sdmmc-core 0.5.0

SD/MMC core data structures and algorithms
Documentation 
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use crate::command::class11::cmd48::Mio;
#[cfg(test)]
use crate::crc::Crc7;
use crate::result::{Error, Result};

/// Check that the byte slice is valid ASCII-encoded for `len` bytes.
#[inline]
pub(crate) const fn check_ascii(val: &[u8], len: usize) -> Result<()> {
    match val.len() {
        vl if vl < len => Err(Error::InvalidVariant(vl)),
        _ => {
            let mut i = 0;
            while i < len {
                if !(val[i] as char).is_ascii() {
                    return Err(Error::InvalidVariant(val[i] as usize));
                }
                i += 1;
            }
            Ok(())
        }
    }
}

#[cfg(test)]
pub(crate) fn raw_with_crc<const N: usize>(mut raw: [u8; N]) -> ([u8; N], Crc7) {
    let crc7 = Crc7::calculate(&raw[..N - 1]);
    let raw_crc = (crc7.bits() << 1) | 1;

    raw[N - 1] = raw_crc;

    (raw, crc7)
}

/// Gets the masked `fno` field of a command argument.
#[inline]
pub(crate) const fn fno_masked(mio: Mio, val: u8, set: bool) -> u8 {
    const MEM_MASK: u8 = 0xf;
    const IO_MASK: u8 = 0xe;

    match mio {
        Mio::Memory => val & MEM_MASK,
        Mio::Io if set => (val << 1) & IO_MASK,
        Mio::Io => (val & IO_MASK) >> 1,
    }
}