Re: [PATCH v2 2/7] usb: dwc3: adapt dwc3 core to use Generic PHYFramework

From: Roger Quadros
Date: Wed Oct 16 2013 - 09:19:39 EST


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 <kishon@xxxxxx>
> ---
> 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/