static int ec_device_probe()

in cros_ec_dev.c [133:271]

• 95 lines of code
• 21 McCabe index (conditional complexity)

static int ec_device_probe(struct platform_device *pdev)
{
	int retval = -ENOMEM;
	struct device_node *node;
	struct device *dev = &pdev->dev;
	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
	int i;

	if (!ec)
		return retval;

	dev_set_drvdata(dev, ec);
	ec->ec_dev = dev_get_drvdata(dev->parent);
	ec->dev = dev;
	ec->cmd_offset = ec_platform->cmd_offset;
	ec->features.flags[0] = -1U; /* Not cached yet */
	ec->features.flags[1] = -1U; /* Not cached yet */
	device_initialize(&ec->class_dev);

	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
		/*
		 * Check whether this is actually a dedicated MCU rather
		 * than an standard EC.
		 */
		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
			dev_info(dev, "CrOS %s MCU detected\n",
				 cros_mcu_devices[i].desc);
			/*
			 * Help userspace differentiating ECs from other MCU,
			 * regardless of the probing order.
			 */
			ec_platform->ec_name = cros_mcu_devices[i].name;
			break;
		}
	}

	/*
	 * Add the class device
	 */
	ec->class_dev.class = &cros_class;
	ec->class_dev.parent = dev;
	ec->class_dev.release = cros_ec_class_release;

	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
	if (retval) {
		dev_err(dev, "dev_set_name failed => %d\n", retval);
		goto failed;
	}

	retval = device_add(&ec->class_dev);
	if (retval)
		goto failed;

	/* check whether this EC is a sensor hub. */
	if (cros_ec_get_sensor_count(ec) > 0) {
		retval = mfd_add_hotplug_devices(ec->dev,
				cros_ec_sensorhub_cells,
				ARRAY_SIZE(cros_ec_sensorhub_cells));
		if (retval)
			dev_err(ec->dev, "failed to add %s subdevice: %d\n",
				cros_ec_sensorhub_cells->name, retval);
	}

	/*
	 * The following subdevices can be detected by sending the
	 * EC_FEATURE_GET_CMD Embedded Controller device.
	 */
	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
		if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
			retval = mfd_add_hotplug_devices(ec->dev,
						cros_subdevices[i].mfd_cells,
						cros_subdevices[i].num_cells);
			if (retval)
				dev_err(ec->dev,
					"failed to add %s subdevice: %d\n",
					cros_subdevices[i].mfd_cells->name,
					retval);
		}
	}

	/*
	 * Lightbar is a special case. Newer devices support autodetection,
	 * but older ones do not.
	 */
	if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
	    dmi_match(DMI_PRODUCT_NAME, "Link")) {
		retval = mfd_add_hotplug_devices(ec->dev,
					cros_ec_lightbar_cells,
					ARRAY_SIZE(cros_ec_lightbar_cells));
		if (retval)
			dev_warn(ec->dev, "failed to add lightbar: %d\n",
				 retval);
	}

	/*
	 * The PD notifier driver cell is separate since it only needs to be
	 * explicitly added on platforms that don't have the PD notifier ACPI
	 * device entry defined.
	 */
	if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
		if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
			retval = mfd_add_hotplug_devices(ec->dev,
					cros_usbpd_notify_cells,
					ARRAY_SIZE(cros_usbpd_notify_cells));
			if (retval)
				dev_err(ec->dev,
					"failed to add PD notify devices: %d\n",
					retval);
		}
	}

	/*
	 * The following subdevices cannot be detected by sending the
	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
	 */
	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
					 ARRAY_SIZE(cros_ec_platform_cells));
	if (retval)
		dev_warn(ec->dev,
			 "failed to add cros-ec platform devices: %d\n",
			 retval);

	/* Check whether this EC instance has a VBC NVRAM */
	node = ec->ec_dev->dev->of_node;
	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
		retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
						ARRAY_SIZE(cros_ec_vbc_cells));
		if (retval)
			dev_warn(ec->dev, "failed to add VBC devices: %d\n",
				 retval);
	}

	return 0;

failed:
	put_device(&ec->class_dev);
	return retval;
}