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-rw-r--r--Documentation/usb/gadget-testing.txt611
1 files changed, 363 insertions, 248 deletions
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt
index 5908a21fddb6..7d7f2340af42 100644
--- a/Documentation/usb/gadget-testing.txt
+++ b/Documentation/usb/gadget-testing.txt
@@ -1,26 +1,32 @@
+==============
+Gadget Testing
+==============
+
This file summarizes information on basic testing of USB functions
provided by gadgets.
-1. ACM function
-2. ECM function
-3. ECM subset function
-4. EEM function
-5. FFS function
-6. HID function
-7. LOOPBACK function
-8. MASS STORAGE function
-9. MIDI function
-10. NCM function
-11. OBEX function
-12. PHONET function
-13. RNDIS function
-14. SERIAL function
-15. SOURCESINK function
-16. UAC1 function (legacy implementation)
-17. UAC2 function
-18. UVC function
-19. PRINTER function
-20. UAC1 function (new API)
+.. contents
+
+ 1. ACM function
+ 2. ECM function
+ 3. ECM subset function
+ 4. EEM function
+ 5. FFS function
+ 6. HID function
+ 7. LOOPBACK function
+ 8. MASS STORAGE function
+ 9. MIDI function
+ 10. NCM function
+ 11. OBEX function
+ 12. PHONET function
+ 13. RNDIS function
+ 14. SERIAL function
+ 15. SOURCESINK function
+ 16. UAC1 function (legacy implementation)
+ 17. UAC2 function
+ 18. UVC function
+ 19. PRINTER function
+ 20. UAC1 function (new API)
1. ACM function
@@ -44,13 +50,23 @@ There can be at most 4 ACM/generic serial/OBEX ports in the system.
Testing the ACM function
------------------------
-On the host: cat > /dev/ttyACM<X>
-On the device : cat /dev/ttyGS<Y>
+On the host::
+
+ cat > /dev/ttyACM<X>
+
+On the device::
+
+ cat /dev/ttyGS<Y>
then the other way round
-On the device: cat > /dev/ttyGS<Y>
-On the host: cat /dev/ttyACM<X>
+On the device::
+
+ cat > /dev/ttyGS<Y>
+
+On the host::
+
+ cat /dev/ttyACM<X>
2. ECM function
===============
@@ -63,13 +79,15 @@ Function-specific configfs interface
The function name to use when creating the function directory is "ecm".
The ECM function provides these attributes in its function directory:
- ifname - network device interface name associated with this
+ =============== ==================================================
+ ifname network device interface name associated with this
function instance
- qmult - queue length multiplier for high and super speed
- host_addr - MAC address of host's end of this
+ qmult queue length multiplier for high and super speed
+ host_addr MAC address of host's end of this
Ethernet over USB link
- dev_addr - MAC address of device's end of this
+ dev_addr MAC address of device's end of this
Ethernet over USB link
+ =============== ==================================================
and after creating the functions/ecm.<instance name> they contain default
values: qmult is 5, dev_addr and host_addr are randomly selected.
@@ -82,8 +100,13 @@ Testing the ECM function
Configure IP addresses of the device and the host. Then:
-On the device: ping <host's IP>
-On the host: ping <device's IP>
+On the device::
+
+ ping <host's IP>
+
+On the host::
+
+ ping <device's IP>
3. ECM subset function
======================
@@ -96,13 +119,15 @@ Function-specific configfs interface
The function name to use when creating the function directory is "geth".
The ECM subset function provides these attributes in its function directory:
- ifname - network device interface name associated with this
+ =============== ==================================================
+ ifname network device interface name associated with this
function instance
- qmult - queue length multiplier for high and super speed
- host_addr - MAC address of host's end of this
+ qmult queue length multiplier for high and super speed
+ host_addr MAC address of host's end of this
Ethernet over USB link
- dev_addr - MAC address of device's end of this
+ dev_addr MAC address of device's end of this
Ethernet over USB link
+ =============== ==================================================
and after creating the functions/ecm.<instance name> they contain default
values: qmult is 5, dev_addr and host_addr are randomly selected.
