linux-phytec-ti

remoteproc/pruss: add support for PRUSS0 on AM437x SoCs

The AM437x SoC has a second smaller PRU-ICSS subsystem (PRUSS0)
in addition to the primary PRUSS1 instance. The PRUSS0 is another
instantiation of the IP, but is not identical to PRUSS1. It is
essentially a cut-down version of the IP, with less DRAM per PRU,
no Shared DRAM etc. It also does not have direct access to L3 bus
regions, there is a single interface to L3 for both PRUSS0 and
PRUSS1, and it would have to go through the PRUSS1's interface.
The PRUSS_SYSCFG register is reserved on PRUSS0, so any external
access requires the programming the corresponding PRUSS_SYSCFG
register in PRUSS1. It does have its own dedicated I/O lines
though. The is managed by the common AM437x PRUSS wrapper module
so that PRUSS1 and PRUSS0 can be independently supported.

The PRUSS remoteproc drivers have been enhanced to support this
smaller PRUSS0 instance using instance-specific data. There is
no PRU Ethernet support for this instance. The reset and the
L3 external access are managed by the common AM437x PRUSS wrapper
module so that PRUSS1 and PRUSS0 can be independently supported.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>