update README, make dmctl usable

README.md

@@ -81,13 +81,15 @@ The pin mapping for the RP2040 is as follows:
 | <end>| <bottom> | <bottom> | <end>|
 
 On the RP2040, two USB CDC interfaces are exposed: the first is the UART
-interface, the second is for Serprog. If you have no other USB CDC devices,
+interface, the second is for Serprog. If you have no other USB-CDC intefaces,
 these will be `/dev/ttyACM0` and `/dev/ttyACM1`, respectively.
 
 The UART pins are for connecting to the device to be debugged, the data is
 echoed back over the USB CDC interface (typically a `/dev/ttyACMx` device on
-Linux). If you want to get stdio readout on your computer, connect GP0 to GP5,
-and GP1 to GP4.
+Linux). If you want to get stdio readout of this program on your computer,
+connect GP0 to GP5, and GP1 to GP4, or alternatively, use the
+`USE_USBCDC_FOR_STDIO` CMake flag, which adds an extra USB-CDC interface for
+which stdio is used exclusively, while disabling stdio on the UART.
 
 In SWD mode, the pin mapping is entirely as with the standard Picoprobe setup,
 as described in Chapter 5 and Appendix A of [Getting Started with Raspberry Pi
@@ -111,6 +113,34 @@ Different serial speeds can be used, too. Serprog support is *techincally*
 untested, as in it does output the correct SPI commands as seen by my logic
 analyzer, but I don't have a SPI flash chip to test it on.
 
+### Runtime configuration
+
+Several settings can be applied at runtime, using the `dmctl` Python script.
+Settings are communicated over the Serprog USB serial port.
+
+The currently implemented options are:
+- `ctsrts`: Enable/disable CTS/RTS-based hardware flow control for the UART port
+
+```
+usage: dmctl [-h] [-v] [--ctsrts [CTSRTS]] tty
+
+Runtime configuration control for DapperMime-JTAG
+
+positional arguments:
+  tty                Path to DapperMime-JTAG Serprog UART device
+
+optional arguments:
+  -h, --help         show this help message and exit
+  -v, --verbose      Verbose logging (for this utility)
+  --ctsrts [CTSRTS]  Enable or disable CTS/RTS flow control (--ctsrts [true|false])
+```
+
+example:
+
+```
+$ ./dmctl.py /dev/ttyACM1 --ctsrts true
+```
+
 ## License
 
 TinyUSB is licensed under the [MIT license](https://opensource.org/licenses/MIT).

dmctl.py

@@ -1,8 +1,17 @@
 #!/usr/bin/env python3
 
-import serial, struct
+import argparse, serial, struct
 from typing import *
 
+class RTOpt(NamedTuple):
+    type: bool
+    optid: int
+    desc: str
+
+option_table = {
+    'ctsrts': RTOpt(bool, 1, "Enable or disable CTS/RTS flow control (--ctsrts [true|false])")
+}
+
 S_ACK = b'\x06'
 S_NAK = b'\x15'
 
@@ -13,7 +22,13 @@ S_CMD_Q_PGMNAME = b'\x03'
 S_CMD_SYNCNOP   = b'\x10'
 S_CMD_MAGIC_SETTINGS = b'\x53'
 
-def do_xfer(cmd:int, arg:int, port: str, baudrate:int=115200) -> Optional[int]:
+def val2byte(t, v) -> int:
+    if t == bool:
+        return 1 if v else 0
+
+    assert False, "unimplemented type %s" % str(t)
+
+def do_xfer(args, cmd:int, arg:int, port: str, baudrate:int=115200) -> Optional[int]:
     with serial.Serial(port, baudrate, timeout=1) as ser:
         cmdmap = [0]*32
         syncok = False
@@ -60,7 +75,7 @@ def do_xfer(cmd:int, arg:int, port: str, baudrate:int=115200) -> Optional[int]:
                 print("q_pgmname failed")
             else:
                 name = ser.read(16).decode('utf-8')
-                print("programmer is '%s'" % name)
+                if args.verbose: print("programmer is '%s'" % name)
 
         ser.write(S_CMD_MAGIC_SETTINGS)
         ser.write(bytes([cmd,arg]))
@@ -72,6 +87,36 @@ def do_xfer(cmd:int, arg:int, port: str, baudrate:int=115200) -> Optional[int]:
             print("settings command failed")
             return None
 
-do_xfer(1, 1, "/dev/ttyACM1")
-do_xfer(1, 0, "/dev/ttyACM1")
+def main():
+    parser = argparse.ArgumentParser(prog="dmctl",
+                                     description="Runtime configuration control for DapperMime-JTAG")
+
+    parser.add_argument('tty', type=str, nargs=1, #'?', #default="/dev/ttyACM1",
+                        help="Path to DapperMime-JTAG Serprog UART device"#+\
+                             #" [/dev/ttyACM1]"
+                        )
+
+    parser.add_argument('-v', '--verbose', default=False, action='store_true',
+                        help="Verbose logging (for this utility)")
+
+    for k, v in option_table.items():
+        parser.add_argument('--%s'%k, type=v.type, nargs='?', default=None,
+                            help=v.desc)
+
+    args = parser.parse_args()
+
+    for k, v in option_table.items():
+        if args.__dict__[k] is not None:
+            resp = do_xfer(args, v.optid, val2byte(v.type, args.__dict__[k]), args.tty)
+            if resp is None:
+                return 1
+            if args.verbose: print("-> %d" % resp)
+
+    return 0
+
+#do_xfer(1, 1, "/dev/ttyACM1")
+#do_xfer(1, 0, "/dev/ttyACM1")
+
+if __name__ == '__main__':
+    main()