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