sdmmc_core/command/class/class9/cmd39/

arg.rs

use crate::lib_bitfield;
use crate::result::{Error, Result};

lib_bitfield! {
    /// Argument for CMD39.
    pub Argument(u32): u16 {
        raw_rca: 31, 16;
        /// Indicates whether to write to (`true`) or read from (`false`) the register.
        pub register_write_flag: 15;
        raw_register_address: 14, 8;
        raw_register_data: 7, 0;
    }
}

impl Argument {
    /// Represents the byte length of the [Argument].
    pub const LEN: usize = 4;
    /// Represents the default value of the [Argument].
    pub const DEFAULT: u32 = 0;

    /// Creates a new [Argument].
    pub const fn new() -> Self {
        Self(Self::DEFAULT)
    }

    /// Gets the `RCA` field of the [Argument].
    pub const fn rca(&self) -> u16 {
        self.raw_rca()
    }

    /// Sets the `RCA` field of the [Argument].
    pub fn set_rca(&mut self, val: u16) {
        self.set_raw_rca(val as u32);
    }

    /// Gets the card register address field of the [Argument].
    pub const fn register_address(&self) -> u8 {
        self.raw_register_address() as u8
    }

    /// Sets the card register address field of the [Argument].
    pub fn set_register_address(&mut self, val: u8) {
        self.set_raw_register_address(val as u32);
    }

    /// Gets the card register data field of the [Argument].
    pub const fn register_data(&self) -> u8 {
        self.raw_register_data() as u8
    }

    /// Sets the card register data field of the [Argument].
    pub fn set_register_data(&mut self, val: u8) {
        self.set_raw_register_data(val as u32);
    }

    /// Converts a [`u32`] into an [`Argument`].
    pub const fn from_bits(val: u32) -> Self {
        Self(val)
    }

    /// Attempts to convert a [`u32`] into an [`Argument`].
    pub const fn try_from_bits(val: u32) -> Result<Self> {
        Ok(Self::from_bits(val))
    }

    /// Converts the [Argument] into a byte array.
    pub const fn bytes(&self) -> [u8; Self::LEN] {
        self.0.to_be_bytes()
    }

    /// Attempts to convert a byte slice into an [`Argument`].
    pub const fn try_from_bytes(val: &[u8]) -> Result<Self> {
        match val.len() {
            len if len < Self::LEN => Err(Error::invalid_length(len, Self::LEN)),
            _ => Self::try_from_bits(u32::from_be_bytes([val[0], val[1], val[2], val[3]])),
        }
    }
}

impl Default for Argument {
    fn default() -> Self {
        Self::new()
    }
}

impl From<Argument> for u32 {
    fn from(val: Argument) -> Self {
        val.bits()
    }
}

impl From<Argument> for [u8; Argument::LEN] {
    fn from(val: Argument) -> Self {
        val.bytes()
    }
}

impl TryFrom<u32> for Argument {
    type Error = Error;

    fn try_from(val: u32) -> Result<Self> {
        Self::try_from_bits(val)
    }
}

impl TryFrom<&[u8]> for Argument {
    type Error = Error;

    fn try_from(val: &[u8]) -> Result<Self> {
        Self::try_from_bytes(val)
    }
}

impl<const N: usize> TryFrom<&[u8; N]> for Argument {
    type Error = Error;

    fn try_from(val: &[u8; N]) -> Result<Self> {
        Self::try_from_bytes(val.as_ref())
    }
}

impl<const N: usize> TryFrom<[u8; N]> for Argument {
    type Error = Error;

    fn try_from(val: [u8; N]) -> Result<Self> {
        Self::try_from_bytes(val.as_ref())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_fields() {
        (1..=u32::BITS)
            .map(|r| ((1u64 << r) - 1) as u32)
            .for_each(|raw_arg| {
                let raw = raw_arg.to_be_bytes();
                let mut exp_arg = Argument(raw_arg);

                let exp_rca = (raw_arg >> 16) as u16;
                let exp_write_flag = (raw_arg & (1 << 15)) != 0;
                let exp_addr = ((raw_arg & 0x7f00) >> 8) as u8;
                let exp_data = (raw_arg & 0xff) as u8;

                assert_eq!(Argument::try_from_bits(raw_arg), Ok(exp_arg));
                assert_eq!(Argument::try_from_bytes(raw.as_ref()), Ok(exp_arg));
                assert_eq!(Argument::try_from(raw_arg), Ok(exp_arg));
                assert_eq!(Argument::try_from(raw), Ok(exp_arg));
                assert_eq!(Argument::try_from(&raw), Ok(exp_arg));

                assert_eq!(exp_arg.bits(), raw_arg);
                assert_eq!(exp_arg.bytes(), raw);

                assert_eq!(exp_arg.rca(), exp_rca);

                exp_arg.set_rca(0);
                assert_eq!(exp_arg.rca(), 0);

                exp_arg.set_rca(exp_rca);
                assert_eq!(exp_arg.rca(), exp_rca);

                assert_eq!(exp_arg.register_write_flag(), exp_write_flag);

                test_field!(exp_arg, register_write_flag: 15);

                assert_eq!(exp_arg.register_address(), exp_addr);

                exp_arg.set_register_address(0);
                assert_eq!(exp_arg.register_address(), 0);

                exp_arg.set_register_address(exp_addr);
                assert_eq!(exp_arg.register_address(), exp_addr);

                assert_eq!(exp_arg.register_data(), exp_data);

                exp_arg.set_register_data(0);
                assert_eq!(exp_arg.register_data(), 0);

                exp_arg.set_register_data(exp_data);
                assert_eq!(exp_arg.register_data(), exp_data);
            });
    }
}