samples: usb: add UAC2 implicit feedback sample
The sample illustates how to achieve bidirectional asynchronous audio. Implicit feedback is the only way to achieve asynchronous USB headset on devices that have only one isochronous IN and one isochronous OUT endpoint. The sample implements stereo playback and mono recording. While it would be possible to have stereo recording, the commonly available headsets are mono only. The number of channels can differ between audio sink and source because the only requirement is that the two run on same clock. Signed-off-by: Tomasz Moń <tomasz.mon@nordicsemi.no>
This commit is contained in:
Tomasz Moń
Anas Nashif
parent
1973bc565f
commit
d3e1bc8b59
14 changed files with 1024 additions and 0 deletions
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@ -603,6 +603,8 @@ The following Product IDs are currently used:
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+----------------------------------------------------+--------+
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+----------------------------------------------------+--------+
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| :zephyr:code-sample:`uac2-explicit-feedback` | 0x000E |
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| :zephyr:code-sample:`uac2-explicit-feedback` | 0x000E |
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+----------------------------------------------------+--------+
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+----------------------------------------------------+--------+
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| :zephyr:code-sample:`uac2-implicit-feedback` | 0x000F |
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+----------------------------------------------------+--------+
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| :zephyr:code-sample:`usb-dfu` (DFU Mode) | 0xFFFF |
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| :zephyr:code-sample:`usb-dfu` (DFU Mode) | 0xFFFF |
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+----------------------------------------------------+--------+
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+----------------------------------------------------+--------+
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@ -55,6 +55,8 @@ Samples
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* :zephyr:code-sample:`uac2-explicit-feedback`
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* :zephyr:code-sample:`uac2-explicit-feedback`
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* :zephyr:code-sample:`uac2-implicit-feedback`
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Samples ported to new USB device support
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Samples ported to new USB device support
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----------------------------------------
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----------------------------------------
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14
samples/subsys/usb/uac2_implicit_feedback/CMakeLists.txt
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14
samples/subsys/usb/uac2_implicit_feedback/CMakeLists.txt
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@ -0,0 +1,14 @@
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# SPDX-License-Identifier: Apache-2.0
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cmake_minimum_required(VERSION 3.20.0)
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find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
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project(usb_audio_async_i2s)
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include(${ZEPHYR_BASE}/samples/subsys/usb/common/common.cmake)
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target_sources(app PRIVATE src/main.c)
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if (CONFIG_SOC_COMPATIBLE_NRF5340_CPUAPP)
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target_sources(app PRIVATE src/feedback_nrf53.c)
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else()
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target_sources(app PRIVATE src/feedback_dummy.c)
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endif()
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9
samples/subsys/usb/uac2_implicit_feedback/Kconfig
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9
samples/subsys/usb/uac2_implicit_feedback/Kconfig
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@ -0,0 +1,9 @@
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# Copyright (c) 2023-2024 Nordic Semiconductor ASA
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# SPDX-License-Identifier: Apache-2.0
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# Source common USB sample options used to initialize new experimental USB
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# device stack. The scope of these options is limited to USB samples in project
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# tree, you cannot use them in your own application.
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source "samples/subsys/usb/common/Kconfig.sample_usbd"
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source "Kconfig.zephyr"
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41
samples/subsys/usb/uac2_implicit_feedback/README.rst
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41
samples/subsys/usb/uac2_implicit_feedback/README.rst
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@ -0,0 +1,41 @@
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.. zephyr:code-sample:: uac2-implicit-feedback
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:name: USB Audio asynchronous implicit feedback sample
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:relevant-api: usbd_api uac2_device i2s_interface
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USB Audio 2 implicit feedback sample playing stereo and recording mono audio
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on I2S interface.
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Overview
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********
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This sample demonstrates how to implement USB asynchronous bidirectional audio
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with implicit feedback. The host adjusts number of stereo samples sent for
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headphones playback based on the number of mono microphone samples received.
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Requirements
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************
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Target must be able to measure I2S block start (i.e. first sample from output
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buffer gets out) relative to USB SOF. The relative offset must be reported with
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single sample accuracy.
