mfd: cros_ec_dev: Add CEC sub-device registration

The EC can expose a CEC bus, thus add the cros-ec-cec MFD sub-device
when the CEC feature bit is present.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/cros_ec_dev.c

@@ -377,6 +377,10 @@ error:
 	kfree(msg);
 }
 
+static const struct mfd_cell cros_ec_cec_cells[] = {
+	{ .name = "cros-ec-cec" }
+};
+
 static const struct mfd_cell cros_ec_rtc_cells[] = {
 	{ .name = "cros-ec-rtc" }
 };
@@ -419,6 +423,18 @@ static int ec_device_probe(struct platform_device *pdev)
 	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
 		cros_ec_sensors_register(ec);
 
+	/* Check whether this EC instance has CEC host command support */
+	if (cros_ec_check_features(ec, EC_FEATURE_CEC)) {
+		retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
+					 cros_ec_cec_cells,
+					 ARRAY_SIZE(cros_ec_cec_cells),
+					 NULL, 0, NULL);
+		if (retval)
+			dev_err(ec->dev,
+				"failed to add cros-ec-cec device: %d\n",
+				retval);
+	}
+
 	/* Check whether this EC instance has RTC host command support */
 	if (cros_ec_check_features(ec, EC_FEATURE_RTC)) {
 		retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,