Server Administration :: How To Get Disk List On Any DB Instance That Uses ASM Instance

My context on our servers is the following one:

- one ASM instance
- X DB instances
- each DB instance uses 2 or more dedicated diskgroups from the ASM instance
- there is one diskgroup named FREEDISK that contains spare disks

On each DB instance you can see:

- the list and global parameters of all diskgroups using v$asm_diskgroup view
- the list and parameters of all disks the instance is using with v$asm_disk view

So my question is: how (if this is possible) to know the list of (spare) disks in FREE DISK disk group?