[U-Boot] [PATCH v2 2/4] board: ti: am57xx: Fix USB configuration

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi Roger,

On Monday 16 May 2016 03:19 PM, Roger Quadros wrote:
> On 16/05/16 12:26, Roger Quadros wrote:
>> On 16/05/16 12:06, Roger Quadros wrote:
>>> On 13/05/16 15:45, Marek Vasut wrote:
>>>> On 05/13/2016 02:36 PM, Roger Quadros wrote:
>>>>> Currently CONFIG_USB_DWC3 is not selected so doing a usb start
>>>>> command results in a serious error [1].
>>>>
>>>> Why does this error happen ? That is what should be fixed. Selecting
>>>> some random options seems like papering over a bug.
>>>
>>> Agreed. I was lazy :P.
>>
>> OK. The issue is like this.
>>
>> CONFIG_CMD_USB and CONFIG_USB_XHCI is defined, so usb_init() calls
>> usb_lowlevel_init() in xhci.c which calls xhci_hcd_init in xhci-omap.c which calls
>> board_usb_init().

IIRC, board_usb_init for xhci (omap) is mostly a NOP.
>>
>> But board_usb_init() in am57xx/board.c is defined only if CONFIG_USB_DWC3 is defined
>> and that is missing in am57xx_evm.h leading to the serious error. We're trying to
>> access the IP without turning on the necessary clocks.

clocks are not turned on in board_usb_init() right? The board_usb_init() in
am57xx/board.c is used only for gadget mode.
>>
>> So it looks like we need to define it based on CONFIG_USB_XHCI_OMAP or something else.

right, but before that we might have to cleanup xhci-omap.
>>
>> But then again looking into the future, what if we want only gadget operation?
>> That would not define XHCI, but we still need board_usb_init(). So board_usb_init()
>> should be defined based on CONFIG_CMD_USB=y?
>>
>> What do you suggest?
> 
> But board_usb_init() calls 
> 
>                 ti_usb_phy_uboot_init(&usb_phy1_device);
>                 dwc3_omap_uboot_init(&usb_otg_ss1_glue);
>                 dwc3_uboot_init(&usb_otg_ss1);
> 
> which depend on CONFIG_USB_DWC3_PHY_OMAP, CONFIG_USB_DWC3_OMAP and CONFIG_USB_DWC3
> respectively.

IMO we should cleanup xhci-omap so that all the initializations are done using
ti_usb_phy_uboot_init, dwc3_omap_uboot_init and dwc3_uboot_init. Then modify
dwc3_uboot_init to initialize host or device based on CONFIG_*.

Thanks
Kishon