firmware: microchip: fix UL_IAP lock check in mpfs_auto_update_state()

To verify that Auto Update is possible, the mpfs_auto_update_state()
function performs a "Query Security Service Request" to the system
controller.

Previously, the check was performed on the first element of the
response message, which was accessed using a 32-bit pointer. This
caused the bitwise operation to reference incorrect data, as the
response should be inspected at the byte level. Fixed this by casting
the response to a  u8 * pointer, ensuring the check correctly inspects
the appropriate byte of the response message.

Additionally, rename "UL_Auto Update" to "UL_IAP" to match the
PolarFire Family System Services User Guide.

Signed-off-by: Valentina Fernandez <[email protected]>
Signed-off-by: Conor Dooley <[email protected]>

Author: vfalanis

drivers/firmware/microchip/mpfs-auto-update.c

@@ -402,10 +402,10 @@ static int mpfs_auto_update_available(struct mpfs_auto_update_priv *priv)
 		return -EIO;
 
 	/*
-	 * Bit 5 of byte 1 is "UL_Auto Update" & if it is set, Auto Update is
+	 * Bit 5 of byte 1 is "UL_IAP" & if it is set, Auto Update is
 	 * not possible.
 	 */
-	if (response_msg[1] & AUTO_UPDATE_FEATURE_ENABLED)
+	if ((((u8 *)response_msg)[1] & AUTO_UPDATE_FEATURE_ENABLED))
 		return -EPERM;
 
 	return 0;