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pub(crate) mod eeconfig;
pub(crate) mod eekeymap;
extern crate alloc;
use self::eeconfig::{Eeconfig, EEPROM_MAGIC};
use crate::{action::KeyAction, keymap::KeyMapConfig};
use alloc::vec;
use core::sync::atomic::{AtomicBool, Ordering::SeqCst};
use defmt::{debug, error, info, warn};
use embedded_storage::nor_flash::NorFlash;
/// A record in the eeprom, with 2-byte address and 2-byte data
/// A record is 4-byte long, so the tracking pos in the `Eeprom` implementation must be a multiple of 4
pub(crate) struct EepromRecord {
address: u16,
data: u16,
}
impl EepromRecord {
fn to_bytes(&self) -> [u8; 4] {
let mut bytes = [0u8; 4];
bytes[0..2].copy_from_slice(&self.address.to_be_bytes());
bytes[2..4].copy_from_slice(&self.data.to_be_bytes());
bytes
}
fn from_bytes(bytes: [u8; 4]) -> Self {
let address = u16::from_be_bytes([bytes[0], bytes[1]]);
let data = u16::from_be_bytes([bytes[2], bytes[3]]);
Self { address, data }
}
}
/// Configuration of eeprom's backend storage.
#[derive(Default)]
pub(crate) struct EepromStorageConfig {
/// The start address in the backend storage.
pub(crate) start_addr: u32,
/// Total used size in backend storage for eeprom.
pub(crate) storage_size: u32,
/// Minimal write size of backend storage.
/// For example, stm32h7's internal flash allows 256-bit(32 bytes) or 128-bit(16 bytes) write, so page_size should be 32/16 for stm32h7.
pub(crate) page_size: u32,
}
/// Eeprom based on any storage device which implements `embedded-storage::NorFlash` trait
/// Data in eeprom is saved in a 4-byte `record`, with 2-byte address in the first 16 bits and 2-byte data in the next 16 bits.
/// Eeprom struct maintains a cache in ram to speed up reads, whose size is same as the logical eeprom capacity.
/// User can specify the size of the logical size of eeprom(maximum 64KB), Eeprom struct maintains a cache in ram to speed up reads, whose size is same as the user defined logical eeprom capacity.
pub(crate) struct Eeprom<F: NorFlash, const EEPROM_SIZE: usize> {
/// Current position in the storage
pos: u32,
/// Backend storage, implements `embedded-storage::NorFlash` trait
storage: F,
/// A eeprom cache in ram to speed up reads, whose size is same as the logical eeprom capacity
cache: [u8; EEPROM_SIZE],
/// Configuration of the backend storage
storage_config: EepromStorageConfig,
/// Lock
lock: AtomicBool,
/// Layout info of dynamic keymap.
/// Each key in keymap used 2 bytes, so the size should be at least 2 * NUM_LAYER * ROW * COL.
///
/// For a 104-key keyboard, with 4 layers, 6 rows and 21 columns, the size is 1008 bytes,
/// EEPROM_SIZE should be at least 1008(keymap) + 15(eeconfig) + 100(macro)
keymap_config: KeyMapConfig,
}
impl<F: NorFlash, const EEPROM_SIZE: usize> Eeprom<F, EEPROM_SIZE> {
pub(crate) fn new<const ROW: usize, const COL: usize, const NUM_LAYER: usize>(
storage: F,
storage_config: EepromStorageConfig,
eeconfig: Option<Eeconfig>,
keymap: &[[[KeyAction; COL]; ROW]; NUM_LAYER],
) -> Option<Self> {
// Check backend storage config
if (!is_power_of_two(storage_config.page_size))
|| storage_config.start_addr == 0
|| storage_config.storage_size == 0
{
return None;
}
let mut eeprom = Eeprom {
pos: 0,
storage,
storage_config,
lock: AtomicBool::new(false),
cache: [0xFF; EEPROM_SIZE],
keymap_config: KeyMapConfig {
row: ROW,
col: COL,
layer: NUM_LAYER,
},
};
// Initialize eeprom using default config
let current_magic = eeprom.get_magic();
// if current_magic != 0 {
if current_magic != EEPROM_MAGIC {
// Need initialize the eeprom, erase the storage first
eeprom
.storage
.erase(
eeprom.storage_config.start_addr,
eeprom.storage_config.start_addr + eeprom.storage_config.storage_size,
)
.unwrap();
match eeconfig {
Some(eeprom_config) => eeprom.init_with_config(eeprom_config),
None => eeprom.init_with_default_config(),
}
eeprom.set_keymap(keymap);
}
// Restore eeprom from storage
let mut buf: [u8; 4] = [0xFF; 4];
while eeprom.pos < eeprom.storage_config.storage_size {
match eeprom
.storage
.read(eeprom.storage_config.start_addr + eeprom.pos, &mut buf)
{
Ok(_) => {
let record = EepromRecord::from_bytes(buf);
if record.address >= EEPROM_SIZE as u16 {
break;
}
eeprom.cache[record.address as usize] = (record.data >> 8) as u8;
eeprom.cache[record.address as usize + 1] = record.data as u8;
eeprom.pos += eeprom.storage_config.page_size;
}
Err(_) => {
error!("Restore eeprom value at pos {} error", eeprom.pos);
break;
}
}
}
Some(eeprom)
}
pub(crate) fn write_byte(&mut self, mut address: u16, data: &[u8]) {
if data.len() == 0 {
warn!("No data to write to eeprom, skip");
return;
}
// Check address
if address as usize + data.len() >= EEPROM_SIZE {
error!("Invalid address");
return;
}
// Update cache first
self.cache[address as usize..(address as usize + data.len())].copy_from_slice(data);
// If the address is odd, add the previous byte to data.