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This sample has been tested on :ref:`nrf5340dk_nrf5340`. While for actual audio
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experience it is necessary to connect external I2S ADC and I2S DAC, simple echo
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can be accomplished by shorting I2S data output with I2S data input.
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Theoretically it should be possible to obtain the timing information based on
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I2S and USB interrupts, but currently neither subsystem currently provides
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necessary timestamp information.
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Building and Running
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********************
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The code can be found in :zephyr_file:`samples/subsys/usb/uac2_implicit_feedback`.
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To build and flash the application:
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.. zephyr-app-commands::
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:zephyr-app: samples/subsys/usb/uac2_implicit_feedback
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:board: nrf5340dk/nrf5340/cpuapp
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:goals: build flash
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:compact:
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74
samples/subsys/usb/uac2_implicit_feedback/app.overlay
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74
samples/subsys/usb/uac2_implicit_feedback/app.overlay
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@ -0,0 +1,74 @@
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/*
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* Copyright (c) 2023 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <dt-bindings/usb/audio.h>
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/ {
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uac2_headset: usb_audio2 {
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compatible = "zephyr,uac2";
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status = "okay";
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audio-function = <AUDIO_FUNCTION_HEADSET>;
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uac_aclk: aclk {
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compatible = "zephyr,uac2-clock-source";
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clock-type = "internal-programmable";
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frequency-control = "host-programmable";
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sampling-frequencies = <48000>;
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};
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out_terminal: out_terminal {
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compatible = "zephyr,uac2-input-terminal";
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clock-source = <&uac_aclk>;
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terminal-type = <USB_TERMINAL_STREAMING>;
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front-left;
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front-right;
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};
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headphones_output: headphones {
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compatible = "zephyr,uac2-output-terminal";
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data-source = <&out_terminal>;
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clock-source = <&uac_aclk>;
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terminal-type = <BIDIRECTIONAL_TERMINAL_HEADSET>;
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assoc-terminal = <&mic_input>;
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};
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mic_input: microphone {
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compatible = "zephyr,uac2-input-terminal";
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clock-source = <&uac_aclk>;
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terminal-type = <BIDIRECTIONAL_TERMINAL_HEADSET>;
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/* Circular reference, macros will figure it out and
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* provide correct associated terminal ID because the
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* terminals associations are always 1-to-1.
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*
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* assoc-terminal = <&headphones_output>;
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*/
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front-left;
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};
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in_terminal: in_terminal {
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compatible = "zephyr,uac2-output-terminal";
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data-source = <&mic_input>;
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clock-source = <&uac_aclk>;
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terminal-type = <USB_TERMINAL_STREAMING>;
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};
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as_iso_out: out_interface {
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compatible = "zephyr,uac2-audio-streaming";
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linked-terminal = <&out_terminal>;
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implicit-feedback;
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subslot-size = <2>;
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bit-resolution = <16>;
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};
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as_iso_in: in_interface {
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compatible = "zephyr,uac2-audio-streaming";
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linked-terminal = <&in_terminal>;
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implicit-feedback;
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subslot-size = <2>;
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bit-resolution = <16>;
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};
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};
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};
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@ -0,0 +1,2 @@
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#Enable timer for asynchronous feedback
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CONFIG_NRFX_TIMER2=y
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@ -0,0 +1,29 @@
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/*
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* Copyright (c) 2023 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include "../app.overlay"
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&pinctrl {
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i2s0_default_alt: i2s0_default_alt {
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group1 {
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psels = <NRF_PSEL(I2S_SCK_M, 1, 15)>,
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<NRF_PSEL(I2S_LRCK_M, 1, 12)>,
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<NRF_PSEL(I2S_SDOUT, 1, 13)>,
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<NRF_PSEL(I2S_SDIN, 1, 14)>;
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};
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};
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};
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&clock {
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hfclkaudio-frequency = <12288000>;
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};
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i2s_rxtx: &i2s0 {
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status = "okay";
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pinctrl-0 = <&i2s0_default_alt>;
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pinctrl-names = "default";
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clock-source = "ACLK";
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};
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12
samples/subsys/usb/uac2_implicit_feedback/prj.conf
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12
samples/subsys/usb/uac2_implicit_feedback/prj.conf
