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

From: [email-masked] (Felipe Balbi)
Date: Tue, 15 Oct 2013 06:57:41 -0500

Hi,

On Mon, Oct 14, 2013 at 01:21:29PM +0300, 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 <[email-masked]>
> >>> ---
> >>>  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?

on OMAP5 we cannot skip USB3 PHY initialization. But then it becomes a
question of supporting a test feature (in OMAP5 case it would be cool to
force controller to lower speeds for testing) or coping with a broken
DTS.

-- 
balbi
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