Firmware: Runtime WRPLL

runtime: drive CLK_SEL to true when si549 is used
runtime & libboard_artiq: allow standalone to use io_expander
si549: add bit bang mmcm dynamic configuration
si549: add frequency counter for refclk
rtio_clocking & si549: add 125Mhz wrpll refclk setup

src/libboard_artiq/Cargo.toml.tpl

@@ -10,6 +10,7 @@ name = "libboard_artiq"
 [features]
 target_zc706 = ["libboard_zynq/target_zc706", "libconfig/target_zc706"]
 target_kasli_soc = ["libboard_zynq/target_kasli_soc", "libconfig/target_kasli_soc"]
+calibrate_wrpll_skew = []
 
 [build-dependencies]
 build_zynq = { path = "../libbuild_zynq" }

src/libboard_artiq/src/lib.rs

@@ -22,7 +22,7 @@ pub mod drtioaux;
 pub mod drtioaux_async;
 pub mod drtioaux_proto;
 pub mod fiq;
-#[cfg(all(feature = "target_kasli_soc", has_drtio))]
+#[cfg(feature = "target_kasli_soc")]
 pub mod io_expander;
 pub mod logger;
 #[cfg(has_drtio)]

src/libboard_artiq/src/si549.rs

@@ -357,6 +357,10 @@ pub mod wrpll {
     mod tag_collector {
         use super::*;
 
+        #[cfg(wrpll_ref_clk = "GTX_CDR")]
+        static TAG_OFFSET: Mutex<u32> = Mutex::new(19050);
+        #[cfg(wrpll_ref_clk = "SMA_CLKIN")]
+        static TAG_OFFSET: Mutex<u32> = Mutex::new(0);
         static REF_TAG: Mutex<u32> = Mutex::new(0);
         static REF_TAG_READY: Mutex<bool> = Mutex::new(false);
         static MAIN_TAG: Mutex<u32> = Mutex::new(0);
@@ -390,6 +394,16 @@ pub mod wrpll {
             *REF_TAG_READY.lock() && *MAIN_TAG_READY.lock()
         }
 
+        #[cfg(feature = "calibrate_wrpll_skew")]
+        pub fn set_tag_offset(offset: u32) {
+            *TAG_OFFSET.lock() = offset;
+        }
+
+        #[cfg(feature = "calibrate_wrpll_skew")]
+        pub fn get_tag_offset() -> u32 {
+            *TAG_OFFSET.lock()
+        }
+
         pub fn get_period_error() -> i32 {
             // n * BEATING_PERIOD - REF_TAG(n) mod BEATING_PERIOD
             let mut period_error = (*REF_TAG.lock()).overflowing_neg().0.rem_euclid(BEATING_PERIOD as u32) as i32;
@@ -402,9 +416,9 @@ pub mod wrpll {
         }
 
         pub fn get_phase_error() -> i32 {
-            // MAIN_TAG(n) - REF_TAG(n) mod BEATING_PERIOD
+            // MAIN_TAG(n) - REF_TAG(n) - TAG_OFFSET mod BEATING_PERIOD
             let mut phase_error = (*MAIN_TAG.lock())
-                .overflowing_sub(*REF_TAG.lock())
+                .overflowing_sub(*REF_TAG.lock() + *TAG_OFFSET.lock())
                 .0
                 .rem_euclid(BEATING_PERIOD as u32) as i32;
 