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CONFIG_I2S=y
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#USB related configs
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CONFIG_USB_DEVICE_STACK_NEXT=y
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CONFIG_USBD_AUDIO2_CLASS=y
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CONFIG_SAMPLE_USBD_PID=0x000F
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CONFIG_SAMPLE_USBD_PRODUCT="UAC2 implicit feedback sample"
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#LOG subsystem related configs
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CONFIG_LOG=y
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CONFIG_USBD_LOG_LEVEL_WRN=y
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CONFIG_UDC_DRIVER_LOG_LEVEL_WRN=y
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10
samples/subsys/usb/uac2_implicit_feedback/sample.yaml
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10
samples/subsys/usb/uac2_implicit_feedback/sample.yaml
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sample:
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name: USB Audio 2 asynchronous implicit feedback sample
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tests:
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sample.subsys.usb.uac2_implicit_feedback:
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depends_on:
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- usbd
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- i2s
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tags: usb i2s
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platform_allow: nrf5340dk/nrf5340/cpuapp
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harness: TBD
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35
samples/subsys/usb/uac2_implicit_feedback/src/feedback.h
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35
samples/subsys/usb/uac2_implicit_feedback/src/feedback.h
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/*
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* Copyright (c) 2024 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef FEEDBACK_H_
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#define FEEDBACK_H_
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#include <stdint.h>
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/* Nominal number of samples received on each SOF. This sample is currently
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* supporting only 48 kHz sample rate.
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*/
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#define SAMPLES_PER_SOF 48
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struct feedback_ctx *feedback_init(void);
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void feedback_reset_ctx(struct feedback_ctx *ctx);
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void feedback_process(struct feedback_ctx *ctx);
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void feedback_start(struct feedback_ctx *ctx, int i2s_blocks_queued);
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/* Return offset between I2S block start and USB SOF in samples.
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*
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* Positive offset means that I2S block started at least 1 sample after SOF and
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* to correct the situation, shorter than nominal buffers are needed.
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*
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* Negative offset means that I2S block started at least 1 sample before SOF and
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* to correct the situation, larger than nominal buffers are needed.
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*
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* Offset 0 means that I2S block started within 1 sample around SOF. This is the
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* dominant value expected during normal operation.
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*/
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int feedback_samples_offset(struct feedback_ctx *ctx);
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#endif /* FEEDBACK_H_ */
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/*
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* Copyright (c) 2024 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/kernel.h>
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#include "feedback.h"
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#warning "No target specific feedback code, overruns/underruns will occur"
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struct feedback_ctx *feedback_init(void)
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{
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return NULL;
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}
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void feedback_process(struct feedback_ctx *ctx)
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{
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ARG_UNUSED(ctx);
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}
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void feedback_reset_ctx(struct feedback_ctx *ctx)
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{
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ARG_UNUSED(ctx);
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}
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void feedback_start(struct feedback_ctx *ctx, int i2s_blocks_queued)
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{
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ARG_UNUSED(ctx);
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ARG_UNUSED(i2s_blocks_queued);
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}
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int feedback_samples_offset(struct feedback_ctx *ctx)
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{
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ARG_UNUSED(ctx);
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/* Always send nominal number of samples */
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return 0;
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}
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185
samples/subsys/usb/uac2_implicit_feedback/src/feedback_nrf53.c
Normal file
185
samples/subsys/usb/uac2_implicit_feedback/src/feedback_nrf53.c
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/*
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* Copyright (c) 2024 Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <stdlib.h>
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#include <zephyr/logging/log.h>
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#include "feedback.h"
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#include <nrfx_dppi.h>
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#include <nrfx_timer.h>
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#include <hal/nrf_usbd.h>
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#include <hal/nrf_i2s.h>
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#include <helpers/nrfx_gppi.h>
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LOG_MODULE_REGISTER(feedback, LOG_LEVEL_INF);
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#define FEEDBACK_TIMER_INSTANCE_NUMBER 2
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#define FEEDBACK_TIMER_USBD_SOF_CAPTURE 0
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#define FEEDBACK_TIMER_I2S_FRAMESTART_CAPTURE 1
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static const nrfx_timer_t feedback_timer_instance =
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NRFX_TIMER_INSTANCE(FEEDBACK_TIMER_INSTANCE_NUMBER);
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/* While it might be possible to determine I2S FRAMESTART to USB SOF offset
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* entirely in software, the I2S API lacks appropriate timestamping. Therefore
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* this sample uses target-specific code to perform the measurements. Note that
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* the use of dedicated target-specific peripheral essentially eliminates
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* software scheduling jitter and it is likely that a pure software only
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* solution would require additional filtering in indirect offset measurements.
