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-rw-r--r--Documentation/usb/chipidea.txt101
1 files changed, 69 insertions, 32 deletions
diff --git a/Documentation/usb/chipidea.txt b/Documentation/usb/chipidea.txt
index d1eedc01b00a..68473abe2823 100644
--- a/Documentation/usb/chipidea.txt
+++ b/Documentation/usb/chipidea.txt
@@ -1,22 +1,37 @@
+==============================================
+ChipIdea Highspeed Dual Role Controller Driver
+==============================================
+
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
----------------------------------------
+-------------------------
+
1.1.1 Select CONFIG_USB_OTG_FSM in menuconfig, rebuild kernel
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
Image and modules. If you want to check some internal
variables for otg fsm, mount debugfs, 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
+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
+
1.1.2 Add below entries in your dts file for your controller node
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+::
+
otg-rev = <0x0200>;
adp-disable;
1.2 Test operations
-------------------
+
1) Power up 2 Freescale i.MX6Q sabre SD boards with gadget class driver loaded
(e.g. g_mass_storage).
@@ -26,19 +41,24 @@ cat /sys/kernel/debug/ci_hdrc.0/registers
The A-device(with micro A plug inserted) should enumerate B-device.
3) Role switch
- On B-device:
- echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
+
+ On B-device::
+
+ echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
B-device should take host role and enumerate 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
+
+ On B-device::
+
+ echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
or, by introducing HNP polling, B-Host can know when A-peripheral wish
to be host role, so this role switch also can be trigged in A-peripheral
- side by answering the polling from B-Host, this can be done on A-device:
- echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
+ side by answering the polling from B-Host, this can be done on A-device::
+
+ echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req
A-device should switch back to host and enumerate B-device.
@@ -49,23 +69,31 @@ cat /sys/kernel/debug/ci_hdrc.0/registers
A-device should NOT enumerate 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
+
+ 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
+
+ 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
+
+ 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
+
+ On B-device::
+
+ echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req
A-device should resume usb bus and enumerate B-device.
@@ -75,22 +103,31 @@ cat /sys/kernel/debug/ci_hdrc.0/registers
July 27, 2012 Revision 2.0 version 1.1a"
2. How to enable USB as system wakeup source
------------------------------------
+--------------------------------------------
Below is the example for how to enable USB as system wakeup source
at imx6 platform.
-2.1 Enable core's wakeup
-echo enabled > /sys/bus/platform/devices/ci_hdrc.0/power/wakeup
-2.2 Enable glue layer's wakeup
-echo enabled > /sys/bus/platform/devices/2184000.usb/power/wakeup
-2.3 Enable PHY's wakeup (optional)
-echo enabled > /sys/bus/platform/devices/20c9000.usbphy/power/wakeup
-2.4 Enable roothub's wakeup
-echo enabled > /sys/bus/usb/devices/usb1/power/wakeup
-2.5 Enable related device's wakeup
-echo enabled > /sys/bus/usb/devices/1-1/power/wakeup
+2.1 Enable core's wakeup::
+
+ echo enabled > /sys/bus/platform/devices/ci_hdrc.0/power/wakeup
+
+2.2 Enable glue layer's wakeup::
+
+ echo enabled > /sys/bus/platform/devices/2184000.usb/power/wakeup
+
+2.3 Enable PHY's wakeup (optional)::
+
+ echo enabled > /sys/bus/platform/devices/20c9000.usbphy/power/wakeup
+
+2.4 Enable roothub's wakeup::
+
+ echo enabled > /sys/bus/usb/devices/usb1/power/wakeup
+
+2.5 Enable related device's wakeup::
+
+ echo enabled > /sys/bus/usb/devices/1-1/power/wakeup
If the system has only one usb port, and you want usb wakeup at this port, you
-can use below script to enable usb wakeup.
-for i in $(find /sys -name wakeup | grep usb);do echo enabled > $i;done;
+can use below script to enable usb wakeup::
+ for i in $(find /sys -name wakeup | grep usb);do echo enabled > $i;done;