@@ -520,6 +534,113 @@ pub mod wrpll {
         Ok(())
     }
 
+    #[cfg(wrpll_ref_clk = "GTX_CDR")]
+    fn test_skew(timer: &mut GlobalTimer) -> Result<(), &'static str> {
+        // wait for PLL to stabilize
+        timer.delay_us(20_000);
+
+        info!("testing the skew of SYS CLK...");
+        if has_timing_error(timer) {
+            return Err("the skew cannot satisfy setup/hold time constraint of RX synchronizer");
+        }
+        info!("the skew of SYS CLK met the timing constraint");
+        Ok(())
+    }
+
+    #[cfg(wrpll_ref_clk = "GTX_CDR")]
+    fn has_timing_error(timer: &mut GlobalTimer) -> bool {
+        unsafe {
+            csr::wrpll_skewtester::error_write(1);
+        }
+        timer.delay_us(5_000);
+        unsafe { csr::wrpll_skewtester::error_read() == 1 }
+    }
+
+    #[cfg(feature = "calibrate_wrpll_skew")]
+    fn find_edge(target: bool, timer: &mut GlobalTimer) -> Result<u32, &'static str> {
+        const STEP: u32 = 8;
+        const STABLE_THRESHOLD: u32 = 10;
+
+        enum FSM {
+            Init,
+            WaitEdge,
+            GotEdge,
+        }
+
+        let mut state: FSM = FSM::Init;
+        let mut offset: u32 = tag_collector::get_tag_offset();
+        let mut median_edge: u32 = 0;
+        let mut stable_counter: u32 = 0;
+
+        for _ in 0..(BEATING_PERIOD as u32 / STEP) as usize {
+            tag_collector::set_tag_offset(offset);
+            offset += STEP;
+            // wait for PLL to stabilize
+            timer.delay_us(20_000);
+
+            let error = has_timing_error(timer);
+            // A median edge deglitcher
+            match state {
+                FSM::Init => {
+                    if error != target {
+                        stable_counter += 1;
+                    } else {
+                        stable_counter = 0;
+                    }
+
+                    if stable_counter >= STABLE_THRESHOLD {
+                        state = FSM::WaitEdge;
+                        stable_counter = 0;
+                    }
+                }
+                FSM::WaitEdge => {
+                    if error == target {
+                        state = FSM::GotEdge;
+                        median_edge = offset;
+                    }
+                }
+                FSM::GotEdge => {
+                    if error != target {
+                        median_edge += STEP;
+                        stable_counter = 0;
+                    } else {
+                        stable_counter += 1;
+                    }
+
+                    if stable_counter >= STABLE_THRESHOLD {
+                        return Ok(median_edge);
+                    }
+                }
+            }
+        }
+        return Err("failed to find timing error edge");
+    }
+
+    #[cfg(feature = "calibrate_wrpll_skew")]
+    fn calibrate_skew(timer: &mut GlobalTimer) -> Result<(), &'static str> {
+        info!("calibrating skew to meet timing constraint...");
+
+        // clear calibrated value
+        tag_collector::set_tag_offset(0);
+        let rising = find_edge(true, timer)? as i32;
+        let falling = find_edge(false, timer)? as i32;
+
+        let width = BEATING_PERIOD - (falling - rising);
+        let result = falling + width / 2;
+        tag_collector::set_tag_offset(result as u32);
+
+        info!(
+            "calibration successful, error zone: {} -> {}, width: {} ({}deg), middle of working region: {}",
+            rising,
+            falling,
+            width,
+            360 * width / BEATING_PERIOD,
+            result,
+        );
+
+        Ok(())
+    }
+
     pub fn select_recovered_clock(rc: bool, timer: &mut GlobalTimer) {
         set_isr(false);
 