@@ -115,8 +140,13 @@ Testing the ECM subset function
Configure IP addresses of the device and the host. Then:
-On the device: ping <host's IP>
-On the host: ping <device's IP>
+On the device::
+
+ ping <host's IP>
+
+On the host::
+
+ ping <device's IP>
4. EEM function
===============
@@ -129,13 +159,15 @@ Function-specific configfs interface
The function name to use when creating the function directory is "eem".
The EEM function provides these attributes in its function directory:
- ifname - network device interface name associated with this
+ =============== ==================================================
+ ifname network device interface name associated with this
function instance
- qmult - queue length multiplier for high and super speed
- host_addr - MAC address of host's end of this
+ qmult queue length multiplier for high and super speed
+ host_addr MAC address of host's end of this
Ethernet over USB link
- dev_addr - MAC address of device's end of this
+ dev_addr MAC address of device's end of this
Ethernet over USB link
+ =============== ==================================================
and after creating the functions/eem.<instance name> they contain default
values: qmult is 5, dev_addr and host_addr are randomly selected.
@@ -148,8 +180,13 @@ Testing the EEM function
Configure IP addresses of the device and the host. Then:
-On the device: ping <host's IP>
-On the host: ping <device's IP>
+On the device::
+
+ ping <host's IP>
+
+On the host::
+
+ ping <device's IP>
5. FFS function
===============
@@ -172,6 +209,7 @@ Testing the FFS function
------------------------
On the device: start the function's userspace daemon, enable the gadget
+
On the host: use the USB function provided by the device
6. HID function
@@ -185,39 +223,43 @@ Function-specific configfs interface
The function name to use when creating the function directory is "hid".
The HID function provides these attributes in its function directory:
- protocol - HID protocol to use
- report_desc - data to be used in HID reports, except data
+ =============== ===========================================
+ protocol HID protocol to use
+ report_desc data to be used in HID reports, except data
passed with /dev/hidg<X>
- report_length - HID report length
- subclass - HID subclass to use
+ report_length HID report length
+ subclass HID subclass to use
+ =============== ===========================================
For a keyboard the protocol and the subclass are 1, the report_length is 8,
-while the report_desc is:
+while the report_desc is::
-$ hd my_report_desc
-00000000 05 01 09 06 a1 01 05 07 19 e0 29 e7 15 00 25 01 |..........)...%.|
-00000010 75 01 95 08 81 02 95 01 75 08 81 03 95 05 75 01 |u.......u.....u.|
-00000020 05 08 19 01 29 05 91 02 95 01 75 03 91 03 95 06 |....).....u.....|
-00000030 75 08 15 00 25 65 05 07 19 00 29 65 81 00 c0 |u...%e....)e...|
-0000003f
+ $ hd my_report_desc
+ 00000000 05 01 09 06 a1 01 05 07 19 e0 29 e7 15 00 25 01 |..........)...%.|
+ 00000010 75 01 95 08 81 02 95 01 75 08 81 03 95 05 75 01 |u.......u.....u.|
+ 00000020 05 08 19 01 29 05 91 02 95 01 75 03 91 03 95 06 |....).....u.....|
+ 00000030 75 08 15 00 25 65 05 07 19 00 29 65 81 00 c0 |u...%e....)e...|
+ 0000003f
-Such a sequence of bytes can be stored to the attribute with echo:
+Such a sequence of bytes can be stored to the attribute with echo::
-$ echo -ne \\x05\\x01\\x09\\x06\\xa1.....
+ $ echo -ne \\x05\\x01\\x09\\x06\\xa1.....
Testing the HID function
------------------------
Device:
+
- create the gadget
- connect the gadget to a host, preferably not the one used
-to control the gadget
+ to control the gadget
- run a program which writes to /dev/hidg<N>, e.g.
-a userspace program found in Documentation/usb/gadget_hid.txt:
+ a userspace program found in Documentation/usb/gadget_hid.txt::
-$ ./hid_gadget_test /dev/hidg0 keyboard
+ $ ./hid_gadget_test /dev/hidg0 keyboard
Host:
+
- observe the keystrokes from the gadget
7. LOOPBACK function
@@ -231,13 +273,16 @@ Function-specific configfs interface
The function name to use when creating the function directory is "Loopback".
The LOOPBACK function provides these attributes in its function directory:
- qlen - depth of loopback queue
- bulk_buflen - buffer length
+ =============== =======================
+ qlen depth of loopback queue
+ bulk_buflen buffer length
+ =============== =======================
Testing the LOOPBACK function
-----------------------------
device: run the gadget
+
host: test-usb (tools/usb/testusb.c)
8. MASS STORAGE function
@@ -252,18 +297,20 @@ The function name to use when creating the function directory is "mass_storage".
The MASS STORAGE function provides these attributes in its directory:
files:
- stall - Set to permit function to halt bulk endpoints.
+ =============== ==============================================
+ stall Set to permit function to halt bulk endpoints.
Disabled on some USB devices known not to work
correctly. You should set it to true.
- num_buffers - Number of pipeline buffers. Valid numbers
+ num_buffers Number of pipeline buffers. Valid numbers
are 2..4. Available only if
CONFIG_USB_GADGET_DEBUG_FILES is set.
+ =============== ==============================================
and a default lun.0 directory corresponding to SCSI LUN #0.
-A new lun can be added with mkdir:
+A new lun can be added with mkdir::
-$ mkdir functions/mass_storage.0/partition.5
+ $ mkdir functions/mass_storage.0/partition.5
Lun numbering does not have to be continuous, except for lun #0 which is
created by default. A maximum of 8 luns can be specified and they all must be
@@ -273,18 +320,20 @@ although it is not mandatory.
In each lun directory there are the following attribute files:
- file - The path to the backing file for the LUN.
+ =============== ==============================================
+ file The path to the backing file for the LUN.
Required if LUN is not marked as removable.
- ro - Flag specifying access to the LUN shall be
+ ro Flag specifying access to the LUN shall be
read-only. This is implied if CD-ROM emulation
is enabled as well as when it was impossible
to open "filename" in R/W mode.
- removable - Flag specifying that LUN shall be indicated as
+ removable Flag specifying that LUN shall be indicated as
being removable.
- cdrom - Flag specifying that LUN shall be reported as
+ cdrom Flag specifying that LUN shall be reported as
being a CD-ROM.
- nofua - Flag specifying that FUA flag
+ nofua Flag specifying that FUA flag
in SCSI WRITE(10,12)
+ =============== ==============================================
Testing the MASS STORAGE function
---------------------------------
@@ -304,12 +353,14 @@ Function-specific configfs interface
The function name to use when creating the function directory is "midi".
The MIDI function provides these attributes in its function directory:
- buflen - MIDI buffer length
- id - ID string for the USB MIDI adapter
- in_ports - number of MIDI input ports
- index - index value for the USB MIDI adapter
- out_ports - number of MIDI output ports
- qlen - USB read request queue length
+ =============== ====================================
+ buflen MIDI buffer length
+ id ID string for the USB MIDI adapter
+ in_ports number of MIDI input ports
+ index index value for the USB MIDI adapter
+ out_ports number of MIDI output ports
+ qlen USB read request queue length
+ =============== ====================================
Testing the MIDI function
-------------------------
@@ -317,60 +368,63 @@ Testing the MIDI function
There are two cases: playing a mid from the gadget to
the host and playing a mid from the host to the gadget.
