kms: Add kms backend module

src/backend/kms/mod.rs

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
+use crate::state::State;
+use anyhow::Result;
+use smithay::reexports::calloop::EventLoop;
+
+pub struct KmsState {}
+
+pub fn init_backend(event_loop: &mut EventLoop<State>, state: &mut State) -> Result<()> {
+    unimplemented!()
+}

src/backend/mod.rs

@@ -4,16 +4,17 @@ use crate::state::State;
 use anyhow::Result;
 use smithay::reexports::calloop::EventLoop;
 
+pub mod kms;
 pub mod winit;
 pub mod x11;
 // TODO
 // pub mod wayland; // tbd in smithay
-// pub mod udev;
 
 pub fn init_backend_auto(event_loop: &mut EventLoop<State>, state: &mut State) -> Result<()> {
     match std::env::var("COSMIC_BACKEND") {
         Ok(x) if x == "x11" => x11::init_backend(event_loop, state),
         Ok(x) if x == "winit" => winit::init_backend(event_loop, state),
+        Ok(x) if x == "kms" => kms::init_backend(event_loop, state),
         Ok(_) => unimplemented!("There is no backend with this identifier"),
         Err(_) => {
             if std::env::var_os("DISPLAY").is_some()
@@ -28,7 +29,7 @@ pub fn init_backend_auto(event_loop: &mut EventLoop<State>, state: &mut State) -
                     }
                 }
             } else {
-                unimplemented!("Currently this runs only nested")
+                kms::init_backend(event_loop, state)
             }
         }
     }

src/state.rs

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
 use crate::{
-    backend::{winit::WinitState, x11::X11State},
+    backend::{kms::KmsState, winit::WinitState, x11::X11State},
     shell::{init_shell, workspaces::Workspaces, ShellStates},
 };
 use smithay::{
@@ -60,13 +60,20 @@ pub struct Fps {
 pub enum BackendData {
     X11(X11State),
     Winit(WinitState),
+    Kms(KmsState),
     // TODO
     // Wayland(WaylandState),
-    // Udev(UdevState),
     Unset,
 }
 
 impl BackendData {
+    pub fn kms(&mut self) -> &mut KmsState {
+        match self {
+            BackendData::Kms(ref mut kms_state) => kms_state,
+            _ => unreachable!("Called kms in non kms backend"),
+        }
+    }
+
     pub fn x11(&mut self) -> &mut X11State {
         match self {
             BackendData::X11(ref mut x11_state) => x11_state,