@@ -539,6 +660,155 @@ pub mod wrpll {
             // use nFIQ to avoid IRQ being disabled by mutex lock and mess up PLL
             set_isr(true);
             info!("WRPLL interrupt enabled");
+
+            #[cfg(feature = "calibrate_wrpll_skew")]
+            calibrate_skew(timer).expect("failed to set the correct skew");
+
+            #[cfg(wrpll_ref_clk = "GTX_CDR")]
+            test_skew(timer).expect("skew test failed");
         }
     }
 }
+
+#[cfg(has_wrpll_refclk)]
+pub mod wrpll_refclk {
+    use super::*;
+
+    pub struct MmcmSetting {
+        pub clkout0_reg1: u16,  //0x08
+        pub clkout0_reg2: u16,  //0x09
+        pub clkfbout_reg1: u16, //0x14
+        pub clkfbout_reg2: u16, //0x15
+        pub div_reg: u16,       //0x16
+        pub lock_reg1: u16,     //0x18
+        pub lock_reg2: u16,     //0x19
+        pub lock_reg3: u16,     //0x1A
+        pub power_reg: u16,     //0x28
+        pub filt_reg1: u16,     //0x4E
+        pub filt_reg2: u16,     //0x4F
+    }
+
+    fn one_clock_cycle(timer: &mut GlobalTimer) {
+        unsafe {
+            csr::wrpll_refclk::mmcm_dclk_write(1);
+            timer.delay_us(1);
+            csr::wrpll_refclk::mmcm_dclk_write(0);
+            timer.delay_us(1);
+        }
+    }
+
+    fn set_addr(address: u8) {
+        unsafe {
+            csr::wrpll_refclk::mmcm_daddr_write(address);
+        }
+    }
+
+    fn set_data(value: u16) {
+        unsafe {
+            csr::wrpll_refclk::mmcm_din_write(value);
+        }
+    }
+
+    fn set_enable(en: bool) {
+        unsafe {
+            let val = if en { 1 } else { 0 };
+            csr::wrpll_refclk::mmcm_den_write(val);
+        }
+    }
+
+    fn set_write_enable(en: bool) {
+        unsafe {
+            let val = if en { 1 } else { 0 };
+            csr::wrpll_refclk::mmcm_dwen_write(val);
+        }
+    }
+
+    fn get_data() -> u16 {
+        unsafe { csr::wrpll_refclk::mmcm_dout_read() }
+    }
+
+    fn drp_ready() -> bool {
+        unsafe { csr::wrpll_refclk::mmcm_dready_read() == 1 }
+    }
+
+    #[allow(dead_code)]
+    fn read(timer: &mut GlobalTimer, address: u8) -> u16 {
+        set_addr(address);
+        set_enable(true);
+        // Set DADDR on the MMCM and assert DEN for one clock cycle
+        one_clock_cycle(timer);
+
+        set_enable(false);
+        while !drp_ready() {
+            // keep the clock signal until data is ready
+            one_clock_cycle(timer);
+        }
+        get_data()
+    }
+
+    fn write(timer: &mut GlobalTimer, address: u8, value: u16) {
+        set_addr(address);
+        set_data(value);
+        set_write_enable(true);
+        set_enable(true);
+        // Set DADDR, DI on the MMCM and assert DWE, DEN for one clock cycle
+        one_clock_cycle(timer);
+
+        set_write_enable(false);
+        set_enable(false);
+        while !drp_ready() {
+            // keep the clock signal until write is finished
+            one_clock_cycle(timer);
+        }
+    }
+
+    fn reset(rst: bool) {
+        unsafe {
+            let val = if rst { 1 } else { 0 };
+            csr::wrpll_refclk::mmcm_reset_write(val)
+        }
+    }
+
+    pub fn setup(timer: &mut GlobalTimer, settings: MmcmSetting, mmcm_bypass: bool) -> Result<(), &'static str> {
+        unsafe {
+            csr::wrpll_refclk::refclk_reset_write(1);
+        }
+
+        if mmcm_bypass {
+            info!("Bypassing mmcm");
+            unsafe {
+                csr::wrpll_refclk::mmcm_bypass_write(1);
+            }
+        } else {
+            // Based on "DRP State Machine" from XAPP888
+            // hold reset HIGH during mmcm config
+            reset(true);
+            write(timer, 0x08, settings.clkout0_reg1);
+            write(timer, 0x09, settings.clkout0_reg2);
+            write(timer, 0x14, settings.clkfbout_reg1);
+            write(timer, 0x15, settings.clkfbout_reg2);
+            write(timer, 0x16, settings.div_reg);
+            write(timer, 0x18, settings.lock_reg1);
+            write(timer, 0x19, settings.lock_reg2);
+            write(timer, 0x1A, settings.lock_reg3);
+            write(timer, 0x28, settings.power_reg);
+            write(timer, 0x4E, settings.filt_reg1);
+            write(timer, 0x4F, settings.filt_reg2);
+            reset(false);
+
+            // wait for the mmcm to lock
+            timer.delay_us(100);
+
+            let locked = unsafe { csr::wrpll_refclk::mmcm_locked_read() == 1 };
+            if !locked {
+                return Err("mmcm failed to generate 125Mhz ref clock from SMA CLKIN");
+            }
+        }
+
+        unsafe {
+            csr::wrpll_refclk::refclk_reset_write(0);
+        }
+
+        Ok(())
+    }
+}