-1) Playing a mid from the gadget to the host
-host)
+1) Playing a mid from the gadget to the host:
+
+host::
-$ arecordmidi -l
- Port Client name Port name
- 14:0 Midi Through Midi Through Port-0
- 24:0 MIDI Gadget MIDI Gadget MIDI 1
-$ arecordmidi -p 24:0 from_gadget.mid
+ $ arecordmidi -l
+ Port Client name Port name
+ 14:0 Midi Through Midi Through Port-0
+ 24:0 MIDI Gadget MIDI Gadget MIDI 1
+ $ arecordmidi -p 24:0 from_gadget.mid
-gadget)
+gadget::
-$ aplaymidi -l
- Port Client name Port name
- 20:0 f_midi f_midi
+ $ aplaymidi -l
+ Port Client name Port name
+ 20:0 f_midi f_midi
-$ aplaymidi -p 20:0 to_host.mid
+ $ aplaymidi -p 20:0 to_host.mid
2) Playing a mid from the host to the gadget
-gadget)
-$ arecordmidi -l
- Port Client name Port name
- 20:0 f_midi f_midi
+gadget::
+
+ $ arecordmidi -l
+ Port Client name Port name
+ 20:0 f_midi f_midi
-$ arecordmidi -p 20:0 from_host.mid
+ $ arecordmidi -p 20:0 from_host.mid
-host)
+host::
-$ aplaymidi -l
- Port Client name Port name
- 14:0 Midi Through Midi Through Port-0
- 24:0 MIDI Gadget MIDI Gadget MIDI 1
+ $ aplaymidi -l
+ Port Client name Port name
+ 14:0 Midi Through Midi Through Port-0
+ 24:0 MIDI Gadget MIDI Gadget MIDI 1
-$ aplaymidi -p24:0 to_gadget.mid
+ $ aplaymidi -p24:0 to_gadget.mid
The from_gadget.mid should sound identical to the to_host.mid.
+
The from_host.id should sound identical to the to_gadget.mid.
-MIDI files can be played to speakers/headphones with e.g. timidity installed
+MIDI files can be played to speakers/headphones with e.g. timidity installed::
-$ aplaymidi -l
- Port Client name Port name
- 14:0 Midi Through Midi Through Port-0
- 24:0 MIDI Gadget MIDI Gadget MIDI 1
-128:0 TiMidity TiMidity port 0
-128:1 TiMidity TiMidity port 1
-128:2 TiMidity TiMidity port 2
-128:3 TiMidity TiMidity port 3
+ $ aplaymidi -l
+ Port Client name Port name
+ 14:0 Midi Through Midi Through Port-0
+ 24:0 MIDI Gadget MIDI Gadget MIDI 1
+ 128:0 TiMidity TiMidity port 0
+ 128:1 TiMidity TiMidity port 1
+ 128:2 TiMidity TiMidity port 2
+ 128:3 TiMidity TiMidity port 3
-$ aplaymidi -p 128:0 file.mid
+ $ aplaymidi -p 128:0 file.mid
-MIDI ports can be logically connected using the aconnect utility, e.g.:
+MIDI ports can be logically connected using the aconnect utility, e.g.::
-$ aconnect 24:0 128:0 # try it on the host
+ $ aconnect 24:0 128:0 # try it on the host
After the gadget's MIDI port is connected to timidity's MIDI port,
whatever is played at the gadget side with aplaymidi -l is audible
@@ -387,13 +441,15 @@ Function-specific configfs interface
The function name to use when creating the function directory is "ncm".
The NCM function provides these attributes in its function directory:
- ifname - network device interface name associated with this
+ =============== ==================================================
+ ifname network device interface name associated with this
function instance
- qmult - queue length multiplier for high and super speed
- host_addr - MAC address of host's end of this
+ qmult queue length multiplier for high and super speed
+ host_addr MAC address of host's end of this
Ethernet over USB link
- dev_addr - MAC address of device's end of this
+ dev_addr MAC address of device's end of this
Ethernet over USB link
+ =============== ==================================================
and after creating the functions/ncm.<instance name> they contain default
values: qmult is 5, dev_addr and host_addr are randomly selected.
@@ -406,8 +462,13 @@ Testing the NCM function
Configure IP addresses of the device and the host. Then:
-On the device: ping <host's IP>
-On the host: ping <device's IP>
+On the device::
+
+ ping <host's IP>
+
+On the host::
+
+ ping <device's IP>
11. OBEX function
=================
@@ -429,13 +490,18 @@ There can be at most 4 ACM/generic serial/OBEX ports in the system.
