Rust: port clock, rtio_crg routines.

artiq/runtime.rs/src/clock.rs

@@ -0,0 +1,77 @@
+use board::csr::timer0;
+
+const INIT: u64 = ::core::i64::MAX as u64;
+const FREQ: u64 = ::board::csr::CONFIG_CLOCK_FREQUENCY as u64;
+
+pub fn init() {
+    unsafe {
+        timer0::en_write(0);
+        timer0::load_write(INIT);
+        timer0::reload_write(INIT);
+        timer0::en_write(1);
+    }
+}
+
+pub fn get_ms() -> u64 {
+    unsafe {
+        timer0::update_value_write(1);
+        (INIT - timer0::value_read()) / (FREQ / 1_000)
+    }
+}
+
+pub fn spin_us(interval: u64) {
+    unsafe {
+        timer0::update_value_write(1);
+        let threshold = timer0::value_read() - interval * (FREQ / 1_000_000);
+        while timer0::value_read() > threshold {
+            timer0::update_value_write(1)
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Watchdog {
+    active:    bool,
+    threshold: u64
+}
+
+pub const MAX_WATCHDOGS: usize = 16;
+
+#[derive(Debug)]
+pub struct WatchdogSet {
+    watchdogs: [Watchdog; MAX_WATCHDOGS]
+}
+
+impl WatchdogSet {
+    pub fn new() -> WatchdogSet {
+        WatchdogSet {
+            watchdogs: [Watchdog { active: false, threshold: 0 }; MAX_WATCHDOGS]
+        }
+    }
+
+    pub fn set_ms(&mut self, interval: u64) -> Result<usize, ()> {
+        for (index, watchdog) in self.watchdogs.iter_mut().enumerate() {
+            if !watchdog.active {
+                watchdog.active = true;
+                watchdog.threshold = get_ms() + interval;
+                return Ok(index)
+            }
+        }
+
+        warn!("cannot add watchdog; all {} watchdogs used", MAX_WATCHDOGS);
+        Err(())
+    }
+
+    pub fn clear(&mut self, index: usize) {
+        if index < MAX_WATCHDOGS {
+            self.watchdogs[index].active = false
+        }
+    }
+
+    pub fn expired(&self) -> bool {
+        self.watchdogs.iter()
+            .filter(|wd| wd.active)
+            .min_by_key(|wd| wd.threshold)
+            .map_or(false, |wd| get_ms() > wd.threshold)
+    }
+}

artiq/runtime.rs/src/lib.rs

@@ -15,6 +15,8 @@ use buffer_logger::BufferLogger;
 pub mod board;
 pub mod io;
 pub mod config;
+pub mod clock;
+pub mod rtio_crg;
 pub mod buffer_logger;
 pub mod session;
 
@@ -28,7 +30,8 @@ pub unsafe extern fn rust_main() {
     static mut log_buffer: [u8; 4096] = [0; 4096];
     BufferLogger::new(&mut log_buffer[..])
                  .register(move |logger| {
-        info!("Accepting network sessions in Rust.");
+        clock::init();
+        rtio_crg::init();
         network_init();
 
         let mut scheduler = io::Scheduler::new();

artiq/runtime.rs/src/rtio_crg.rs

@@ -0,0 +1,47 @@
+use board::csr;
+use {clock, config};
+
+pub fn init() {
+    unsafe { csr::rtio_crg::pll_reset_write(0) }
+
+    let mut opt = [b'i'];
+    let clk;
+    match config::read("startup_clock", &mut opt) {
+        Ok(0) | Ok(1) if &opt == b"i" => {
+            info!("startup RTIO clock: internal");
+            clk = 0
+        }
+        Ok(1) if &opt == b"e" => {
+            info!("startup RTIO clock: external");
+            clk = 1
+        }
+        _ => {
+            error!("unrecognized startup_clock configuration entry");
+            clk = 0
+        }
+    };
+
+    if !switch_clock(clk) {
+        error!("startup RTIO clock failed");
+        warn!("this may cause the system initialization to fail");
+        warn!("fix clocking and reset the device");
+    }
+}
+
+pub fn check() -> bool {
+    unsafe { csr::rtio_crg::pll_locked_read() != 0 }
+}
+
+pub fn switch_clock(clk: u8) -> bool {
+    unsafe {
+        let cur_clk = csr::rtio_crg::clock_sel_read();
+        if clk != cur_clk {
+            csr::rtio_crg::pll_reset_write(1);
+            csr::rtio_crg::clock_sel_write(clk);
+            csr::rtio_crg::pll_reset_write(0);
+        }
+    }
+
+    clock::spin_us(150);
+    return check()
+}

artiq/runtime.rs/src/session/mod.rs

@@ -1,7 +1,7 @@
 use std::prelude::v1::*;
 use std::str;
 use std::io::{self, Read, ErrorKind};
-use config;
+use {config, rtio_crg};
 use self::protocol::*;
 
 mod protocol;
@@ -26,14 +26,23 @@ extern {
 }
 
 impl Session {
-    pub fn start() -> Session {
+    pub fn new() -> Session {
         unsafe { kloader_stop(); }
         Session {
             kernel_state: KernelState::Absent
         }
     }
 
