From 4ce0e3df3bd89075df9cdce662ba0d2cda38a328 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Wed, 28 Aug 2019 15:56:54 +0800
Subject: [PATCH] move to glasgow (faster sample rate and no USB bug)

---
 config.json         |  4 +--
 glasgow-applet.diff | 82 +++++++++++++++++++++++++++++++++++++++++++++
 src/noptica.rs      | 16 +++++----
 3 files changed, 93 insertions(+), 9 deletions(-)
 create mode 100644 glasgow-applet.diff

diff --git a/config.json b/config.json
index 4921f4c..e2460fd 100644
--- a/config.json
+++ b/config.json
@@ -1,6 +1,6 @@
 {
-    "sample_command": "sudo sigrok-cli -O binary -d fx2lafw --config samplerate=6000000 --continuous",
-    "sample_rate": 6e6,
+    "sample_command": "glasgow run logic -V 3.3 --pins-d 0,1",
+    "sample_rate": 48e6,
     "freq_min": 1.9e6,
     "freq_max": 2.1e6,
     "bit_ref": 0,
diff --git a/glasgow-applet.diff b/glasgow-applet.diff
new file mode 100644
index 0000000..c9b8e95
--- /dev/null
+++ b/glasgow-applet.diff
@@ -0,0 +1,82 @@
+diff --git a/software/glasgow/applet/all.py b/software/glasgow/applet/all.py
+index 5aa86ea..715e5ec 100644
+--- a/software/glasgow/applet/all.py
++++ b/software/glasgow/applet/all.py
+@@ -43,3 +43,5 @@ from .video.rgb_input import VideoRGBInputApplet
+ from .video.vga_output import VGAOutputApplet
+ from .video.vga_terminal import VGATerminalApplet
+ from .video.ws2812_output import VideoWS2812OutputApplet
++
++from .logic import LogicApplet
+diff --git a/software/glasgow/applet/logic.py b/software/glasgow/applet/logic.py
+new file mode 100644
+index 0000000..eabca52
+--- /dev/null
++++ b/software/glasgow/applet/logic.py
+@@ -0,0 +1,66 @@
++import sys
++import logging
++import asyncio
++from nmigen.compat import *
++
++from . import *
++
++
++class LogicSubtarget(Module):
++    def __init__(self, pads, in_fifo):
++        latch = Signal(4)
++
++        self.comb += [
++            in_fifo.din.eq(Cat(pads.d_t.i[:4], latch)),
++        ]
++
++        self.submodules.fsm = FSM()
++        self.fsm.act("CAPTURE-1",
++            NextValue(latch, pads.d_t.i),
++            NextState("CAPTURE-2")
++        )
++        self.fsm.act("CAPTURE-2",
++            in_fifo.we.eq(1),
++            NextState("CAPTURE-1")
++        )
++
++
++class LogicApplet(GlasgowApplet, name="logic"):
++    logger = logging.getLogger(__name__)
++    preview = True
++
++    @classmethod
++    def add_build_arguments(cls, parser, access):
++        super().add_build_arguments(parser, access)
++
++        access.add_pin_set_argument(parser, "d", required=True, width=range(5))
++
++    def build(self, target, args):
++        self.mux_interface = iface = target.multiplexer.claim_interface(self, args)
++        iface.add_subtarget(LogicSubtarget(
++            pads=iface.get_pads(args, pin_sets=("d",)),
++            in_fifo=iface.get_in_fifo(auto_flush=False),
++        ))
++
++    @classmethod
++    def add_run_arguments(cls, parser, access):
++        super().add_run_arguments(parser, access)
++
++    async def run(self, device, args):
++        return await device.demultiplexer.claim_interface(self, self.mux_interface, args)
++
++    @classmethod
++    def add_interact_arguments(cls, parser):
++        pass
++
++    async def interact(self, device, args, iface):
++        while True:
++            data = await iface.read(65536)
++            sys.stdout.buffer.write(data)
++
++# -------------------------------------------------------------------------------------------------
++
++class LogicAppletTestCase(GlasgowAppletTestCase, applet=LogicApplet):
++    @synthesis_test
++    def test_build(self):
++        self.assertBuilds()
diff --git a/src/noptica.rs b/src/noptica.rs
index cfcb8e4..ee20297 100644
--- a/src/noptica.rs
+++ b/src/noptica.rs
@@ -110,14 +110,16 @@ pub fn sample(command: &str, mut callback: impl FnMut(u8, u8)) {
         .spawn()
         .unwrap();  
     let mut reader = BufReader::new(child.stdout.unwrap());
-    let mut br_sample = [0; 1];
+    let mut buffer = [0; 1];
     let mut last_sample = 0;
     loop {
-        reader.read_exact(&mut br_sample).unwrap();
-        let sample = br_sample[0];
-        let rising = sample & !last_sample;
-        let falling = !sample & last_sample;
-        callback(rising, falling);
-        last_sample = sample;
+        reader.read_exact(&mut buffer).unwrap();
+        for shift in [4u8, 0u8].iter() {
+            let sample = (buffer[0] >> shift) & 0x0f;
+            let rising = sample & !last_sample;
+            let falling = !sample & last_sample;
+            callback(rising, falling);
+            last_sample = sample;
+        }
     }
 }