Cleanup deinit and document lifecyclev0.2

6 files changed, 60 insertions, 34 deletions

diff --git a/README.md b/README.md
index 94e1af1..c114db7 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,22 @@ Since there isn't (?) any good USB device mocking setup, for tests to pass an RT
 
 ## Design
 
-Similarly to the original rtl-sdr driver, we use libusb via the `rusb` bindings as the main interface to issue commands to the rtl-sdr USB dongle.
+### Overview
+
+RusTL-SDR is very similar to the original rtl-sdr driver. It uses libusb, via the [rusb](https://github.com/a1ien/rusb/) bindings, as the main interface to issue commands to the rtl-sdr USB dongle.
+
+### Lifecycle
+
+Devices generally go through the following lifecycle:
+
+1. Get a libusb context/handle, and find a compatible and supported RTL-SDR device
+2. Initialize the device baseband
+3. Probe the device for known tuners via the I2C interface
+4. Run any special initialization required for the detected tuner
+5. Interact with the device, usually this is where samples are read
+6. Deinitialize the tuner
+7. Deinitialize the baseband
+8. Close the USB handle
 
 ## License
 
diff --git a/src/lib.rs b/src/lib.rs
index d068e57..b350616 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,9 +1,9 @@
 extern crate rusb;
 
-mod devices;
+mod tuners;
 mod usb;
 
-use devices::*;
+use tuners::*;
 use usb::RtlSdrDeviceHandle;
 
 const INTERFACE_ID: u8 = 0;
@@ -51,28 +51,24 @@ impl RtlSdr {
                     handle.init_baseband();
                     handle.set_i2c_repeater(true);
 
-                    let tuner: Box<dyn Tuner> = match self.search_tuner(&handle) {
-                        Some(tuner) => match tuner {
-                            r820t::TUNER_ID => Box::new(r820t::R820T::new(&handle)),
-                            fc0013::TUNER_ID => Box::new(fc0013::FC0013::new(&handle)),
-                            _ => {
+                    {
+                        let tuner: Box<dyn Tuner> = match self.search_tuner(&handle) {
+                            Some(tuner) => match tuner {
+                                r820t::TUNER_ID => Box::new(r820t::R820T::new(&handle)),
+                                fc0013::TUNER_ID => Box::new(fc0013::FC0013::new(&handle)),
+                                _ => {
+                                    println!("No valid tuner found");
+                                    return;
+                                }
+                            },
+                            None => {
                                 println!("No valid tuner found");
                                 return;
                             }
-                        },
-                        None => {
-                            println!("No valid tuner found");
-                            return;
-                        }
-                    };
+                        };
 
-                    tuner.init();
-
-                    // handle.deinit_baseband();
-
-                    // if kernel_driver_attached {
-                    //     handle.attach_kernel_driver();
-                    // }
+                        tuner.init();
+                    }
                 } else {
                     println!("No match for vid {} and pid {}", vid, pid);
                 }
diff --git a/src/devices/fc0013.rs b/src/tuners/fc0013.rs
index 9eb03f4..9eb03f4 100644
--- a/src/devices/fc0013.rs
+++ b/src/tuners/fc0013.rs
diff --git a/src/devices/mod.rs b/src/tuners/mod.rs
index cbd7edf..cbd7edf 100644
--- a/src/devices/mod.rs
+++ b/src/tuners/mod.rs
diff --git a/src/devices/r820t.rs b/src/tuners/r820t.rs
index ec0f173..2638917 100644
--- a/src/devices/r820t.rs
+++ b/src/tuners/r820t.rs
@@ -28,7 +28,9 @@ impl<'a> R820T<'a> {
 }
 
 impl<'a> Drop for R820T<'a> {
-    fn drop(&mut self) {}
+    fn drop(&mut self) {
+        self.exit();
+    }
 }
 
 impl<'a> Tuner for R820T<'a> {
@@ -47,9 +49,7 @@ impl<'a> Tuner for R820T<'a> {
         self.handle.demod_write_reg(1, 0x15, 0x01, 1);
     }
 
-    fn exit(&self) {
-        unimplemented!()
-    }
+    fn exit(&self) {}
 
     fn set_freq(&self, _freq: u32) {
         unimplemented!()
diff --git a/src/usb.rs b/src/usb.rs
index 92f99d1..0a0003f 100644
--- a/src/usb.rs
+++ b/src/usb.rs
@@ -36,27 +36,37 @@ const CTRL_TIMEOUT: Duration = Duration::from_millis(300);
 pub struct RtlSdrDeviceHandle {
     handle: DeviceHandle<GlobalContext>,
     iface_id: u8,
+    kernel_driver_active: bool,
 }
 
+/// A wrapper around libusb's DeviceHandle that implements
+/// various rtl-sdr specific methods
 impl RtlSdrDeviceHandle {
-    /// A wrapper around libusb's DeviceHandle that implements
-    /// various rtl-sdr specific methods
     pub fn new(handle: DeviceHandle<GlobalContext>, iface_id: u8) -> RtlSdrDeviceHandle {
-        RtlSdrDeviceHandle { handle, iface_id }
+        let mut handle = RtlSdrDeviceHandle {
+            handle,
+            iface_id,
+            kernel_driver_active: false,
+        };
+        handle.detach_kernel_driver();
+        handle
     }
 
-    pub fn detach_kernel_driver(&mut self) -> bool {
-        match self.handle.kernel_driver_active(self.iface_id) {
+    pub fn detach_kernel_driver(&mut self) {
+        let active = match self.handle.kernel_driver_active(self.iface_id) {
             Ok(true) => {
                 self.handle.detach_kernel_driver(self.iface_id).ok();
                 true
             }
             _ => false,
-        }
+        };
+        self.kernel_driver_active = active;
     }
 
     pub fn attach_kernel_driver(&mut self) {
-        self.handle.attach_kernel_driver(self.iface_id).ok();
+        if self.kernel_driver_active {
+            self.handle.attach_kernel_driver(self.iface_id).ok();
+        }
     }
 
     pub fn claim_interface(&mut self) {
@@ -237,9 +247,14 @@ impl RtlSdrDeviceHandle {
     }
 
     pub fn deinit_baseband(&self) {
-        // deinit tuner?
-
         // power off demod and ADCs
         self.write_reg(BLOCK_SYSB, ADDR_SYS_DEMOD_CTL, 0x20, 1);
     }
 }
+
+impl Drop for RtlSdrDeviceHandle {
+    fn drop(&mut self) {
+        self.deinit_baseband();
+        self.attach_kernel_driver();
+    }
+}