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Documentation: usb: chipidea: Update test procedure for HNP polling
Update HNP test procedure as HNP polling is supported.
Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
authored by
Li Jun
and committed by
Felipe Balbi
dfbae330
75d2f754
+5
-4
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-4
Documentation/usb/chipidea.txt
+5
-4
Documentation/usb/chipidea.txt
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On B-device:
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echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
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if HNP polling is not supported, also need:
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On A-device:
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echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
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B-device should take host role and enumrate A-device.
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4) A-device switch back to host.
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On B-device:
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echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
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or, by introducing HNP polling, B-Host can know when A-peripheral wish
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to be host role, so this role switch also can be trigged in A-peripheral
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side by answering the polling from B-Host, this can be done on A-device:
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echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
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A-device should switch back to host and enumrate B-device.
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