Testing the OBEX function
-------------------------
-On device: seriald -f /dev/ttyGS<Y> -s 1024
-On host: serialc -v <vendorID> -p <productID> -i<interface#> -a1 -s1024 \
- -t<out endpoint addr> -r<in endpoint addr>
+On device::
+
+ seriald -f /dev/ttyGS<Y> -s 1024
+
+On host::
+
+ serialc -v <vendorID> -p <productID> -i<interface#> -a1 -s1024 \
+ -t<out endpoint addr> -r<in endpoint addr>
where seriald and serialc are Felipe's utilities found here:
-https://github.com/felipebalbi/usb-tools.git master
+ https://github.com/felipebalbi/usb-tools.git master
12. PHONET function
===================
@@ -448,8 +514,10 @@ Function-specific configfs interface
The function name to use when creating the function directory is "phonet".
The PHONET function provides just one attribute in its function directory:
- ifname - network device interface name associated with this
+ =============== ==================================================
+ ifname network device interface name associated with this
function instance
+ =============== ==================================================
Testing the PHONET function
---------------------------
@@ -464,41 +532,41 @@ These tools are required:
git://git.gitorious.org/meego-cellular/phonet-utils.git
-On the host:
+On the host::
-$ ./phonet -a 0x10 -i usbpn0
-$ ./pnroute add 0x6c usbpn0
-$./pnroute add 0x10 usbpn0
-$ ifconfig usbpn0 up
+ $ ./phonet -a 0x10 -i usbpn0
+ $ ./pnroute add 0x6c usbpn0
+ $./pnroute add 0x10 usbpn0
+ $ ifconfig usbpn0 up
-On the device:
+On the device::
-$ ./phonet -a 0x6c -i upnlink0
-$ ./pnroute add 0x10 upnlink0
-$ ifconfig upnlink0 up
+ $ ./phonet -a 0x6c -i upnlink0
+ $ ./pnroute add 0x10 upnlink0
+ $ ifconfig upnlink0 up
-Then a test program can be used:
+Then a test program can be used::
-http://www.spinics.net/lists/linux-usb/msg85690.html
+ http://www.spinics.net/lists/linux-usb/msg85690.html
-On the device:
+On the device::
-$ ./pnxmit -a 0x6c -r
+ $ ./pnxmit -a 0x6c -r
-On the host:
+On the host::
-$ ./pnxmit -a 0x10 -s 0x6c
+ $ ./pnxmit -a 0x10 -s 0x6c
As a result some data should be sent from host to device.
Then the other way round:
-On the host:
+On the host::
-$ ./pnxmit -a 0x10 -r
+ $ ./pnxmit -a 0x10 -r
-On the device:
+On the device::
-$ ./pnxmit -a 0x6c -s 0x10
+ $ ./pnxmit -a 0x6c -s 0x10
13. RNDIS function
==================
@@ -511,13 +579,15 @@ Function-specific configfs interface
The function name to use when creating the function directory is "rndis".
The RNDIS function provides these attributes in its function directory:
- ifname - network device interface name associated with this
+ =============== ==================================================
+ ifname network device interface name associated with this
function instance
- qmult - queue length multiplier for high and super speed
- host_addr - MAC address of host's end of this
+ qmult queue length multiplier for high and super speed
+ host_addr MAC address of host's end of this
Ethernet over USB link
- dev_addr - MAC address of device's end of this
+ dev_addr MAC address of device's end of this
Ethernet over USB link
+ =============== ==================================================
and after creating the functions/rndis.<instance name> they contain default
values: qmult is 5, dev_addr and host_addr are randomly selected.
@@ -530,8 +600,13 @@ Testing the RNDIS function
Configure IP addresses of the device and the host. Then:
-On the device: ping <host's IP>
-On the host: ping <device's IP>
+On the device::
+
+ ping <host's IP>
+
+On the host::
+
+ ping <device's IP>
14. SERIAL function
===================
@@ -553,15 +628,28 @@ There can be at most 4 ACM/generic serial/OBEX ports in the system.
