From 4f56710e4beb1c767dc10f7ddbdc283742540508 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Tue, 10 Jul 2018 02:06:37 +0800
Subject: [PATCH] grabber: add parser, report detected frame size in core
 device log

---
 artiq/firmware/libboard_artiq/grabber.rs | 26 ++++++--
 artiq/gateware/grabber/core.py           | 77 ++++++++++++++++++++++++
 artiq/gateware/rtio/phy/grabber.py       |  5 +-
 3 files changed, 103 insertions(+), 5 deletions(-)
 create mode 100644 artiq/gateware/grabber/core.py

diff --git a/artiq/firmware/libboard_artiq/grabber.rs b/artiq/firmware/libboard_artiq/grabber.rs
index a70cb0e28..7df41d3cc 100644
--- a/artiq/firmware/libboard_artiq/grabber.rs
+++ b/artiq/firmware/libboard_artiq/grabber.rs
@@ -1,6 +1,13 @@
 use board_misoc::csr;
 
-static mut GRABBER_UP: &'static mut [bool] = &mut [false; csr::GRABBER_LEN];
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum State {
+    Down,
+    WaitResolution,
+    Up
+}
+
+static mut GRABBER_STATE: &'static mut [State] = &mut [State::Down; csr::GRABBER_LEN];
 
 fn get_pll_reset(g: usize) -> bool {
     unsafe { (csr::GRABBER[g].pll_reset_read)() != 0 }
@@ -64,14 +71,25 @@ fn clock_align(g: usize) -> bool {
     true
 }
 
+fn get_last_pixels(g: usize) -> (u16, u16) {
+    unsafe { ((csr::GRABBER[g].last_x_read)(),
+              (csr::GRABBER[g].last_y_read)()) }
+}
+
 pub fn tick() {
     for g in 0..csr::GRABBER.len() {
-        if unsafe { GRABBER_UP[g] } {
+        if unsafe { GRABBER_STATE[g] != State::Down } {
             if !clock_pattern_ok(g) || !pll_locked(g) {
                 set_pll_reset(g, true);
-                unsafe { GRABBER_UP[g] = false; }
+                unsafe { GRABBER_STATE[g] = State::Down; }
                 info!("grabber{} is down", g);
             }
+            if unsafe { GRABBER_STATE[g] == State::WaitResolution } {
+                let (last_x, last_y) = get_last_pixels(g);
+                info!("grabber{} detected frame size: {}x{}",
+                    g, last_x + 1, last_y + 1);
+                unsafe { GRABBER_STATE[g] = State::Up; }
+            }
         } else {
             if get_pll_reset(g) {
                 set_pll_reset(g, false);
@@ -80,7 +98,7 @@ pub fn tick() {
                     info!("grabber{} PLL is locked", g);
                     if clock_align(g) {
                         info!("grabber{} is up", g);
-                        unsafe { GRABBER_UP[g] = true; }
+                        unsafe { GRABBER_STATE[g] = State::WaitResolution; }
                     } else {
                         set_pll_reset(g, true);
                     }
diff --git a/artiq/gateware/grabber/core.py b/artiq/gateware/grabber/core.py
new file mode 100644
index 000000000..6385a27ee
--- /dev/null
+++ b/artiq/gateware/grabber/core.py
@@ -0,0 +1,77 @@
+from migen import *
+from migen.genlib.cdc import MultiReg
+from misoc.interconnect.csr import *
+
+
+bitseq = [
+    #  0   1   2   3   4   5   6
+       6,  5,  4,  3,  2,  1, 27,
+
+    #  7   8   9  10  11  12  13
+      26,  0, 13, 12, 11, 10,  9,
+
+    # 14  15  16  17  18  19  20
+      25, 24,  8,  7, 20, 19, 18,
+
+    # 21  22  23
+      17, 23, 22
+]
+
+assert len(set(bitseq)) == 24
+
+
+class Parser(Module, AutoCSR):
+    """Parses 28 bit encoded words and track pixel coordinates."""
+    def __init__(self, width=12):
+        self.cl = cl = Signal(28)
+
+        self.last_x = CSRStatus(width)
+        self.last_y = CSRStatus(width)
+
+        self.pix = pix = Record([
+            ("x", width),
+            ("y", width),
+            ("a", 8),
+            ("b", 8),
+            ("c", 8),
+            ("stb", 1),  # dval
+            ("eop", 1),  # ~fval (i.e. not together with stb)
+        ])
+
+        # # #
+
+        last_x = Signal(width)
+        last_y = Signal(width)
+
+        lval = Signal()
+        fval = Signal()
+        dval = Signal()
+        self.comb += [
+            Cat(dval, fval, lval).eq(cl[14:17]),
+            pix.stb.eq(dval),
+            pix.eop.eq(~fval),
+            Cat(pix.a, pix.b, pix.c).eq(Cat(cl[i] for i in bitseq))
+        ]
+        last_lval = Signal()
+        last_fval = Signal()
+        self.sync.cl += [
+            last_lval.eq(lval),
+            last_fval.eq(fval),
+            pix.x.eq(pix.x + 1),
+            If(~lval,
+                pix.x.eq(0),
+                If(last_lval, last_x.eq(pix.x)),
+                If(last_fval & last_lval,
+                    pix.y.eq(pix.y + 1)
+                )
+            ),
+            If(~fval,
+                If(last_fval, last_y.eq(pix.y)),
+                pix.y.eq(0)
+            )
+        ]
+
+        self.specials += [
+            MultiReg(last_x, self.last_x.status),
+            MultiReg(last_y, self.last_y.status)
+        ]
diff --git a/artiq/gateware/rtio/phy/grabber.py b/artiq/gateware/rtio/phy/grabber.py
index 9d1a151d7..5639cfaae 100644
--- a/artiq/gateware/rtio/phy/grabber.py
+++ b/artiq/gateware/rtio/phy/grabber.py
@@ -2,6 +2,7 @@ from migen import *
 
 from artiq.gateware.rtio import rtlink
 from artiq.gateware.grabber import deserializer_7series
+from artiq.gateware.grabber.core import *
 
 
 class Grabber(Module):
@@ -11,6 +12,8 @@ class Grabber(Module):
                                           rtlink.IInterface(10))
 
         self.submodules.deserializer = deserializer_7series.Deserializer(pins)
+        self.submodules.parser = Parser()
+        self.comb += self.parser.cl.eq(self.deserializer.q)
 
     def get_csrs(self):
-        return self.deserializer.get_csrs()
+        return self.deserializer.get_csrs() + self.parser.get_csrs()