Depends on the vendor really.
Mali has two different hardware sets and along with that two driver sets.
ARM Mali Utgard(Mali-200,300,400,450) all run one driver and I think the driver is currently at r3p2.
Arm Mali Midgard(Mali-T6xx, Mali-T7xx) all run another driver, which released is r3p0 and not currently available to end users is r4p0.
Qualcomm drivers are shared drivers with hardware specific backends. Qualcomm no longer releases drivers for their their a2xx series, the a3xx and a4xx series share a "backend."
I don't know how Tegra 2/3/4 work in regard to their driver versions, I assume PowerVR has one driver for all PVR5 hardware and a new driver for PVR6, but without and hardware it is hard to tell.
Mali has two different hardware sets and along with that two driver sets.
ARM Mali Utgard(Mali-200,300,400,450) all run one driver and I think the driver is currently at r3p2.
Arm Mali Midgard(Mali-T6xx, Mali-T7xx) all run another driver, which released is r3p0 and not currently available to end users is r4p0.
Qualcomm drivers are shared drivers with hardware specific backends. Qualcomm no longer releases drivers for their their a2xx series, the a3xx and a4xx series share a "backend."
I don't know how Tegra 2/3/4 work in regard to their driver versions, I assume PowerVR has one driver for all PVR5 hardware and a new driver for PVR6, but without and hardware it is hard to tell.