let mut data_len = data.len();
if address % 2 != 0 {
address -= 1;
data_len += 1;
}
for i in (0..data_len).step_by(2) {
let data_idx = address as usize + i;
let data;
if i + 1 == data_len {
// Last byte, append 0xFF
data = ((self.cache[data_idx] as u16) << 8) | (0xFF << 8);
} else {
data = ((self.cache[data_idx] as u16) << 8) | (self.cache[data_idx + 1] as u16);
}
let record = EepromRecord { address, data };
// If the storage is full, do consolidation
if self.check_consolidation() {
self.write_record(record);
} else {
warn!("Write eeprom error, the backend storage is full")
}
address += 2;
}
}
/// Read bytes from eeprom, starting from the given address, and reading `read_size` bytes.
/// Returns a slice of eeprom cache, which is immutable
pub(crate) fn read_byte(&self, address: u16, read_size: usize) -> &[u8] {
&self.cache[address as usize..(address as usize + read_size)]
}
// Each write should be aligned to 16 bytes / 32 bytes for
fn write_record(&mut self, record: EepromRecord) {
let mut buf = [0xFF; 1];
// Find a free page to write
while self.pos <= self.storage_config.storage_size {
match self
.storage
.read(self.storage_config.start_addr + self.pos, &mut buf)
{
Ok(_) => {
// Check buf
if buf[0] == 0xFF {
break;
} else {
warn!(
"Writing addr {:#X} is not 0xFF",
self.storage_config.start_addr + self.pos
);
self.pos += self.storage_config.page_size;
}
}
Err(_) => {
warn!(
"Check addr {:#X} error before writing",
self.storage_config.start_addr + self.pos
);
// Go to next possible addr
self.pos += self.storage_config.page_size;
}
}
}
let bytes = record.to_bytes();
let mut buf = vec![0xFF_u8; self.storage_config.page_size as usize];
buf[..bytes.len()].copy_from_slice(&bytes);
debug!(
"EEPROM write storage length {} at {:#X}: {=[u8]:#X} ",
buf.len(),
self.storage_config.start_addr + self.pos,
buf,
);
match self
.storage
.write(self.storage_config.start_addr + self.pos, &buf)
{
// `pos` should be aligned by write size
Ok(_) => self.pos += self.storage_config.page_size,
Err(_) => {
error!(
"Failed to write record to storage at 0x{:#X}",
self.storage_config.start_addr + self.pos
)
}
}
}
/// Read a eeprom record at the given address from the storage
fn read_record(&mut self, address: u16) -> Option<EepromRecord> {
let mut bytes = [0u8; 4];
let mut end = self.pos;
// Before the eeprom initialized, check all the storage to read a record
if self.pos == 0 {
end = self.storage_config.storage_size;
}
// Scan the storage, find the record with the given address
for p in (0..end).step_by(16) {
match self
.storage
.read(self.storage_config.start_addr + p, &mut bytes)
{
Ok(_) => {
// Check address
let record = EepromRecord::from_bytes(bytes);
if record.address == address {
return Some(record);
} else if record.address == 0xFFFF {
// Reach the end of current records
break;
}
}
Err(_) => error!("Failed to read record from storage"),
}
}
None
}
fn check_consolidation(&mut self) -> bool {
if self.pos + self.storage_config.page_size > self.storage_config.storage_size {
info!("Backend storage is full, consolidating records");
self.consolidate_records();
// Check position again
if self.pos + self.storage_config.page_size > self.storage_config.storage_size {
error!("Backend storage is full, failed to write record");
return false;
}
}
true
}
fn consolidate_records(&mut self) {
// Lock the eeprom when reconstructing
// Some targets doesn't support CAS operation, so we cannot use `self.lock.compare_exchange`
let locked = self.lock.load(SeqCst);
if locked {
return;
}
self.lock.store(true, SeqCst);
// Erase the flash page first
match self.storage.erase(
self.storage_config.start_addr,
self.storage_config.start_addr + self.pos,
) {
Ok(_) => {
// Consolidate records
self.pos = 0;
for idx in (0..self.cache.len()).step_by(2) {
// Skip default value
if self.cache[idx] == 0xFF && self.cache[idx + 1] == 0xFF {
continue;
}
// Build Eeprom record and write to flash
let record = EepromRecord {
address: idx as u16,
data: ((self.cache[idx + 1] as u16) << 8) | (self.cache[idx] as u16),
};
self.write_record(record);
}
}
Err(_) => error!("Failed to erase storage"),
}
// Unlock
self.lock.store(false, SeqCst);
}
}
fn is_power_of_two(n: u32) -> bool {
n > 0 && (n & (n - 1)) == 0
}