platform/chrome: chromeos_laptop - factor out getting IRQ from DMI

This will make code instantiating I2C device a bit clearer.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

drivers/platform/chrome/chromeos_laptop.c

@@ -120,36 +120,47 @@ static struct i2c_board_info atmel_1664s_device = {
 	.flags		= I2C_CLIENT_WAKE,
 };
 
+static int chromeos_laptop_get_irq_from_dmi(const char *dmi_name)
+{
+	const struct dmi_device *dmi_dev;
+	const struct dmi_dev_onboard *dev_data;
+
+	dmi_dev = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, dmi_name, NULL);
+	if (!dmi_dev) {
+		pr_err("failed to find DMI device '%s'\n", dmi_name);
+		return -ENOENT;
+	}
+
+	dev_data = dmi_dev->device_data;
+	if (!dev_data) {
+		pr_err("failed to get data from DMI for '%s'\n", dmi_name);
+		return -EINVAL;
+	}
+
+	return dev_data->instance;
+}
+
 static struct i2c_client *__add_probed_i2c_device(
 		const char *name,
 		int bus,
 		struct i2c_board_info *info,
 		const unsigned short *alt_addr_list)
 {
-	const struct dmi_device *dmi_dev;
-	const struct dmi_dev_onboard *dev_data;
 	struct i2c_adapter *adapter;
 	struct i2c_client *client = NULL;
 	const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
 
 	if (bus < 0)
 		return NULL;
+
 	/*
 	 * If a name is specified, look for irq platform information stashed
 	 * in DMI_DEV_TYPE_DEV_ONBOARD by the Chrome OS custom system firmware.
 	 */
 	if (name) {
-		dmi_dev = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, name, NULL);
-		if (!dmi_dev) {
-			pr_err("failed to dmi find device %s\n", name);
-			return NULL;
-		}
-		dev_data = (struct dmi_dev_onboard *)dmi_dev->device_data;
-		if (!dev_data) {
-			pr_err("failed to get data from dmi for %s\n", name);
+		info->irq = chromeos_laptop_get_irq_from_dmi(name);
+		if (info->irq < 0)
 			return NULL;
-		}
-		info->irq = dev_data->instance;
 	}
 
 	adapter = i2c_get_adapter(bus);