wip: experimental async usb stack

embassy-usb/src/control.rs

@@ -0,0 +1,134 @@
+use core::mem;
+
+use super::types::*;
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum ParseError {
+    InvalidLength,
+}
+
+/// Control request type.
+#[repr(u8)]
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum RequestType {
+    /// Request is a USB standard request. Usually handled by
+    /// [`UsbDevice`](crate::device::UsbDevice).
+    Standard = 0,
+    /// Request is intended for a USB class.
+    Class = 1,
+    /// Request is vendor-specific.
+    Vendor = 2,
+    /// Reserved.
+    Reserved = 3,
+}
+
+/// Control request recipient.
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Recipient {
+    /// Request is intended for the entire device.
+    Device = 0,
+    /// Request is intended for an interface. Generally, the `index` field of the request specifies
+    /// the interface number.
+    Interface = 1,
+    /// Request is intended for an endpoint. Generally, the `index` field of the request specifies
+    /// the endpoint address.
+    Endpoint = 2,
+    /// None of the above.
+    Other = 3,
+    /// Reserved.
+    Reserved = 4,
+}
+
+/// A control request read from a SETUP packet.
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub struct Request {
+    /// Direction of the request.
+    pub direction: UsbDirection,
+    /// Type of the request.
+    pub request_type: RequestType,
+    /// Recipient of the request.
+    pub recipient: Recipient,
+    /// Request code. The meaning of the value depends on the previous fields.
+    pub request: u8,
+    /// Request value. The meaning of the value depends on the previous fields.
+    pub value: u16,
+    /// Request index. The meaning of the value depends on the previous fields.
+    pub index: u16,
+    /// Length of the DATA stage. For control OUT transfers this is the exact length of the data the
+    /// host sent. For control IN transfers this is the maximum length of data the device should
+    /// return.
+    pub length: u16,
+}
+
+impl Request {
+    /// Standard USB control request Get Status
+    pub const GET_STATUS: u8 = 0;
+
+    /// Standard USB control request Clear Feature
+    pub const CLEAR_FEATURE: u8 = 1;
+
+    /// Standard USB control request Set Feature
+    pub const SET_FEATURE: u8 = 3;
+
+    /// Standard USB control request Set Address
+    pub const SET_ADDRESS: u8 = 5;
+
+    /// Standard USB control request Get Descriptor
+    pub const GET_DESCRIPTOR: u8 = 6;
+
+    /// Standard USB control request Set Descriptor
+    pub const SET_DESCRIPTOR: u8 = 7;
+
+    /// Standard USB control request Get Configuration
+    pub const GET_CONFIGURATION: u8 = 8;
+
+    /// Standard USB control request Set Configuration
+    pub const SET_CONFIGURATION: u8 = 9;
+
+    /// Standard USB control request Get Interface
+    pub const GET_INTERFACE: u8 = 10;
+
+    /// Standard USB control request Set Interface
+    pub const SET_INTERFACE: u8 = 11;
+
+    /// Standard USB control request Synch Frame
+    pub const SYNCH_FRAME: u8 = 12;
+
+    /// Standard USB feature Endpoint Halt for Set/Clear Feature
+    pub const FEATURE_ENDPOINT_HALT: u16 = 0;
+
+    /// Standard USB feature Device Remote Wakeup for Set/Clear Feature
+    pub const FEATURE_DEVICE_REMOTE_WAKEUP: u16 = 1;
+
+    pub(crate) fn parse(buf: &[u8]) -> Result<Request, ParseError> {
+        if buf.len() != 8 {
+            return Err(ParseError::InvalidLength);
+        }
+
+        let rt = buf[0];
+        let recipient = rt & 0b11111;
+
+        Ok(Request {
+            direction: rt.into(),
+            request_type: unsafe { mem::transmute((rt >> 5) & 0b11) },
+            recipient: if recipient <= 3 {
+                unsafe { mem::transmute(recipient) }
+            } else {
+                Recipient::Reserved
+            },
+            request: buf[1],
+            value: (buf[2] as u16) | ((buf[3] as u16) << 8),
+            index: (buf[4] as u16) | ((buf[5] as u16) << 8),
+            length: (buf[6] as u16) | ((buf[7] as u16) << 8),
+        })
+    }
+
+    /// Gets the descriptor type and index from the value field of a GET_DESCRIPTOR request.
+    pub fn descriptor_type_index(&self) -> (u8, u8) {
+        ((self.value >> 8) as u8, self.value as u8)
+    }
+}