[U-Boot] [PATCH v2 06/13] drivers: usb: dwc3: add ti dwc3 peripheral driver with driver model support

[Vignesh R]

Hi Lukasz,

Revisiting this old thread...
On 21-Jun-17 1:39 PM, Lukasz Majewski wrote:
> Hi Vignesh,
[...]
>>>> This is something to consult with Lukasz then.
>>>
>>> And it seems that we are heading to adding "gadget" infrastructure
>>> to DM.....
>>>
>>
>> Yes, U-Boot is moving to DM for good and this has cascading effect.
>> I was actually trying to enable DM_ETH on some TI platforms which
>> forced me to move USB_ETH to DM as well and therefore seems like USB
>> gadget framework needs tweaks to adapt to DM...
> 

Did you get a chance to work on DM conversion of USB gadget framework?
Are there any plans to work on it as such?

> I've sketched following plan for gadget conversion:
> 
> 1. Each u-boot command (dfu, ums, thor and in the future rockchip I
> hope), which uses gadget goes through g_dnl_{register|unregister}, so
> the idea is to add this driver first to DM.
> 
> 2. Afterwards, we could add functions as children of g_dnl.
> 
> This would be easily modeled in Kconfig (to have g_dnl - gadget - menu
> with submenu to chose the USB function - e.g. f_dfu*).
> 
> However, we also need to take care of several UDC (USB device
> controller) drivers including also the "composite" usb layer.
> 
> This would be tougher to do since there are many udc drivers - but it
> should be possible to separate DM's UDC drivers and g_dnl/function
> code. 
> 
> Another problem is that some archs use gadgets (RNDIS?) without g_dnl
> and composite - on top of UDC driver (like musb).....
> 
> For example:
> 
> board/ti/beagle/beagle.c -> board_eth_init()
> 		|
> 	       \|/
> drivers/usb/gadget/ether.c -> usb_eth_initialize()
> [ether.c seems to partially support DM]
> 		|
> 	       \|/
> (also in the ether.c)
> 	_usb_eth_init() in which we loop on
> 	usb_gadget_handle_interrupts()
> 
> 
> From what I see, the ether.c now supports DM and legacy code, so some
> work has been already done for DM....
> 
>>
>>> I will do my best to provide some ideas for this task.....
>>>