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Interface refactor

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fromost
2026-08-30 18:56:13 +08:00
parent 13e64ab91a
commit 2e25cda230
4 changed files with 154 additions and 158 deletions
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pn532/src/interface.rs → pn532/src/interface/i2c.rs
+9 -145
View File
@@ -1,85 +1,8 @@
//! Transport abstraction and the I2C implementation.
//!
//! The PN532 communicates over a framed protocol regardless of the physical
//! transport (I2C, SPI or HSU). The [`Interface`] trait mirrors that boundary:
//! the driver builds logical commands, the interface handles framing and the
//! acknowledgement/response handshake.
use embedded_hal::delay::DelayNs;
use embedded_hal::digital::{ErrorKind, ErrorType, InputPin, OutputPin};
use embedded_hal::digital::{InputPin, OutputPin};
use embedded_hal::i2c::{I2c, Operation};
use crate::{Error, Interface, NoIrq, NoReset, PN532Command};
use crate::types::constants::*;
use crate::error::Error;
use crate::PN532Command;
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct UnreachError;
impl embedded_hal::digital::Error for UnreachError {
fn kind(&self) -> ErrorKind {
ErrorKind::Other
}
}
/// Marker type for when no reset pin is connected.
#[derive(Clone, Copy, Debug, Default)]
pub struct NoReset;
impl ErrorType for NoReset { type Error = UnreachError; }
impl OutputPin for NoReset {
fn set_low(&mut self) -> Result<(), Self::Error> {
Err(UnreachError)
}
fn set_high(&mut self) -> Result<(), Self::Error> {
Err(UnreachError)
}
}
/// Marker type for when no IRQ pin is connected.
#[derive(Clone, Copy, Debug, Default)]
pub struct NoIrq;
impl ErrorType for NoIrq { type Error = UnreachError; }
impl InputPin for NoIrq {
fn is_high(&mut self) -> Result<bool, Self::Error> {
panic!("NoIrq should not be used");
}
fn is_low(&mut self) -> Result<bool, Self::Error> {
panic!("NoIrq should not be used");
}
}
/// A framed transport to the PN532.
///
/// Implementations are responsible for the frame/ack handshake described in
/// the PN532 user manual (UM0701-02).
pub trait Interface {
/// The error type produced by the underlying physical transport.
type TransportError;
/// Initialise the hardware: pulse the reset pin (if provided) and wait for
/// the PN532 to become ready.
fn begin(&mut self) -> Result<(), Error<Self::TransportError>>;
/// Write a command frame (`header` + optional `body`) and wait for the ACK.
fn write_command(
&mut self,
header: &[u8],
body: &[u8],
) -> Result<(), Error<Self::TransportError>>;
/// Read a response frame, returning the length of the payload (excluding
/// the `TFI` and command bytes) placed in `buf`.
fn read_response(
&mut self,
buf: &mut [u8],
timeout_ms: u16,
) -> Result<usize, Error<Self::TransportError>>;
}
/// [`Interface`] implementation over a blocking `embedded_hal::i2c::I2c` bus.
///
@@ -182,39 +105,10 @@ where
body: &[u8],
) -> Result<(), Error<Self::TransportError>> {
self.command = Some(PN532Command::from_bits(header[0]));
let data_len = header.len() + body.len() + 1; // TFI + payload
if data_len > 0xFF {
return Err(Error::NoSpace);
}
// PREAMBLE + STARTCODE1 + STARTCODE2 + LEN + LCS + TFI + payload + DCS + POSTAMBLE
let frame_len = 6 + header.len() + body.len() + 2;
let mut frame = [0u8; MAX_DATA_LEN];
if frame_len > frame.len() {
return Err(Error::NoSpace);
}
frame[0] = PN532_PREAMBLE;
frame[1] = PN532_START_CODE_1;
frame[2] = PN532_START_CODE_2;
frame[3] = data_len as u8;
frame[4] = (!(data_len as u8)).wrapping_add(1);
frame[5] = PN532_HOST_TO_PN532;
let mut sum = PN532_HOST_TO_PN532;
let mut idx = 6;
for &b in header.iter().chain(body.iter()) {
frame[idx] = b;
idx += 1;
sum = sum.wrapping_add(b);
}
frame[idx] = (!sum).wrapping_add(1);
frame[idx + 1] = PN532_POSTAMBLE;
crate::trace!("pn532: write cmd=0x{:02X} len={}", header[0], frame_len);
let frame = super::to_request_frame(header, body)?;
crate::trace!("pn532: write cmd=0x{:02X} len={}", header[0], frame.len());
self.i2c
.write(PN532_I2C_ADDRESS, &frame[..frame_len])
.write(PN532_I2C_ADDRESS, &frame)
.map_err(Error::Transport)?;
crate::trace!("pn532: write ACKed, reading ACK frame");
self.read_ack_frame()
@@ -231,10 +125,10 @@ where
// Read the full response frame in a single transaction, stripping the
// RDY byte. Frame layout: PREAMBLE(3) + LEN + LCS + TFI + CMD + payload + DCS + POSTAMBLE.
