON` ioctl.
+pub fn streamon(fd: &impl AsRawFd, queue: QueueType) -> Result<(), StreamOnError> {
+    match unsafe { ioctl::vidioc_streamon(fd.as_raw_fd(), &(queue as u32)) } {
+        Ok(_) => Ok(()),
+        Err(Errno::EINVAL) => Err(StreamOnError::InvalidQueue(queue)),
+        Err(Errno::EPIPE) => Err(StreamOnError::InvalidPadConfig),
+        Err(Errno::ENOLINK) => Err(StreamOnError::InvalidPipelineConfig),
+        Err(e) => Err(StreamOnError::IoctlError(e)),
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum StreamOffError {
+    #[error("queue type not supported")]
+    InvalidQueue,
+    #[error("ioctl error: {0}")]
+    IoctlError(Errno),
+}
+
+impl From<StreamOffError> for Errno {
+    fn from(err: StreamOffError) -> Self {
+        match err {
+            StreamOffError::InvalidQueue => Errno::EINVAL,
+            StreamOffError::IoctlError(e) => e,
+        }
+    }
+}
+
+/// Safe wrapper around the `VIDIOC_STREAMOFF` ioctl.
+pub fn streamoff(fd: &impl AsRawFd, queue: QueueType) -> Result<(), StreamOffError> {
+    match unsafe { ioctl::vidioc_streamoff(fd.as_raw_fd(), &(queue as u32)) } {
+        Ok(_) => Ok(()),
+        Err(Errno::EINVAL) => Err(StreamOffError::InvalidQueue),
+        Err(e) => Err(StreamOffError::IoctlError(e)),
+    }
+}