Add raspihats binary sensor (#7508)

* Added raspihats binary_sensor platform

* Updated .coveragerc to ommit raspihats platforms.

* Using vol.Coerce(int) for validation and casting of I2CHat config address

.coveragerc

@@ -87,6 +87,7 @@ omit =
     homeassistant/components/*/qwikswitch.py
 
     homeassistant/components/raspihats.py
+    homeassistant/components/*/raspihats.py
 
     homeassistant/components/rfxtrx.py
     homeassistant/components/*/rfxtrx.py

homeassistant/components/binary_sensor/raspihats.py

@@ -0,0 +1,131 @@
+"""
+Configure a binary_sensor using a digital input from a raspihats board.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/binary_sensor.raspihats/
+"""
+import logging
+import voluptuous as vol
+from homeassistant.const import (
+    CONF_NAME, CONF_DEVICE_CLASS, DEVICE_DEFAULT_NAME
+)
+import homeassistant.helpers.config_validation as cv
+from homeassistant.components.binary_sensor import (
+    PLATFORM_SCHEMA, BinarySensorDevice
+)
+from homeassistant.components.raspihats import (
+    CONF_I2C_HATS, CONF_BOARD, CONF_ADDRESS, CONF_CHANNELS, CONF_INDEX,
+    CONF_INVERT_LOGIC, I2C_HAT_NAMES, I2C_HATS_MANAGER, I2CHatsException
+)
+
+_LOGGER = logging.getLogger(__name__)
+
+DEPENDENCIES = ['raspihats']
+
+DEFAULT_INVERT_LOGIC = False
+DEFAULT_DEVICE_CLASS = None
+
+_CHANNELS_SCHEMA = vol.Schema([{
+    vol.Required(CONF_INDEX): cv.positive_int,
+    vol.Required(CONF_NAME): cv.string,
+    vol.Optional(CONF_INVERT_LOGIC, default=DEFAULT_INVERT_LOGIC): cv.boolean,
+    vol.Optional(CONF_DEVICE_CLASS, default=DEFAULT_DEVICE_CLASS): cv.string,
+}])
+
+_I2C_HATS_SCHEMA = vol.Schema([{
+    vol.Required(CONF_BOARD): vol.In(I2C_HAT_NAMES),
+    vol.Required(CONF_ADDRESS): vol.Coerce(int),
+    vol.Required(CONF_CHANNELS): _CHANNELS_SCHEMA
+}])
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Optional(CONF_I2C_HATS): _I2C_HATS_SCHEMA,
+})
+
+
+# pylint: disable=unused-argument
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """Setup the raspihats binary_sensor devices."""
+    I2CHatBinarySensor.I2C_HATS_MANAGER = hass.data[I2C_HATS_MANAGER]
+    binary_sensors = []
+    i2c_hat_configs = config.get(CONF_I2C_HATS)
+    for i2c_hat_config in i2c_hat_configs:
+        address = i2c_hat_config[CONF_ADDRESS]
+        board = i2c_hat_config[CONF_BOARD]
+        try:
+            I2CHatBinarySensor.I2C_HATS_MANAGER.register_board(board, address)
+            for channel_config in i2c_hat_config[CONF_CHANNELS]:
+                binary_sensors.append(
+                    I2CHatBinarySensor(
+                        address,
+                        channel_config[CONF_INDEX],
+                        channel_config[CONF_NAME],
+                        channel_config[CONF_INVERT_LOGIC],
+                        channel_config[CONF_DEVICE_CLASS]
+                    )
+                )
+        except I2CHatsException as ex:
+            _LOGGER.error(
+                "Failed to register " + board + "I2CHat@" + hex(address) + " "
+                + str(ex)
+            )
+    add_devices(binary_sensors)
+
+
+class I2CHatBinarySensor(BinarySensorDevice):
+    """Represents a binary sensor that uses a I2C-HAT digital input."""
+
+    I2C_HATS_MANAGER = None
+
+    def __init__(self, address, channel, name, invert_logic, device_class):
+        """Initialize sensor."""
+        self._address = address
+        self._channel = channel
+        self._name = name or DEVICE_DEFAULT_NAME
+        self._invert_logic = invert_logic
+        self._device_class = device_class
+        self._state = self.I2C_HATS_MANAGER.read_di(
+            self._address,
+            self._channel
+        )
+
+        def online_callback():
+            """Callback fired when board is online."""
+            self.schedule_update_ha_state()
+
+        self.I2C_HATS_MANAGER.register_online_callback(
+            self._address,
+            self._channel,
+            online_callback
+        )
+
+        def edge_callback(state):
+            """Read digital input state."""
+            self._state = state
+            self.schedule_update_ha_state()
+
+        self.I2C_HATS_MANAGER.register_di_callback(
+            self._address,
+            self._channel,
+            edge_callback
+        )
+
+    @property
+    def device_class(self):
+        """Return the class of this sensor."""
+        return self._device_class
+
+    @property
+    def name(self):
+        """Return the name of this sensor."""
+        return self._name
+
+    @property
+    def should_poll(self):
+        """Polling not needed for this sensor."""
+        return False
+
+    @property
+    def is_on(self):
+        """Return the state of this sensor."""
+        return self._state != self._invert_logic