usb: unify ControlHandler+DeviceStateHandler, route all control reque…

…sts to all handlers. - Allows classes to handle vendor requests. - Allows classes to use a single handler for multiple interfaces. - Allows classes to access the other events (previously only `reset` was available).
embassy-rs · Feb 7, 2023 · 3af991a · 3af991a
1 parent 1d841cc
commit 3af991a
Show file tree

Hide file tree

Showing 31 changed files with 380 additions and 337 deletions.
diff --git a/embassy-usb-logger/src/lib.rs b/embassy-usb-logger/src/lib.rs
@@ -74,7 +74,6 @@ impl<const N: usize> UsbLogger<N> {
             &mut state.config_descriptor,
             &mut state.bos_descriptor,
             &mut state.control_buf,
-            None,
         );
 
         // Create classes on the builder.

diff --git a/embassy-usb/Cargo.toml b/embassy-usb/Cargo.toml
@@ -27,6 +27,15 @@ max-interface-count-6 = []
 max-interface-count-7 = []
 max-interface-count-8 = []
 
+max-handler-count-1 = []
+max-handler-count-2 = []
+max-handler-count-3 = []
+max-handler-count-4 = [] # Default
+max-handler-count-5 = []
+max-handler-count-6 = []
+max-handler-count-7 = []
+max-handler-count-8 = []
+
 # END AUTOGENERATED CONFIG FEATURES
 
 [dependencies]

diff --git a/embassy-usb/build.rs b/embassy-usb/build.rs
@@ -7,6 +7,7 @@ static CONFIGS: &[(&str, usize)] = &[
     // BEGIN AUTOGENERATED CONFIG FEATURES
     // Generated by gen_config.py. DO NOT EDIT.
     ("MAX_INTERFACE_COUNT", 4),
+    ("MAX_HANDLER_COUNT", 4),
     // END AUTOGENERATED CONFIG FEATURES
 ];
 

diff --git a/embassy-usb/gen_config.py b/embassy-usb/gen_config.py
@@ -28,6 +28,7 @@ def feature(name, default, min, max, pow2=None):
 
 
 feature("max_interface_count", default=4, min=1, max=8)
+feature("max_handler_count", default=4, min=1, max=8)
 
 # ========= Update Cargo.toml
 

diff --git a/embassy-usb/src/builder.rs b/embassy-usb/src/builder.rs
@@ -1,12 +1,12 @@
 use heapless::Vec;
 
-use crate::control::ControlHandler;
+use crate::config::*;
 use crate::descriptor::{BosWriter, DescriptorWriter};
 use crate::driver::{Driver, Endpoint, EndpointType};
 #[cfg(feature = "msos-descriptor")]
 use crate::msos::{DeviceLevelDescriptor, FunctionLevelDescriptor, MsOsDescriptorWriter};
 use crate::types::*;
-use crate::{DeviceStateHandler, Interface, UsbDevice, MAX_INTERFACE_COUNT, STRING_INDEX_CUSTOM_START};
+use crate::{Handler, Interface, UsbDevice, MAX_INTERFACE_COUNT, STRING_INDEX_CUSTOM_START};
 
 #[derive(Debug, Copy, Clone)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -122,8 +122,8 @@ impl<'a> Config<'a> {
 /// [`UsbDevice`] builder.
 pub struct Builder<'d, D: Driver<'d>> {
     config: Config<'d>,
-    handler: Option<&'d dyn DeviceStateHandler>,
-    interfaces: Vec<Interface<'d>, MAX_INTERFACE_COUNT>,
+    handlers: Vec<&'d mut dyn Handler, MAX_HANDLER_COUNT>,
+    interfaces: Vec<Interface, MAX_INTERFACE_COUNT>,
     control_buf: &'d mut [u8],
 
     driver: D,
@@ -151,7 +151,6 @@ impl<'d, D: Driver<'d>> Builder<'d, D> {
         bos_descriptor_buf: &'d mut [u8],
         #[cfg(feature = "msos-descriptor")] msos_descriptor_buf: &'d mut [u8],
         control_buf: &'d mut [u8],
-        handler: Option<&'d dyn DeviceStateHandler>,
     ) -> Self {
         // Magic values specified in USB-IF ECN on IADs.
         if config.composite_with_iads
@@ -179,9 +178,9 @@ impl<'d, D: Driver<'d>> Builder<'d, D> {
 
