diff options
Diffstat (limited to 'Documentation/usb')
| -rw-r--r-- | Documentation/usb/authorization.rst | 9 | ||||
| -rw-r--r-- | Documentation/usb/gadget-testing.rst | 154 | ||||
| -rw-r--r-- | Documentation/usb/gadget_uvc.rst | 2 |
3 files changed, 158 insertions, 7 deletions
diff --git a/Documentation/usb/authorization.rst b/Documentation/usb/authorization.rst index 9e53909d04c2..150a14970e95 100644 --- a/Documentation/usb/authorization.rst +++ b/Documentation/usb/authorization.rst @@ -33,12 +33,9 @@ Remove the lock down:: $ echo 1 > /sys/bus/usb/devices/usbX/authorized_default -By default, Wired USB devices are authorized by default to -connect. Wireless USB hosts deauthorize by default all new connected -devices (this is so because we need to do an authentication phase -before authorizing). Writing "2" to the authorized_default attribute -causes kernel to only authorize by default devices connected to internal -USB ports. +By default, all USB devices are authorized. Writing "2" to the +authorized_default attribute causes the kernel to authorize by default +only devices connected to internal USB ports. Example system lockdown (lame) diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst index 2fca40443dc9..394cd226bfae 100644 --- a/Documentation/usb/gadget-testing.rst +++ b/Documentation/usb/gadget-testing.rst @@ -27,6 +27,7 @@ provided by gadgets. 18. UVC function 19. PRINTER function 20. UAC1 function (new API) + 21. MIDI2 function 1. ACM function @@ -965,3 +966,156 @@ e.g.:: $ arecord -f dat -t wav -D hw:CARD=UAC1Gadget,DEV=0 | \ aplay -D default:CARD=OdroidU3 + + +21. MIDI2 function +================== + +The function is provided by usb_f_midi2.ko module. +It will create a virtual ALSA card containing a UMP rawmidi device +where the UMP packet is looped back. In addition, a legacy rawmidi +device is created. The UMP rawmidi is bound with ALSA sequencer +clients, too. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "midi2". +The midi2 function provides these attributes in its function directory +as the card top-level information: + + ============= ================================================= + process_ump Bool flag to process UMP Stream messages (0 or 1) + static_block Bool flag for static blocks (0 or 1) + iface_name Optional interface name string + ============= ================================================= + +The directory contains a subdirectory "ep.0", and this provides the +attributes for a UMP Endpoint (which is a pair of USB MIDI Endpoints): + + ============= ================================================= + protocol_caps MIDI protocol capabilities; + 1: MIDI 1.0, 2: MIDI 2.0, or 3: both protocols + protocol Default MIDI protocol (either 1 or 2) + ep_name UMP Endpoint name string + product_id Product ID string + manufacturer Manufacture ID number (24 bit) + family Device family ID number (16 bit) + model Device model ID number (16 bit) + sw_revision Software revision (32 bit) + ============= ================================================= + +Each Endpoint subdirectory contains a subdirectory "block.0", which +represents the Function Block for Block 0 information. +Its attributes are: + + ================= =============================================== + name Function Block name string + direction Direction of this FB + 1: input, 2: output, or 3: bidirectional + first_group The first UMP Group number (0-15) + num_groups The number of groups in this FB (1-16) + midi1_first_group The first UMP Group number for MIDI 1.0 (0-15) + midi1_num_groups The number of groups for MIDI 1.0 (0-16) + ui_hint UI-hint of this FB + 0: unknown, 1: receiver, 2: sender, 3: both + midi_ci_verison Supported MIDI-CI version number (8 bit) + is_midi1 Legacy MIDI 1.0 device (0-2) + 0: MIDI 2.0 device, + 1: MIDI 1.0 without restriction, or + 2: MIDI 1.0 with low speed + sysex8_streams Max number of SysEx8 streams (8 bit) + active Bool flag for FB activity (0 or 1) + ================= =============================================== + +If multiple Function Blocks are required, you can add more Function +Blocks by creating subdirectories "block.