[U-Boot] [PATCH 3/3] rockchip: evb-rv1108: add usb init function for dwc2 gadget

[Simon Glass <sjg@chromium.org>]

Hi,

On 14 August 2017 at 04:05, wlf <wulf@rock-chips.com> wrote:
> Dear Simon,
>
>
> 在 2017年08月14日 05:35, Simon Glass 写道:
>>
>> On 8 August 2017 at 21:36, William Wu <william.wu@rock-chips.com> wrote:
>>>
>>> This patch implements board_usb_init() for dwc2 gadget, it
>>> generally called from do_fastboot to do dwc2 udc probe and
>>> support fastboot over USB.
>>>
>>> Signed-off-by: William Wu <william.wu@rock-chips.com>
>>> ---
>>>   board/rockchip/evb_rv1108/evb_rv1108.c | 47
>>> ++++++++++++++++++++++++++++++++++
>>>   1 file changed, 47 insertions(+)
>>>
>>> diff --git a/board/rockchip/evb_rv1108/evb_rv1108.c
>>> b/board/rockchip/evb_rv1108/evb_rv1108.c
>>> index fe37eac..8ca5ee6 100644
>>> --- a/board/rockchip/evb_rv1108/evb_rv1108.c
>>> +++ b/board/rockchip/evb_rv1108/evb_rv1108.c
>>> @@ -50,3 +50,50 @@ int dram_init_banksize(void)
>>>
>>>          return 0;
>>>   }
>>> +
>>> +#if defined(CONFIG_USB_GADGET) && defined(CONFIG_USB_GADGET_DWC2_OTG)
>>> +#include <usb.h>
>>> +#include <usb/dwc2_udc.h>
>>> +
>>> +static struct dwc2_plat_otg_data rv1108_otg_data = {
>>> +       .rx_fifo_sz     = 512,
>>> +       .np_tx_fifo_sz  = 16,
>>> +       .tx_fifo_sz     = 128,
>>> +};
>>> +
>>> +int board_usb_init(int index, enum usb_init_type init)
>>> +{
>>> +       int node;
>>> +       const char *mode;
>>> +       bool matched = false;
>>> +       const void *blob = gd->fdt_blob;
>>> +
>>> +       /* find the usb_otg node */
>>> +       node = fdt_node_offset_by_compatible(blob, -1,
>>> +                                       "rockchip,rv1108-usb");
>>> +
>>> +       while (node > 0) {
>>> +               mode = fdt_getprop(blob, node, "dr_mode", NULL);
>>> +               if (mode && strcmp(mode, "otg") == 0) {
>>> +                       matched = true;
>>> +                       break;
>>> +               }
>>> +
>>> +               node = fdt_node_offset_by_compatible(blob, node,
>>> +                                       "rockchip,rv1108-usb");
>>> +       }
>>> +       if (!matched) {
>>> +               debug("Not found usb_otg device\n");
>>> +               return -ENODEV;
>>> +       }
>>> +
>>> +       rv1108_otg_data.regs_otg = fdtdec_get_addr(blob, node, "reg");
>>> +
>>> +       return dwc2_udc_probe(&rv1108_otg_data);
>>
>> These USB init things have been bothering me for a while. Do you think
>> this could be changed into a driver that you could probe with
>> device_probe()? Then much of the code in here would not be needed and
>> it might be easier to tidy it up when we have proper driver-model
>> support for USB device mode.
>
> Yes,  on rockchip platforms, it did most of the same USB init things in
> different board special drivers.
> I think may be we can try to optimize the code in two different ways.
>
> Method1.
> 1. Move the USB init things from board_usb_init(), just simply call
> dwc2_udc_probe().
> 2. Create a new USB init  function in drivers/usb/gadget/dwc2_udc_otg.c，
>      and call it in dwc2_udc_probe().
> 3. Use fdt (Flat Device Tree manipulation )  to parse the dts, and get the
> regs_phy, regs_otg and so on.
>
> Method2.
> Just like your  suggestion， use driver-model method to probe with
> device_probe,
> actually, I don't know much about the driver-model, as far as I know, we may
> need
> to do the following work:
> 1. Create a new uclass id for usb udc, and declare a new uclass_driver with
> UCLASS_DRIVER,
>     and also need to create a  new U-boot driver for dwc2 controller with
> U_BOOT_DRIVER.
> 2. How to call device_probe()? Maybe it's better to create a new driver
> (like drivers/usb/host/usb-uclass.c)
>     in drivers/usb/gadget to match different usb gadget controllers, and
> wrap the device_probe()
>     to a new function (like udc_pre_probe()), and then different udc driver
> can call it,
>     e.g.
>     dwc2_udc_probe() --> udc_pre_probe() --> device_probe()
>
> In summary, method1 is easily to be done, but method2 is more generic.
>
> I hope I haven't misunderstood your proposal, and hope to get your reply.
> Thank you!

Yes I think method 2 is better.

You will have to call device_probe() as you say. I think what you
suggest is reasonable, since something has to decide that the USB
device mode should be started.

Regards,
Simon