         Builder {
             driver,
-            handler,
             config,
             interfaces: Vec::new(),
+            handlers: Vec::new(),
             control_buf,
             next_string_index: STRING_INDEX_CUSTOM_START,
 
@@ -205,7 +204,7 @@ impl<'d, D: Driver<'d>> Builder<'d, D> {
         UsbDevice::build(
             self.driver,
             self.config,
-            self.handler,
+            self.handlers,
             self.device_descriptor.into_buf(),
             self.config_descriptor.into_buf(),
             self.bos_descriptor.writer.into_buf(),
@@ -248,6 +247,26 @@ impl<'d, D: Driver<'d>> Builder<'d, D> {
         }
     }
 
+    /// Add a Handler.
+    ///
+    /// The Handler is called on some USB bus events, and to handle all control requests not already
+    /// handled by the USB stack.
+    pub fn handler(&mut self, handler: &'d mut dyn Handler) {
+        if self.handlers.push(handler).is_err() {
+            panic!(
+                "embassy-usb: handler list full. Increase the `max_handler_count` compile-time setting. Current value: {}",
+                MAX_HANDLER_COUNT
+            )
+        }
+    }
+
+    /// Allocates a new string index.
+    pub fn string(&mut self) -> StringIndex {
+        let index = self.next_string_index;
+        self.next_string_index += 1;
+        StringIndex::new(index)
+    }
+
     #[cfg(feature = "msos-descriptor")]
     /// Add an MS OS 2.0 Descriptor Set.
     ///
@@ -301,10 +320,8 @@ impl<'a, 'd, D: Driver<'d>> FunctionBuilder<'a, 'd, D> {
 
         let number = self.builder.interfaces.len() as _;
         let iface = Interface {
-            handler: None,
             current_alt_setting: 0,
             num_alt_settings: 0,
-            num_strings: 0,
         };
 
         if self.builder.interfaces.push(iface).is_err() {
@@ -350,17 +367,9 @@ impl<'a, 'd, D: Driver<'d>> InterfaceBuilder<'a, 'd, D> {
         self.interface_number
     }
 
-    pub fn handler(&mut self, handler: &'d mut dyn ControlHandler) {
-        self.builder.interfaces[self.interface_number.0 as usize].handler = Some(handler);
-    }
-
     /// Allocates a new string index.
     pub fn string(&mut self) -> StringIndex {
-        let index = self.builder.next_string_index;
-        self.builder.next_string_index += 1;
-        self.builder.interfaces[self.interface_number.0 as usize].num_strings += 1;
-
-        StringIndex::new(index)
+        self.builder.string()
     }
 
     /// Add an alternate setting to the interface and write its descriptor.

diff --git a/embassy-usb/src/class/cdc_acm.rs b/embassy-usb/src/class/cdc_acm.rs
@@ -6,10 +6,10 @@ use core::sync::atomic::{AtomicBool, Ordering};
 
 use embassy_sync::blocking_mutex::CriticalSectionMutex;
 
-use crate::control::{self, ControlHandler, InResponse, OutResponse, Request};
+use crate::control::{self, InResponse, OutResponse, Recipient, Request, RequestType};
 use crate::driver::{Driver, Endpoint, EndpointError, EndpointIn, EndpointOut};
 use crate::types::*;
-use crate::Builder;
+use crate::{Builder, Handler};
 
 /// This should be used as `device_class` when building the `UsbDevice`.
 pub const USB_CLASS_CDC: u8 = 0x02;
@@ -67,6 +67,7 @@ pub struct CdcAcmClass<'d, D: Driver<'d>> {
 }
 
 struct Control<'a> {
+    comm_if: InterfaceNumber,
     shared: &'a ControlShared,
 }
 
@@ -98,20 +99,26 @@ impl<'a> Control<'a> {
     }
 }
 
-impl<'d> ControlHandler for Control<'d> {
+impl<'d> Handler for Control<'d> {
     fn reset(&mut self) {
         let shared = self.shared();
         shared.line_coding.lock(|x| x.set(LineCoding::default()));
         shared.dtr.store(false, Ordering::Relaxed);
         shared.rts.store(false, Ordering::Relaxed);
     }
 
