use libregister::{RegisterR, RegisterW, RegisterRW}; use super::regs; use super::{SpiWord, Flash, Manual}; pub struct Transfer<'a, Args: Iterator, W: Into> { flash: &'a mut Flash, args: Args, sent: usize, received: usize, len: usize, } impl<'a, Args: Iterator, W: Into> Transfer<'a, Args, W> { pub fn new(flash: &'a mut Flash, args: Args, len: usize) -> Self { flash.regs.config.modify(|_, w| w.pcs(false)); flash.regs.enable.write( regs::Enable::zeroed() .spi_en(true) ); let mut xfer = Transfer { flash, args, sent: 0, received: 0, len, }; xfer.fill_tx_fifo(); xfer.flash.regs.config.modify(|_, w| w.man_start_com(true)); xfer } fn fill_tx_fifo(&mut self) { while self.sent < self.len && !self.flash.regs.intr_status.read().tx_fifo_full() { let arg = self.args.next() .map(|n| n.into()) .unwrap_or(SpiWord::W32(0)); match arg { SpiWord::W32(w) => { // println!("txd0 {:08X}", w); unsafe { self.flash.regs.txd0.write(w); } self.sent += 4; } // Only txd0 can be used without flushing _ => { if !self.flash.regs.intr_status.read().tx_fifo_not_full() { // Flush if necessary self.flash.wait_tx_fifo_flush(); } match arg { SpiWord::W8(w) => { // println!("txd1 {:02X}", w); unsafe { self.flash.regs.txd1.write(u32::from(w) << 24); } self.sent += 1; } SpiWord::W16(w) => { unsafe { self.flash.regs.txd2.write(u32::from(w) << 16); } self.sent += 2; } SpiWord::W24(w) => { unsafe { self.flash.regs.txd3.write(w << 8); } self.sent += 3; } SpiWord::W32(_) => unreachable!(), } self.flash.wait_tx_fifo_flush(); } } } } fn can_read(&mut self) -> bool { self.flash.regs.intr_status.read().rx_fifo_not_empty() } fn read(&mut self) -> u32 { let rx = self.flash.regs.rx_data.read(); self.received += 4; rx } } impl<'a, Args: Iterator, W: Into> Drop for Transfer<'a, Args, W> { fn drop(&mut self) { // Discard remaining rx_data while self.can_read() { self.read(); } // Stop self.flash.regs.enable.write( regs::Enable::zeroed() .spi_en(false) ); self.flash.regs.config.modify(|_, w| w .pcs(true) .man_start_com(false) ); } } impl<'a, Args: Iterator, W: Into> Iterator for Transfer<'a, Args, W> { type Item = u32; fn next<'s>(&'s mut self) -> Option { if self.received >= self.len { return None; } self.fill_tx_fifo(); while !self.can_read() {} Some(self.read()) } }