Hi Chanwoo,
after getting interrupts working on my Samsung Galaxy A5 (2015),
I am now trying to make the extcon device detect USB-HOST=1
when I plug in an USB OTG adapter.
At the moment, the driver can sucessfully detect:
- USB=1 + SDP=1 when I detect the phone to a PC
- DCP=1 when I connect it to an AC charger
but it does not set USB-HOST=1 when I connect the USB OTG adapter.
It seems to be a problem in the sm5502 driver, since I do get an
SM5502_IRQ_INT1_ATTACH interrupt when I plug in the USB OTG adapter.
In this case, SM5502 reports:
SM5502_REG_ADC = 0x00 (SM5502_MUIC_ADC_GROUND)
SM5502_REG_DEV_TYPE1 = 0x80 (SM5502_REG_DEV_TYPE1_USB_OTG_MASK)
However, at the moment the sm5502 driver ignores all attach events with
SM5502_REG_ADC == SM5502_MUIC_ADC_GROUND:
/*
* If ADC is SM5502_MUIC_ADC_GROUND(0x0), external cable hasn't
* connected with to MUIC device.
*/
cable_type = adc & SM5502_REG_ADC_MASK;
if (cable_type == SM5502_MUIC_ADC_GROUND)
return SM5502_MUIC_ADC_GROUND;
However, I definitely have a cable attached in this case...
The sm5502 driver seems to expect SM5502_REG_ADC == SM5502_MUIC_ADC_OPEN.
Any idea why my hardware reports ADC_GROUND for the USB OTG adapter
instead of ADC_OPEN?
Confusingly, the driver used in the original downstream kernel of
the Samsung Galaxy A5 [1] calls ADC = 0x00 "ADC_OTG" instead of
"ADC_GROUND".
So getting ADC = 0x00 may not be entirely unexpected here...
Thanks in advance,
Stephan
[1]:
https://github.com/msm8916-mainline/android_kernel_qcom_msm8916/blob/SM-A500FU/drivers/misc/sm5502.c#L195
