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Diffstat (limited to 'Documentation/usb/chipidea.txt')
| -rw-r--r-- | Documentation/usb/chipidea.txt | 57 |
1 files changed, 24 insertions, 33 deletions
diff --git a/Documentation/usb/chipidea.txt b/Documentation/usb/chipidea.txt index 5b3878cbf070..d0321e027661 100644 --- a/Documentation/usb/chipidea.txt +++ b/Documentation/usb/chipidea.txt @@ -3,16 +3,14 @@ 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 +1.1 How to enable OTG HNP and SRP --------------------------------------- -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 +Pass otg-rev to be 0x0200, remove srp-disable and hnp-disable in dts like below: +dr_mode = "otg"; +otg-rev = <0x0200>; +adp-disable; -1.2 Test operations +1.2 HNP and SRP test operations ------------------- 1) Power up 2 Freescale i.MX6Q sabre SD boards with gadget class driver loaded (e.g. g_mass_storage). @@ -64,12 +62,22 @@ cat /sys/kernel/debug/ci_hdrc.0/registers A-device should resume usb bus and enumrate B-device. -1.3 Reference document +1.3 Enable and test USB OTG ADP +---------------------- +Enable ADP in dts: +1) Based on 1.2, remove adp-disable in dts. + +Test sequence: +1) After A-device ends session(remove B-device and wait 10s, or a_bus_drop) +2) Remove B-device, B-device will show "OTG device detached". +3) Insert B-device, A-device will enumerate B-device. + +1.4 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" -1.4 OTG compliance test +1.5 OTG compliance test ---------------------- Only below 3 popular gadget drivers are declared to be USB OTG and EH 2.0 compliant(with otg descriptor comply with USB OTG and EH 2.0 as a peripheral): @@ -77,29 +85,12 @@ compliant(with otg descriptor comply with USB OTG and EH 2.0 as a peripheral): - ether - serial -1.5 Runtime enable and disable full HNP ---------------------------------------- -One more input file is created: -/sys/bus/platform/devices/ci_hdrc.0/inputs/hnp_enable - -Defaultly USB OTG full HNP(do role switch by SW protocol, no need exchange OTG -plug) is not enabled, user can enable or disable it after disconnect from other -end device by: - echo 1 or 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/hnp_enable -If this input is 0, only OTG role switch by ID pin detection can be supported. - -1.6 Enable and test USB OTG ADP ----------------------- -Enable: -1) Enable OTG FSM as 1.1 -2) Add "adp-support" properity in dts for your hardware - -Test sequence: -1) Connect 2 OTG devices, enable HNP by enable hnp_enable at 2 boards - echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/hnp_enable -2) After A-device ends session(remove B-device and wait 10s, or a_bus_drop) -3) Remove B-device, B-device will show "OTG device detached". -4) Insert B-device, A-device will enumerate B-device. +1.6 Debug +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 2. How to enable USB as system wakeup source ----------------------------------- |