bus: Add UART support

klippy/extras/bus.py

@@ -3,7 +3,7 @@
 # Copyright (C) 2018,2019  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
-import mcu
+import mcu, msgproto
 
 def resolve_bus_name(mcu, param, bus):
     # Find enumerations for the given bus
@@ -220,6 +220,96 @@ def MCU_I2C_from_config(config, default_addr=None, default_speed=100000):
     return MCU_I2C(i2c_mcu, bus, addr, speed)
 
 
+######################################################################
+# UART
+######################################################################
+
+# Helper code for working with devices connected to an MCU via a UART bus
+class MCU_UART:
+    def __init__(self, mcu, bus, receive_cb, baud, rx_buffer, tx_buffer,
+                 rx_interval):
+        self.mcu = mcu
+        self.bus = bus
+        self.receive_cb = receive_cb
+        self.oid = mcu.create_oid()
+        self.rx_buffer = rx_buffer
+        self.tx_buffer = tx_buffer
+        self.rx_interval = rx_interval
+        mcu.add_config_cmd(
+            "config_uart oid=%d rx_buffer=%d tx_buffer=%d rx_interval=%d"
+            % (self.oid, rx_buffer, tx_buffer, rx_interval))
+        self.config_fmt = (
+            "uart_set_bus oid=%d uart_bus=%%s baud=%d"
+            % (self.oid, baud))
+        self.cmd_queue = mcu.alloc_command_queue()
+        mcu.register_config_callback(self.build_config)
+        self.uart_send_cmd = None
+    def setup_shutdown_msg(self, data):
+        data_len = len(data)
+        if data_len > self.tx_buffer:
+            raise ValueError("Data size exceeds TX buffer size")
+        chunk_size = msgproto.MESSAGE_PAYLOAD_MAX - 4
+        chunks = [data[i:i+chunk_size] for i in range(0, data_len, chunk_size)]
+        for chunk in chunks:
+            data_msg = "".join(["%02x" % (x,) for x in chunk])
+            self.mcu.add_config_cmd(
+                "config_uart_shutdown oid=%d uart_oid=%d shutdown_msg=%s"
+                % (self.mcu.create_oid(), self.oid, data_msg))
+    def get_oid(self):
+        return self.oid
+    def get_mcu(self):
+        return self.mcu
+    def get_command_queue(self):
+        return self.cmd_queue
+    def build_config(self):
+        bus = resolve_bus_name(self.mcu, "uart_bus", self.bus)
+        self.mcu.add_config_cmd(self.config_fmt % (bus,))
+        self.uart_send_cmd = self.mcu.lookup_command(
+            "uart_send oid=%c data=%*s", cq=self.cmd_queue)
+        if self.receive_cb is not None:
+            self.mcu.register_response(self._handle_uart_receive,
+                                       "uart_receive",
+                                       self.oid)
+    def uart_send(self, data, minclock=0, reqclock=0):
+        data_len = len(data)
+        if data_len > self.tx_buffer:
+            raise ValueError("Data size exceeds TX buffer size")
+        chunk_size = msgproto.MESSAGE_PAYLOAD_MAX - 3
+        chunks = [data[i:i+chunk_size] for i in range(0, data_len, chunk_size)]
+        for chunk in chunks:
+            if self.uart_send_cmd is None:
+                # Send setup message via mcu initialization
+                data_msg = "".join(["%02x" % (x,) for x in chunk])
+                self.mcu.add_config_cmd(
+                    "uart_send oid=%d data=%s"
+                    % (self.oid, data_msg),
+                    is_init=True)
+                return
+            self.uart_send_cmd.send([self.oid, chunk],
+                                    minclock=minclock, reqclock=reqclock)
+    def _handle_uart_receive(self, params):
+        data = bytearray(params['data'])
+        self.receive_cb(data)
+
+def MCU_UART_from_config(config, receive_cb, default_baud=115200,
+                         default_rx_buffer=64, default_tx_buffer=128,
+                         default_rx_interval=50):
+    # Load bus parameters
+    printer = config.get_printer()
+    uart_mcu = mcu.get_printer_mcu(printer, config.get('uart_mcu', 'mcu'))
+    bus = config.get('uart_bus', None)
+    baud = config.getint('uart_baud', default_baud, minval=9600, maxval=460800)
+    rx_buffer = config.getint('uart_rx_buffer', default_rx_buffer,
+                              minval=1, maxval=255)
+    tx_buffer = config.getint('uart_tx_buffer', default_tx_buffer,
+                              minval=1, maxval=255)
+    rx_interval = config.getint('uart_rx_interval', default_rx_interval,
+                              minval=0, maxval=1000)
+    # Create MCU_UART object
+    return MCU_UART(uart_mcu, bus, receive_cb, baud, rx_buffer, tx_buffer,
+                    rx_interval)
+
+
 ######################################################################
 # Bus synchronized digital outputs
 ######################################################################