zynq-rs/src/zynq/flash/mod.rs
2019-12-12 00:11:42 +01:00

434 lines
12 KiB
Rust

//! Quad-SPI Flash Controller
use core::marker::PhantomData;
use crate::regs::{RegisterR, RegisterW, RegisterRW};
use super::slcr;
use super::clocks::CpuClocks;
mod regs;
mod bytes;
pub use bytes::{BytesTransferExt, BytesTransfer};
const FLASH_BAUD_RATE: u32 = 50_000_000;
const SINGLE_CAPACITY: u32 = 16 * 1024 * 1024;
/// Instruction: Read Configure Register
const INST_RDCR: u8 = 0x35;
/// Instruction: Read Identification
const INST_RDID: u8 = 0x9F;
pub struct LinearAddressing;
pub struct Manual;
/// Flash Interface Driver
///
/// For 2x Spansion S25FL128SAGMFIR01
pub struct Flash<MODE> {
regs: &'static mut regs::RegisterBlock,
_mode: PhantomData<MODE>,
}
impl<MODE> Flash<MODE> {
fn transition<TO>(self) -> Flash<TO> {
Flash {
regs: self.regs,
_mode: PhantomData,
}
}
fn disable_interrupts(&mut self) {
self.regs.intr_dis.write(
regs::IntrDis::zeroed()
.rx_overflow(true)
.tx_fifo_not_full(true)
.tx_fifo_full(true)
.rx_fifo_not_empty(true)
.rx_fifo_full(true)
.tx_fifo_underflow(true)
);
}
fn enable_interrupts(&mut self) {
self.regs.intr_en.write(
regs::IntrEn::zeroed()
.rx_overflow(true)
.tx_fifo_not_full(true)
.tx_fifo_full(true)
.rx_fifo_not_empty(true)
.rx_fifo_full(true)
.tx_fifo_underflow(true)
);
}
fn clear_rx_fifo(&self) {
while self.regs.intr_status.read().rx_fifo_not_empty() {
let _ = self.regs.rx_data.read();
}
}
fn clear_interrupt_status(&mut self) {
self.regs.intr_status.write(
regs::IntrStatus::zeroed()
.rx_overflow(true)
.tx_fifo_underflow(true)
);
}
}
impl Flash<()> {
pub fn new(clock: u32) -> Self {
Self::enable_clocks(clock);
Self::setup_signals();
Self::reset();
let regs = regs::RegisterBlock::qspi();
let mut flash = Flash { regs, _mode: PhantomData };
flash.configure((FLASH_BAUD_RATE - 1 + clock) / FLASH_BAUD_RATE);
flash
}
fn enable_clocks(clock: u32) {
let io_pll = CpuClocks::get().io;
let divisor = ((clock - 1 + io_pll) / clock)
.max(1).min(63) as u8;
slcr::RegisterBlock::unlocked(|slcr| {
slcr.lqspi_clk_ctrl.write(
slcr::LqspiClkCtrl::zeroed()
.src_sel(slcr::PllSource::IoPll)
.divisor(divisor)
.clkact(true)
);
});
}
fn setup_signals() {
slcr::RegisterBlock::unlocked(|slcr| {
// 1. Configure MIO pin 1 for chip select 0 output.
slcr.mio_pin_01.write(
slcr::MioPin01::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
.pullup(true)
);
// Configure MIO pins 2 through 5 for I/O.
slcr.mio_pin_02.write(
slcr::MioPin02::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
slcr.mio_pin_03.write(
slcr::MioPin03::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
slcr.mio_pin_04.write(
slcr::MioPin04::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
slcr.mio_pin_05.write(
slcr::MioPin05::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
// 3. Configure MIO pin 6 for serial clock 0 output.
slcr.mio_pin_06.write(
slcr::MioPin06::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
// Option: Add Second Device Chip Select
// 4. Configure MIO pin 0 for chip select 1 output.
slcr.mio_pin_00.write(
slcr::MioPin00::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
.pullup(true)
);
// Option: Add Second Serial Clock
// 5. Configure MIO pin 9 for serial clock 1 output.
slcr.mio_pin_09.write(
slcr::MioPin09::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
// Option: Add 4-bit Data
// 6. Configure MIO pins 10 through 13 for I/O.
slcr.mio_pin_10.write(
slcr::MioPin10::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
slcr.mio_pin_11.write(
slcr::MioPin11::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
slcr.mio_pin_12.write(
slcr::MioPin12::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
slcr.mio_pin_13.write(
slcr::MioPin13::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
// Option: Add Feedback Output Clock
// 7. Configure MIO pin 8 for feedback clock.
