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

From: [email-masked] (Roger Quadros)
Date: Mon, 14 Oct 2013 13:21:29 +0300

+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?

cheers,
-roger