platform/input: cros_ec: Replace -ENOTSUPP with -ENOPROTOOPT

-ENOTSUPP is not a SUSV4 error code and should not be used. Use
-ENOPROTOOPT instead to report EC_RES_INVALID_VERSION responses
from the EC. This matches match the NFS response for unsupported
protocol versions.

Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Cc: Prashant Malani <pmalani@chromium.org>
Cc: Brian Norris <briannorris@chromium.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

drivers/input/keyboard/cros_ec_keyb.c

@@ -348,7 +348,7 @@ static int cros_ec_keyb_info(struct cros_ec_device *ec_dev,
 	params->event_type = event_type;
 
 	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
-	if (ret == -ENOTSUPP) {
+	if (ret == -ENOPROTOOPT) {
 		/* With older ECs we just return 0 for everything */
 		memset(result, 0, result_size);
 		ret = 0;

drivers/platform/chrome/cros_ec_proto.c

@@ -579,7 +579,7 @@ static int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
  *
  * Return:
  * >=0 - The number of bytes transferred
- * -ENOTSUPP - Operation not supported
+ * -ENOPROTOOPT - Operation not supported
  * -EPROTO - Protocol error
  */
 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
@@ -593,7 +593,7 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
 	} else if (msg->result == EC_RES_INVALID_VERSION) {
 		dev_dbg(ec_dev->dev, "Command invalid version (err:%d)\n",
 			msg->result);
-		return -ENOTSUPP;
+		return -ENOPROTOOPT;
 	} else if (msg->result != EC_RES_SUCCESS) {
 		dev_dbg(ec_dev->dev, "Command result (err: %d)\n", msg->result);
 		return -EPROTO;