1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146

#[macro_use]
extern crate bitflags;
#[macro_use]
extern crate failure;
extern crate libudev;

mod cmds;
mod types;
mod utils;

pub use cmds::*;
pub use types::*;

use libudev::Device;
use std::cmp::min;
use std::ffi::OsStr;
use std::fs::{File, OpenOptions};
use std::io;
use std::path::{Path, PathBuf};

#[derive(Fail, Debug)]
pub enum Mcp2210Error {
    #[fail(display = "IO error ({})", _0)]
    Io(#[cause] io::Error),
    #[fail(display = "Invalid command code (expected {:2x}, got {:2x})", expected, actual)]
    CommandCode { expected: u8, actual: u8 },
    #[fail(display = "Invalid sub-command code (expected {:2x}, got {:2x})", expected, actual)]
    SubCommandCode { expected: u8, actual: u8 },
    #[fail(display = "Invalid response ({})", _0)]
    InvalidResponse(String),
    #[fail(display = "Unknown error code {:2x}", _0)]
    UnknownErrorCode(u8),
    #[fail(
        display = "String is too long (expected at most 29 UTF-16 encoded u16 values, got {})", _0
    )]
    StringSize(usize),
    #[fail(display = "Payload is too big (expected at most 60 bytes, got {})", _0)]
    PayloadSize(usize),
    #[fail(display = "Unexpected SPI transfer status")]
    TransferStatus(SpiTransferStatus),

    // MCP2210 error codes
    #[fail(display = "EEPROM write failure")]
    EepromWrite, // 0xFA
    #[fail(display = "Access denied")]
    AccessDenied, // 0xFB
    #[fail(display = "Access rejected")]
    AccessRejected, // 0xFC
    #[fail(display = "Access denied, retrying allowed")]
    AccessDeniedRetry, // 0xFD
    #[fail(display = "SPI bus unavailable")]
    Unavailable, // 0xF7
    #[fail(display = "SPI bus busy")]
    Busy, // 0xF8
    #[fail(display = "Unknown command code {:2x}", _0)]
    UnknownCommandCode(u8), // 0xF9
}

pub type Buffer = [u8; 64];

pub const MAX_BIT_RATE: u32 = 12_000_000;

pub struct Mcp2210 {
    file: File,
}

impl CommandResponse for Mcp2210 {
    fn command_response(&mut self, cmd: &Buffer, res: &mut Buffer) -> io::Result<()> {
        self.file.command_response(cmd, res)
    }
}

impl Mcp2210 {
    pub fn open<P: AsRef<Path>>(path: P) -> Result<Mcp2210, Mcp2210Error> {
        let file = OpenOptions::new()
            .read(true)
            .write(true)
            .open(path)
            .map_err(Mcp2210Error::Io)?;
        Ok(Mcp2210 { file })
    }
    pub fn spi_transfer_to_end(
        &mut self,
        mut data: &[u8],
        buf: &mut Vec<u8>,
    ) -> Result<(), Mcp2210Error> {
        let mut res: Buffer = [0; 64];
        {
            let len = min(data.len(), 60);
            let res = self.spi_transfer(&data[..len], &mut res)?;
            data = &data[len..];
            if res.status != SpiTransferStatus::Started {
                return Err(Mcp2210Error::TransferStatus(res.status));
            }
        }
        loop {
            let len = min(data.len(), 60);
            match self.spi_transfer(&data[..len], &mut res) {
                Ok(res) => {
                    data = &data[len..];
                    buf.extend(res.data);
                    if res.status == SpiTransferStatus::Finished {
                        break;
                    }
                }
                Err(Mcp2210Error::Busy) => (),
                Err(err) => return Err(err),
            }
        }
        Ok(())
    }
}

pub fn scan_devices() -> io::Result<Vec<PathBuf>> {
    scan_devices_with_filter(|d| {
        let vendor_id = d.property_value("ID_VENDOR_ID");
        let model_id = d.property_value("ID_MODEL_ID");
        vendor_id == Some(OsStr::new("04d8")) && model_id == Some(OsStr::new("00de"))
    })
}

pub fn scan_devices_with_filter<F: FnMut(Device) -> bool>(mut f: F) -> io::Result<Vec<PathBuf>> {
    let mut results = Vec::new();
    if let Ok(context) = libudev::Context::new() {
        let mut enumerator = libudev::Enumerator::new(&context)?;
        enumerator.match_subsystem("hidraw")?;
        let devices = enumerator.scan_devices()?;
        for d in devices {
            if let Some(devnode) = d.devnode() {
                if let Some(d) = d.parent() {
                    if let Some(d) = d.parent() {
                        if let Some(d) = d.parent() {
                            if d.property_value("ID_BUS") != Some(OsStr::new("usb")) {
                                continue;
                            }
                            if f(d) {
                                results.push(devnode.to_owned());
                            }
                        }
                    }
                }
            }
        }
    }
    Ok(results)
}