cros_alsa: add ControlTLV

Add ControlTLV to support read and write of alsa TLV byte controls.

BUG=b:157210111
TEST=cargo build

Change-Id: I31e76d3d64a12f4ec50609d6eaf095525143eb8d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/2595659
Tested-by: Judy Hsiao <judyhsiao@chromium.org>
Reviewed-by: Chih-Yang Hsia <paulhsia@chromium.org>
Commit-Queue: Judy Hsiao <judyhsiao@chromium.org>

1 files changed, 22 insertions, 1 deletions

diff --git a/cros_alsa/src/card.rs b/cros_alsa/src/card.rs
index fa88018f..99f72210 100644
--- a/cros_alsa/src/card.rs
+++ b/cros_alsa/src/card.rs
@@ -10,6 +10,7 @@ use remain::sorted;
 use crate::control::{self, Control};
 use crate::control_primitive;
 use crate::control_primitive::{Ctl, ElemId, ElemIface};
+use crate::control_tlv::{self, ControlTLV};
 
 pub type Result<T> = std::result::Result<T, Error>;
 
@@ -21,6 +22,8 @@ pub enum Error {
     AlsaControlAPI(control_primitive::Error),
     /// Error occurs in Control.
     Control(control::Error),
+    /// Error occurs in ControlTLV.
+    ControlTLV(control_tlv::Error),
 }
 
 impl error::Error for Error {}
@@ -31,6 +34,12 @@ impl From<control::Error> for Error {
     }
 }
 
+impl From<control_tlv::Error> for Error {
+    fn from(err: control_tlv::Error) -> Error {
+        Error::ControlTLV(err)
+    }
+}
+
 impl From<control_primitive::Error> for Error {
     fn from(err: control_primitive::Error) -> Error {
         Error::AlsaControlAPI(err)
@@ -43,6 +52,7 @@ impl fmt::Display for Error {
         match self {
             AlsaControlAPI(e) => write!(f, "{}", e),
             Control(e) => write!(f, "{}", e),
+            ControlTLV(e) => write!(f, "{}", e),
         }
     }
 }
@@ -82,7 +92,7 @@ impl Card {
     /// # Errors
     ///
     /// * If control name is an invalid CString.
-    /// * If control dose not exist.
+    /// * If control does not exist.
     /// * If `Control` elem_type() mismatches the type of underlying mixer control.
     /// * If `Control` size() mismatches the number of value entries of underlying mixer control.
     pub fn control_by_name<'a, T: 'a>(&'a mut self, control_name: &str) -> Result<T>
@@ -92,4 +102,15 @@ impl Card {
         let id = ElemId::new(ElemIface::Mixer, control_name)?;
         Ok(T::from(&mut self.handle, id)?)
     }
+
+    /// Creates a `ControlTLV` from control name.
+    ///
+    /// # Errors
+    ///
+    /// * If control name is an invalid CString.
+    /// * If control does not exist.
+    pub fn control_tlv_by_name<'a>(&'a mut self, control_name: &str) -> Result<ControlTLV<'a>> {
+        let id = ElemId::new(ElemIface::Mixer, control_name)?;
+        Ok(ControlTLV::new(&mut self.handle, id)?)
+    }
 }