mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-23 02:54:32 +08:00
ecefae6db0
While there are a mix of things here, most of the stuff were written from Kernel developer's PoV. So, add them to the driver-api book. A follow up for this patch would be to move documents from there that are specific to sysadmins, adding them to the admin-guide. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Johan Hovold <johan@kernel.org> Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
134 lines
3.7 KiB
ReStructuredText
134 lines
3.7 KiB
ReStructuredText
==============================================
|
|
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
|
|
|
|
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).
|
|
|
|
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 enumerate B-device.
|
|
|
|
3) Role switch
|
|
|
|
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
|
|
|
|
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
|
|
|
|
A-device should switch back to host and enumerate B-device.
|
|
|
|
5) Remove B-device(unplug micro B plug) and insert again in 10 seconds,
|
|
A-device should enumerate B-device again.
|
|
|
|
6) Remove B-device(unplug micro B plug) and insert again after 10 seconds,
|
|
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
|
|
|
|
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 enumerate 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"
|
|
|
|
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
|
|
|
|
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;
|