use super::I2c; use crate::time::Milliseconds; use embedded_hal::timer::CountDown; pub struct EEPROM<'a> { i2c: &'a mut I2c, port: u8, address: u8, page_size: u8, count_down: crate::timer::global::CountDown } impl<'a> EEPROM<'a> { #[cfg(feature = "target_zc706")] pub fn new(i2c: &'a mut I2c, page_size: u8) -> Self { EEPROM { i2c: i2c, port: 2, address: 0b1010100, page_size: page_size, count_down: unsafe { crate::timer::GlobalTimer::get() }.countdown() } } #[cfg(feature = "target_zc706")] fn select(&mut self) -> Result<(), &'static str> { let mask: u16 = 1 << self.port; self.i2c.pca9548_select(0b1110100, mask as u8)?; Ok(()) } /// Random read pub fn read<'r>(&mut self, addr: u8, buf: &'r mut [u8]) -> Result<(), &'static str> { self.select()?; self.i2c.start()?; self.i2c.write(self.address << 1)?; self.i2c.write(addr)?; self.i2c.restart()?; self.i2c.write((self.address << 1) | 1)?; let buf_len = buf.len(); for (i, byte) in buf.iter_mut().enumerate() { *byte = self.i2c.read(i < buf_len - 1)?; } self.i2c.stop()?; Ok(()) } /// Smart multi-page writing /// Using the "Page Write" function of an EEPROM, the memory region for each transaction /// (i.e. from byte `addr` to byte `addr+buf.len()`) should fit under each page /// (i.e. `addr+buf.len()` < `addr/self.page_size+1`); otherwise, a roll-oever occurs, /// where bytes beyond the page end. This smart function takes care of the scenario to avoid /// any roll-over when writing ambiguous memory regions. pub fn write(&mut self, addr: u8, buf: &[u8]) -> Result<(), &'static str> { self.select()?; let buf_len = buf.len(); let mut pb: u8 = addr % self.page_size; for (i, byte) in buf.iter().enumerate() { if (i == 0) || (pb == 0) { self.i2c.start()?; self.i2c.write(self.address << 1)?; self.i2c.write(addr + (i as u8))?; } self.i2c.write(*byte)?; pb += 1; if (i == buf_len-1) || (pb == self.page_size) { self.i2c.stop()?; self.poll(1_000)?; pb = 0; } } Ok(()) } /// Poll pub fn poll(&mut self, timeout_ms: u64) -> Result<(), &'static str> { self.select()?; self.count_down.start(Milliseconds(timeout_ms)); loop { self.i2c.start()?; let ack = self.i2c.write(self.address << 1)?; self.i2c.stop()?; if ack { break }; if !self.count_down.waiting() { return Err("I2C polling timeout") } } Ok(()) } pub fn read_eui48<'r>(&mut self) -> Result<[u8; 6], &'static str> { let mut buffer = [0u8; 6]; self.read(0xFA, &mut buffer)?; Ok(buffer) } }