#!/usr/bin/env python3
"""I2C debug tool for SkyWalker-1.

First powers on the BCM4500 via GPIO debug mode (0x81), then:
1. Runs I2C bus scan (0xB4) to find any devices
2. Tries raw I2C reads (0xB5) to common BCM4500 addresses
3. Tests different post-reset delays
"""

import usb.core
import usb.util
import sys
import time

BOOT_8PSK = 0x89

def find_device():
    dev = usb.core.find(idVendor=0x09C0, idProduct=0x0203)
    if not dev:
        print("Device not found!")
        sys.exit(1)
    return dev

def setup_device(dev):
    try:
        if dev.is_kernel_driver_active(0):
            dev.detach_kernel_driver(0)
    except Exception:
        pass
    try:
        dev.set_configuration()
    except usb.core.USBError:
        pass

def main():
    dev = find_device()
    setup_device(dev)

    # Verify firmware
    ret = dev.ctrl_transfer(0xC0, 0x92, 0, 0, 6, timeout=2000)
    major, minor, patch = ret[2], ret[1], ret[0]
    print(f"Firmware: v{major}.{minor:02d}.{patch}")

    # Step 1: Power on BCM4500 via GPIO-only debug mode
    print("\n--- Step 1: Power on BCM4500 (GPIO mode 0x81) ---")
    ret = dev.ctrl_transfer(0xC0, BOOT_8PSK, 0x81, 0, 3, timeout=3000)
    print(f"  GPIO setup: stage=0x{ret[1]:02X}")

    # Step 2: I2C bus scan immediately
    print("\n--- Step 2: I2C bus scan (immediately after power-on) ---")
    try:
        ret = dev.ctrl_transfer(0xC0, 0xB4, 0, 0, 16, timeout=5000)
        addrs = []
        for bi in range(16):
            for bit in range(8):
                if ret[bi] & (1 << bit):
                    addrs.append(bi * 8 + bit)
        if addrs:
            print(f"  Found devices at: {[f'0x{a:02X}' for a in addrs]}")
        else:
            print("  No I2C devices found!")
    except usb.core.USBError as e:
        print(f"  Bus scan error: {e}")

    # Step 3: Wait longer and scan again
    print("\n--- Step 3: Wait 500ms and scan again ---")
    time.sleep(0.5)
    try:
        ret = dev.ctrl_transfer(0xC0, 0xB4, 0, 0, 16, timeout=5000)
        addrs = []
        for bi in range(16):
            for bit in range(8):
                if ret[bi] & (1 << bit):
                    addrs.append(bi * 8 + bit)
        if addrs:
            print(f"  Found devices at: {[f'0x{a:02X}' for a in addrs]}")
        else:
            print("  No I2C devices found!")
    except usb.core.USBError as e:
        print(f"  Bus scan error: {e}")

    # Step 4: Try raw I2C reads to various addresses
    print("\n--- Step 4: Raw I2C reads (0xB5) to likely BCM4500 addresses ---")
    # BCM4500 could be at different addresses depending on pin strapping
    # Common: 0x08 (AD=low), 0x0A (AD=high), or even other addresses
    candidates = [0x08, 0x09, 0x0A, 0x0B, 0x10, 0x11, 0x68, 0x69, 0x60, 0x61]
    for addr in candidates:
        for reg in [0xA2, 0x00]:
            try:
                r = dev.ctrl_transfer(0xC0, 0xB5, addr, reg, 1, timeout=1000)
                print(f"  Addr 0x{addr:02X} Reg 0x{reg:02X} = 0x{r[0]:02X}  <--- RESPONDS!")
            except usb.core.USBError:
                print(f"  Addr 0x{addr:02X} Reg 0x{reg:02X} = (no response)")

    # Step 5: Check I2C bus state
    print("\n--- Step 5: I2C controller state ---")
    try:
        # Read I2CTL and I2CS by inspecting them through a known-working address
        # Actually, we can just observe what happens when we try reads
        print("  (Bus scan and raw reads above show bus health)")
    except Exception as e:
        print(f"  Error: {e}")

    # Step 6: Try I2C probe via debug mode 0x82 again with a delay
    print("\n--- Step 6: Debug probe (0x82) after additional 1s delay ---")
    time.sleep(1.0)
    ret = dev.ctrl_transfer(0xC0, BOOT_8PSK, 0x82, 0, 3, timeout=3000)
    stage = ret[1]
    probe = ret[2]
    if stage == 0xA2:
        print(f"  PROBE SUCCESS! BCM4500 status = 0x{probe:02X}")
    else:
        print(f"  Probe failed: stage=0x{stage:02X} probe=0x{probe:02X}")

    print("\nDone.")

if __name__ == "__main__":
    main()