ioctl: add input/output selection/enumeration support

lu-zero · Mar 1, 2023 · b0cfeef · b0cfeef
1 parent a065259
commit b0cfeef
Showing 2 changed files with 108 additions and 0 deletions.
diff --git a/lib/src/ioctl.rs b/lib/src/ioctl.rs
@@ -13,6 +13,7 @@ mod encoder_cmd;
 mod enum_fmt;
 mod expbuf;
 mod g_fmt;
+mod g_input;
 mod g_selection;
 mod mmap;
 mod qbuf;
@@ -29,6 +30,7 @@ pub use encoder_cmd::*;
 pub use enum_fmt::*;
 pub use expbuf::*;
 pub use g_fmt::*;
+pub use g_input::*;
 pub use g_selection::*;
 pub use mmap::*;
 use nix::errno::Errno;

diff --git a/lib/src/ioctl/g_input.rs b/lib/src/ioctl/g_input.rs
@@ -0,0 +1,106 @@
+use std::ffi::c_int;
+use std::mem;
+use std::os::unix::io::AsRawFd;
+
+use nix::errno::Errno;
+use thiserror::Error;
+
+use crate::bindings::v4l2_input;
+use crate::bindings::v4l2_output;
+
+#[doc(hidden)]
+mod ioctl {
+    use std::ffi::c_int;
+
+    use crate::bindings::v4l2_input;
+    use crate::bindings::v4l2_output;
+
+    nix::ioctl_readwrite!(vidioc_enuminput, b'V', 26, v4l2_input);
+    nix::ioctl_read!(vidioc_g_input, b'V', 38, c_int);
+    nix::ioctl_readwrite!(vidioc_s_input, b'V', 39, c_int);
+
+    nix::ioctl_read!(vidioc_g_output, b'V', 46, c_int);
+    nix::ioctl_readwrite!(vidioc_s_output, b'V', 47, c_int);
+    nix::ioctl_readwrite!(vidioc_enumoutput, b'V', 48, v4l2_output);
+}
+
+#[derive(Debug, Error)]
+pub enum SelectionError {
+    #[error("selection {0} is out of range")]
+    OutOfRange(usize),
+    #[error("ioctl error: {0}")]
+    IoctlError(Errno),
+}
+
+impl From<SelectionError> for Errno {
+    fn from(err: SelectionError) -> Self {
+        match err {
+            SelectionError::OutOfRange(_) => Errno::EINVAL,
+            SelectionError::IoctlError(e) => e,
+        }
+    }
+}
+
+pub fn enuminput<F: AsRawFd, R: From<v4l2_input>>(
+    fd: &F,
+    index: usize,
+) -> Result<R, SelectionError> {
+    let mut input = v4l2_input {
+        index: index as u32,
+        ..unsafe { mem::zeroed() }
+    };
+
+    match unsafe { ioctl::vidioc_enuminput(fd.as_raw_fd(), &mut input) } {
+        Ok(_) => Ok(R::from(input)),
+        Err(Errno::EINVAL) => Err(SelectionError::OutOfRange(index)),
+        Err(e) => Err(SelectionError::IoctlError(e)),
+    }
+}
+
+pub fn g_input<F: AsRawFd>(fd: &F) -> Result<usize, Errno> {
+    let mut input: c_int = 0;
+
+    unsafe { ioctl::vidioc_g_input(fd.as_raw_fd(), &mut input) }.map(|r| r as usize)
+}
+
+pub fn s_input<F: AsRawFd>(fd: &F, index: usize) -> Result<(), SelectionError> {
+    let mut input: c_int = index as c_int;
+
+    match unsafe { ioctl::vidioc_s_input(fd.as_raw_fd(), &mut input) } {
+        Ok(_) => Ok(()),
+        Err(Errno::EINVAL) => Err(SelectionError::OutOfRange(index)),
+        Err(e) => Err(SelectionError::IoctlError(e)),
+    }
+}
+
+pub fn enumoutput<F: AsRawFd, R: From<v4l2_output>>(
+    fd: &F,
+    index: usize,
+) -> Result<R, SelectionError> {
+    let mut output = v4l2_output {
+        index: index as u32,
+        ..unsafe { mem::zeroed() }
+    };
+
+    match unsafe { ioctl::vidioc_enumoutput(fd.as_raw_fd(), &mut output) } {
+        Ok(_) => Ok(R::from(output)),
+        Err(Errno::EINVAL) => Err(SelectionError::OutOfRange(index)),
+        Err(e) => Err(SelectionError::IoctlError(e)),
+    }
+}
+
+pub fn g_output<F: AsRawFd>(fd: &F) -> Result<usize, Errno> {
+    let mut output: c_int = 0;
+
+    unsafe { ioctl::vidioc_g_output(fd.as_raw_fd(), &mut output) }.map(|r| r as usize)
+}
+
+pub fn s_output<F: AsRawFd>(fd: &F, index: usize) -> Result<(), SelectionError> {
+    let mut output: c_int = index as c_int;
+
+    match unsafe { ioctl::vidioc_s_output(fd.as_raw_fd(), &mut output) } {
+        Ok(_) => Ok(()),
+        Err(Errno::EINVAL) => Err(SelectionError::OutOfRange(index)),
+        Err(e) => Err(SelectionError::IoctlError(e)),
+    }
+}