-    pub fn end(self) {
+    pub fn running(&self) -> bool {
+        match self.kernel_state {
+            KernelState::Absent  | KernelState::Loaded  => false,
+            KernelState::Running | KernelState::RpcWait => true
+        }
+    }
+}
+
+impl Drop for Session {
+    fn drop(&mut self) {
         unsafe {
             kloader_stop();
             watchdog_init();
@@ -55,10 +64,14 @@ fn check_magic(stream: &mut ::io::TcpStream) -> io::Result<()> {
 }
 
 fn handle_request(stream: &mut ::io::TcpStream,
-                  logger: &::buffer_logger::BufferLogger) -> io::Result<()> {
+                  logger: &::buffer_logger::BufferLogger,
+                  session: &mut Session) -> io::Result<()> {
     fn read_request(stream: &mut ::io::TcpStream) -> io::Result<Request> {
         let request = try!(Request::read_from(stream));
-        trace!("comm<-host {:?}", request);
+        match &request {
+            &Request::LoadLibrary(_) => trace!("comm<-host LoadLibrary(...)"),
+            _ => trace!("comm<-host {:?}", request)
+        }
         Ok(request)
     }
 
@@ -71,6 +84,7 @@ fn handle_request(stream: &mut ::io::TcpStream,
         Request::Ident =>
             write_reply(stream, Reply::Ident(::board::ident(&mut [0; 64]))),
 
+        // artiq_corelog
         Request::Log => {
             // Logging the packet with the log is inadvisable
             trace!("comm->host Log(...)");
@@ -84,6 +98,7 @@ fn handle_request(stream: &mut ::io::TcpStream,
             write_reply(stream, Reply::Log(""))
         }
 
+        // artiq_coreconfig
         Request::FlashRead { ref key } => {
             let value = config::read_to_end(key);
             write_reply(stream, Reply::FlashRead(&value))
@@ -106,6 +121,20 @@ fn handle_request(stream: &mut ::io::TcpStream,
             write_reply(stream, Reply::FlashOk)
         }
 
+        // artiq_run/artiq_master
+        Request::SwitchClock(clk) => {
+            if session.running() {
+                error!("attempted to switch RTIO clock while kernel was running");
+                write_reply(stream, Reply::ClockSwitchFailed)
+            } else {
+                if rtio_crg::switch_clock(clk) {
+                    write_reply(stream, Reply::ClockSwitchCompleted)
+                } else {
+                    write_reply(stream, Reply::ClockSwitchFailed)
+                }
+            }
+        }
+
         _ => unreachable!()
     }
 }
@@ -113,8 +142,10 @@ fn handle_request(stream: &mut ::io::TcpStream,
 fn handle_requests(stream: &mut ::io::TcpStream,
                    logger: &::buffer_logger::BufferLogger) -> io::Result<()> {
     try!(check_magic(stream));
+
+    let mut session = Session::new();
     loop {
-        try!(handle_request(stream, logger))
+        try!(handle_request(stream, logger, &mut session))
     }
 }
 
@@ -122,6 +153,8 @@ pub fn handler(waiter: ::io::Waiter,
                logger: &::buffer_logger::BufferLogger) {
     let addr = ::io::SocketAddr::new(::io::IP_ANY, 1381);
     let listener = ::io::TcpListener::bind(waiter, addr).unwrap();
+    info!("accepting network sessions in Rust");
+
     loop {
         let (mut stream, addr) = listener.accept().unwrap();
         info!("new connection from {:?}", addr);

artiq/runtime/main.c

@@ -206,6 +206,8 @@ static struct net_server_instance analyzer_inst = {
 
 static void regular_main(void)
 {
+    clock_init();
+    rtiocrg_init();
     session_startup_kernel();
 
     puts("Accepting network sessions.");
@@ -242,11 +244,9 @@ int main(void)
     puts("ARTIQ runtime built "__DATE__" "__TIME__"\n");
 
     alloc_give(&_fheap, &_eheap - &_fheap);
-    clock_init();
-    rtiocrg_init();
 
-    rust_main();
+    // rust_main();
-    // regular_main();
+    regular_main();
 
     return 0;
 }