I am uncircumcised. my foreskin towards the top is dry and cracked. i have been using bar soap lately. can this be the reason? should i use lotion

No soap penis: You should not use soap to clean under your foreskin. Warm water is the most commonly recommended way to clean yourself there.

Do U have phimosis?: You should be able to use soap if your foreskin is nice & loose & retracts easily. Most common cause for foreskin to crack is because it is tight (phimosis) causing you to develop small splits in it. Unfortunately these splits/cracks tend to scar & circumcision becomes necessary because steroid cream can not loosen a scarred phimotic foreskin. Suggest you see a urologist if problem continues.