Hi all, This series implements: * Support for multiple rates in the audio gadget * Notification of gadget-side alsa processes about playback/capture start/stop on the host side via Playback/Capture Rate controls. * Detection of the USB cable disconnection by handling SUSPEND call in f_uac1/2. The disconnection generates a stop notification. * Dynamic bInterval calculation for HS and SS Patches for the multirate support, originally authored by Julian Scheel, were rebased and modified for the current code base. Julian has acknowledged the presented patches. The detection of cable disconnection was discussed with dwc2 maintainer Minas Harutyunyan who confirmed that the suspend event can be used (https://lore.kernel.org/all/5aada8e3-f385-0589-8d58-187abd1a924d@xxxxxxxxxxxx/T/). Tests on dwc2 have confirmed reliable detection, the gadget correctly reports playback/capture stop at cable disconnection. The start/stop/current rate notification feature is accompanied by example implementation of audio gadget controller https://github.com/pavhofman/gaudio_ctl. The controller also handles debouncing fast start/stop events when USB host audio driver is loaded and/or audio daemon re/started. Changes: -------- v2: Fixed compilation of "usb: gadget: f_uac1: Support multiple sampling rates" - added changes for CONFIG_GADGET_UAC1 --------- Julian Scheel (4): usb: gadget: u_audio: Support multiple sampling rates usb: gadget: f_uac2: Support multiple sampling rates usb: gadget: f_uac1: Support multiple sampling rates usb: gadget: f_uac2: Renaming Clock Sources to fixed names Pavel Hofman (7): usb: gadget: u_audio: Subdevice 0 for capture ctls usb: gadget: u_audio: Rate ctl notifies about current srate (0=stopped) usb: gadget: u_audio: Stopping PCM substream at capture/playback stop usb: gadget: u_audio: Adding suspend call usb: gadget: f_uac2: Adding suspend callback usb: gadget: f_uac1: Adding suspend callback usb: gadget: f_uac2: Determining bInterval for HS and SS .../ABI/testing/configfs-usb-gadget-uac1 | 4 +- .../ABI/testing/configfs-usb-gadget-uac2 | 4 +- Documentation/usb/gadget-testing.rst | 8 +- drivers/usb/gadget/function/f_uac1.c | 121 ++++++++-- drivers/usb/gadget/function/f_uac2.c | 221 ++++++++++++------ drivers/usb/gadget/function/u_audio.c | 162 ++++++++++++- drivers/usb/gadget/function/u_audio.h | 12 +- drivers/usb/gadget/function/u_uac1.h | 63 ++++- drivers/usb/gadget/function/u_uac2.h | 62 +++++ drivers/usb/gadget/function/uac_common.h | 9 + drivers/usb/gadget/legacy/audio.c | 40 +++- 11 files changed, 597 insertions(+), 109 deletions(-) create mode 100644 drivers/usb/gadget/function/uac_common.h -- 2.25.1
