sdmmc_core/command/class/class2/cmd16/
arg.rs

1use crate::lib_bitfield;
2use crate::result::{Error, Result};
3
4lib_bitfield! {
5    /// Argumentument for CMD16.
6    pub Argument(u32): u32 {
7        /// Configures the block length of memory read/write operations.
8        ///
9        /// Only has an effect for standard SD cards.
10        ///
11        /// SDHC, SDXC, and SDUC cards have a fixed block length of 512 bytes.
12        pub block_length: 31, 0;
13    }
14}
15
16impl Argument {
17    /// Represents the byte length of the [Argument].
18    pub const LEN: usize = 4;
19    /// Represents the default value of the [Argument].
20    pub const DEFAULT: u32 = 0;
21
22    /// Creates a new [Argument].
23    pub const fn new() -> Self {
24        Self(Self::DEFAULT)
25    }
26
27    /// Converts a [`u32`] into an [Argument].
28    pub const fn from_bits(val: u32) -> Self {
29        Self(val)
30    }
31
32    /// Converts a [`u32`] into an [Argument].
33    pub const fn try_from_bits(val: u32) -> Result<Self> {
34        Ok(Self::from_bits(val))
35    }
36
37    /// Converts the [Argument] into a byte array.
38    pub const fn bytes(&self) -> [u8; Self::LEN] {
39        self.0.to_be_bytes()
40    }
41
42    /// Attempts to convert a byte slice into an [Argument].
43    pub const fn try_from_bytes(val: &[u8]) -> Result<Self> {
44        match val.len() {
45            len if len < Self::LEN => Err(Error::invalid_length(len, Self::LEN)),
46            _ => Ok(Self::from_bits(u32::from_be_bytes([
47                val[0], val[1], val[2], val[3],
48            ]))),
49        }
50    }
51}
52
53impl Default for Argument {
54    fn default() -> Self {
55        Self::new()
56    }
57}
58
59impl From<u32> for Argument {
60    fn from(val: u32) -> Self {
61        Self::from_bits(val)
62    }
63}
64
65impl From<Argument> for u32 {
66    fn from(val: Argument) -> Self {
67        val.bits()
68    }
69}
70
71impl From<Argument> for [u8; Argument::LEN] {
72    fn from(val: Argument) -> Self {
73        val.bytes()
74    }
75}
76
77impl TryFrom<&[u8]> for Argument {
78    type Error = Error;
79
80    fn try_from(val: &[u8]) -> Result<Self> {
81        Self::try_from_bytes(val)
82    }
83}
84
85impl<const N: usize> TryFrom<&[u8; N]> for Argument {
86    type Error = Error;
87
88    fn try_from(val: &[u8; N]) -> Result<Self> {
89        Self::try_from_bytes(val.as_ref())
90    }
91}
92
93impl<const N: usize> TryFrom<[u8; N]> for Argument {
94    type Error = Error;
95
96    fn try_from(val: [u8; N]) -> Result<Self> {
97        Self::try_from_bytes(val.as_ref())
98    }
99}
100
101#[cfg(test)]
102mod tests {
103    use super::*;
104
105    #[test]
106    fn test_fields() {
107        (1..=u32::BITS)
108            .map(|r| ((1u64 << r) - 1) as u32)
109            .for_each(|block_length| {
110                let raw = block_length;
111                let raw_bytes = raw.to_be_bytes();
112
113                let mut exp_arg = Argument(raw);
114
115                assert_eq!(Argument::try_from_bits(raw), Ok(exp_arg));
116                assert_eq!(Argument::from_bits(raw), exp_arg);
117                assert_eq!(Argument::from(raw), exp_arg);
118
119                assert_eq!(Argument::try_from_bytes(&raw_bytes), Ok(exp_arg));
120                assert_eq!(Argument::try_from(raw_bytes), Ok(exp_arg));
121                assert_eq!(Argument::try_from(&raw_bytes), Ok(exp_arg));
122
123                assert_eq!(exp_arg.bytes(), raw_bytes);
124                assert_eq!(<[u8; Argument::LEN]>::from(exp_arg), raw_bytes);
125
126                assert_eq!(exp_arg.block_length(), block_length);
127
128                exp_arg.set_block_length(0);
129                assert_eq!(exp_arg.block_length(), 0);
130
131                exp_arg.set_block_length(block_length);
132                assert_eq!(exp_arg.block_length(), block_length);
133            });
134    }
135}
sdmmc_core/command/class/class2/cmd16/arg.rs

sdmmc_core/command/class/class2/cmd16/
arg.rs