src/runtime/src/main.rs

@@ -8,14 +8,14 @@
 #[macro_use]
 extern crate alloc;
 
-#[cfg(all(feature = "target_kasli_soc", has_drtio))]
+#[cfg(all(feature = "target_kasli_soc", has_virtual_leds))]
 use core::cell::RefCell;
 
 use ksupport;
 use libasync::task;
 #[cfg(has_drtio_eem)]
 use libboard_artiq::drtio_eem;
-#[cfg(all(feature = "target_kasli_soc", has_drtio))]
+#[cfg(feature = "target_kasli_soc")]
 use libboard_artiq::io_expander;
 use libboard_artiq::{identifier_read, logger, pl};
 use libboard_zynq::{gic, mpcore, timer::GlobalTimer};
@@ -43,7 +43,7 @@ extern "C" {
     static __exceptions_start: u32;
 }
 
-#[cfg(all(feature = "target_kasli_soc", has_drtio))]
+#[cfg(all(feature = "target_kasli_soc", has_virtual_leds))]
 async fn io_expanders_service(
     i2c_bus: RefCell<&mut libboard_zynq::i2c::I2c>,
     io_expander0: RefCell<io_expander::IoExpander>,
@@ -101,7 +101,7 @@ pub fn main_core0() {
     info!("gateware ident: {}", identifier_read(&mut [0; 64]));
 
     ksupport::i2c::init();
-    #[cfg(all(feature = "target_kasli_soc", has_drtio))]
+    #[cfg(feature = "target_kasli_soc")]
     {
         let i2c_bus = unsafe { (ksupport::i2c::I2C_BUS).as_mut().unwrap() };
         let mut io_expander0 = io_expander::IoExpander::new(i2c_bus, 0).unwrap();
@@ -112,6 +112,11 @@ pub fn main_core0() {
         io_expander1
             .init(i2c_bus)
             .expect("I2C I/O expander #1 initialization failed");
+
+        // Drive CLK_SEL to true
+        #[cfg(has_si549)]
+        io_expander0.set(1, 7, true);
+
         // Drive TX_DISABLE to false on SFP0..3
         io_expander0.set(0, 1, false);
         io_expander1.set(0, 1, false);
@@ -119,6 +124,7 @@ pub fn main_core0() {
         io_expander1.set(1, 1, false);
         io_expander0.service(i2c_bus).unwrap();
         io_expander1.service(i2c_bus).unwrap();
+        #[cfg(has_virtual_leds)]
         task::spawn(io_expanders_service(
             RefCell::new(i2c_bus),
             RefCell::new(io_expander0),

src/runtime/src/rtio_clocking.rs

@@ -4,6 +4,8 @@ use ksupport::i2c;
 use libboard_artiq::pl;
 #[cfg(has_si5324)]
 use libboard_artiq::si5324;
+#[cfg(has_si549)]
+use libboard_artiq::si549;
 #[cfg(has_si5324)]
 use libboard_zynq::i2c::I2c;
 use libboard_zynq::timer::GlobalTimer;
@@ -260,6 +262,150 @@ fn setup_si5324(i2c: &mut I2c, timer: &mut GlobalTimer, clk: RtioClock) {
     si5324::setup(i2c, &si5324_settings, si5324_ref_input, timer).expect("cannot initialize Si5324");
 }
 
