Add gp8403 output component (#4495)

Co-authored-by: Samuel Sieb <samuel-github@sieb.net>

esphome/components/gp8403/output/__init__.py

@@ -0,0 +1,31 @@
+import esphome.config_validation as cv
+import esphome.codegen as cg
+
+from esphome.components import i2c, output
+from esphome.const import CONF_ID, CONF_CHANNEL
+
+from .. import gp8403_ns, GP8403, CONF_GP8403_ID
+
+DEPENDENCIES = ["gp8403"]
+
+GP8403Output = gp8403_ns.class_(
+    "GP8403Output", cg.Component, i2c.I2CDevice, output.FloatOutput
+)
+
+CONFIG_SCHEMA = output.FLOAT_OUTPUT_SCHEMA.extend(
+    {
+        cv.GenerateID(): cv.declare_id(GP8403Output),
+        cv.GenerateID(CONF_GP8403_ID): cv.use_id(GP8403),
+        cv.Required(CONF_CHANNEL): cv.one_of(0, 1),
+    }
+).extend(cv.COMPONENT_SCHEMA)
+
+
+async def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+    await output.register_output(var, config)
+
+    await cg.register_parented(var, config[CONF_GP8403_ID])
+
+    cg.add(var.set_channel(config[CONF_CHANNEL]))