tmc_uart: Move UART code from tmc2208.py to new file tmc_uart.py

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 216 insertions, 0 deletions

diff --git a/klippy/extras/tmc_uart.py b/klippy/extras/tmc_uart.py
new file mode 100644
index 00000000..6db689a2
--- /dev/null
+++ b/klippy/extras/tmc_uart.py
@@ -0,0 +1,216 @@
+# Helper code for communicating with TMC stepper drivers via UART
+#
+# Copyright (C) 2018-2019  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+
+
+######################################################################
+# TMC uart analog mux support
+######################################################################
+
+class MCU_analog_mux:
+    def __init__(self, mcu, cmd_queue, select_pins_desc):
+        self.mcu = mcu
+        self.cmd_queue = cmd_queue
+        ppins = mcu.get_printer().lookup_object("pins")
+        select_pin_params = [ppins.lookup_pin(spd, can_invert=True)
+                             for spd in select_pins_desc.split(',')]
+        self.oids = [self.mcu.create_oid() for pp in select_pin_params]
+        self.pins = [pp['pin'] for pp in select_pin_params]
+        self.pin_values = tuple([0 for pp in select_pin_params])
+        for oid, pin, value in zip(self.oids, self.pins, self.pin_values):
+            self.mcu.add_config_cmd("config_digital_out oid=%d pin=%s"
+                                    " value=%d default_value=0 max_duration=0"
+                                    % (oid, pin, value))
+        self.update_pin_cmd = None
+        self.mcu.register_config_callback(self.build_config)
+    def build_config(self):
+        self.update_pin_cmd = self.mcu.lookup_command(
+            "update_digital_out oid=%c value=%c", cq=self.cmd_queue)
+    def get_instance_id(self, select_pins_desc):
+        ppins = self.mcu.get_printer().lookup_object("pins")
+        select_pin_params = [ppins.parse_pin(spd, can_invert=True)
+                             for spd in select_pins_desc.split(',')]
+        for pin_params in select_pin_params:
+            if pin_params['chip'] != self.mcu:
+                raise self.mcu.get_printer().config_error(
+                    "TMC mux pins must be on the same mcu")
+        pins = [pp['pin'] for pp in select_pin_params]
+        if pins != self.pins:
+            raise self.mcu.get_printer().config_error(
+                "All TMC mux instances must use identical pins")
+        return tuple([not pp['invert'] for pp in select_pin_params])
+    def activate(self, instance_id):
+        for oid, old, new in zip(self.oids, self.pin_values, instance_id):
+            if old != new:
+                self.update_pin_cmd.send([oid, new])
+        self.pin_values = instance_id
+
+
+######################################################################
+# TMC2208 uart communication
+######################################################################
+
+# Code for sending messages on a TMC uart
+class MCU_TMC_uart_bitbang:
+    def __init__(self, rx_pin_params, tx_pin_params, select_pins_desc):
+        self.mcu = rx_pin_params['chip']
+        self.pullup = rx_pin_params['pullup']
+        self.rx_pin = rx_pin_params['pin']
+        self.tx_pin = tx_pin_params['pin']
+        self.oid = self.mcu.create_oid()
+        self.cmd_queue = self.mcu.alloc_command_queue()
+        self.analog_mux = None
+        if select_pins_desc is not None:
+            self.analog_mux = MCU_analog_mux(self.mcu, self.cmd_queue,
+                                             select_pins_desc)
+        self.instances = {}
+        self.tmcuart_send_cmd = None
+        self.mcu.register_config_callback(self.build_config)
+    def build_config(self):
+        bit_ticks = int(self.mcu.get_adjusted_freq() / 9000.)
+        self.mcu.add_config_cmd(
+            "config_tmcuart oid=%d rx_pin=%s pull_up=%d tx_pin=%s bit_time=%d"
+            % (self.oid, self.rx_pin, self.pullup, self.tx_pin, bit_ticks))
+        self.tmcuart_send_cmd = self.mcu.lookup_command(
+            "tmcuart_send oid=%c write=%*s read=%c", cq=self.cmd_queue)
+    def register_instance(self, rx_pin_params, tx_pin_params, select_pins_desc):
+        if (rx_pin_params['pin'] != self.rx_pin
+            or tx_pin_params['pin'] != self.tx_pin
+            or (select_pins_desc is None) != (self.analog_mux is None)):
+            raise self.mcu.get_printer().config_error(
+                "Shared TMC uart must use identical pins")
+        instance_id = None
+        if self.analog_mux is not None:
+            instance_id = self.analog_mux.get_instance_id(select_pins_desc)
+        if instance_id in self.instances:
+            raise self.mcu.get_printer().config_error(
+                "Each TMC uart must have unique select pins polarity")
+        self.instances[instance_id] = True
+        return instance_id
+    def _calc_crc8(self, data):
+        # Generate a CRC8-ATM value for a bytearray
+        crc = 0
+        for b in data:
+            for i in range(8):
+                if (crc >> 7) ^ (b & 0x01):
+                    crc = (crc << 1) ^ 0x07
+                else:
