display: add support for multiple displays

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

3 files changed, 52 insertions, 4 deletions

diff --git a/config/example-extras.cfg b/config/example-extras.cfg
index dbf3a6f4..5d319fe0 100644
--- a/config/example-extras.cfg
+++ b/config/example-extras.cfg
@@ -1868,6 +1868,37 @@
 #   template. This field is evaluated using command templates (see
 #   docs/Command_Templates.md). This parameter must be provided.
 
+# If a primary [display] section has been defined in printer.cfg as shown
+# above it is possible to define multiple auxilary displays.  Note that
+# auxilary displays do not currently support menu functionality, thus they
+# do not support the "menu" options or button configuration.
+#[display my_display]
+#lcd_type:
+#rs_pin:
+#e_pin:
+#d4_pin:
+#d5_pin:
+#d6_pin:
+#d7_pin:
+#cs_pin:
+#sclk_pin:
+#sid_pin:
+#cs_pin:
+#a0_pin:
+#rst_pin:
+#contrast: 40
+#cs_pin:
+#dc_pin:
+#spi_bus:
+#spi_speed:
+#spi_software_sclk_pin:
+#spi_software_mosi_pin:
+#spi_software_miso_pin:
+#reset_pin:
+#display_group:
+#   See the [display] section above for details on each configuration
+#   option above.
+
 
 ######################################################################
 # Filament sensors
diff --git a/klippy/extras/display/__init__.py b/klippy/extras/display/__init__.py
index 3b5e999e..c839b098 100644
--- a/klippy/extras/display/__init__.py
+++ b/klippy/extras/display/__init__.py
@@ -7,3 +7,15 @@ import display
 
 def load_config(config):
     return display.load_config(config)
+
+def load_config_prefix(config):
+    if not config.has_section('display'):
+        raise config.error(
+            "A primary [display] section must be defined in printer.cfg "
+            "to use auxilary displays")
+    name = config.get_name().split()[-1]
+    if name == "display":
+        raise config.error(
+            "Section name [display display] is not valid. "
+            "Please choose a different postfix.")
+    return display.load_config(config)
diff --git a/klippy/extras/display/display.py b/klippy/extras/display/display.py
index 19483802..4d594329 100644
--- a/klippy/extras/display/display.py
+++ b/klippy/extras/display/display.py
@@ -84,7 +84,11 @@ class PrinterLCD:
         self.lcd_chip = config.getchoice('lcd_type', LCD_chips)(config)
         self.lcd_type = config.get('lcd_type')
         # Load menu and display_status
-        self.menu = menu.MenuManager(config, self.lcd_chip)
+        self.menu = None
+        name = config.get_name()
+        if name == 'display':
+            # only load menu for primary display
+            self.menu = menu.MenuManager(config, self.lcd_chip)
         self.printer.try_load_module(config, "display_status")
         # Configurable display
         self.display_templates = {}
@@ -145,9 +149,10 @@ class PrinterLCD:
     # Screen updating
     def screen_update_event(self, eventtime):
         # update menu component
-        ret = self.menu.screen_update_event(eventtime)
-        if ret:
-            return ret
+        if self.menu is not None:
+            ret = self.menu.screen_update_event(eventtime)
+            if ret:
+                return ret
         # Update normal display
         self.lcd_chip.clear()
         try: