Re: [RFC 00/19] dwc3: add USB OTG role switch support

[Robert Baldyga <r.baldyga@samsung.com>]

Hi Chanwoo,

On 03/19/2015 03:33 AM, Chanwoo Choi wrote:
> Hi Robert,
> 
> Did you test the extcon-odroid-otg driver on Odroid-U3?

Yes, I tested it with Odroid U3, U3+, X2, XU3 and it works well.

Best regards,
Robert

> 
> Thanks,
> Chanwoo Choi
> 
> On 03/18/2015 11:04 PM, Robert Baldyga wrote:
>> Hello,
>>
>> This patchset introduces OTG feature in DWC3 DRD driver. This allows
>> to change dynamically between host and peripheral mode depending on
>> detected USB cable type.
>>
>> DWC3 driver behaviour is changed only in situation when selected operation
>> mode (dr_mode) is "otg", and hardware OTG support is available or extended
>> OTG operations are supplied for given platform.
>>
>> It such conditions are fulfilled, none of modes is enabled by default
>> and dwc3 core Best regards,
>> Robert Baldygais being uninitialized. After USB cable detection relevant
>> mode is selected and dwc3 core is initialized. Cable disconnection causes
>> deinitialization of dwc3 core.
>>
>> File otg.c is inspired by code of DWC3 driver from Hardkernel linux
>> sources [1]. I have never tested it on DWC3 version equipped with hardware
>> OTG support, but I belive that this code have chance to work or at least
>> it's easy to fix. I have tested this on OdroidXU3 board which has USB
>> cable detection mechanism based on two gpio pins. I used extcon driver
>> for those feature, which is also attached to following patchset.
>>
>> I consider if ext_otg_ops it the right solution. Current solution is
>> based on Hardkernel sources, but it's very likely that adding extcon
>> support directly to otg.c would be generic enough, as most of cable
>> detection mechanisms can be simply represented by extcon devices.
>>
>> Thanks in advance for your comments.
>>
>> Best regards,
>> Robert Baldyga
>>
>> [1] https://github.com/hardkernel/linux
>>
>> Robert Baldyga (19):
>>   extcon: add extcon-odroid-usbotg driver
>>   dt-bindings: extcon: Add doc for extcon-odroid-usbotg
>>   ARM: dts: exynos5422-odroidxu3: add odroid-usbotg extcon support
>>   dwc3: gadget: add VBUS session handling
>>   dwc3: gadget: enable/disable ep0 in dwc3_gadget_run_stop()
>>   dwc3: gadget: check returned value in suspend/resume
>>   dwc3: core: cleanup suspend/resume code
>>   dwc3: core: handle event buffers in core_init/exit
>>   dwc3: core: make dwc3_core_init/exit non-static
>>   dwc3: add missing OTG register definitions
>>   dwc3: add OTG handling code
>>   dwc3: otg: add ext_otg_ops support
>>   dwc3: gadget: register gadget in OTG core
>>   dwc3: host: don't add XHCI device only if in OTG mode
>>   dwc3: core: initialize OTG in DWC3 core
>>   dwc3: exynos: add software role switching code
>>   ARM: dts: exynos5420: set usb3_lpm_capable in dwc3 controllers
>>   ARM: dts: exynos5420: add snps,dis_u3_susphy_quirk to dwc3 controllers
>>   ARM: dts: exynos5422-odroidxu3: make usbdrd3 extcon client
>>
>>  .../bindings/extcon/extcon-odroid-usbotg.txt       |  16 +
>>  .../devicetree/bindings/usb/exynos-usb.txt         |   4 +
>>  arch/arm/boot/dts/exynos5420.dtsi                  |   6 +
>>  arch/arm/boot/dts/exynos5422-odroidxu3.dts         |  24 +
>>  drivers/extcon/Kconfig                             |   4 +
>>  drivers/extcon/Makefile                            |   1 +
>>  drivers/extcon/extcon-odroid-usbotg.c              | 257 +++++++++
>>  drivers/usb/dwc3/Kconfig                           |   1 +
>>  drivers/usb/dwc3/Makefile                          |   4 +
>>  drivers/usb/dwc3/core.c                            |  66 ++-
>>  drivers/usb/dwc3/core.h                            |  22 +
>>  drivers/usb/dwc3/dwc3-exynos.c                     | 162 ++++++
>>  drivers/usb/dwc3/gadget.c                          | 106 ++--
>>  drivers/usb/dwc3/host.c                            |  10 +-
>>  drivers/usb/dwc3/otg.c                             | 577 +++++++++++++++++++++
>>  drivers/usb/dwc3/otg.h                             | 113 ++++
>>  16 files changed, 1320 insertions(+), 53 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/extcon/extcon-odroid-usbotg.txt
>>  create mode 100644 drivers/extcon/extcon-odroid-usbotg.c
>>  create mode 100644 drivers/usb/dwc3/otg.c
>>  create mode 100644 drivers/usb/dwc3/otg.h
>>
> 
>