<num>" with the corresponding +Function Block number (1, 2, ....). The FB subdirectories can be +dynamically removed, too. Note that the Function Block numbers must be +continuous. + +Similarly, if you multiple UMP Endpoints are required, you can add +more Endpoints by creating subdirectories "ep.<num>". The number must +be continuous. + +For emulating the old MIDI 2.0 device without UMP v1.1 support, pass 0 +to `process_ump` flag. Then the whole UMP v1.1 requests are ignored. + +Testing the MIDI2 function +-------------------------- + +On the device: run the gadget, and running:: + + $ cat /proc/asound/cards + +will show a new sound card containing a MIDI2 device. + +OTOH, on the host:: + + $ cat /proc/asound/cards + +will show a new sound card containing either MIDI1 or MIDI2 device, +depending on the USB audio driver configuration. + +On both, when ALSA sequencer is enabled on the host, you can find the +UMP MIDI client such as "MIDI 2.0 Gadget". + +As the driver simply loops back the data, there is no need for a real +device just for testing. + +For testing a MIDI input from the gadget to the host (e.g. emulating a +MIDI keyboard), you can send a MIDI stream like the following. + +On the gadget:: + + $ aconnect -o + .... + client 20: 'MIDI 2.0 Gadget' [type=kernel,card=1] + 0 'MIDI 2.0 ' + 1 'Group 1 (MIDI 2.0 Gadget I/O)' + $ aplaymidi -p 20:1 to_host.mid + +On the host:: + + $ aconnect -i + .... + client 24: 'MIDI 2.0 Gadget' [type=kernel,card=2] + 0 'MIDI 2.0 ' + 1 'Group 1 (MIDI 2.0 Gadget I/O)' + $ arecordmidi -p 24:1 from_gadget.mid + +If you have a UMP-capable application, you can use the UMP port to +send/receive the raw UMP packets, too. For example, aseqdump program +with UMP support can receive from UMP port. On the host:: + + $ aseqdump -u 2 -p 24:1 + Waiting for data. Press Ctrl+C to end. + Source Group Event Ch Data + 24:1 Group 0, Program change 0, program 0, Bank select 0:0 + 24:1 Group 0, Channel pressure 0, value 0x80000000 + +For testing a MIDI output to the gadget to the host (e.g. emulating a +MIDI synth), it'll be just other way round. + +On the gadget:: + + $ arecordmidi -p 20:1 from_host.mid + +On the host:: + + $ aplaymidi -p 24:1 to_gadget.mid + +The access to MIDI 1.0 on altset 0 on the host is supported, and it's +translated from/to UMP packets on the gadget. It's bound to only +Function Block 0. + +The current operation mode can be observed in ALSA control element +"Operation Mode" for SND_CTL_IFACE_RAWMIDI. For example:: + + $ amixer -c1 contents + numid=1,iface=RAWMIDI,name='Operation Mode' + ; type=INTEGER,access=r--v----,values=1,min=0,max=2,step=0 + : values=2 + +where 0 = unused, 1 = MIDI 1.0 (altset 0), 2 = MIDI 2.0 (altset 1). +The example above shows it's running in 2, i.e. MIDI 2.0. diff --git a/Documentation/usb/gadget_uvc.rst b/Documentation/usb/gadget_uvc.rst index 62bd81ba3dd1..80a1f031b593 100644 --- a/Documentation/usb/gadget_uvc.rst +++ b/Documentation/usb/gadget_uvc.rst @@ -168,7 +168,7 @@ Header linking The UVC specification requires that Format and Frame descriptors be preceded by Headers detailing things such as the number and cumulative size of the different -Format descriptors that follow. This and similar operations are acheived in +Format descriptors that follow. This and similar operations are achieved in configfs by linking between the configfs item representing the header and the config items representing those other descriptors, in this manner: |