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path: root/Documentation/usb/gadget-testing.rst
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* docs: usb: fix malformed tableHu Haowen2021-08-051-42/+42
| | | | | | | | | | The tables are separated with tabs and spaces mixed together, leading to malformation. Changed the characters all into spaces to solve this issue. Signed-off-by: Hu Haowen <src.res@email.cn> Link: https://lore.kernel.org/r/20210805040146.121526-1-src.res@email.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* usb: gadget: f_uac1: add volume and mute supportRuslan Bilovol2021-07-211-8/+18
| | | | | | | | | | | | | | | | | | | | | This adds bi-directional (host->device, device->host) volume/mute support to the f_uac1 driver by adding Feature Units and interrupt endpoint. Currently only master channel is supported. Volume and mute are configurable through configfs, by default volume has -100..0 dB range with 1 dB step. Similar to existing flexible endpoints configuration, Feature Unit won't be added to the topology if both mute and volume are not enabled, also interrupt endpoint isn't added to the device if no feature unit is present Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com> Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com> Link: https://lore.kernel.org/r/20210712125529.76070-5-pavel.hofman@ivitera.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* usb: gadget: f_uac2: add volume and mute supportRuslan Bilovol2021-07-211-1/+11
| | | | | | | | | | | | | | | | | | | | | This adds bi-directional (host->device, device->host) volume/mute support to the f_uac2 driver by adding Feature Units and interrupt endpoint. Currently only master channel is supported. Volume and mute are configurable through configfs, by default volume has -100..0 dB range with 1 dB step. Similar to existing flexible endpoints configuration, Feature Unit won't be added to the topology if both mute and volume are not enabled, also interrupt endpoint isn't added to the device if no feature unit is present Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com> Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com> Link: https://lore.kernel.org/r/20210712125529.76070-4-pavel.hofman@ivitera.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* usb: gadget: u_audio: add real feedback implementationRuslan Bilovol2021-06-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds interface between userspace and feedback endpoint to report real feedback frequency to the Host. Current implementation adds new userspace interface ALSA mixer control "Capture Pitch 1000000" (similar to aloop driver's "PCM Rate Shift 100000" mixer control) Value in PPM is chosen to have correction value agnostic of the actual HW rate, which the application is not necessarily dealing with, while still retaining a good enough precision to allow smooth clock correction on the playback side, if necessary. Similar to sound/usb/endpoint.c, a slow down is allowed up to 25%. This has no impact on the required bandwidth. Speedup correction has an impact on the bandwidth reserved for the isochronous endpoint. The default allowed speedup is 500ppm. This seems to be more than enough but, if necessary, this is configurable through a module parameter. The reserved bandwidth is rounded up to the next packet size. Usage of this new control is easy to implement in existing userspace tools like alsaloop from alsa-utils. Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://lore.kernel.org/r/20210603220104.1216001-4-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* usb: gadget: f_uac2: add adaptive sync support for captureRuslan Bilovol2021-06-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Current f_uac2 USB OUT (aka 'capture') synchronization implements 'ASYNC' scenario which means USB Gadget has it's own freerunning clock and can update Host about real clock frequency through feedback endpoint so Host can align number of samples sent to the USB gadget to prevent overruns/underruns In case if Gadget can has no it's internal clock and can consume audio samples at any rate (for example, on the Gadget side someone records audio directly to a file, or audio samples are played through an external DAC as soon as they arrive), UAC2 spec suggests 'ADAPTIVE' synchronization type. Change UAC2 driver to make it configurable through additional 'c_sync' configfs file. Default remains 'asynchronous' with possibility to switch it to 'adaptive' Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://lore.kernel.org/r/20210603220104.1216001-3-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* usb: gadget: u_ether: support configuring interface names.Lorenzo Colitti2021-01-151-15/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows the administrator to configure the interface name of a function using u_ether (e.g., eem, ncm, rndis). Currently, all such interfaces, regardless of function type, are always called usb0, usb1, etc. This makes it very cumbersome to use more than one such type at a time, because userspace cannnot easily tell the interfaces apart and apply the right configuration to each one. Interface renaming in userspace based on driver doesn't help, because the interfaces all have the same driver. Without this patch, doing this require hacks/workarounds such as setting fixed MAC addresses on the functions, and then renaming by MAC address, or scraping configfs after each interface is created to find out what it is. Setting the interface name is done by writing to the same "ifname" configfs attribute that reports the interface name after the function is bound. The write must contain an interface pattern such as "usb%d" (which will cause the net core to pick the next available interface name starting with "usb"). This patch does not allow writing an exact interface name (as opposed to a pattern) because if the interface already exists at bind time, the bind will fail and the whole gadget will fail to activate. This could be allowed in a future patch. For compatibility with current userspace, when reading an ifname that has not currently been set, the result is still "(unnamed net_device)". Once a write to ifname happens, then reading ifname will return whatever was last written. Tested by configuring an rndis function and an ncm function on the same gadget, and writing "rndis%d" to ifname on the rndis function and "ncm%d" to ifname on the ncm function. When the gadget was bound, the rndis interface was rndis0 and the ncm interface was ncm0. Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Link: https://lore.kernel.org/r/20210113234222.3272933-1-lorenzo@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* docs: usb: rename files to .rst and add them to drivers-apiMauro Carvalho Chehab2019-06-201-0/+934
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>