Re: [PATCH v1 5/9] of: Add NVIDIA Tegra XHCI controller binding

[Andrew Bresticker]

On Wed, Jun 25, 2014 at 2:52 PM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote:
> On 06/18/2014 12:16 AM, Andrew Bresticker wrote:
>> Add device-tree binding documentation for the XHCI controller present
>> on Tegra124 and later SoCs.
>
>> diff --git a/Documentation/devicetree/bindings/usb/nvidia,tegra124-xhci.txt b/Documentation/devicetree/bindings/usb/nvidia,tegra124-xhci.txt
>
>> +Required properties:
>> +--------------------
>
>> + - clock-names: Must include the following entries:
>> +    - xusb_host
>> +    - xusb_falcon_src
>> +    - xusb_ss
>> +    - xusb_ss_src
>> +    - xusb_hs_src
>> +    - xusb_fs_src
>> +    - pll_u_480m
>> +    - clk_m
>> +    - pll_e
>
>> + - reset-names: Must include the following entries:
>> +   - xusb_host
>> +   - xusb_ss
>
> Usually the CAR has a reset control for each clock. So, I would expect
> as many entries in reset-names as in clock-names. Even if the SW doesn't
> currently touch all the reset lines, we should make sure the binding
> requires them to be present so that any DT will contain the entries if
> they're ever needed in the future.

The xusb_{falcon,host,hs,fs,ss}_src clocks all share the same reset
bit (143), so I can add a single entry for those.

> In the CAR documentation, I see "XUSB_DEV" as a clock/reset bit. Is that
> missing from the list above?

This is used when XUSB is in device mode, which the driver does not
support.  I can add those clocks here though if you want.

>> +Optional properties:
>
>> + - s1p05v-supply: 1.05V supply regulator.
>> + - s1p8v-supply: 1.8V supply regulator.
>> + - s3p3v-supply: 3.3V supply regulator.
>
> What are those supplies for? I would have expected any input to the SoC
> to have a name that described its purpose, and the pins and DT
> properties would be named to match.

I *think* this what they are from looking at the schematic, but I'll
have to ask around:
 - s1p05v: avddio_pex, dvddio_pex, and maybe avdd_pll_erefe
 - s1p8v: avdd_pll_utmip
 - s3p3v: avdd_usb, hvdd_pex, hvdd_pex_pll_e
Should these be separated out as they are for PCIe?
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