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*
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* Use timer clock (independent from both Audio clock and USB host SOF clock)
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* values directly to determine samples offset. This works fine because the
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* regulator cares only about error (SOF offset is both error and regulator
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* input) and achieves its goal by sending nominal + 1 or nominal - 1 samples.
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* SOF offset is around 0 when regulated and therefore the relative clock
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* frequency discrepancies are essentially negligible.
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*/
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#define CLKS_PER_SAMPLE (16000000 / (SAMPLES_PER_SOF * 1000))
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static struct feedback_ctx {
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int32_t rel_sof_offset;
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int32_t base_sof_offset;
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} fb_ctx;
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struct feedback_ctx *feedback_init(void)
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{
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nrfx_err_t err;
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uint8_t usbd_sof_gppi_channel;
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uint8_t i2s_framestart_gppi_channel;
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const nrfx_timer_config_t cfg = {
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.frequency = NRFX_MHZ_TO_HZ(16UL),
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.mode = NRF_TIMER_MODE_TIMER,
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.bit_width = NRF_TIMER_BIT_WIDTH_32,
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.interrupt_priority = NRFX_TIMER_DEFAULT_CONFIG_IRQ_PRIORITY,
|
||||||
|
.p_context = NULL,
|
||||||
|
};
|
||||||
|
|
||||||
|
feedback_reset_ctx(&fb_ctx);
|
||||||
|
|
||||||
|
err = nrfx_timer_init(&feedback_timer_instance, &cfg, NULL);
|
||||||
|
if (err != NRFX_SUCCESS) {
|
||||||
|
LOG_ERR("nrfx timer init error - Return value: %d", err);
|
||||||
|
return &fb_ctx;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Subscribe TIMER CAPTURE task to USBD SOF event */
|
||||||
|
err = nrfx_gppi_channel_alloc(&usbd_sof_gppi_channel);
|
||||||
|
if (err != NRFX_SUCCESS) {
|
||||||
|
LOG_ERR("gppi_channel_alloc failed with: %d\n", err);
|
||||||
|
return &fb_ctx;
|
||||||
|
}
|
||||||
|
|
||||||
|
nrfx_gppi_channel_endpoints_setup(usbd_sof_gppi_channel,
|
||||||
|
nrf_usbd_event_address_get(NRF_USBD, NRF_USBD_EVENT_SOF),
|
||||||
|
nrfx_timer_capture_task_address_get(&feedback_timer_instance,
|
||||||
|
FEEDBACK_TIMER_USBD_SOF_CAPTURE));
|
||||||
|
nrfx_gppi_fork_endpoint_setup(usbd_sof_gppi_channel,
|
||||||
|
nrfx_timer_task_address_get(&feedback_timer_instance,
|
||||||
|
NRF_TIMER_TASK_CLEAR));
|
||||||
|
|
||||||
|
nrfx_gppi_channels_enable(BIT(usbd_sof_gppi_channel));
|
||||||
|
|
||||||
|
/* Subscribe TIMER CAPTURE task to I2S FRAMESTART event */
|
||||||
|
err = nrfx_gppi_channel_alloc(&i2s_framestart_gppi_channel);
|
||||||
|
if (err != NRFX_SUCCESS) {
|
||||||
|
LOG_ERR("gppi_channel_alloc failed with: %d\n", err);
|
||||||
|
return &fb_ctx;
|
||||||
|
}
|
||||||
|
|
||||||
|
nrfx_gppi_channel_endpoints_setup(i2s_framestart_gppi_channel,
|
||||||
|
nrf_i2s_event_address_get(NRF_I2S0, NRF_I2S_EVENT_FRAMESTART),
|
||||||
|
nrfx_timer_capture_task_address_get(&feedback_timer_instance,
|
||||||
|
FEEDBACK_TIMER_I2S_FRAMESTART_CAPTURE));
|
||||||
|
|
||||||
|
nrfx_gppi_channels_enable(BIT(i2s_framestart_gppi_channel));
|
||||||
|
|
||||||
|
/* Enable feedback timer */
|
||||||
|
nrfx_timer_enable(&feedback_timer_instance);
|
||||||
|
|
||||||
|
return &fb_ctx;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void update_sof_offset(struct feedback_ctx *ctx, uint32_t sof_cc,
|
||||||
|
uint32_t framestart_cc)
|
||||||
|
{
|
||||||
|
int sof_offset;
|
||||||
|
|
||||||
|
/* /2 because we treat the middle as a turning point from being
|
||||||
|
* "too late" to "too early".