+#[cfg(all(has_si549, has_wrpll))]
+fn wrpll_setup(timer: &mut GlobalTimer, clk: RtioClock, si549_settings: &si549::FrequencySetting) {
+    // register values are directly copied from preconfigured mmcm
+    let (mmcm_setting, mmcm_bypass) = match clk {
+        RtioClock::Ext0_Synth0_10to125 => (
+            si549::wrpll_refclk::MmcmSetting {
+                // CLKFBOUT_MULT = 62.5, DIVCLK_DIVIDE = 1 , CLKOUT0_DIVIDE = 5
+                clkout0_reg1: 0x1083,
+                clkout0_reg2: 0x0080,
+                clkfbout_reg1: 0x179e,
+                clkfbout_reg2: 0x4c00,
+                div_reg: 0x1041,
+                lock_reg1: 0x00fa,
+                lock_reg2: 0x7c01,
+                lock_reg3: 0xffe9,
+                power_reg: 0x9900,
+                filt_reg1: 0x0808,
+                filt_reg2: 0x0800,
+            },
+            false,
+        ),
+        RtioClock::Ext0_Synth0_80to125 => (
+            si549::wrpll_refclk::MmcmSetting {
+                // CLKFBOUT_MULT = 15.625, DIVCLK_DIVIDE = 1 , CLKOUT0_DIVIDE = 10
+                clkout0_reg1: 0x1145,
+                clkout0_reg2: 0x0000,
+                clkfbout_reg1: 0x11c7,
+                clkfbout_reg2: 0x5880,
+                div_reg: 0x1041,
+                lock_reg1: 0x028a,
+                lock_reg2: 0x7c01,
+                lock_reg3: 0xffe9,
+                power_reg: 0x9900,
+                filt_reg1: 0x0808,
+                filt_reg2: 0x9800,
+            },
+            false,
+        ),
+        RtioClock::Ext0_Synth0_100to125 => (
+            si549::wrpll_refclk::MmcmSetting {
+                // CLKFBOUT_MULT = 12.5, DIVCLK_DIVIDE = 1 , CLKOUT0_DIVIDE = 10
+                clkout0_reg1: 0x1145,
+                clkout0_reg2: 0x0000,
+                clkfbout_reg1: 0x1145,
+                clkfbout_reg2: 0x4c00,
+                div_reg: 0x1041,
+                lock_reg1: 0x0339,
+                lock_reg2: 0x7c01,
+                lock_reg3: 0xffe9,
+                power_reg: 0x9900,
+                filt_reg1: 0x0808,
+                filt_reg2: 0x9800,
+            },
+            false,
+        ),
+        RtioClock::Ext0_Synth0_125to125 => (
+            si549::wrpll_refclk::MmcmSetting {
+                // CLKFBOUT_MULT = 10, DIVCLK_DIVIDE = 1 , CLKOUT0_DIVIDE = 10
+                clkout0_reg1: 0x1145,
+                clkout0_reg2: 0x0000,
+                clkfbout_reg1: 0x1145,
+                clkfbout_reg2: 0x0000,
+                div_reg: 0x1041,
+                lock_reg1: 0x03e8,
+                lock_reg2: 0x7001,
+                lock_reg3: 0xf3e9,
+                power_reg: 0x0100,
+                filt_reg1: 0x0808,
+                filt_reg2: 0x1100,
+            },
+            true,
+        ),
+        _ => unreachable!(),
+    };
+
+    si549::helper_setup(timer, &si549_settings).expect("cannot initialize helper Si549");
+    si549::wrpll_refclk::setup(timer, mmcm_setting, mmcm_bypass).expect("cannot initialize ref clk for wrpll");
+    si549::wrpll::select_recovered_clock(true, timer);
+}
+
+#[cfg(has_si549)]
+fn get_si549_setting(clk: RtioClock) -> si549::FrequencySetting {
+    match clk {
+        RtioClock::Ext0_Synth0_10to125 => {
+            info!("using 10MHz reference to make 125MHz RTIO clock with WRPLL");
+        }
+        RtioClock::Ext0_Synth0_80to125 => {
+            info!("using 80MHz reference to make 125MHz RTIO clock with WRPLL");
+        }
+        RtioClock::Ext0_Synth0_100to125 => {
+            info!("using 100MHz reference to make 125MHz RTIO clock with WRPLL");
+        }
+        RtioClock::Ext0_Synth0_125to125 => {
+            info!("using 125MHz reference to make 125MHz RTIO clock with WRPLL");
+        }
+        RtioClock::Int_100 => {
+            info!("using internal 100MHz RTIO clock");
+        }
+        RtioClock::Int_125 => {
+            info!("using internal 125MHz RTIO clock");
+        }
+        _ => {
+            warn!(
+                "rtio_clock setting '{:?}' is unsupported. Falling back to default internal 125MHz RTIO clock.",
+                clk
+            );
+        }
+    };
+
+    match clk {
+        RtioClock::Int_100 => {
+            si549::FrequencySetting {
+                main: si549::DividerConfig {
+                    hsdiv: 0x06C,
+                    lsdiv: 0,
+                    fbdiv: 0x046C5F49797,
+                },
+                helper: si549::DividerConfig {
+                    // 100Mhz*32767/32768
+                    hsdiv: 0x06C,
+                    lsdiv: 0,
+                    fbdiv: 0x046C5670BBD,
+                },
+            }
+        }
+        _ => {
+            // Everything else use 125Mhz
+            si549::FrequencySetting {
+                main: si549::DividerConfig {
+                    hsdiv: 0x058,
+                    lsdiv: 0,
+                    fbdiv: 0x04815791F25,
+                },
+                helper: si549::DividerConfig {
+                    // 125Mhz*32767/32768
+                    hsdiv: 0x058,
+                    lsdiv: 0,
+                    fbdiv: 0x04814E8F442,
+                },
+            }
+        }
+    }
+}
+
 pub fn init(timer: &mut GlobalTimer, cfg: &Config) {
     let clk = get_rtio_clock_cfg(cfg);
     #[cfg(has_si5324)]
@@ -274,9 +420,29 @@ pub fn init(timer: &mut GlobalTimer, cfg: &Config) {
         }
     }
 