let frame_len = buf.len() + 9;
let mut frame = [0u8; MAX_DATA_LEN + 10];
if frame_len > frame.len() {
if frame_len > MAX_DATA_LEN + 10 {
return Err(Error::NoSpace);
}
let mut frame = [0u8; MAX_DATA_LEN + 10];
self.i2c
.transaction(
PN532_I2C_ADDRESS,
@@ -244,37 +138,7 @@ where
],
)
.map_err(Error::Transport)?;
if frame[0] != PN532_PREAMBLE
|| frame[1] != PN532_START_CODE_1
|| frame[2] != PN532_START_CODE_2
{
return Err(Error::InvalidFrame);
}
let length = frame[3] as usize;
if frame[3].wrapping_add(frame[4]) != 0 {
return Err(Error::InvalidFrame);
}
let cmd = self.command.unwrap().as_response();
if frame[5] != PN532_PN532_TO_HOST || frame[6] != cmd {
return Err(Error::InvalidFrame);
}
let data_len = length.saturating_sub(2);
if data_len > buf.len() {
return Err(Error::NoSpace);
}
let mut sum = frame[5].wrapping_add(frame[6]);
for i in 0..data_len {
buf[i] = frame[7 + i];
sum = sum.wrapping_add(frame[7 + i]);
}
if sum.wrapping_add(frame[7 + data_len]) != 0 {
return Err(Error::InvalidFrame);
}
Ok(data_len)
super::from_response_frame(self.command.unwrap(), &frame[..frame_len], buf)
}
}
@@ -340,4 +204,4 @@ where
Err(Error::InvalidAck)
}
}
}
}
pn532/src/interface/mod.rs
+145
View File
@@ -0,0 +1,145 @@
//! Transport abstraction and the I2C implementation.
//!
//! The PN532 communicates over a framed protocol regardless of the physical
//! transport (I2C, SPI or HSU). The [`Interface`] trait mirrors that boundary:
//! the driver builds logical commands, the interface handles framing and the
//! acknowledgement/response handshake.
mod i2c;
pub use i2c::I2cInterface;
use embedded_hal::digital::{ErrorKind, ErrorType, InputPin, OutputPin};
use crate::error::Error;
use crate::PN532Command;
use crate::types::constants::{MAX_DATA_LEN, PN532_HOST_TO_PN532, PN532_PN532_TO_HOST, PN532_POSTAMBLE, PN532_PREAMBLE, PN532_START_CODE_1, PN532_START_CODE_2};
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct UnreachError;
impl embedded_hal::digital::Error for UnreachError {
fn kind(&self) -> ErrorKind {
ErrorKind::Other
}
}
/// Marker type for when no reset pin is connected.
#[derive(Clone, Copy, Debug, Default)]
pub struct NoReset;
impl ErrorType for NoReset { type Error = UnreachError; }
impl OutputPin for NoReset {
fn set_low(&mut self) -> Result<(), Self::Error> {
Err(UnreachError)
}
fn set_high(&mut self) -> Result<(), Self::Error> {
Err(UnreachError)
}
}
/// Marker type for when no IRQ pin is connected.
#[derive(Clone, Copy, Debug, Default)]
pub struct NoIrq;
impl ErrorType for NoIrq { type Error = UnreachError; }
impl InputPin for NoIrq {
fn is_high(&mut self) -> Result<bool, Self::Error> {
panic!("NoIrq should not be used");
}
fn is_low(&mut self) -> Result<bool, Self::Error> {
panic!("NoIrq should not be used");
}
}
/// A framed transport to the PN532.
