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

From: Roger Quadros
Date: Mon Oct 14 2013 - 06:22:29 EST


+Vivek

On 10/14/2013 12:26 PM, Kishon Vijay Abraham I wrote:
> Hi Roger,
>
> On Friday 11 October 2013 08:39 PM, Roger Quadros wrote:
>> Hi,
>>
>> On 09/02/2013 06:43 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 <kishon@xxxxxx>
>>> ---
>>> 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);
>>
>> How about adding
>> + if (dwc->usb2_phy)
>> + usb_phy_init(dwc->usb2_phy);
>> + if (dwc->usb3_phy)
>> + usb_phy_init(dwc->usb3_phy);
>
> Thankfully that usb_phy_init will check if phy is NULL.
>>
>> both usb phy and generic phy shouldn't be present together.
>
> ok.
>>
>>> +
>>> + 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);
>>
>> here as well
>>
>>> +
>>> + 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);
>>> + }
>>> +
>>> + 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);
>>> + }
>>
>> better to add
>> + /* Don't use USB PHY if generic PHY was found */
>> + dwc->usb2_phy = dwc->usb3_phy = NULL;
>
> ok.
>>
>>> + } else {
>>
>> not required as we've used kzalloc for dwc.
>>
>>> + dwc->usb2_generic_phy = NULL;
>>> + dwc->usb3_generic_phy = NULL;
>>> + }
>>> +
>>> /* default to superspeed if no maximum_speed passed */
>>> if (dwc->maximum_speed == USB_SPEED_UNKNOWN)
>>> dwc->maximum_speed = USB_SPEED_SUPER;
>>> @@ -450,6 +478,11 @@ static int dwc3_probe(struct platform_device *pdev)
>>
>> if (dwc->usb2_phy)
>>
>>> usb_phy_set_suspend(dwc->usb2_phy, 0);
>>
>> if (dwc->usb3_phy)
>>
>>> 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);
>>> +
>>> spin_lock_init(&dwc->lock);
>>> platform_set_drvdata(pdev, dwc);
>>>
>>> @@ -576,6 +609,11 @@ static int dwc3_remove(struct platform_device *pdev)
>>
>> if (dwc->usb2_phy)
>>> usb_phy_set_suspend(dwc->usb2_phy, 1);
>>
>> if (dwc->usb3_phy)
>>> usb_phy_set_suspend(dwc->usb3_phy, 1);
>>>
>>> + if (dwc->usb2_generic_phy)
>>> + phy_power_off(dwc->usb2_generic_phy);
>>> + if (dwc->usb3_generic_phy)
>>> + phy_power_off(dwc->usb3_generic_phy);
>>> +
>>> pm_runtime_put(&pdev->dev);
>>> pm_runtime_disable(&pdev->dev);
>>>
>>> @@ -673,6 +711,11 @@ static int dwc3_suspend(struct device *dev)
>>
>> if (dwc->usb3_phy)
>>> usb_phy_shutdown(dwc->usb3_phy);
>>
>> if (dwc->usb2_phy)
>>> usb_phy_shutdown(dwc->usb2_phy);
>>>
>>> + if (dwc->usb2_generic_phy)
>>> + phy_exit(dwc->usb2_generic_phy);
>>> + if (dwc->usb3_generic_phy)
>>> + phy_exit(dwc->usb3_generic_phy);
>>> +
>>> return 0;
>>> }
>>>
>>> @@ -683,6 +726,12 @@ static int dwc3_resume(struct device *dev)
>>>
>>
>> if (dwc->usb3_phy)
>>> usb_phy_init(dwc->usb3_phy);
>>
>> if (dwc->usb2_phy)
>>> usb_phy_init(dwc->usb2_phy);
>>> +
>>> + if (dwc->usb2_generic_phy)
>>> + phy_init(dwc->usb2_generic_phy);
>>> + if (dwc->usb3_generic_phy)
>>> + phy_init(dwc->usb3_generic_phy);
>>> +
>>> msleep(100);
>>>
>>> spin_lock_irqsave(&dwc->lock, flags);
>>> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
>>> index f8af8d4..01ec7d7 100644
>>> --- a/drivers/usb/dwc3/core.h
>>> +++ b/drivers/usb/dwc3/core.h
>>> @@ -31,6 +31,8 @@
>>> #include <linux/usb/gadget.h>
>>> #include <linux/usb/otg.h>
>>>
>>> +#include <linux/phy/phy.h>
>>> +
>>> /* Global constants */
>>> #define DWC3_EP0_BOUNCE_SIZE 512
>>> #define DWC3_ENDPOINTS_NUM 32
>>> @@ -613,6 +615,8 @@ struct dwc3_scratchpad_array {
>>> * @dr_mode: requested mode of operation
>>> * @usb2_phy: pointer to USB2 PHY
>>> * @usb3_phy: pointer to USB3 PHY
>>> + * @usb2_generic_phy: pointer to USB2 PHY
>>> + * @usb3_generic_phy: pointer to USB3 PHY
>>> * @dcfg: saved contents of DCFG register
>>> * @gctl: saved contents of GCTL register
>>> * @is_selfpowered: true when we are selfpowered
>>> @@ -665,6 +669,9 @@ struct dwc3 {
>>> struct usb_phy *usb2_phy;
>>> struct usb_phy *usb3_phy;
>>>
>>> + struct phy *usb2_generic_phy;
>>> + struct phy *usb3_generic_phy;
>>> +
>>> void __iomem *regs;
>>> size_t regs_size;
>>>
>>>
>
> Do you have any suggestions on how to get only individual PHYs? like only
> usb2phy or usb3phy?

My earlier understanding was that both PHYs are needed only if .speed is "super-speed"
and only usb2phy is needed for "high-speed". But as per Vivek's email it seems
Samsung's exynos5 SoC doesn't need usb2phy for "super-speed".

So to keeps things flexible, I can propose the following approach
- if speed == 'high-speed' usb2phy must be present. usb3phy will be ignored if supplied.
- if speed == 'super-speed' usb3phy must be present and usb2phy is optional but must be
initialized if supplied.
- if speed is not specified, we default to 'super-speed'.

Felipe, does this address the issue you were facing with OMAP5?

cheers,
-roger
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