slcr.mio_pin_08.write(
slcr::MioPin08::zeroed()
.l0_sel(true)
.io_type(slcr::IoBufferType::Lvcmos18)
);
});
}
fn reset() {
slcr::RegisterBlock::unlocked(|slcr| {
slcr.lqspi_rst_ctrl.write(
slcr::LqspiRstCtrl::zeroed()
.ref_rst(true)
.cpu1x_rst(true)
);
slcr.lqspi_rst_ctrl.write(
slcr::LqspiRstCtrl::zeroed()
);
});
}
fn configure(&mut self, divider: u32) {
// Disable
self.regs.enable.write(
regs::Enable::zeroed()
);
self.disable_interrupts();
self.regs.lqspi_cfg.write(
regs::LqspiCfg::zeroed()
);
self.clear_rx_fifo();
self.clear_interrupt_status();
// for a baud_rate_div=1 LPBK_DLY_ADJ would be required
let mut baud_rate_div = 2u32;
while baud_rate_div < 7 && 2u32.pow(1 + baud_rate_div) < divider {
baud_rate_div += 1;
}
self.regs.config.write(regs::Config::zeroed()
.baud_rate_div(baud_rate_div as u8)
.mode_sel(true)
.leg_flsh(true)
.holdb_dr(true)
// 32 bits TX FIFO width
.fifo_width(0b11)
);
// Initialize RX/TX pipes thresholds
unsafe {
self.regs.rx_thres.write(1);
self.regs.tx_thres.write(1);
}
}
pub fn linear_addressing_mode(self) -> Flash<LinearAddressing> {
// Set manual start enable to auto mode.
// Assert the chip select.
self.regs.config.modify(|_, w| w
.man_start_en(false)
.pcs(false)
.manual_cs(false)
);
self.regs.lqspi_cfg.write(regs::LqspiCfg::zeroed()
// Quad I/O Fast Read
.inst_code(0xEB)
.mode_bits(0xFF)
.dummy_byte(0x2)
.mode_en(true)
// 2 devices
.two_mem(true)
.u_page(false)
// Linear Addressing Mode
.lq_mode(true)
);
self.regs.enable.write(
regs::Enable::zeroed()
.spi_en(true)
);
self.transition()
}
pub fn manual_mode(self, chip_index: usize) -> Flash<Manual> {
self.regs.config.modify(|_, w| w
.man_start_en(true)
.manual_cs(true)
.endian(true)
);
self.regs.lqspi_cfg.write(regs::LqspiCfg::zeroed()
.mode_bits(0xFF)
.dummy_byte(0x2)
.mode_en(true)
// 2 devices
.two_mem(true)
.sep_bus(true)
.u_page(chip_index != 0)
// Manual I/O mode
.lq_mode(false)
);
self.transition()
}
}
impl Flash<LinearAddressing> {
/// Stop linear addressing mode
pub fn stop(self) -> Flash<()> {
self.regs.enable.modify(|_, w| w.spi_en(false));
// De-assert chip select.
self.regs.config.modify(|_, w| w.pcs(true));
self.transition()
}
pub fn ptr<T>(&mut self) -> *mut T {
0xFC00_0000 as *mut _
}
pub fn size(&self) -> usize {
2 * (SINGLE_CAPACITY as usize)
}
}
impl Flash<Manual> {
pub fn stop(self) -> Flash<()> {
self.transition()
}
/// Read Configuration Register
pub fn rdcr(&mut self) -> u8 {
let args = Some((INST_RDCR as u32) << 24);
self.transfer(args.into_iter(), 4)
.bytes_transfer().skip(1)
.next().unwrap() as u8
}
/// Read Identifiaction
pub fn rdid(&mut self) -> core::iter::Skip<BytesTransfer<Transfer<core::option::IntoIter<u32>>>> {
let args = Some((INST_RDID as u32) << 24);
self.transfer(args.into_iter(), 0x44)
.bytes_transfer().skip(1)
}
/// Read flash data
pub fn read(&mut self, offset: u32, len: usize) -> core::iter::Take<core::iter::Skip<BytesTransfer<Transfer<core::option::IntoIter<u32>>>>> {
// INST_READ
let args = Some((0x03 << 24) | (offset as u32));
self.transfer(args.into_iter(), len + 6)
.bytes_transfer().skip(6).take(len)
}
pub fn transfer<'s: 't, 't, Args>(&'s mut self, args: Args, len: usize) -> Transfer<'t, Args>
where
Args: Iterator<Item = u32>,
{
Transfer::new(self, args, len)
}
}
pub struct Transfer<'a, Args: Iterator<Item = u32>> {
flash: &'a mut Flash<Manual>,
args: Args,
sent: usize,
received: usize,
len: usize,
}
impl<'a, Args: Iterator<Item = u32>> Transfer<'a, Args> {
pub fn new(flash: &'a mut Flash<Manual>, args: Args, len: usize) -> Self
where
Args: Iterator<Item = u32>,
{
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().unwrap_or(0);
unsafe {
self.flash.regs.txd0.write(arg);
}
self.sent += 4;
}
}
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<Item = u32>> Drop for Transfer<'a, Args> {
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<Item = u32>> Iterator for Transfer<'a, Args> {
type Item = u32;
fn next<'s>(&'s mut self) -> Option<u32> {
if self.received >= self.len {
return None;
}
self.fill_tx_fifo();
while !self.can_read() {}
Some(self.read())
}
}