///
/// Implementations are responsible for the frame/ack handshake described in
/// the PN532 user manual (UM0701-02).
pub trait Interface {
/// The error type produced by the underlying physical transport.
type TransportError;
/// Initialise the hardware: pulse the reset pin (if provided) and wait for
/// the PN532 to become ready.
fn begin(&mut self) -> Result<(), Error<Self::TransportError>>;
/// Write a command frame (`header` + optional `body`) and wait for the ACK.
fn write_command(
&mut self,
header: &[u8],
body: &[u8],
) -> Result<(), Error<Self::TransportError>>;
/// Read a response frame, returning the length of the payload (excluding
/// the `TFI` and command bytes) placed in `buf`.
fn read_response(
&mut self,
buf: &mut [u8],
timeout_ms: u16,
) -> Result<usize, Error<Self::TransportError>>;
}
pub(crate) fn to_request_frame<E>(header: &[u8], body: &[u8]) -> Result<heapless::Vec<u8, MAX_DATA_LEN>, Error<E>> {
let data_len = header.len() + body.len() + 1; // TFI + payload
if data_len > 0xFF {
return Err(Error::NoSpace);
}
// PREAMBLE + STARTCODE1 + STARTCODE2 + LEN + LCS + TFI + payload + DCS + POSTAMBLE
let frame_len = 6 + header.len() + body.len() + 2;
if frame_len > MAX_DATA_LEN {
return Err(Error::NoSpace);
}
let mut frame = heapless::Vec::new();
frame.push(PN532_PREAMBLE).unwrap();
frame.push(PN532_START_CODE_1).unwrap();
frame.push(PN532_START_CODE_2).unwrap();
frame.push(data_len as u8).unwrap();
frame.push((!(data_len as u8)).wrapping_add(1)).unwrap();
frame.push(PN532_HOST_TO_PN532).unwrap();
let mut sum = PN532_HOST_TO_PN532;
for &b in header.iter().chain(body.iter()) {
frame.push(b).unwrap();
sum = sum.wrapping_add(b);
}
frame.push((!sum).wrapping_add(1)).unwrap();
frame.push(PN532_POSTAMBLE).unwrap();
Ok(frame)
}
pub(crate) fn from_response_frame<E>(command: PN532Command, frame: &[u8], buf: &mut [u8]) -> Result<usize, Error<E>> {
if frame[0] != PN532_PREAMBLE
|| frame[1] != PN532_START_CODE_1
|| frame[2] != PN532_START_CODE_2
{
return Err(Error::InvalidFrame);
}
let length = frame[3] as usize;
if frame[3].wrapping_add(frame[4]) != 0 {
return Err(Error::InvalidFrame);
}
let cmd = command.as_response();
if frame[5] != PN532_PN532_TO_HOST || frame[6] != cmd {
return Err(Error::InvalidFrame);
}
let data_len = length.saturating_sub(2);
if data_len > buf.len() {
return Err(Error::NoSpace);
}
let mut sum = frame[5].wrapping_add(frame[6]);
for i in 0..data_len {
buf[i] = frame[7 + i];
sum = sum.wrapping_add(frame[7 + i]);
}
if sum.wrapping_add(frame[7 + data_len]) != 0 {
return Err(Error::InvalidFrame);
}
Ok(data_len)
}
pn532/src/types/frame.rs
-12
View File
@@ -1,12 +0,0 @@
use crate::{Error, PN532Command};
use crate::types::constants::*;
pub struct DataFrame {
command: PN532Command
}
impl DataFrame {
pub fn new<E>(header: &[u8], body: &[u8]) -> Result<Self, Error<E>> {
Ok(Self { command: PN532Command::TgGetData } )
}
}
pn532/src/types/mod.rs
-1
View File
@@ -3,7 +3,6 @@ use bitfields::bitflag;
#[cfg(feature = "felica")]
pub mod felica;
pub mod constants;
pub mod frame;
/// Passive target baud rates supported by [`crate::Pn532::read_passive_target_id`].
#[derive(PartialEq, Eq, Debug)]