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 with 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 wish
58   to be host role, so this role switch also can be trigged in A-peripheral
59   side by answering the polling from B-Host, this can be done on A-device::
60
61	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
62
63   A-device should switch back to host and enumerate B-device.
64
655) Remove B-device(unplug micro B plug) and insert again in 10 seconds,
66   A-device should enumerate B-device again.
67
686) Remove B-device(unplug micro B plug) and insert again after 10 seconds,
69   A-device should NOT enumerate B-device.
70
71   if A-device wants to use bus:
72
73   On A-device::
74
75	echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop
76	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
77
78   if B-device wants to use bus:
79
80   On B-device::
81
82	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
83
847) A-device power down the bus.
85
86   On A-device::
87
88	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop
89
90   A-device should disconnect with B-device and power down the bus.
91
928) B-device does data pulse for SRP.
93
94   On B-device::
95
96	echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
97
98   A-device should resume usb bus and enumerate B-device.
99
1001.3 Reference document
101----------------------
102"On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification
103July 27, 2012 Revision 2.0 version 1.1a"
104
1052. How to enable USB as system wakeup source
106--------------------------------------------
107Below is the example for how to enable USB as system wakeup source
108at imx6 platform.
109
1102.1 Enable core's wakeup::
111
112	echo enabled > /sys/bus/platform/devices/ci_hdrc.0/power/wakeup
113
1142.2 Enable glue layer's wakeup::
115
116	echo enabled > /sys/bus/platform/devices/2184000.usb/power/wakeup
117
1182.3 Enable PHY's wakeup (optional)::
119
120	echo enabled > /sys/bus/platform/devices/20c9000.usbphy/power/wakeup
121
1222.4 Enable roothub's wakeup::
123
124	echo enabled > /sys/bus/usb/devices/usb1/power/wakeup
125
1262.5 Enable related device's wakeup::
127
128	echo enabled > /sys/bus/usb/devices/1-1/power/wakeup
129
130If the system has only one usb port, and you want usb wakeup at this port, you
131can use below script to enable usb wakeup::
132
133	for i in $(find /sys -name wakeup | grep usb);do echo enabled > $i;done;
134