[U-Boot] [PATCH v5 4/6] mvebu: usb: xhci: Add VBUS regulator supply to the host driver

[Konstantin Porotchkin]

On 02/09/2017 07:24 PM, Marek Vasut wrote:
> On 02/09/2017 05:43 PM, Konstantin Porotchkin wrote:
>>
>> On 02/09/2017 06:15 PM, Marek Vasut wrote:
>>> On 02/09/2017 04:54 PM, Konstantin Porotchkin wrote:
>>>>
>>>> On 02/09/2017 05:36 PM, Marek Vasut wrote:
>>>>> On 02/09/2017 04:30 PM, Konstantin Porotchkin wrote:
>>>>>>
>>>>>>
>>>>>> On 02/09/2017 03:37 PM, Marek Vasut wrote:
>>>>>>> On 02/09/2017 12:32 PM, kostap at marvell.com wrote:
>>>>>>>> From: Konstantin Porotchkin <kostap at marvell.com>
>>>>>>>>
>>>>>>>> The USB device should linked to VBUS regulator through
>>> "vbus-supply"
>>>>>>>> DTS property.
>>>>>>>> This patch adds handling for "vbus-supply" property inside the USB
>>>>>>>> device entry for turning on the VBUS regulator upon the host
>>> adapter
>>>>>>>> probe.
>>>>>>>>
>>>>>>>> Signed-off-by: Konstantin Porotchkin <kostap at marvell.com>
>>>>>>>> Cc: Stefan Roese <sr at denx.de>
>>>>>>>> Cc: Marek Vasut <marex at denx.de>
>>>>>>>> Cc: Nadav Haklai <nadavh at marvell.com>
>>>>>>>> Cc: Neta Zur Hershkovits <neta at marvell.com>
>>>>>>>> Cc: Igal Liberman <igall at marvell.com>
>>>>>>>> Cc: Haim Boot <hayim at marvell.com>
>>>>>>>> ---
>>>>>>>> Changes for v5:
>>>>>>>> - Extended clocks description in documentation
>>>>>>>> - Removed print for regulator not found case
>>>>>>>>
>>>>>>>>  doc/device-tree-bindings/usb/marvell.xhci-usb.txt | 29
>>>>>>>> +++++++++++++++++++++++
>>>>>>>>  drivers/usb/host/Kconfig                          |  1 +
>>>>>>>>  drivers/usb/host/xhci-mvebu.c                     | 13 +++++++++-
>>>>>>>>  3 files changed, 42 insertions(+), 1 deletion(-)
>>>>>>>>  create mode 100644
>>> doc/device-tree-bindings/usb/marvell.xhci-usb.txt
>>>>>>>>
>>>>>>>> diff --git a/doc/device-tree-bindings/usb/marvell.xhci-usb.txt
>>>>>>>> b/doc/device-tree-bindings/usb/marvell.xhci-usb.txt
>>>>>>>> new file mode 100644
>>>>>>>> index 0000000..6cc370c
>>>>>>>> --- /dev/null
>>>>>>>> +++ b/doc/device-tree-bindings/usb/marvell.xhci-usb.txt
>>>>>>>> @@ -0,0 +1,29 @@
>>>>>>>> +Marvell SOC USB controllers
>>>>>>>> +
>>>>>>>> +This controller is integrated in Armada 3700/8K.
>>>>>>>> +It uses the same properties as a generic XHCI host controller
>>>>>>>> +
>>>>>>>> +Required properties :
>>>>>>>> + - compatible: should be one or more of:
>>>>>>>> +   - "marvell,armada3700-xhci", "generic-xhci" for Armada 37xx
>>> SoCs
>>>>>>>> +   - "marvell,armada-8k-xhci", "generic-xhci" for Armada A8K SoCs
>>>>>>>> + - reg: should contain address and length of the standard XHCI
>>>>>>>> +   register set for the device.
>>>>>>>> + - interrupts: one XHCI interrupt should be described here.
>>>>>>>> +
>>>>>>>> +Optional properties:
>>>>>>>> + - clocks: reference to a platform clocks that should be
>>>>>>>> enabled/configured
>>>>>>>> +   upon interface initialization. May not exist on all platforms.
>>>>>>>
>>>>>>> This is probably block clock then ?
>>>>>>>
>>>>>>> Otherwise,
>>>>>>> Acked-by: Marek Vasut <marex at denx.de>
>>>>>> Otherwise the the internal SoC clock does not require
>>> gating/muxing or
>>>>>> any other configuration for making this USB host adapter running.
>>>>>> Not sure if I understood your question well.
>>>>>
>>>>> Well,  do these clock drive the USB block or do they drive the
>>> register
>>>>> interface or what ?
>>>> This entry is generic and applicable to all XHCI controllers, so it is
>>>> hard to answer your question.  It supposes to be a clock that drives
>>> the
>>>> data transfer. It can be directly connected to the internal clock
>>>> generator and divider or pass though an additional gate/mux. In the
>>> last
>>>> case it can be inhibited or redirected.
>>>
>>> So it's a PHY clock then ? Or XHCI block clock ?
>>>
>>> marvell.xhci-usb.txt probably doesn't contain generic stuff, but marvell
>>> XHCI implementation specific stuff, right ?
>> No, in this particular case this entry is generic. That is why I
>> proposed to remove it in the past.
>> For the purpose of mvebu XHCI driver this entry is not required.
>> In general and in Marvell case particularly, every unit is driven by
>> some kind of internal clock.
>
> And those internal clock can never ever be gated ? That's some odd
> design, I would not expect that on an advanced ARM chip ... I guess
> marvell is not power conscious ? :) The example contradicts what you
> just said though, it points into some clock module ...
Yes, it can be gated. It is a gated clock coming from system controller.
This XHCI driver supports two different SoC families, so the real clock 
names may vary.
Please help me to understand what is missing in this description?
Should I add "this clock is a gated unit clock driven by system 
controller" to th description?
Should I drop this description file and submit it in a separate patch?
>
>