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

[Vivek Gautam]

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)
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 ?
Because if it is just for musb controller then which usb2-phy will
DWC3 be getting when it requests that type of phy.

As of now phy-samsung-usb3 driver is the interface for both UTMI+ and
PIPE3 phys for DWC3 DRD controller, and phy-samsung-usb2 driver is the
interface
for a separate USB 2.0 controller itself (not DWC3). So we have
something to correct things up for Samsung, since dwc3 initializing
the phy-samsung-usb2 is not a valid scenerio.

Can you please clarify things here ?
Thanks !!

> +
> +               dwc->usb3_generic_phy = devm_phy_get(dev, "usb3-phy");
> +               if (IS_ERR(dwc->usb3_generic_phy)) {
> +                       dev_err(dev, "no usb3 phy configured yet");
> +                       return PTR_ERR(dwc->usb3_generic_phy);
> +               }
> +       } else {
> +               dwc->usb2_generic_phy = NULL;
> +               dwc->usb3_generic_phy = NULL;
> +       }
> +

[...]


-- 
Best Regards
Vivek