From c7fbd177d4bcf0d04dfca9edb168230cb7ba8633 Mon Sep 17 00:00:00 2001
From: Robbe Derks <robbe.derks@gmail.com>
Date: Tue, 20 Jan 2026 16:52:25 +0100
Subject: [PATCH] USBGPU: debug script for comma chestnut (#14252)

* initial debug script

* improvements
---
 extra/usbgpu/debug.py | 102 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100755 extra/usbgpu/debug.py

diff --git a/extra/usbgpu/debug.py b/extra/usbgpu/debug.py
new file mode 100755
index 0000000000..0741c47d93
--- /dev/null
+++ b/extra/usbgpu/debug.py
@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+
+import sys
+import time
+from argparse import ArgumentParser
+
+from pyftdi.ftdi import Ftdi
+from pyftdi.eeprom import FtdiEeprom
+from pyftdi.misc import hexdump
+
+class USBGPUDebug:
+  CBUS_RESET = (1 << 2)
+  CBUS_BOOTLOADER = (1 << 1)
+
+  def __init__(self, device_url: str = 'ftdi://ftdi:230x/1'):
+    self.device_url = device_url
+    self.ftdi = None
+    self.eeprom = None
+    self.provisioned = False
+
+  def __enter__(self):
+    self.open()
+    return self
+
+  def __exit__(self, exc_type, exc_value, traceback):
+    self.close()
+
+  def open(self):
+    self.ftdi = Ftdi()
+    self.ftdi.open_from_url(self.device_url)
+    self.ftdi.set_baudrate(921600)
+    self.ftdi.set_line_property(8, 1, 'N')
+
+    self.eeprom = FtdiEeprom()
+    self.eeprom.connect(self.ftdi)
+
+    self.provisioned = (self.eeprom.cbus_func_1 == "GPIO" and self.eeprom.cbus_func_2 == "GPIO")
+
+    if not self.provisioned:
+      print("Warning: Device not provisioned for usbgpu debugging. Use --provision to provision it.")
+      return
+
+    # setup gpio for reset control
+    self.ftdi.set_cbus_direction(self.CBUS_RESET | self.CBUS_BOOTLOADER, self.CBUS_RESET | self.CBUS_BOOTLOADER)
+    self.ftdi.set_cbus_gpio(0x00)
+
+  def close(self):
+    self.ftdi.close()
+
+  def provision(self):
+    print("Provisioning FTDI device for usbgpu debugging...")
+    self.eeprom.set_property('cbus_func_1', 'GPIO')
+    self.eeprom.set_property('cbus_func_2', 'GPIO')
+    if self.eeprom.commit(dry_run=False):
+      self.eeprom.reset_device()
+    self.ftdi.reset()
+    self.provisioned = True
+    print("Provisioning complete.")
+
+  def reset(self, bootloader=False):
+    if not self.provisioned:
+      raise RuntimeError("Device not provisioned for usbgpu debugging. Use --provision to provision it.")
+
+    self.ftdi.set_cbus_gpio(self.CBUS_RESET | (self.CBUS_BOOTLOADER if bootloader else 0))
+    time.sleep(0.5)
+    self.ftdi.set_cbus_gpio(self.CBUS_BOOTLOADER if bootloader else 0)
+    if bootloader:
+      time.sleep(1)
+      self.ftdi.set_cbus_gpio(0)
+    print("Device reset complete.")
+
+  def read(self) -> bytes:
+    return self.ftdi.read_data(256).decode('utf-8', errors='replace')
+
+
+if __name__ == "__main__":
+  args = ArgumentParser()
+  args.add_argument('--device', '-d', type=str, default='ftdi://ftdi:230x/1', help="FTDI device URL")
+  args.add_argument('--provision', '-p', action='store_true', default=False, help="Provision the connected FTDI for usbgpu debugging")
+  args.add_argument('--reset', '-r', action='store_true', default=False, help="Reset the device")
+  args.add_argument('--bootloader', '-b', action='store_true', default=False, help="Reset to bootloader")
+  args.add_argument('--no-read', '-n', action='store_true', default=False, help="Do not read debug output")
+
+  args = args.parse_args()
+
+  with USBGPUDebug(args.device) as dbg:
+    if args.provision:
+      dbg.provision()
+
+    if args.reset:
+      dbg.reset(bootloader=False)
+
+    if args.bootloader:
+      dbg.reset(bootloader=True)
+
+    if not args.no_read:
+      print("Starting debug output. Press Ctrl-C to exit.\n------")
+      while True:
+        sys.stdout.write(dbg.read())
+        sys.stdout.flush()
+        time.sleep(0.001)
+