stm32/wpan: modify evtbox to use slice view

embassy-stm32-wpan/src/cmd.rs

@@ -1,8 +1,7 @@
 use core::ptr;
 
 use crate::consts::TlPacketType;
-use crate::evt::{EvtPacket, EvtSerial};
-use crate::{PacketHeader, TL_EVT_HEADER_SIZE};
+use crate::PacketHeader;
 
 #[derive(Copy, Clone)]
 #[repr(C, packed)]
@@ -60,31 +59,6 @@ impl CmdPacket {
 
         ptr::copy_nonoverlapping(payload as *const _ as *const u8, p_payload, payload.len());
     }
-
-    /// Writes an underlying CmdPacket into the provided buffer.
-    /// Returns a number of bytes that were written.
-    /// Returns an error if event kind is unknown or if provided buffer size is not enough.
-    #[allow(clippy::result_unit_err)]
-    pub fn write(&self, buf: &mut [u8]) -> Result<usize, ()> {
-        unsafe {
-            let cmd_ptr: *const CmdPacket = self;
-            let self_as_evt_ptr: *const EvtPacket = cmd_ptr.cast();
-            let evt_serial: *const EvtSerial = &(*self_as_evt_ptr).evt_serial;
-
-            let acl_data: *const AclDataPacket = cmd_ptr.cast();
-            let acl_serial: *const AclDataSerial = &(*acl_data).acl_data_serial;
-            let acl_serial_buf: *const u8 = acl_serial.cast();
-
-            let len = (*evt_serial).evt.payload_len as usize + TL_EVT_HEADER_SIZE;
-            if len > buf.len() {
-                return Err(());
-            }
-
-            core::ptr::copy(acl_serial_buf, buf.as_mut_ptr(), len);
-
-            Ok(len)
-        }
-    }
 }
 
 #[derive(Copy, Clone)]
@@ -96,9 +70,35 @@ pub struct AclDataSerial {
     pub acl_data: [u8; 1],
 }
 
+#[derive(Copy, Clone)]
+#[repr(C, packed)]
+pub struct AclDataSerialStub {
+    pub ty: u8,
+    pub handle: u16,
+    pub length: u16,
+}
+
 #[derive(Copy, Clone)]
 #[repr(C, packed)]
 pub struct AclDataPacket {
     pub header: PacketHeader,
     pub acl_data_serial: AclDataSerial,
 }
+
+impl AclDataPacket {
+    pub unsafe fn write_into(cmd_buf: *mut AclDataPacket, packet_type: TlPacketType, handle: u16, payload: &[u8]) {
+        let p_cmd_serial = &mut (*cmd_buf).acl_data_serial as *mut _ as *mut AclDataSerialStub;
+        let p_payload = &mut (*cmd_buf).acl_data_serial.acl_data as *mut _;
+
+        ptr::write_volatile(
+            p_cmd_serial,
+            AclDataSerialStub {
+                ty: packet_type as u8,
+                handle: handle,
+                length: payload.len() as u16,
+            },
+        );
+
+        ptr::copy_nonoverlapping(payload as *const _ as *const u8, p_payload, payload.len());
+    }
+}