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artiq/artiq/firmware/libboard_artiq/spi.rs

64 lines
2.1 KiB
Rust

#[cfg(has_converter_spi)]
mod imp {
use board_misoc::csr;
pub fn set_config(busno: u8, flags: u8, length: u8, div: u8, cs: u8) -> Result<(), ()> {
if busno != 0 {
return Err(())
}
unsafe {
while csr::converter_spi::writable_read() == 0 {}
csr::converter_spi::offline_write(flags >> 0 & 1);
csr::converter_spi::end_write(flags >> 1 & 1);
// input (in RTIO): flags >> 2 & 1
// cs_polarity is a mask in the CSR interface
// only affect the bits that are selected
let mut cs_polarity = csr::converter_spi::cs_polarity_read();
if flags >> 3 & 1 != 0 {
cs_polarity |= cs;
} else {
cs_polarity &= !cs;
}
csr::converter_spi::cs_polarity_write(cs_polarity);
csr::converter_spi::clk_polarity_write(flags >> 4 & 1);
csr::converter_spi::clk_phase_write(flags >> 5 & 1);
csr::converter_spi::lsb_first_write(flags >> 6 & 1);
csr::converter_spi::half_duplex_write(flags >> 7 & 1);
csr::converter_spi::length_write(length - 1);
csr::converter_spi::div_write(div - 2);
csr::converter_spi::cs_write(cs);
}
Ok(())
}
pub fn write(busno: u8, data: u32) -> Result<(), ()> {
if busno != 0 {
return Err(())
}
unsafe {
while csr::converter_spi::writable_read() == 0 {}
csr::converter_spi::data_write(data);
}
Ok(())
}
pub fn read(busno: u8) -> Result<u32, ()> {
if busno != 0 {
return Err(())
}
Ok(unsafe {
while csr::converter_spi::writable_read() == 0 {}
csr::converter_spi::data_read()
})
}
}
#[cfg(not(has_converter_spi))]
mod imp {
pub fn set_config(_busno: u8, _flags: u8, _length: u8, _div: u8, _cs: u8) -> Result<(), ()> { Err(()) }
pub fn write(_busno: u8,_data: u32) -> Result<(), ()> { Err(()) }
pub fn read(_busno: u8,) -> Result<u32, ()> { Err(()) }
}
pub use self::imp::*;