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

From: Kishon Vijay Abraham I
Date: Wed Oct 16 2013 - 09:53:17 EST


Hi,

On Wednesday 16 October 2013 06:48 PM, Roger Quadros wrote:
> 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.

of_property_match_string will give a error value if the node is not present.
*count >= 0* can take care of this.
> - 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.

Why? As long as both the frameworks co-exist (and we support both in dwc3), I
don't see any reason why we shouldn't allow it. We can avoid adding a few more
checks by leaving it the way it is currently.

Thanks
Kishon
--
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/