[U-Boot] [PATCH] usb: dwc2_udc_otg: support 8-bit interface

[Marek Vasut]

On 06/06/2016 06:50 PM, Steve Rae wrote:
> 
> 
> On Mon, Jun 6, 2016 at 9:30 AM, Marek Vasut <marex at denx.de
> <mailto:marex at denx.de>> wrote:
> 
>     On 06/06/2016 06:15 PM, Steve Rae wrote:
>     > On Mon, Jun 6, 2016 at 8:59 AM, Marek Vasut <marex at denx.de <mailto:marex at denx.de>> wrote:
>     >>
>     >> On 06/06/2016 05:57 PM, Steve Rae wrote:
>     >>> Define CONFIG_USB_GADGET_DWC2_PHY_8_BIT to allow the
>     >>> physical interface to be 8-bit (rather than 16-bit).
>     >>>
>     >>> Signed-off-by: Steve Rae <srae at broadcom.com <mailto:srae at broadcom.com>>
>     >>
>     >> Can this config option be picked from DT rather than hard-coded by some
>     >> new ad-hoc config option ? Also, new options should be Kconfig'd .
>     >>
>     >> Thanks
>     >>
>     >
>     > Marek,
> 
>     Hi,
> 
>     > would this be the correct place to add this Kconfig???
>     > is the wording sufficient?
>     > Thanks, Steve
>     >
>     > diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
>     > index a35a1c7..e957df4 100644
>     > --- a/drivers/usb/gadget/Kconfig
>     > +++ b/drivers/usb/gadget/Kconfig
>     > @@ -45,20 +45,26 @@ config USB_GADGET_ATMEL_USBA
>     >
>     >  config USB_GADGET_DWC2_OTG
>     >         bool "DesignWare USB2.0 HS OTG controller (gadget mode)"
>     >         select USB_GADGET_DUALSPEED
>     >         help
>     >           The Designware USB2.0 high-speed gadget controller
>     >           integrated into many SoCs. Select this option if you want the
>     >           driver to operate in Peripheral mode. This option requires
>     >           USB_GADGET to be enabled.
>     >
>     > +config USB_GADGET_DWC2_PHY_8_BIT
>     > +       bool "DesignWare USB2.0 controller (gadget mode)"
> 
>     This is wrong, right ?
> 
> (see below) 
> 
> 
>     > +       help
>     > +         Set the Designware USB2.0 high-speed gadget controller
>     > +         to 8-bit mode, rather than the default 16-bit mode.
> 
>     You mean 8bit mode ULPI, don't you ?
> 
> (see below) 
> 
> 
>     >  config CI_UDC
>     >         bool "ChipIdea device controller"
>     >         select USB_GADGET_DUALSPEED
>     >         help
>     >           Say Y here to enable device controller functionality of the
>     >           ChipIdea driver.
>     >
>     >  config USB_GADGET_VBUS_DRAW
>     >         int "Maximum VBUS Power usage (2-500 mA)"
>     >         range 2 500
>     >
>     >>
>     >>> ---
>     >>>
>     >>>  drivers/usb/gadget/dwc2_udc_otg.c | 4 ++++
>     >>>  include/configs/bcm28155_ap.h     | 1 +
>     >>>  2 files changed, 5 insertions(+)
>     >>>
>     >>> diff --git a/drivers/usb/gadget/dwc2_udc_otg.c
>     b/drivers/usb/gadget/dwc2_udc_otg.c
>     >>> index cb20b00..a95c8d5 100644
>     >>> --- a/drivers/usb/gadget/dwc2_udc_otg.c
>     >>> +++ b/drivers/usb/gadget/dwc2_udc_otg.c
>     >>> @@ -415,7 +415,11 @@ static void reconfig_usbd(struct dwc2_udc *dev)
>     >>>               |0<<7           /* Ulpi DDR sel*/
>     >>>               |0<<6           /* 0: high speed utmi+, 1: full
>     speed serial*/
>     >>>               |0<<4           /* 0: utmi+, 1:ulpi*/
>     >>> +#ifdef CONFIG_USB_GADGET_DWC2_PHY_8_BIT
>     >>> +             |0<<3           /* phy i/f  0:8bit, 1:16bit*/
>     >>> +#else
>     >>>               |1<<3           /* phy i/f  0:8bit, 1:16bit*/
>     >>> +#endif
>     >>>               |0x7<<0;        /* HS/FS Timeout**/
> 
> 
> Marek,
> The _only_ thing that I know is that this structure contains settings to
> make the USB-OTG interface work on Broadcom boards. Broadcom "hardcoded"
> these values to "utmi+" and "8bit" ("years ago"...), and I am attempting
> to upstream this change (which I think requires a CONFIG option -- so
> that I don't break the current usage; unless there is a better method???)

The best method is to pull such configuration from device tree. I don't
know if DT is used on the BCM28155 chip yet. The acceptable option is to
add the Kconfig option.

> So what this CONFIG is "called" and what is its "explanation" is
> completely unknown to me -- hence, I am asking for help in determining
> what the Kconfig option should actually be....

Something like "DesignWare USB2.0 HS OTG controller PHY interface width"
? The bit which this alters has to be described in the controller
manual, so just call it the same.

btw the Kconfig option should be moved under the DWC2 controller entry,
something like this will do:

if USB_GADGET_DWC2
config USB_GADGET_DWC2_PHY_8_BIT
    .......
endif


> Thanks in advance, Steve
> 
>     >>>
>     >>>       if (dev->pdata->usb_gusbcfg)
>     >>> diff --git a/include/configs/bcm28155_ap.h
>     b/include/configs/bcm28155_ap.h
>     >>> index 889e5db..e04cfbe 100644
>     >>> --- a/include/configs/bcm28155_ap.h
>     >>> +++ b/include/configs/bcm28155_ap.h
>     >>> @@ -134,6 +134,7 @@
>     >>>  #define CONFIG_SYS_CACHELINE_SIZE    64
>     >>>  #define CONFIG_FASTBOOT_BUF_SIZE     (CONFIG_SYS_SDRAM_SIZE -
>     SZ_1M)
>     >>>  #define CONFIG_FASTBOOT_BUF_ADDR     CONFIG_SYS_SDRAM_BASE
>     >>> +#define CONFIG_USB_GADGET_DWC2_PHY_8_BIT
>     >>>  #define CONFIG_USB_GADGET_BCM_UDC_OTG_PHY
>     >>>  #define CONFIG_USBID_ADDR            0x34052c46
>     >>>
>     >>>
>     >>
>     >>
>     >> --
>     >> Best regards,
>     >> Marek Vasut
> 
> 
>     --
>     Best regards,
>     Marek Vasut
> 
> 


-- 
Best regards,
Marek Vasut