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get-descriptor-device.rs: add SET_ADDRESS handling; comments to solution

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This commit is contained in:
Lotte Steenbrink 2020-07-03 15:25:01 +02:00
parent c3d680e76d
commit 44d3bfe32a
1 changed files with 41 additions and 23 deletions
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64
advanced/common/usb/src/get-descriptor-device.rs
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@ -5,9 +5,11 @@
#![deny(warnings)]
#![no_std]
#[cfg(TODO)]
use core::num::NonZeroU8;
/// Device address assigned by the host; will be in the range 1..=127
pub type Address = NonZeroU8;
/// Standard USB request
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum Request {
@ -22,10 +24,9 @@ pub enum Request {
/// SET_ADDRESS
// see section 9.4.6 of the USB specification
#[cfg(TODO)]
SetAddress {
/// New device address, in the range `1..=127`
address: Option<NonZeroU8>,
address: Option<Address>,
},
/// SET_CONFIGURATION
@ -50,17 +51,24 @@ impl Request {
windex: u16,
wlength: u16,
) -> Result<Self, ()> {
// see table 9-4
// see table 9-4 (USB specification)
const SET_ADDRESS: u8 = 5;
const GET_DESCRIPTOR: u8 = 6;
if bmrequesttype == 0b10000000 && brequest == GET_DESCRIPTOR {
// see table 9-5
const DEVICE: u8 = 1;
// 1. get descriptor type and descriptor index from wValue
let desc_ty = (wvalue >> 8) as u8;
let desc_index = wvalue as u8;
let langid = windex;
// 2. confirm that the descriptor
// - is of type DEVICE and
// - has descriptor index 0 (i.e. it is the first implemented descriptor for this type) and
// - has wIndex 0 (i.e. no language ID since it's not a string descriptor)
if desc_ty == DEVICE && desc_index == 0 && langid == 0 {
Ok(Request::GetDescriptor {
descriptor: Descriptor::Device,
@ -69,6 +77,18 @@ impl Request {
} else {
Err(())
}
} else if bmrequesttype == 0b00000000 && brequest == SET_ADDRESS {
// Set the device address for all future accesses.
// (Needed to successfully init when conected to Apple devices)
// Section 9.4.6 Set Address of the USB specification explains which values for wvalue,
// windex and wlength are valid.
if wvalue < 128 && windex == 0 && wlength == 0 {
Ok(Request::SetAddress {
address: NonZeroU8::new(wvalue as u8),
})
} else {
Err(())
}
} else {
Err(())
}
@ -92,7 +112,6 @@ pub enum Descriptor {
#[cfg(test)]
mod tests {
#[cfg(TODO)]
use core::num::NonZeroU8;
use crate::{Descriptor, Request};
@ -117,24 +136,6 @@ mod tests {
// ^^^^
}
#[cfg(TODO)]
#[test]
fn get_descriptor_configuration() {
// OK: GET_DESCRIPTOR Configuration 0 [length=9]
assert_eq!(
Request::parse(0b1000_0000, 0x06, 0x02_00, 0, 9),
Ok(Request::GetDescriptor {
descriptor: Descriptor::Configuration { index: 0 },
length: 9
})
);
// has language ID but shouldn't
assert!(Request::parse(0b1000_0000, 0x06, 0x02_00, 1033, 9).is_err());
// ^^^^
}
#[cfg(TODO)]
#[test]
fn set_address() {
// OK: SET_ADDRESS 16
@ -164,6 +165,23 @@ mod tests {
// ^
}
#[cfg(TODO)]
#[test]
fn get_descriptor_configuration() {
// OK: GET_DESCRIPTOR Configuration 0 [length=9]
assert_eq!(
Request::parse(0b1000_0000, 0x06, 0x02_00, 0, 9),
Ok(Request::GetDescriptor {
descriptor: Descriptor::Configuration { index: 0 },
length: 9
})
);
// has language ID but shouldn't
assert!(Request::parse(0b1000_0000, 0x06, 0x02_00, 1033, 9).is_err());
// ^^^^
}
#[cfg(TODO)]
#[test]
fn set_configuration() {