added siphaser driver code for drtio satellites

This commit is contained in:
mwojcik 2021-08-04 12:55:03 +02:00
parent b95692548e
commit e17b398483
2 changed files with 79 additions and 1 deletions

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@ -13,9 +13,15 @@ pub mod pl;
#[cfg(has_drtio)] #[cfg(has_drtio)]
pub mod drtioaux; pub mod drtioaux;
pub mod drtio_routing; pub mod drtio_routing;
pub mod si5324;
pub mod logger; pub mod logger;
#[cfg(has_si5324)]
pub mod si5324;
#[cfg(has_siphaser)]
pub mod siphaser;
use core::{cmp, str}; use core::{cmp, str};
pub fn identifier_read(buf: &mut [u8]) -> &str { pub fn identifier_read(buf: &mut [u8]) -> &str {

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@ -271,4 +271,76 @@ pub fn select_input(i2c: &mut I2c, input: Input, timer: GlobalTimer) -> Result<(
} }
monitor_lock(i2c, timer)?; monitor_lock(i2c, timer)?;
Ok(()) Ok(())
}
#[cfg(has_siphaser)]
pub mod siphaser {
use super::*;
use pl::csr;
pub fn select_recovered_clock(i2c: &mut I2c, rc: bool, timer: GlobalTimer) -> Result<()> {
write(i2c, 3, (read(3)? & 0xdf) | (1 << 5))?; // DHOLD=1
unsafe {
csr::siphaser::switch_clocks_write(if rc { 1 } else { 0 });
}
write(i2c, 3, (read(3)? & 0xdf) | (0 << 5))?; // DHOLD=0
monitor_lock(timer)?;
Ok(())
}
fn phase_shift(direction: u8, timer: GlobalTimer) {
unsafe {
csr::siphaser::phase_shift_write(direction);
while csr::siphaser::phase_shift_done_read() == 0 {}
}
// wait for the Si5324 loop to stabilize
timer.delay_us(500);
}
fn has_error(timer: GlobalTimer) -> bool {
unsafe {
csr::siphaser::error_write(1);
}
timer.delay_us(5_000);
unsafe {
csr::siphaser::error_read() != 0
}
}
fn find_edge(target: bool, timer: GlobalTimer) -> Result<u32> {
let mut nshifts = 0;
let mut previous = has_error(timer);
loop {
phase_shift(1, timer);
nshifts += 1;
let current = has_error(timer);
if previous != target && current == target {
return Ok(nshifts);
}
if nshifts > 5000 {
return Err("failed to find timing error edge");
}
previous = current;
}
}
pub fn calibrate_skew(timer: GlobalTimer) -> Result<()> {
let jitter_margin = 32;
let lead = find_edge(false, timer)?;
for _ in 0..jitter_margin {
phase_shift(1, timer);
}
let width = find_edge(true, timer)? + jitter_margin;
// width is 360 degrees (one full rotation of the phase between s/h limits) minus jitter
info!("calibration successful, lead: {}, width: {} ({}deg)", lead, width, width*360/(56*8));
// Apply reverse phase shift for half the width to get into the
// middle of the working region.
for _ in 0..width/2 {
phase_shift(0, timer);
}
Ok(())
}
} }