Re: [PATCH v4 3/4] dt-bindings: phy: Add support for QMP phy

From: Vivek Gautam
Date: Thu Jan 19 2017 - 00:20:52 EST



On 01/19/2017 06:10 AM, Stephen Boyd wrote:
On 01/18, Bjorn Andersson wrote:
On Tue 17 Jan 22:54 PST 2017, Vivek Gautam wrote:
On 01/16/2017 02:19 PM, Kishon Vijay Abraham I wrote:
On Tuesday 10 January 2017 04:21 PM, Vivek Gautam wrote:
[..]
+ reset-names = "phy", "common", "cfg",
+ "lane0", "lane1", "lane2";
Each lane has a separate clock, separate reset.. why not create sub-nodes for
each lane?
Yes, each lane has separate pipe clock and resets.
I can have a binding such as written below.
+1

Does it makes sense to pull in the tx, rx and pcs offsets as well
to the child node, and iomap the entire address space of the phy ?

Note that you don't have to follow the same structure in your device
driver as you describe your hardware in devicetree.

I would suggest that you replace the lane-offset and various lane
specific resources with subnodes, but keep the driver "as is".

Didn't we already move away from subnodes for lanes in an earlier
revision of these patches? I seem to recall we did that because
lanes are not devices and the whole "phy as a bus" concept not
making sense.

Yea, we started out without having any sub-nodes and we
argued that we don't require them since the qmp device is
represented by the qmp node itself.
The lanes otoh are representative of gen_phys and related properties.

In the driver -
"struct qmp_phy " represents the lanes and holds "struct phy",
"struct qcom_qmp" represents the qmp block as a whole and holds "struct device"
Does this make lanes qualify to be childs of qmp ?

"phy as a bus" (just trying to understand here) -
let's say a usb phy controller has one HSIC phy port and one USB2 phy port.
So, should this phy controller be a bus providing two ports (and so we will have
couple of child nodes to the phy controller) ?


Regards
Vivek

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