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

[Kishon Vijay Abraham I <kishon@ti.com>]

On Thursday 12 September 2013 03:57 PM, Vivek Gautam wrote:
> On Thu, Sep 12, 2013 at 3:40 PM, Kishon Vijay Abraham I <kishon@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@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@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.

Should we have separate properties to indicate whether it has a usb2-phy or
usb3-phy instead of checking for *phys* property?

Thanks
Kishon