+                    crc = (crc << 1)
+                crc &= 0xff
+                b >>= 1
+        return crc
+    def _add_serial_bits(self, data):
+        # Add serial start and stop bits to a message in a bytearray
+        out = 0
+        pos = 0
+        for d in data:
+            b = (d << 1) | 0x200
+            out |= (b << pos)
+            pos += 10
+        res = bytearray()
+        for i in range((pos+7)//8):
+            res.append((out >> (i*8)) & 0xff)
+        return res
+    def _encode_read(self, sync, addr, reg):
+        # Generate a tmc2208 read register message
+        msg = bytearray([sync, addr, reg])
+        msg.append(self._calc_crc8(msg))
+        return self._add_serial_bits(msg)
+    def _encode_write(self, sync, addr, reg, val):
+        # Generate a tmc2208 write register message
+        msg = bytearray([sync, addr, reg, (val >> 24) & 0xff,
+                         (val >> 16) & 0xff, (val >> 8) & 0xff, val & 0xff])
+        msg.append(self._calc_crc8(msg))
+        return self._add_serial_bits(msg)
+    def _decode_read(self, reg, data):
+        # Extract a tmc2208 read response message
+        if len(data) != 10:
+            return None
+        # Convert data into a long integer for easy manipulation
+        mval = pos = 0
+        for d in bytearray(data):
+            mval |= d << pos
+            pos += 8
+        # Extract register value
+        val = ((((mval >> 31) & 0xff) << 24) | (((mval >> 41) & 0xff) << 16)
+               | (((mval >> 51) & 0xff) << 8) | ((mval >> 61) & 0xff))
+        # Verify start/stop bits and crc
+        encoded_data = self._encode_write(0x05, 0xff, reg, val)
+        if data != encoded_data:
+            return None
+        return val
+    def reg_read(self, instance_id, addr, reg):
+        if self.analog_mux is not None:
+            self.analog_mux.activate(instance_id)
+        msg = self._encode_read(0xf5, addr, reg)
+        params = self.tmcuart_send_cmd.send_with_response(
+            [self.oid, msg, 10], 'tmcuart_response', self.oid)
+        return self._decode_read(reg, params['read'])
+    def reg_write(self, instance_id, addr, reg, val):
+        if self.analog_mux is not None:
+            self.analog_mux.activate(instance_id)
+        msg = self._encode_write(0xf5, 0x00, reg | 0x80, val)
+        self.tmcuart_send_cmd.send_with_response(
+            [self.oid, msg, 0], 'tmcuart_response', self.oid)
+
+# Lookup a (possibly shared) tmc uart
+def lookup_tmc_uart_bitbang(config):
+    ppins = config.get_printer().lookup_object("pins")
+    rx_pin_params = ppins.lookup_pin(
+        config.get('uart_pin'), can_pullup=True, share_type="tmc_uart_rx")
+    tx_pin_desc = config.get('tx_pin', None)
+    if tx_pin_desc is None:
+        tx_pin_params = rx_pin_params
+    else:
+        tx_pin_params = ppins.lookup_pin(tx_pin_desc, share_type="tmc_uart_tx")
+    if rx_pin_params['chip'] is not tx_pin_params['chip']:
+        raise ppins.error("TMC uart rx and tx pins must be on the same mcu")
+    select_pins_desc = config.get('select_pins', None)
+    mcu_uart = rx_pin_params.get('class')
+    if mcu_uart is None:
+        mcu_uart = MCU_TMC_uart_bitbang(rx_pin_params, tx_pin_params,
+                                        select_pins_desc)
+        rx_pin_params['class'] = mcu_uart
+    instance_id = mcu_uart.register_instance(rx_pin_params, tx_pin_params,
+                                             select_pins_desc)
+    return instance_id, mcu_uart
+
+# Helper code for communicating via TMC uart
+class MCU_TMC_uart:
+    def __init__(self, config, name_to_reg, fields):
+        self.printer = config.get_printer()
+        self.name = config.get_name().split()[-1]
+        self.name_to_reg = name_to_reg
+        self.fields = fields
+        self.ifcnt = None
+        self.addr = 0
+        self.instance_id, self.mcu_uart = lookup_tmc_uart_bitbang(config)
+    def get_fields(self):
+        return self.fields
+    def get_register(self, reg_name):
+        reg = self.name_to_reg[reg_name]
+        if self.printer.get_start_args().get('debugoutput') is not None:
+            return 0
+        for retry in range(5):
+            val = self.mcu_uart.reg_read(self.instance_id, self.addr, reg)
+            if val is not None:
+                return val
+        raise self.printer.command_error(
+            "Unable to read tmc2208 '%s' register %s" % (self.name, reg_name))
+    def set_register(self, reg_name, val, print_time=0.):
+        reg = self.name_to_reg[reg_name]
+        if self.printer.get_start_args().get('debugoutput') is not None:
+            return
+        for retry in range(5):
+            ifcnt = self.ifcnt
+            if ifcnt is None:
+                self.ifcnt = ifcnt = self.get_register("IFCNT")
+            self.mcu_uart.reg_write(self.instance_id, self.addr, reg, val)
+            self.ifcnt = self.get_register("IFCNT")
+            if self.ifcnt == (ifcnt + 1) & 0xff:
+                return
+        raise self.printer.command_error(
+            "Unable to write tmc2208 '%s' register %s" % (self.name, reg_name))