board_pins: Use an explicit parameter to specify mcu name(s)

Add an 'mcu' option to the board_pins config and use that to specify
the name of the mcu to apply the aliases to.  Support applying the
aliases to multiple mcus.

Add support for any number of options starting with an "aliases_"
prefix.

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

4 files changed, 43 insertions, 25 deletions

diff --git a/config/generic-replicape.cfg b/config/generic-replicape.cfg
index f8e3063e..a00ef1ba 100644
--- a/config/generic-replicape.cfg
+++ b/config/generic-replicape.cfg
@@ -124,7 +124,8 @@ aliases:
    SERVO_0=P9_14, SERVO_1=P9_16,
 
 [board_pins host]
-aliases:
+mcu: host
+aliases_foo:
    # Host aliases for Linux MCU
    HOST_X2_STOP=gpio30, HOST_Y2_STOP=gpio113, HOST_Z2_STOP=gpio4
    # Thermistors
diff --git a/docs/Config_Changes.md b/docs/Config_Changes.md
index 39dcafb7..ff3a2028 100644
--- a/docs/Config_Changes.md
+++ b/docs/Config_Changes.md
@@ -6,6 +6,12 @@ All dates in this document are approximate.
 
 # Changes
 
+20201120: The `[board_pins]` config section now specifies the mcu name
+in an explicit `mcu:` parameter.  If using board_pins for a secondary
+mcu, then the config must be updated to specify that name.  See the
+[config reference](Config_Reference.md#[board_pins]) for further
+details.
+
 20201112: The time reported by `print_stats.print_duration` has
 changed.  The duration prior to the first detected extrusion is
 now excluded.
diff --git a/docs/Config_Reference.md b/docs/Config_Reference.md
index d507d81a..dbc8d7d2 100644
--- a/docs/Config_Reference.md
+++ b/docs/Config_Reference.md
@@ -1396,19 +1396,23 @@ software dependencies must be installed; refer to
 
 ## [board_pins]
 
-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 pin aliases (one may define any number of sections with a
+"board_pins" prefix). Use this to define aliases for the pins on a
+micro-controller.
 
 ```
-[board_pins mcu]
+[board_pins my_aliases]
+mcu: mcu
+#   A comma separated list of micro-controllers that may use the
+#   aliases. The default is to apply the aliases to the main "mcu".
 aliases:
+aliases_<name>:
 #   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.
+#   "EXP1_9=<GND>" would reserve "EXP1_9"). Any number of options
+#   starting with "aliases_" may be specified.
 ```
 
 ## [include]
diff --git a/klippy/extras/board_pins.py b/klippy/extras/board_pins.py
index d8388cbd..780a49b6 100644
--- a/klippy/extras/board_pins.py
+++ b/klippy/extras/board_pins.py
@@ -1,29 +1,36 @@
 # Support for custom board pin aliases
 #
-# Copyright (C) 2019  Kevin O'Connor <kevin@koconnor.net>
+# Copyright (C) 2019-2020  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):
+    def __init__(self, config):
         ppins = config.get_printer().lookup_object('pins')
-        pin_resolver = ppins.get_pin_resolver(chip_name)
-        aliases = config.get("aliases").strip()
-        if aliases.endswith(','):
-            aliases = aliases[:-1]
-        parts = [a.split('=', 1) for a in aliases.split(',')]
-        for pair in parts:
-            if len(pair) != 2:
-                raise ppins.error("Unable to parse aliases in %s"
-                                  % (config.get_name(),))
-            name, value = [s.strip() for s in pair]
-            if value.startswith('<') and value.endswith('>'):
-                pin_resolver.reserve_pin(name, value)
-            else:
-                pin_resolver.alias_pin(name, value)
+        mcu_names = [n.strip() for n in config.get('mcu', 'mcu').split(',')]
+        pin_resolvers = [ppins.get_pin_resolver(n) for n in mcu_names]
+        options = ["aliases"] + config.get_prefix_options("aliases_")
+        for opt in options:
+            aliases = config.get(opt, "").strip()
+            if not aliases:
+                continue
+            if aliases.endswith(','):
+                aliases = aliases[:-1]
+            parts = [a.split('=', 1) for a in aliases.split(',')]
+            for pair in parts:
+                if len(pair) != 2:
+                    raise ppins.error("Unable to parse aliases in %s"
+                                      % (config.get_name(),))
+                name, value = [s.strip() for s in pair]
+                if value.startswith('<') and value.endswith('>'):
+                    for pin_resolver in pin_resolvers:
+                        pin_resolver.reserve_pin(name, value)
+                else:
+                    for pin_resolver in pin_resolvers:
+                        pin_resolver.alias_pin(name, value)
 
 def load_config(config):
-    return PrinterBoardAliases(config, "mcu")
+    return PrinterBoardAliases(config)
 
 def load_config_prefix(config):
-    return PrinterBoardAliases(config, config.get_name().split()[1])
+    return PrinterBoardAliases(config)