-    fn control_out(&mut self, req: control::Request, data: &[u8]) -> OutResponse {
+    fn control_out(&mut self, req: control::Request, data: &[u8]) -> Option<OutResponse> {
+        if (req.request_type, req.recipient, req.index)
+            != (RequestType::Class, Recipient::Interface, self.comm_if.0 as u16)
+        {
+            return None;
+        }
+
         match req.request {
             REQ_SEND_ENCAPSULATED_COMMAND => {
                 // We don't actually support encapsulated commands but pretend we do for standards
                 // compatibility.
-                OutResponse::Accepted
+                Some(OutResponse::Accepted)
             }
             REQ_SET_LINE_CODING if data.len() >= 7 => {
                 let coding = LineCoding {
@@ -123,7 +130,7 @@ impl<'d> ControlHandler for Control<'d> {
                 self.shared().line_coding.lock(|x| x.set(coding));
                 debug!("Set line coding to: {:?}", coding);
 
-                OutResponse::Accepted
+                Some(OutResponse::Accepted)
             }
             REQ_SET_CONTROL_LINE_STATE => {
                 let dtr = (req.value & 0x0001) != 0;
@@ -134,13 +141,19 @@ impl<'d> ControlHandler for Control<'d> {
                 shared.rts.store(rts, Ordering::Relaxed);
                 debug!("Set dtr {}, rts {}", dtr, rts);
 
-                OutResponse::Accepted
+                Some(OutResponse::Accepted)
             }
-            _ => OutResponse::Rejected,
+            _ => Some(OutResponse::Rejected),
         }
     }
 
-    fn control_in<'a>(&'a mut self, req: Request, buf: &'a mut [u8]) -> InResponse<'a> {
+    fn control_in<'a>(&'a mut self, req: Request, buf: &'a mut [u8]) -> Option<InResponse<'a>> {
+        if (req.request_type, req.recipient, req.index)
+            != (RequestType::Class, Recipient::Interface, self.comm_if.0 as u16)
+        {
+            return None;
+        }
+
         match req.request {
             // REQ_GET_ENCAPSULATED_COMMAND is not really supported - it will be rejected below.
             REQ_GET_LINE_CODING if req.length == 7 => {
@@ -151,9 +164,9 @@ impl<'d> ControlHandler for Control<'d> {
                 buf[4] = coding.stop_bits as u8;
                 buf[5] = coding.parity_type as u8;
                 buf[6] = coding.data_bits;
-                InResponse::Accepted(&buf[0..7])
+                Some(InResponse::Accepted(&buf[0..7]))
             }
-            _ => InResponse::Rejected,
+            _ => Some(InResponse::Rejected),
         }
     }
 }
@@ -162,17 +175,12 @@ impl<'d, D: Driver<'d>> CdcAcmClass<'d, D> {
     /// Creates a new CdcAcmClass with the provided UsbBus and max_packet_size in bytes. For
     /// full-speed devices, max_packet_size has to be one of 8, 16, 32 or 64.
     pub fn new(builder: &mut Builder<'d, D>, state: &'d mut State<'d>, max_packet_size: u16) -> Self {
-        let control = state.control.write(Control { shared: &state.shared });
-
-        let control_shared = &state.shared;
-
         assert!(builder.control_buf_len() >= 7);
 
         let mut func = builder.function(USB_CLASS_CDC, CDC_SUBCLASS_ACM, CDC_PROTOCOL_NONE);
 
         // Control interface
         let mut iface = func.interface();
-        iface.handler(control);
         let comm_if = iface.interface_number();
         let data_if = u8::from(comm_if) + 1;
         let mut alt = iface.alt_setting(USB_CLASS_CDC, CDC_SUBCLASS_ACM, CDC_PROTOCOL_NONE, None);
@@ -213,6 +221,16 @@ impl<'d, D: Driver<'d>> CdcAcmClass<'d, D> {
         let read_ep = alt.endpoint_bulk_out(max_packet_size);
         let write_ep = alt.endpoint_bulk_in(max_packet_size);
 
+        drop(func);
+
+        let control = state.control.write(Control {
+            shared: &state.shared,
+            comm_if,
+        });
+        builder.handler(control);
+
+        let control_shared = &state.shared;
+
         CdcAcmClass {
             _comm_ep: comm_ep,
             _data_if: data_if,
Original file line number	Diff line number	Diff line change
Expand Up		@@ -28,6 +28,7 @@ def feature(name, default, min, max, pow2=None):


		feature("max_interface_count", default=4, min=1, max=8)
		feature("max_handler_count", default=4, min=1, max=8)

		# ========= Update Cargo.toml

Expand Down