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72 lines
2.3 KiB
Plaintext
72 lines
2.3 KiB
Plaintext
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1. How to test OTG FSM(HNP and SRP)
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-----------------------------------
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To show how to demo OTG HNP and SRP functions via sys input files
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with 2 Freescale i.MX6Q sabre SD boards.
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1.1 How to enable OTG FSM in menuconfig
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---------------------------------------
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Select CONFIG_USB_OTG_FSM.
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If you want to check some internal variables for otg fsm,
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select CONFIG_USB_CHIPIDEA_DEBUG, there are 2 files which
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can show otg fsm variables and some controller registers value:
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cat /sys/kernel/debug/ci_hdrc.0/otg
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cat /sys/kernel/debug/ci_hdrc.0/registers
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1.2 Test operations
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-------------------
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1) Power up 2 Freescale i.MX6Q sabre SD boards with gadget class driver loaded
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(e.g. g_mass_storage).
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2) Connect 2 boards with usb cable with one end is micro A plug, the other end
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is micro B plug.
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The A-device(with micro A plug inserted) should enumrate B-device.
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3) Role switch
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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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A-device should switch back to host and enumrate B-device.
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5) Remove B-device(unplug micro B plug) and insert again in 10 seconds,
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A-device should enumrate B-device again.
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6) Remove B-device(unplug micro B plug) and insert again after 10 seconds,
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A-device should NOT enumrate B-device.
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if A-device wants to use bus:
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On A-device:
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echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop
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echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
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if B-device wants to use bus:
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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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7) A-device power down the bus.
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On A-device:
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echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop
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A-device should disconnect with B-device and power down the bus.
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8) B-device does data pulse for SRP.
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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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A-device should resume usb bus and enumrate B-device.
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1.3 Reference document
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----------------------
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"On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification
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July 27, 2012 Revision 2.0 version 1.1a"
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