Testing the SERIAL function
---------------------------
-On host: insmod usbserial
- echo VID PID >/sys/bus/usb-serial/drivers/generic/new_id
-On host: cat > /dev/ttyUSB<X>
-On target: cat /dev/ttyGS<Y>
+On host::
+
+ insmod usbserial
+ echo VID PID >/sys/bus/usb-serial/drivers/generic/new_id
+
+On host::
+
+ cat > /dev/ttyUSB<X>
+
+On target::
+
+ cat /dev/ttyGS<Y>
then the other way round
-On target: cat > /dev/ttyGS<Y>
-On host: cat /dev/ttyUSB<X>
+On target::
+
+ cat > /dev/ttyGS<Y>
+
+On host::
+
+ cat /dev/ttyUSB<X>
15. SOURCESINK function
=======================
@@ -574,24 +662,27 @@ Function-specific configfs interface
The function name to use when creating the function directory is "SourceSink".
The SOURCESINK function provides these attributes in its function directory:
- pattern - 0 (all zeros), 1 (mod63), 2 (none)
- isoc_interval - 1..16
- isoc_maxpacket - 0 - 1023 (fs), 0 - 1024 (hs/ss)
- isoc_mult - 0..2 (hs/ss only)
- isoc_maxburst - 0..15 (ss only)
- bulk_buflen - buffer length
- bulk_qlen - depth of queue for bulk
- iso_qlen - depth of queue for iso
+ =============== ==================================
+ pattern 0 (all zeros), 1 (mod63), 2 (none)
+ isoc_interval 1..16
+ isoc_maxpacket 0 - 1023 (fs), 0 - 1024 (hs/ss)
+ isoc_mult 0..2 (hs/ss only)
+ isoc_maxburst 0..15 (ss only)
+ bulk_buflen buffer length
+ bulk_qlen depth of queue for bulk
+ iso_qlen depth of queue for iso
+ =============== ==================================
Testing the SOURCESINK function
-------------------------------
device: run the gadget
+
host: test-usb (tools/usb/testusb.c)
16. UAC1 function (legacy implementation)
-=================
+=========================================
The function is provided by usb_f_uac1_legacy.ko module.
@@ -602,12 +693,14 @@ The function name to use when creating the function directory
is "uac1_legacy".
The uac1 function provides these attributes in its function directory:
- audio_buf_size - audio buffer size
- fn_cap - capture pcm device file name
- fn_cntl - control device file name
- fn_play - playback pcm device file name
- req_buf_size - ISO OUT endpoint request buffer size
- req_count - ISO OUT endpoint request count
+ =============== ====================================
+ audio_buf_size audio buffer size
+ fn_cap capture pcm device file name
+ fn_cntl control device file name
+ fn_play playback pcm device file name
+ req_buf_size ISO OUT endpoint request buffer size
+ req_count ISO OUT endpoint request count
+ =============== ====================================
The attributes have sane default values.
@@ -615,7 +708,10 @@ Testing the UAC1 function
-------------------------
device: run the gadget
-host: aplay -l # should list our USB Audio Gadget
+
+host::
+
+ aplay -l # should list our USB Audio Gadget
17. UAC2 function
=================
@@ -628,14 +724,16 @@ Function-specific configfs interface
The function name to use when creating the function directory is "uac2".
The uac2 function provides these attributes in its function directory:
- c_chmask - capture channel mask
- c_srate - capture sampling rate
- c_ssize - capture sample size (bytes)
- p_chmask - playback channel mask
- p_srate - playback sampling rate
- p_ssize - playback sample size (bytes)
- req_number - the number of pre-allocated request for both capture
- and playback
+ =============== ====================================================
+ c_chmask capture channel mask
+ c_srate capture sampling rate
+ c_ssize capture sample size (bytes)
+ p_chmask playback channel mask
+ p_srate playback sampling rate
+ p_ssize playback sample size (bytes)
+ req_number the number of pre-allocated request for both capture
+ and playback
+ =============== ====================================================
The attributes have sane default values.
