platform/chrome: cros_ec_typec: Defer probe on missing EC parent

If cros_typec_probe is called before EC device is registered,
cros_typec_probe will fail. It may happen when cros-ec-typec.ko is
loaded before EC bus layer module (e.g. cros_ec_lpcs.ko,
cros_ec_spi.ko).

Return -EPROBE_DEFER when cros_typec_probe doesn't get EC device, so
the probe function can be called again after EC device is registered.

Signed-off-by: Tomasz Michalec <[email protected]>
Reviewed-by: Abhishek Pandit-Subedi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Tzung-Bi Shih <[email protected]>

Author: Chimstaz

drivers/platform/chrome/cros_ec_typec.c

@@ -1272,8 +1272,8 @@ static int cros_typec_probe(struct platform_device *pdev)
 
 	typec->ec = dev_get_drvdata(pdev->dev.parent);
 	if (!typec->ec) {
-		dev_err(dev, "couldn't find parent EC device\n");
-		return -ENODEV;
+		dev_warn(dev, "couldn't find parent EC device\n");
+		return -EPROBE_DEFER;
 	}
 
 	platform_set_drvdata(pdev, typec);