Subject: [PATCH v2 2/7] usb: dwc3: adapt dwc3 core to use Generic PHY Framework

From: [email-masked] (Roger Quadros)
Date: Wed, 16 Oct 2013 16:18:42 +0300

Hi,

On 10/15/2013 10:54 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                        |   52 ++++++++++++++++++++++++
>  drivers/usb/dwc3/core.h                        |    7 ++++
>  drivers/usb/dwc3/platform_data.h               |    2 +
>  5 files changed, 66 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 8e385b4..64eed6f 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -2,6 +2,7 @@ config USB_DWC3
>  	tristate "DesignWare USB3 DRD Core Support"
>  	depends on (USB || USB_GADGET) && HAS_DMA
>  	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 cb91d70..28bfa5b 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);
> +
> +	if (dwc->usb2_generic_phy)
> +		phy_init(dwc->usb2_generic_phy);
> +	if (dwc->usb3_generic_phy)
> +		phy_init(dwc->usb3_generic_phy);
> +

dwc3_core_soft_reset() is called from dwc3_core_init() which is called from
dwc3_probe() but before the PHYs are initialized.

This will cause phy power_on() to be called before phy_init() which is wrong.

>  	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);
> +
> +	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)
> @@ -439,6 +450,26 @@ static int dwc3_probe(struct platform_device *pdev)
>  		dwc->usb3_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB3);
>  	}
>  
> +	count = of_property_match_string(node, "phy-names", "usb2-phy");
> +	if (count >= 0 || (pdata && pdata->usb2_generic_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->usb2_phy = NULL;
> +	}
> +
> +	count = of_property_match_string(node, "phy-names", "usb3-phy");
> +	if (count >= 0 || (pdata && pdata->usb3_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);
> +		}
> +		dwc->usb3_phy = NULL;
> +	}
> +

There are a couple of issues here.
- The above code must be executed only if it node is valid.
- We must either get both PHYs via old method or via new method and not support mix matching
them. e.g. it is possible with this code that usb2_phy is set and usb3_generic_phy is set.
If you give the new method preference then you don't even need to attempt a devm_usb_get_phy()
if the generic phy is present in the node.

>  	/* default to superspeed if no maximum_speed passed */
>  	if (dwc->maximum_speed == USB_SPEED_UNKNOWN)
>  		dwc->maximum_speed = USB_SPEED_SUPER;
> @@ -462,6 +493,11 @@ 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);
> +
>  	spin_lock_init(&dwc->lock);
>  	platform_set_drvdata(pdev, dwc);
>  
> @@ -588,6 +624,11 @@ static int dwc3_remove(struct platform_device *pdev)
>  	usb_phy_set_suspend(dwc->usb2_phy, 1);
>  	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);
>  
> @@ -685,6 +726,11 @@ static int dwc3_suspend(struct device *dev)
>  	usb_phy_shutdown(dwc->usb3_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;
>  }
>  
> @@ -695,6 +741,12 @@ static int dwc3_resume(struct device *dev)
>  
>  	usb_phy_init(dwc->usb3_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;
>  
> diff --git a/drivers/usb/dwc3/platform_data.h b/drivers/usb/dwc3/platform_data.h
> index 49ffa6d..fc62a0f 100644
> --- a/drivers/usb/dwc3/platform_data.h
> +++ b/drivers/usb/dwc3/platform_data.h
> @@ -26,4 +26,6 @@ struct dwc3_platform_data {
>  	bool tx_fifo_resize;
>  	bool usb2_phy;
>  	bool usb3_phy;
> +	bool usb2_generic_phy;
> +	bool usb3_generic_phy;
>  };
> 

cheers,
-roger