@@ -648,14 +746,14 @@ host: aplay -l # should list our USB Audio Gadget
This function does not require real hardware support, it just
sends a stream of audio data to/from the host. In order to
actually hear something at the device side, a command similar
-to this must be used at the device side:
+to this must be used at the device side::
-$ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 &
+ $ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 &
-e.g.:
+e.g.::
-$ arecord -f dat -t wav -D hw:CARD=UAC2Gadget,DEV=0 | \
-aplay -D default:CARD=OdroidU3
+ $ arecord -f dat -t wav -D hw:CARD=UAC2Gadget,DEV=0 | \
+ aplay -D default:CARD=OdroidU3
18. UVC function
================
@@ -668,66 +766,73 @@ Function-specific configfs interface
The function name to use when creating the function directory is "uvc".
The uvc function provides these attributes in its function directory:
- streaming_interval - interval for polling endpoint for data transfers
- streaming_maxburst - bMaxBurst for super speed companion descriptor
- streaming_maxpacket - maximum packet size this endpoint is capable of
- sending or receiving when this configuration is
- selected
+ =================== ================================================
+ streaming_interval interval for polling endpoint for data transfers
+ streaming_maxburst bMaxBurst for super speed companion descriptor
+ streaming_maxpacket maximum packet size this endpoint is capable of
+ sending or receiving when this configuration is
+ selected
+ =================== ================================================
There are also "control" and "streaming" subdirectories, each of which contain
a number of their subdirectories. There are some sane defaults provided, but
the user must provide the following:
- control header - create in control/header, link from control/class/fs
- and/or control/class/ss
- streaming header - create in streaming/header, link from
- streaming/class/fs and/or streaming/class/hs and/or
- streaming/class/ss
- format description - create in streaming/mjpeg and/or
- streaming/uncompressed
- frame description - create in streaming/mjpeg/<format> and/or in
- streaming/uncompressed/<format>
+ ================== ====================================================
+ control header create in control/header, link from control/class/fs
+ and/or control/class/ss
+ streaming header create in streaming/header, link from
+ streaming/class/fs and/or streaming/class/hs and/or
+ streaming/class/ss
+ format description create in streaming/mjpeg and/or
+ streaming/uncompressed
+ frame description create in streaming/mjpeg/<format> and/or in
+ streaming/uncompressed/<format>
+ ================== ====================================================
Each frame description contains frame interval specification, and each
such specification consists of a number of lines with an inverval value
-in each line. The rules stated above are best illustrated with an example:
-
-# mkdir functions/uvc.usb0/control/header/h
-# cd functions/uvc.usb0/control/
-# ln -s header/h class/fs
-# ln -s header/h class/ss
-# mkdir -p functions/uvc.usb0/streaming/uncompressed/u/360p
-# cat <<EOF > functions/uvc.usb0/streaming/uncompressed/u/360p/dwFrameInterval
-666666
-1000000
-5000000
-EOF
-# cd $GADGET_CONFIGFS_ROOT
-# mkdir functions/uvc.usb0/streaming/header/h
-# cd functions/uvc.usb0/streaming/header/h
-# ln -s ../../uncompressed/u
-# cd ../../class/fs
-# ln -s ../../header/h
-# cd ../../class/hs
-# ln -s ../../header/h
-# cd ../../class/ss
-# ln -s ../../header/h
+in each line. The rules stated above are best illustrated with an example::
+
+ # mkdir functions/uvc.usb0/control/header/h
+ # cd functions/uvc.usb0/control/
+ # ln -s header/h class/fs
+ # ln -s header/h class/ss
+ # mkdir -p functions/uvc.usb0/streaming/uncompressed/u/360p
+ # cat <<EOF > functions/uvc.usb0/streaming/uncompressed/u/360p/dwFrameInterval
+ 666666
+ 1000000
+ 5000000
+ EOF
+ # cd $GADGET_CONFIGFS_ROOT
+ # mkdir functions/uvc.usb0/streaming/header/h
+ # cd functions/uvc.usb0/streaming/header/h
+ # ln -s ../../uncompressed/u
+ # cd ../../class/fs
+ # ln -s ../../header/h
+ # cd ../../class/hs
+ # ln -s ../../header/h
+ # cd ../../class/ss
+ # ln -s ../../header/h
Testing the UVC function
------------------------
-device: run the gadget, modprobe vivid
+device: run the gadget, modprobe vivid::
-# uvc-gadget -u /dev/video<uvc video node #> -v /dev/video<vivid video node #>
+ # uvc-gadget -u /dev/video<uvc video node #> -v /dev/video<vivid video node #>
where uvc-gadget is this program:
-http://git.ideasonboard.org/uvc-gadget.git
+ http://git.ideasonboard.org/uvc-gadget.git
with these patches:
-http://www.spinics.net/lists/linux-usb/msg99220.html
-host: luvcview -f yuv
+ http://www.spinics.net/lists/linux-usb/msg99220.html
+
+host::
+
+ luvcview -f yuv
19. PRINTER function
====================
@@ -740,16 +845,19 @@ Function-specific configfs interface
The function name to use when creating the function directory is "printer".