+    #[cfg(has_si549)]
+    let si549_settings = get_si549_setting(clk);
+
+    #[cfg(has_si549)]
+    si549::main_setup(timer, &si549_settings).expect("cannot initialize main Si549");
+
     #[cfg(has_drtio)]
     init_drtio(timer);
 
     #[cfg(not(has_drtio))]
     init_rtio(timer);
+
+    #[cfg(all(has_si549, has_wrpll))]
+    {
+        // SYS CLK switch will reset CSRs that are used by WRPLL
+        match clk {
+            RtioClock::Ext0_Synth0_10to125
+            | RtioClock::Ext0_Synth0_80to125
+            | RtioClock::Ext0_Synth0_100to125
+            | RtioClock::Ext0_Synth0_125to125 => {
+                wrpll_setup(timer, clk, &si549_settings);
+            }
+            _ => {}
+        }
+    }
 }

src/satman/Cargo.toml.tpl

@@ -7,6 +7,7 @@ build = "build.rs"
 [features]
 target_zc706 = ["libboard_zynq/target_zc706", "libsupport_zynq/target_zc706", "libconfig/target_zc706", "libboard_artiq/target_zc706"]
 target_kasli_soc = ["libboard_zynq/target_kasli_soc", "libsupport_zynq/target_kasli_soc", "libconfig/target_kasli_soc", "libboard_artiq/target_kasli_soc"]
+calibrate_wrpll_skew = ["libboard_artiq/calibrate_wrpll_skew"]
 default = ["target_zc706", ]
 
 [build-dependencies]