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

[Felipe Balbi <balbi@ti.com>]

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On Tue, Oct 15, 2013 at 10:57:16AM +0300, Roger Quadros wrote:
> On 10/15/2013 08:31 AM, Kishon Vijay Abraham I wrote:
> > Hi Roger,
> > 
> > On Monday 14 October 2013 03:51 PM, Roger Quadros wrote:
> >> +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@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);
> >>>>
> >>>> 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?
> > 
> > IIRC, even if the speed is high speed, you still need to power on the USB3 PHY.
> > Or else even high speed mode wasn't working in OMAP5.
> 
> Maybe for OMAP5 we can somehow indicate to dwc3 core code that only 'super-speed' mode
> is supported by the platform. I'm not aware of any OMAP5 platform using the USB port as 'high-speed'.
> 
> So there needs to be some mechanism for dwc3-<platform>.c to indicate
> to dwc3-core.c the speeds supported by the platform. e.g. via
> of_dev_auxdata through of_platform_populate()?

that's not the problem. We can temm dwc3 core that dwc3-omap supports
full, high and super speeds, but nothing prevents the user from passing
speed = highspeed on their DTS right ? Even for OMAP5. Now comes the
question, do we assume that's a broken DTB and don't support it ? Or do
we require nop xceiv for highspeed-only implementations ?

If you think of it, not wiring the superspeed side of a *superspeed*
controller is quite an abomination :-)

cheers

-- 
balbi

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