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SubjectRe: [PATCH v2 0/3] usb: musb: da8xx: Fix few issues
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On 10/27/2016 08:44 PM, David Lechner wrote:
> On 10/27/2016 12:16 PM, David Lechner wrote:
>> On 10/26/2016 05:58 AM, Alexandre Bailon wrote:
>>> Currently, the USB OTG of the da8xx doesn't work.
>>> This series intend to fix them.
>>>
>>> Change in v2:
>>> * Fix the error path da8xx_musb_init()
>>>
>>> Alexandre Bailon (3):
>>> usb: musb: da8xx: Call earlier clk_prepare_enable()
>>> phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround
>>> usb: musb: da8xx: Only execute the OTG workaround when phy in OTG mode
>>>
>>> drivers/phy/phy-da8xx-usb.c | 17 ++++++++++++-----
>>> drivers/usb/musb/da8xx.c | 28 +++++++++++++++++++---------
>>> 2 files changed, 31 insertions(+), 14 deletions(-)
>>>
>>
>> I have found another problem with peripheral mode. When we force
>> peripheral mode, the glue layer currently uses CFGCHIP2 to override the
>> VBUS and ID. This causes it to not be able to detect disconnection
>> because the VBUS is overridden.
How have you found it ? Does it cause any issues ?
I mean I had to enable traces to see that disconnect was not happening.
>>
>> Here is a patch to fix the problem. I have tested this on LEGO
>> MINDSTORMS EV3 (AM1808). This works because the ID pin is internally
>> pulled up on the SoC, so we don't need to override it.
Actually, I'm wonder if that if not related to VBUS sensing.
May be we should set CFGCHIP2_VBDTCTEN in device mode.
>>
>> ---
>>
>> diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
>> index 2bc12a2..33daa3b 100644
>> --- a/drivers/usb/musb/da8xx.c
>> +++ b/drivers/usb/musb/da8xx.c
>> @@ -374,9 +374,7 @@ static int da8xx_musb_set_mode(struct musb *musb, u8
>> musb_mode)
>> case MUSB_HOST: /* Force VBUS valid, ID = 0 */
>> phy_mode = PHY_MODE_USB_HOST;
>> break;
>> - case MUSB_PERIPHERAL: /* Force VBUS valid, ID = 1 */
>> - phy_mode = PHY_MODE_USB_DEVICE;
>> - break;
>> + case MUSB_PERIPHERAL:
>> case MUSB_OTG: /* Don't override the VBUS/ID
>> comparators */
>> phy_mode = PHY_MODE_USB_OTG;
>> break;
>>
>> ---
>>
>> If this works for other SoCs/boards, I think we should make this change.
>> If it doesn't work, we could work around the VBUS problem by polling
>> VBUSSENSE in CFGCHIP2. But, I like the simple solution above better.
>
> I have realized that due to the way my device is wired, I can actually
> use OTG mode and it will behave exactly as peripheral mode because the
> ID pin is not connected. So, maybe this patch is not needed after all.
>
Actually, I'm sure that is related to ID
I have the same issue except the disconnect is called when I use the
OTG mode.

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