Got some progress, no longer same error still another error but that is I call progress
Key was to move the scull_major = MAJOR(dev); call to after alloc_chrdev_region.
Then the scull_major gets updated with the number 240 from system and subsequent initailization was using that number.
[ 27.725570] scull, world. Build No. 6
[ 27.725615] param_scull_major is an integer: 3
[ 27.725616] 3. dev: 0
[ 27.725847] 4. dev: 251658240
[ 27.725849] acquired major number, result: 0
[ 27.725850] 2. scull_major/minor: 240 0
[ 27.725852] scull_setup_cdev: entered...
[ 27.725854] major minor index: 240 0 0
[ 27.725855] devno: 251658240
[ 27.725857] scull_setup_cdev: entered...
[ 27.725858] major minor index: 240 0 1
[ 27.725859] devno: 251658241
[ 27.725860] scull_setup_cdev: entered...
[ 27.725861] major minor index: 240 0 2
[ 27.725862] devno: 251658242
[ 27.725863] scull_setup_cdev: entered...
[ 27.725864] major minor index: 240 0 3
[ 27.725865] devno: 251658243
root@guyen-Standard-PC-i440FX-PIIX-1996:/git.co/dev-learn/device-drivers/src# ls -l /dev/ | grep scull
lrwxrwxrwx 1 root root 6 Oct 28 23:27 scull -> scull0
crw-rw-r-- 1 root staff 240, 0 Oct 28 23:27 scull0
crw-rw-r-- 1 root staff 240, 1 Oct 28 23:27 scull1
crw-rw-r-- 1 root staff 240, 2 Oct 28 23:27 scull2
crw-rw-r-- 1 root staff 240, 3 Oct 28 23:27 scull3
lrwxrwxrwx 1 root root 10 Oct 28 23:27 scullpipe -> scullpipe0
crw-rw-r-- 1 root staff 240, 4 Oct 28 23:27 scullpipe0
crw-rw-r-- 1 root staff 240, 5 Oct 28 23:27 scullpipe1
crw-rw-r-- 1 root staff 240, 6 Oct 28 23:27 scullpipe2
crw-rw-r-- 1 root staff 240, 7 Oct 28 23:27 scullpipe3
crw-rw-r-- 1 root staff 240, 11 Oct 28 23:27 scullpriv
crw-rw-r-- 1 root staff 240, 8 Oct 28 23:27 scullsingle
crw-rw-r-- 1 root staff 240, 9 Oct 28 23:27 sculluid
crw-rw-r-- 1 root staff 240, 10 Oct 28 23:27 scullwuid
root@guyen-Standard-PC-i440FX-PIIX-1996:/git.co/dev-learn/device-drivers/src# cat /proc/devices | grep scull
240 scull
root@guyen-Standard-PC-i440FX-PIIX-1996:/git.co/dev-learn/device-drivers/src# ls -l > /dev/scull
ls: write error: Invalid argument
root@guyen-Standard-PC-i440FX-PIIX-1996:/git.co/dev-learn/device-drivers/src#