Hi Jassi,

On 12/29/2017 08:14 AM, Jassi Brar wrote:

Hi Bjorn,

On Sun, Dec 24, 2017 at 10:36 AM, Bjorn Andersson
[off-list ref] wrote:

quoted

On Fri 22 Dec 20:57 PST 2017, Jassi Brar wrote:

quoted

On Tue, Dec 5, 2017 at 9:16 PM, Georgi Djakov [off-list ref] wrote:

quoted

There is a clock controller functionality provided by the APCS hardware
block of msm8916 devices. The device-tree would represent an APCS node
with both mailbox and clock provider properties.

The spec might depict a 'clock' box and 'mailbox' box inside the
bigger APCS box. However, from the code I see in this patchset, they
are orthogonal and can & should be represented as independent DT
nodes.

The APCS consists of a number of different hardware blocks, one of them
being the "APCS global" block, which is what this node and drivers
relate to. On 8916 this contains both the IPC register and clock
control. But it's still just one block according to the hardware
specification.

As such DT should describe the one hardware block by one node IMHO.

In my even humbler opinion, DT should describe a h/w functional unit
which _could_ be seen as a standalone component.

The APCS is one separate register block related to the CPU cluster. I
haven't seen any strict guidelines for such cases in the DT docs, and
during the discussion got the impression that this is the preferred
binding. Rob has also reviewed the binding, so we should be fine to move
forward with this one.

For example, if this APCS had a mac controller, would we also populate
a netdev from mailbox driver? And what if next revision moves/drops
this clock controller out of APCS, keeping mailbox controller exactly
same?

The clock controller may change in some next SoC architecture and that's
why the SoC version is also part of the the compatible string.

Thanks,
Georgi