[PATCH 2/7] usb: dwc3: adapt dwc3 core to use Generic PHY Framework

[Vivek Gautam]

On Thu, Sep 12, 2013 at 3:40 PM, Kishon Vijay Abraham I <kishon at ti.com> wrote:
> On Thursday 12 September 2013 02:57 PM, Vivek Gautam wrote:
>> Hi Kishon,
>>
>>
>> On Mon, Sep 2, 2013 at 9:13 PM, Kishon Vijay Abraham I <kishon at ti.com> wrote:
>>> Adapted dwc3 core to use the Generic PHY Framework. So for init, exit,
>>> power_on and power_off the following APIs are used phy_init(), phy_exit(),
>>> phy_power_on() and phy_power_off().
>>>
>>> However using the old USB phy library wont be removed till the PHYs of all
>>> other SoC's using dwc3 core is adapted to the Generic PHY Framework.
>>>
>>> Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
>>> ---
>>>  Documentation/devicetree/bindings/usb/dwc3.txt |    6 ++-
>>>  drivers/usb/dwc3/Kconfig                       |    1 +
>>>  drivers/usb/dwc3/core.c                        |   49 ++++++++++++++++++++++++
>>>  drivers/usb/dwc3/core.h                        |    7 ++++
>>>  4 files changed, 61 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
>>> index e807635..471366d 100644
>>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>>> @@ -6,11 +6,13 @@ Required properties:
>>>   - compatible: must be "snps,dwc3"
>>>   - reg : Address and length of the register set for the device
>>>   - interrupts: Interrupts used by the dwc3 controller.
>>> +
>>> +Optional properties:
>>>   - usb-phy : array of phandle for the PHY device.  The first element
>>>     in the array is expected to be a handle to the USB2/HS PHY and
>>>     the second element is expected to be a handle to the USB3/SS PHY
>>> -
>>> -Optional properties:
>>> + - phys: from the *Generic PHY* bindings
>>> + - phy-names: from the *Generic PHY* bindings
>>>   - tx-fifo-resize: determines if the FIFO *has* to be reallocated.
>>>
>>>  This is usually a subnode to DWC3 glue to which it is connected.
>>> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>>> index cfc16dd..ad7ce83 100644
>>> --- a/drivers/usb/dwc3/Kconfig
>>> +++ b/drivers/usb/dwc3/Kconfig
>>> @@ -3,6 +3,7 @@ config USB_DWC3
>>>         depends on (USB || USB_GADGET) && GENERIC_HARDIRQS && HAS_DMA
>>>         depends on EXTCON
>>>         select USB_PHY
>>> +       select GENERIC_PHY
>>>         select USB_XHCI_PLATFORM if USB_SUPPORT && USB_XHCI_HCD
>>>         help
>>>           Say Y or M here if your system has a Dual Role SuperSpeed
>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>> index 428c29e..485d365 100644
>>> --- a/drivers/usb/dwc3/core.c
>>> +++ b/drivers/usb/dwc3/core.c
>>> @@ -82,6 +82,12 @@ static void dwc3_core_soft_reset(struct dwc3 *dwc)
>>>
>>>         usb_phy_init(dwc->usb2_phy);
>>>         usb_phy_init(dwc->usb3_phy);
>>> +
>>> +       if (dwc->usb2_generic_phy)
>>> +               phy_init(dwc->usb2_generic_phy);
>>> +       if (dwc->usb3_generic_phy)
>>> +               phy_init(dwc->usb3_generic_phy);
>>> +
>>>         mdelay(100);
>>>
>>>         /* Clear USB3 PHY reset */
>>> @@ -343,6 +349,11 @@ static void dwc3_core_exit(struct dwc3 *dwc)
>>>  {
>>>         usb_phy_shutdown(dwc->usb2_phy);
>>>         usb_phy_shutdown(dwc->usb3_phy);
>>> +
>>> +       if (dwc->usb2_generic_phy)
>>> +               phy_power_off(dwc->usb2_generic_phy);
>>> +       if (dwc->usb3_generic_phy)
>>> +               phy_power_off(dwc->usb3_generic_phy);
>>>  }
>>>
>>>  #define DWC3_ALIGN_MASK                (16 - 1)
>>> @@ -427,6 +438,23 @@ static int dwc3_probe(struct platform_device *pdev)
>>>                 dwc->usb3_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB3);
>>>         }
>>>
>>> +       if (of_property_read_bool(node, "phys") || pdata->has_phy) {
>>> +               dwc->usb2_generic_phy = devm_phy_get(dev, "usb2-phy");
>>> +               if (IS_ERR(dwc->usb2_generic_phy)) {
>>> +                       dev_err(dev, "no usb2 phy configured yet");
>>> +                       return PTR_ERR(dwc->usb2_generic_phy);
>>> +               }
>>
>> I have a doubt here.
>> As i can see in the current phy drivers structuring, for OMAP there
>> are two phy drivers :
>> omap phy-omap-usb2 (talking to musb controller)
>
> It talks to dwc3 controller also ;-)

Ok

>
>> and phy-omap-usb3(talking to dwc3 controller).
>>
>> Now dwc3 controller requests both usb2-phy (supported by phy-omap-usb2
>> ?) and usb3-phy (supported by phy-omap-usb3 ?).
>> But phy-omap-usb2 is not the one designated to talk to DWC3
>> controller, then why does still DWC3 want to request usb2-phy, which
>> end of the day will be phy-omap-usb2.
>> May be i am wrong here since i don't have knowledge about OMAP h/w architecture.
>>
>> Is it like phy-omap-usb2 includes UTMI phys for both musb controller
>> as well as dwc3 controller ?
>
> right. It's needed for dwc3 too. The same USB2 PHY IP is used for both MUSB in
> OMAP2+ platforms and DWC3 in OMAP5.

Ok, but on Samsung's exynos5 series of SoCs, the USB2.0 controller has
a separate USB-PHY interface talking to phy-samsung-usb2 driver;
and DWC3 drd controller has separate USB-PHY interface (including both
UTMI+ and PIPE3 control registers) talking to phy-samsung-usb3 driver.
So in this case DWC3 doesn't need phy-samsung-usb2 at all. It's phy is
configured by just phy-samsung-usb3 driver only.
So don't you think DWC3 driver should have the flexibility to have
either (mostly usb3-phy) _or_ both "usb2-phy" and "usb3-phy".
Thereby,in case of Samsung driver, DWC3 will just have "usb3-phy" and
that will be enough to get things working.
Want your opinions about it.


-- 
Best Regards
Vivek