The printer function provides these attributes in its function directory:
- pnp_string - Data to be passed to the host in pnp string
- q_len - Number of requests per endpoint
+ ========== ===========================================
+ pnp_string Data to be passed to the host in pnp string
+ q_len Number of requests per endpoint
+ ========== ===========================================
Testing the PRINTER function
----------------------------
The most basic testing:
-device: run the gadget
-# ls -l /devices/virtual/usb_printer_gadget/
+device: run the gadget::
+
+ # ls -l /devices/virtual/usb_printer_gadget/
should show g_printer<number>.
@@ -761,23 +869,28 @@ If udev is active, then e.g. /dev/usb/lp0 should appear.
host->device transmission:
-device:
-# cat /dev/g_printer<number>
-host:
-# cat > /dev/usb/lp0
+device::
-device->host transmission:
+ # cat /dev/g_printer<number>
-# cat > /dev/g_printer<number>
-host:
-# cat /dev/usb/lp0
+host::
+
+ # cat > /dev/usb/lp0
+
+device->host transmission::
+
+ # cat > /dev/g_printer<number>
+
+host::
+
+ # cat /dev/usb/lp0
More advanced testing can be done with the prn_example
described in Documentation/usb/gadget_printer.txt.
20. UAC1 function (virtual ALSA card, using u_audio API)
-=================
+========================================================
The function is provided by usb_f_uac1.ko module.
It will create a virtual ALSA card and the audio streams are simply
@@ -789,14 +902,16 @@ Function-specific configfs interface
The function name to use when creating the function directory is "uac1".
The uac1 function provides these attributes in its function directory:
- c_chmask - capture channel mask
- c_srate - capture sampling rate
- c_ssize - capture sample size (bytes)
- p_chmask - playback channel mask
- p_srate - playback sampling rate
- p_ssize - playback sample size (bytes)
- req_number - the number of pre-allocated request for both capture
- and playback
+ ========== ====================================================
+ c_chmask capture channel mask
+ c_srate capture sampling rate
+ c_ssize capture sample size (bytes)
+ p_chmask playback channel mask
+ p_srate playback sampling rate
+ p_ssize playback sample size (bytes)
+ req_number the number of pre-allocated request for both capture
+ and playback
+ ========== ====================================================
The attributes have sane default values.
@@ -809,11 +924,11 @@ host: aplay -l # should list our USB Audio Gadget
This function does not require real hardware support, it just
sends a stream of audio data to/from the host. In order to
actually hear something at the device side, a command similar
-to this must be used at the device side:
+to this must be used at the device side::
-$ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 &
+ $ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 &
-e.g.:
+e.g.::
-$ arecord -f dat -t wav -D hw:CARD=UAC1Gadget,DEV=0 | \
-aplay -D default:CARD=OdroidU3
+ $ arecord -f dat -t wav -D hw:CARD=UAC1Gadget,DEV=0 | \
+ aplay -D default:CARD=OdroidU3