mpr121: Add GPIO support (#6776)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/mpr121/__init__.py

@@ -1,19 +1,32 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
+import esphome.final_validate as fv
+from esphome import pins
 from esphome.components import i2c
-from esphome.const import CONF_ID
+from esphome.const import (
+    CONF_BINARY_SENSOR,
+    CONF_CHANNEL,
+    CONF_ID,
+    CONF_INPUT,
+    CONF_INVERTED,
+    CONF_MODE,
+    CONF_NUMBER,
+    CONF_OUTPUT,
+)
 
 CONF_TOUCH_THRESHOLD = "touch_threshold"
 CONF_RELEASE_THRESHOLD = "release_threshold"
 CONF_TOUCH_DEBOUNCE = "touch_debounce"
 CONF_RELEASE_DEBOUNCE = "release_debounce"
+CONF_MAX_TOUCH_CHANNEL = "max_touch_channel"
+CONF_MPR121 = "mpr121"
+CONF_MPR121_ID = "mpr121_id"
 
 DEPENDENCIES = ["i2c"]
-AUTO_LOAD = ["binary_sensor"]
 
 mpr121_ns = cg.esphome_ns.namespace("mpr121")
-CONF_MPR121_ID = "mpr121_id"
 MPR121Component = mpr121_ns.class_("MPR121Component", cg.Component, i2c.I2CDevice)
+MPR121GPIOPin = mpr121_ns.class_("MPR121GPIOPin", cg.GPIOPin)
 
 MULTI_CONF = True
 CONFIG_SCHEMA = (
@@ -28,6 +41,7 @@ CONFIG_SCHEMA = (
             cv.Optional(CONF_RELEASE_THRESHOLD, default=0x06): cv.int_range(
                 min=0x05, max=0x30
             ),
+            cv.Optional(CONF_MAX_TOUCH_CHANNEL): cv.int_range(min=3, max=11),
         }
     )
     .extend(cv.COMPONENT_SCHEMA)
@@ -35,11 +49,79 @@ CONFIG_SCHEMA = (
 )
 
 
+def _final_validate(config):
+    fconf = fv.full_config.get()
+    max_touch_channel = 3
+    if (binary_sensors := fconf.get(CONF_BINARY_SENSOR)) is not None:
+        for binary_sensor in binary_sensors:
+            if binary_sensor.get(CONF_MPR121_ID) == config[CONF_ID]:
+                max_touch_channel = max(max_touch_channel, binary_sensor[CONF_CHANNEL])
+    if max_touch_channel_in_config := config.get(CONF_MAX_TOUCH_CHANNEL):
+        if max_touch_channel != max_touch_channel_in_config:
+            raise cv.Invalid(
+                "Max touch channel must equal the highest binary sensor channel or be removed for auto calculation",
+                path=[CONF_MAX_TOUCH_CHANNEL],
+            )
+    path = fconf.get_path_for_id(config[CONF_ID])[:-1]
+    this_config = fconf.get_config_for_path(path)
+    this_config[CONF_MAX_TOUCH_CHANNEL] = max_touch_channel
+
+
+FINAL_VALIDATE_SCHEMA = _final_validate
+
+
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     cg.add(var.set_touch_debounce(config[CONF_TOUCH_DEBOUNCE]))
     cg.add(var.set_release_debounce(config[CONF_RELEASE_DEBOUNCE]))
     cg.add(var.set_touch_threshold(config[CONF_TOUCH_THRESHOLD]))
     cg.add(var.set_release_threshold(config[CONF_RELEASE_THRESHOLD]))
+    cg.add(var.set_max_touch_channel(config[CONF_MAX_TOUCH_CHANNEL]))
     await cg.register_component(var, config)
     await i2c.register_i2c_device(var, config)
+
+
+def validate_mode(value):
+    if bool(value[CONF_INPUT]) == bool(value[CONF_OUTPUT]):
+        raise cv.Invalid("Mode must be either input or output")
+    return value
+
+
+# https://www.nxp.com/docs/en/data-sheet/MPR121.pdf, page 4
+#
+# Among the 12 electrode inputs, 8 inputs are designed as multifunctional pins. When these pins are
+# not configured as electrodes, they may be used to drive LEDs or used for general purpose input or
+# output.
+MPR121_GPIO_PIN_SCHEMA = pins.gpio_base_schema(
+    MPR121GPIOPin,
+    cv.int_range(min=4, max=11),
+    modes=[CONF_INPUT, CONF_OUTPUT],
+    mode_validator=validate_mode,
+).extend(
+    {
+        cv.Required(CONF_MPR121): cv.use_id(MPR121Component),
+    }
+)
+
+
+def mpr121_pin_final_validate(pin_config, parent_config):
+    if pin_config[CONF_NUMBER] <= parent_config[CONF_MAX_TOUCH_CHANNEL]:
+        raise cv.Invalid(
+            "Pin number must be higher than the max touch channel of the MPR121 component",
+        )
+
+
+@pins.PIN_SCHEMA_REGISTRY.register(
+    CONF_MPR121, MPR121_GPIO_PIN_SCHEMA, mpr121_pin_final_validate
+)
+async def mpr121_gpio_pin_to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    parent = await cg.get_variable(config[CONF_MPR121])
+
+    cg.add(var.set_parent(parent))
+
+    num = config[CONF_NUMBER]
+    cg.add(var.set_pin(num))
+    cg.add(var.set_inverted(config[CONF_INVERTED]))
+    cg.add(var.set_flags(pins.gpio_flags_expr(config[CONF_MODE])))
+    return var