From bfbcb90751aa263f1ac87739dec05f7746c697ef Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Fri, 9 Aug 2019 11:53:09 -0400
Subject: [PATCH] board_pins: Add a new "extras" module to support per-board
 pin aliases

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 config/example-extras.cfg   | 13 +++++++++++++
 klippy/extras/board_pins.py | 24 ++++++++++++++++++++++++
 klippy/pins.py              | 16 ++++++++++++++--
 3 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 klippy/extras/board_pins.py

diff --git a/config/example-extras.cfg b/config/example-extras.cfg
index 184f690a..4f220502 100644
--- a/config/example-extras.cfg
+++ b/config/example-extras.cfg
@@ -1366,6 +1366,19 @@
 #   be provided.
 
 
+# Board pin aliases. One may define aliases for the pins on a
+# micro-controller. (If a micro-controller name is omitted in the
+# board_pins config section name then it defaults to "mcu".)
+#[board_pins mcu]
+#aliases:
+#   A comma separated list of "name=value" aliases to create for the
+#   given micro-controller. For example, "EXP1_1=PE6" would create an
+#   "EXP1_1" alias for the "PE6" pin. However, if "value" is enclosed
+#   in "<>" then "name" is created as a reserved pin (for example,
+#   "EXP1_9=<GND>" would reserve "EXP1_9"). This parameter must be
+#   provided.
+
+
 # Support for a display attached to the micro-controller.
 #[display]
 #lcd_type:
diff --git a/klippy/extras/board_pins.py b/klippy/extras/board_pins.py
new file mode 100644
index 00000000..d8084b02
--- /dev/null
+++ b/klippy/extras/board_pins.py
@@ -0,0 +1,24 @@
+# Support for custom board pin aliases
+#
+# Copyright (C) 2019  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+class PrinterBoardAliases:
+    def __init__(self, config, chip_name):
+        ppins = config.get_printer().lookup_object('pins')
+        pin_resolver = ppins.get_pin_resolver(chip_name)
+        aliases = config.get("aliases")
+        parts = [a.split('=', 1) for a in aliases.split(',')]
+        for name, value in parts:
+            name, value = name.strip(), value.strip()
+            if value.startswith('<') and value.endswith('>'):
+                pin_resolver.reserve_pin(name, value)
+            else:
+                pin_resolver.alias_pin(name, value)
+
+def load_config(config):
+    return PrinterBoardAliases(config, "mcu")
+
+def load_config_prefix(config):
+    return PrinterBoardAliases(config, config.get_name().split()[1])
diff --git a/klippy/pins.py b/klippy/pins.py
index c1b4588f..a4b93762 100644
--- a/klippy/pins.py
+++ b/klippy/pins.py
@@ -161,13 +161,25 @@ class PinResolver:
             raise error("Pin %s reserved for %s - can't reserve for %s" % (
                 pin, self.reserved[pin], reserve_name))
         self.reserved[pin] = reserve_name
+    def alias_pin(self, alias, pin):
+        if alias in self.aliases and self.aliases[alias] != pin:
+            raise error("Alias %s mapped to %s - can't alias to %s" % (
+                alias, self.aliases[alias], pin))
+        if pin in self.aliases:
+            pin = self.aliases[pin]
+        self.aliases[alias] = pin
+        for existing_alias, existing_pin in self.aliases.items():
+            if existing_pin == alias:
+                self.aliases[existing_alias] = pin
     def add_pin_mapping(self, mcu_type, mapping_name):
         if mapping_name == 'arduino':
-            self.aliases = get_aliases_arduino(mcu_type)
+            pin_mapping = get_aliases_arduino(mcu_type)
         elif mapping_name == 'beaglebone':
-            self.aliases = get_aliases_beaglebone(mcu_type)
+            pin_mapping = get_aliases_beaglebone(mcu_type)
         else:
             raise error("Unknown pin alias mapping '%s'" % (mapping_name,))
+        for alias, pin in pin_mapping.items():
+            self.alias_pin(alias, pin)
     def update_command(self, cmd):
         def pin_fixup(m):
             name = m.group('name')