Hi Mark,

On Mon, Jun 6, 2016 at 10:29 AM, Mark Rutland [off-list ref] wrote:

On Tue, May 31, 2016 at 06:25:56PM -0700, Tai Tri Nguyen wrote:

quoted

Hi Mark,

[...]

quoted

I'm facing a problem after removing the index for MCU and MC sub-nodes.
The MCUs and MCs aren't always enabled depending on how DRAM DIMMs are
installed on the system.
I still need a way to associate the MCU with its indicator bit in the
enable mask retrieved from CSR.

Ah, I see.

Can you elaborate on how the indicator bits are laid out? From the
example binding, I see multiple nodes with the same index property, so
I'm a little confused.

I guess that there's a CSR per class of node (e.g. all MCBs in one CSR
register)? Or do several nodes share the same bit?

Is there a single CSR register? Are there several? Is that bit index
used in other registers?

In our current XGene platforms, there are 2 MCBs and each MCB has 2 MCs.
   MCB0 --> MC0 and MC1
   MCB1 --> MC2 and MC3
There are 2 CSR are being used (each uses 1 bit) together as indicators:
  CSR1 indicates if both MCBs are active.
  CSR2 indicates if both MCs of the same MCB are active.

This is the true table:
dual MCB      dual MC
0                   0            --> MC0 active
0                   1            --> MC0/MC1 active
1                   0            --> MC0/MC2 active
1                   1            --> MC0/MC1/MC2/MC3 active

At the time the driver initializes, I check the 2 CSRs to come up with
the mcb_active_mask and mc_active_mask.
The index bits are used to compare against the mcb_active_mask/mc_active_mask.

quoted

For MC and MCB nodes only, can I introduce an "enable-mask" field?
For example:
"
pmucmcb at 7e710000 {
        compatible = "apm,xgene-pmu-mcb";
        reg = <0x0 0x7e710000 0x0 0x1000>;
        enable-mask = <0x00000001>;
};

pmucmcb at 7e730000 {
        compatible = "apm,xgene-pmu-mcb";
        reg = <0x0 0x7e730000 0x0 0x1000>;
        enable-mask = <0x00000002>;
};
"
Or can you please give a suggestion how I can fix it?

Assuming it's always a single bit, a *-bit-index property may be fine,
and probably preferable.

Yes, it's always a single bit. I'll use *-bit-index for these sub-nodes.

Thanks,
--
Tai