73 lines
1.8 KiB
Rust
73 lines
1.8 KiB
Rust
use hwio::{Io, Pio};
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use crate::{
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Error,
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Timeout,
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timeout
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};
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pub struct Pmc<T: Timeout> {
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data: Pio<u8>,
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cmd: Pio<u8>,
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timeout: T,
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}
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impl<T: Timeout> Pmc<T> {
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/// Create a new PMC instance. `base` identifies the data port. The command
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/// port will be `base + 4`
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pub fn new(base: u16, timeout: T) -> Self {
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Self {
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data: Pio::new(base),
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cmd: Pio::new(base + 4),
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timeout,
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}
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}
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/// Returns true if PMC can be read from
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pub unsafe fn can_read(&mut self) -> bool {
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self.cmd.read() & 1 == 1
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}
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/// Returns true if PMC can be written to
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pub unsafe fn can_write(&mut self) -> bool {
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self.cmd.read() & 2 == 0
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}
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/// Write a command to the PMC. Returns None if unable to write
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pub unsafe fn command(&mut self, data: u8) -> Result<(), Error> {
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if self.can_write() {
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self.cmd.write(data);
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Ok(())
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} else {
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Err(Error::WouldBlock)
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}
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}
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/// Read data from the PMC. Returns None if unable to read
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pub unsafe fn read(&mut self) -> Result<u8, Error> {
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if self.can_read() {
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Ok(self.data.read())
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} else {
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Err(Error::WouldBlock)
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}
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}
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/// Write data to the PMC. Returns false if unable to write
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pub unsafe fn write(&mut self, data: u8) -> Result<(), Error> {
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if self.can_write() {
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self.data.write(data);
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Ok(())
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} else {
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Err(Error::WouldBlock)
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}
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}
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pub unsafe fn acpi_read(&mut self, addr: u8) -> Result<u8, Error> {
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self.timeout.reset();
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timeout!(self.timeout, self.command(0x80))?;
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timeout!(self.timeout, self.write(addr))?;
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timeout!(self.timeout, self.read())
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}
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}
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