Subject: [PATCH v4 2/2] usb: dwc3: adapt dwc3 core to use Generic PHY Framework

From: [email-masked] (Kishon Vijay Abraham I)
Date: Wed, 22 Jan 2014 15:44:31 +0530

On Wednesday 22 January 2014 01:29 PM, Roger Quadros wrote:
> On 01/22/2014 08:04 AM, Vivek Gautam wrote:
>> Hi,
>>
>>
>> On Tue, Jan 21, 2014 at 7:30 PM, Roger Quadros <[email-masked]> wrote:
>>> Hi Kishon,
>>>
>>> On 01/21/2014 12:11 PM, Kishon Vijay Abraham I 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 <[email-masked]>
>>>> ---
>>>> Changes from v3:
>>>> * avoided using quirks
>>>>
>>>>  Documentation/devicetree/bindings/usb/dwc3.txt |    6 ++-
>>>>  drivers/usb/dwc3/core.c                        |   60 ++++++++++++++++++++++++
>>>>  drivers/usb/dwc3/core.h                        |    7 +++
>>>>  3 files changed, 71 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/core.c b/drivers/usb/dwc3/core.c
>>>> index e009d4e..036d589 100644
>>>> --- a/drivers/usb/dwc3/core.c
>>>> +++ b/drivers/usb/dwc3/core.c
>>>> @@ -82,6 +82,11 @@ 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);
>>>
>>> What if phy_init() fails? You need to report and fail. Same applies for all PHY apis in this patch.
>>>
>>>> +     if (dwc->usb3_generic_phy)
>>>> +             phy_init(dwc->usb3_generic_phy);
>>>> +
>>>>       mdelay(100);
>>>>
>>>>       /* Clear USB3 PHY reset */
>>>> @@ -343,6 +348,11 @@ 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_exit(dwc->usb2_generic_phy);
>>>> +     if (dwc->usb3_generic_phy)
>>>> +             phy_exit(dwc->usb3_generic_phy);
>>>> +
>>>>  }
>>>>
>>>>  #define DWC3_ALIGN_MASK              (16 - 1)
>>>> @@ -433,6 +443,32 @@ static int dwc3_probe(struct platform_device *pdev)
>>>>               }
>>>>       }
>>>>
>>>> +     dwc->usb2_generic_phy = devm_phy_get(dev, "usb2-phy");
>>>> +     if (IS_ERR(dwc->usb2_generic_phy)) {
>>>> +             ret = PTR_ERR(dwc->usb2_generic_phy);
>>>> +             if (ret == -ENOSYS || ret == -ENODEV) {
>>>> +                     dwc->usb2_generic_phy = NULL;
>>>> +             } else if (ret == -EPROBE_DEFER) {
>>>> +                     return ret;
>>>> +             } else {
>>>> +                     dev_err(dev, "no usb2 phy configured\n");
>>>> +                     return ret;
>>>> +             }
>>>> +     }
>>>> +
>>>> +     dwc->usb3_generic_phy = devm_phy_get(dev, "usb3-phy");
>>>> +     if (IS_ERR(dwc->usb3_generic_phy)) {
>>>> +             ret = PTR_ERR(dwc->usb3_generic_phy);
>>>> +             if (ret == -ENOSYS || ret == -ENODEV) {
>>>> +                     dwc->usb3_generic_phy = NULL;
>>>> +             } else if (ret == -EPROBE_DEFER) {
>>>> +                     return ret;
>>>> +             } else {
>>>> +                     dev_err(dev, "no usb3 phy configured\n");
>>>> +                     return ret;
>>>> +             }
>>>> +     }
>>>> +
>>>>       dwc->xhci_resources[0].start = res->start;
>>>>       dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
>>>>                                       DWC3_XHCI_REGS_END;
>>>> @@ -482,6 +518,11 @@ static int dwc3_probe(struct platform_device *pdev)
>>>>       usb_phy_set_suspend(dwc->usb2_phy, 0);
>>>>       usb_phy_set_suspend(dwc->usb3_phy, 0);
>>>>
>>>> +     if (dwc->usb2_generic_phy)
>>>> +             phy_power_on(dwc->usb2_generic_phy);
>>>> +     if (dwc->usb3_generic_phy)
>>>> +             phy_power_on(dwc->usb3_generic_phy);
>>>> +
>>>
>>> Is it OK to power on the phy before phy_init()?
>>
>> Isn't phy_init() being done before phy_power_on() in the
>> core_soft_reset() in this patch ?
>> Isn't that what you want here ?
>>
>>>
>>> I suggest to move phy_init() from core_soft_reset() to here, just before phy_power_on().
>>
>> core_soft_reset() is called before phy_power_on() itself from
>> dwc3_core_init(), right ?
>> will moving the phy_inti() here make nay difference ?
> 
> You are right. This part is fine then.

Yeah.. it was fixed in one of the earlier patches which got merged.

commit 3088f1085d1c08f31f02db26796555a66cdf7ca1
Author: Kishon Vijay Abraham I <[email-masked]>
Date:   Mon Nov 25 15:31:21 2013 +0530

    usb: dwc3: invoke phy_resume after phy_init

    usb_phy_set_suspend(phy, 0) is called before usb_phy_init. Fix it.

    Reported-by: Roger Quadros <[email-masked]>
    Signed-off-by: Kishon Vijay Abraham I <[email-masked]>
    Signed-off-by: Felipe Balbi <[email-masked]>

Cheers,
Kishon
> cheers,
> -roger