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wrpll: si549 initialization

This commit is contained in:
Sebastien Bourdeauducq 2019-11-27 22:58:08 +08:00
parent 4832bfb08c
commit bcd2383c9d

View File

@ -179,10 +179,98 @@ mod i2c {
}
}
mod si549 {
use board_misoc::clock;
use super::i2c;
const ADDRESS: u8 = 0x55;
pub fn write(dcxo: i2c::Dcxo, reg: u8, val: u8) -> Result<(), &'static str> {
i2c::start(dcxo);
if !i2c::write(dcxo, ADDRESS << 1) {
return Err("Si549 failed to ack write address")
}
if !i2c::write(dcxo, reg) {
return Err("Si549 failed to ack register")
}
if !i2c::write(dcxo, val) {
return Err("Si549 failed to ack value")
}
i2c::stop(dcxo);
Ok(())
}
pub fn write_no_ack_value(dcxo: i2c::Dcxo, reg: u8, val: u8) -> Result<(), &'static str> {
i2c::start(dcxo);
if !i2c::write(dcxo, ADDRESS << 1) {
return Err("Si549 failed to ack write address")
}
if !i2c::write(dcxo, reg) {
return Err("Si549 failed to ack register")
}
i2c::write(dcxo, val);
i2c::stop(dcxo);
Ok(())
}
pub fn read(dcxo: i2c::Dcxo, reg: u8) -> Result<u8, &'static str> {
i2c::start(dcxo);
if !i2c::write(dcxo, ADDRESS << 1) {
return Err("Si549 failed to ack write address")
}
if !i2c::write(dcxo, reg) {
return Err("Si549 failed to ack register")
}
i2c::restart(dcxo);
if !i2c::write(dcxo, (ADDRESS << 1) | 1) {
return Err("Si549 failed to ack read address")
}
let val = i2c::read(dcxo, false);
i2c::stop(dcxo);
Ok(val)
}
pub fn program(dcxo: i2c::Dcxo, hsdiv: u16, lsdiv: u8, fbdiv: u64) -> Result<(), &'static str> {
i2c::init(dcxo)?;
write(dcxo, 255, 0x00)?; // PAGE
write_no_ack_value(dcxo, 7, 0x80)?; // RESET
clock::spin_us(50_000); // required? not specified in datasheet.
write(dcxo, 255, 0x00)?; // PAGE
write(dcxo, 69, 0x00)?; // Disable FCAL override. Should bit 0 be 1?
write(dcxo, 17, 0x00)?; // Synchronously disable output
// The Si549 has no ID register, so we check that it responds correctly
// by writing values to a RAM-like register and reading them back.
for test_value in 0..255 {
write(dcxo, 23, test_value)?;
let readback = read(dcxo, 23)?;
if readback != test_value {
return Err("Si549 detection failed");
}
}
write(dcxo, 23, hsdiv as u8)?;
write(dcxo, 24, (hsdiv >> 8) as u8 | (lsdiv << 4))?;
write(dcxo, 26, fbdiv as u8)?;
write(dcxo, 27, (fbdiv >> 8) as u8)?;
write(dcxo, 28, (fbdiv >> 16) as u8)?;
write(dcxo, 29, (fbdiv >> 24) as u8)?;
write(dcxo, 30, (fbdiv >> 32) as u8)?;
write(dcxo, 31, (fbdiv >> 40) as u8)?;
write(dcxo, 7, 0x08)?; // Start FCAL
write(dcxo, 17, 0x01)?; // Synchronously enable output
Ok(())
}
}
pub fn init() {
info!("initializing...");
i2c::init(i2c::Dcxo::Main);
i2c::init(i2c::Dcxo::Helper);
si549::program(i2c::Dcxo::Main, 0x017, 2, 0x04b5badb98a).expect("cannot initialize main Si549");
si549::program(i2c::Dcxo::Helper, 0x017, 2, 0x04b5c447213).expect("cannot initialize helper Si549");
}
pub fn select_recovered_clock(rc: bool) {