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Old 08-23-2018, 01:17 PM   #1
vivin_28
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Registered: Nov 2017
Location: india
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USB dr_mode understanding


Hi,

How to confirm the configured USB otg dr_mode option in dts is correctly fixed or not?

I am getting following value for dr_mode = "peripheral" in the dts for usbotg1 and 2.

# cat /sys/bus/platform/devices/ci_hdrc.0/udc/ci_hdrc.0/is_a_peripheral
0
# cat /sys/bus/platform/devices/ci_hdrc.0/udc/ci_hdrc.0/is_otg
1

Configuring dr_mode = "host" in the dts also resulting is_a_peripheral=0 and is_otg=1.

Or Can I check the following entry?
$cat /sys/firmware/devicetree/base/soc/aips-bus@02100000/usb@02184200/dr_mode

If you aware of any better option, please let me know. Please explain what it means is_a_peripheral=0 and is_otg=1?

Thanks.
 
Old 08-24-2018, 03:40 AM   #2
vivin_28
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Registered: Nov 2017
Location: india
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Hi,

Anyone have any suggestion on this?

Thanks.
 
Old 08-24-2018, 09:38 AM   #3
vivin_28
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Registered: Nov 2017
Location: india
Posts: 8

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I can read the current dr_mode value on a running target, by executing the following command:

# cat /sys/firmware/devicetree/base/soc/aips-bus@02100000/usb@02184600/dr_mode

But still looking for other option and explanation for s_a_peripheral=0 and is_otg=1 value?

Thanks.
 
  


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device driver, device tree, kernel 4.1, usb


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