1==============================================
2ChipIdea Highspeed Dual Role Controller Driver
3==============================================
4
51. How to test OTG FSM(HNP and SRP)
6-----------------------------------
7
8To show how to demo OTG HNP and SRP functions via sys input files
9with 2 Freescale i.MX6Q sabre SD boards.
10
111.1 How to enable OTG FSM
12-------------------------
13
141.1.1 Select CONFIG_USB_OTG_FSM in menuconfig, rebuild kernel
15^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
16
17Image and modules. If you want to check some internal
18variables for otg fsm, mount debugfs, there are 2 files
19which can show otg fsm variables and some controller registers value::
20
21	cat /sys/kernel/debug/ci_hdrc.0/otg
22	cat /sys/kernel/debug/ci_hdrc.0/registers
23
241.1.2 Add below entries in your dts file for your controller node
25^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
26
27::
28
29	otg-rev = <0x0200>;
30	adp-disable;
31
321.2 Test operations
33-------------------
34
351) Power up 2 Freescale i.MX6Q sabre SD boards with gadget class driver loaded
36   (e.g. g_mass_storage).
37
382) Connect 2 boards with usb cable: one end is micro A plug, the other end
39   is micro B plug.
40
41   The A-device (with micro A plug inserted) should enumerate B-device.
42
433) Role switch
44
45   On B-device::
46
47	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
48
49   B-device should take host role and enumerate A-device.
50
514) A-device switch back to host.
52
53   On B-device::
54
55	echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
56
57   or, by introducing HNP polling, B-Host can know when A-peripheral wishes to
58   be in the host role, so this role switch also can be triggered in
59   A-peripheral side by answering the polling from B-Host. This can be done on
60   A-device::
61
62	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
63
64   A-device should switch back to host and enumerate B-device.
65
665) Remove B-device (unplug micro B plug) and insert again in 10 seconds;
67   A-device should enumerate B-device again.
68
696) Remove B-device (unplug micro B plug) and insert again after 10 seconds;
70   A-device should NOT enumerate B-device.
71
72   if A-device wants to use bus:
73
74   On A-device::
75
76	echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop
77	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
78
79   if B-device wants to use bus:
80
81   On B-device::
82
83	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
84
857) A-device power down the bus.
86
87   On A-device::
88
89	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop
90
91   A-device should disconnect with B-device and power down the bus.
92
938) B-device does data pulse for SRP.
94
95   On B-device::
96
97	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
98
99   A-device should resume usb bus and enumerate B-device.
100
1011.3 Reference document
102----------------------
103"On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification
104July 27, 2012 Revision 2.0 version 1.1a"
105
1062. How to enable USB as system wakeup source
107--------------------------------------------
108Below is the example for how to enable USB as system wakeup source
109on an imx6 platform.
110
1112.1 Enable core's wakeup::
112
113	echo enabled > /sys/bus/platform/devices/ci_hdrc.0/power/wakeup
114
1152.2 Enable glue layer's wakeup::
116
117	echo enabled > /sys/bus/platform/devices/2184000.usb/power/wakeup
118
1192.3 Enable PHY's wakeup (optional)::
120
121	echo enabled > /sys/bus/platform/devices/20c9000.usbphy/power/wakeup
122
1232.4 Enable roothub's wakeup::
124
125	echo enabled > /sys/bus/usb/devices/usb1/power/wakeup
126
1272.5 Enable related device's wakeup::
128
129	echo enabled > /sys/bus/usb/devices/1-1/power/wakeup
130
131If the system has only one usb port, and you want usb wakeup at this port, you
132can use the below script to enable usb wakeup::
133
134	for i in $(find /sys -name wakeup | grep usb);do echo enabled > $i;done;
135