|
||||||
|
*/
|
||||||
|
if (framestart_cc > (SAMPLES_PER_SOF * CLKS_PER_SAMPLE)/2) {
|
||||||
|
sof_offset = framestart_cc - SAMPLES_PER_SOF * CLKS_PER_SAMPLE;
|
||||||
|
} else {
|
||||||
|
sof_offset = framestart_cc;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* The heuristic above is not enough when the offset gets too large.
|
||||||
|
* If the sign of the simple heuristic changes, check whether the offset
|
||||||
|
* crossed through the zero or the outer bound.
|
||||||
|
*/
|
||||||
|
if ((ctx->rel_sof_offset >= 0) != (sof_offset >= 0)) {
|
||||||
|
uint32_t abs_diff;
|
||||||
|
int32_t base_change;
|
||||||
|
|
||||||
|
if (sof_offset >= 0) {
|
||||||
|
abs_diff = sof_offset - ctx->rel_sof_offset;
|
||||||
|
base_change = -(SAMPLES_PER_SOF * CLKS_PER_SAMPLE);
|
||||||
|
} else {
|
||||||
|
abs_diff = ctx->rel_sof_offset - sof_offset;
|
||||||
|
base_change = SAMPLES_PER_SOF * CLKS_PER_SAMPLE;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Adjust base offset only if the change happened through the
|
||||||
|
* outer bound. The actual changes should be significantly lower
|
||||||
|
* than the threshold here.
|
||||||
|
*/
|
||||||
|
if (abs_diff > (SAMPLES_PER_SOF * CLKS_PER_SAMPLE)/2) {
|
||||||
|
ctx->base_sof_offset += base_change;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
ctx->rel_sof_offset = sof_offset;
|
||||||
|
}
|
||||||
|
|
||||||
|
void feedback_process(struct feedback_ctx *ctx)
|
||||||
|
{
|
||||||
|
uint32_t sof_cc;
|
||||||
|
uint32_t framestart_cc;
|
||||||
|
|
||||||
|
sof_cc = nrfx_timer_capture_get(&feedback_timer_instance,
|
||||||
|
FEEDBACK_TIMER_USBD_SOF_CAPTURE);
|
||||||
|
framestart_cc = nrfx_timer_capture_get(&feedback_timer_instance,
|
||||||
|
FEEDBACK_TIMER_I2S_FRAMESTART_CAPTURE);
|
||||||
|
|
||||||
|
update_sof_offset(ctx, sof_cc, framestart_cc);
|
||||||
|
}
|
||||||
|
|
||||||
|
void feedback_reset_ctx(struct feedback_ctx *ctx)
|
||||||
|
{
|
||||||
|
ARG_UNUSED(ctx);
|
||||||
|
}
|
||||||
|
|
||||||
|
void feedback_start(struct feedback_ctx *ctx, int i2s_blocks_queued)
|
||||||
|
{
|
||||||
|
/* I2S data was supposed to go out at SOF, but it is inevitably
|
||||||
|
* delayed due to triggering I2S start by software. Set relative
|
||||||
|
* SOF offset value in a way that ensures that values past "half
|
||||||
|
* frame" are treated as "too late" instead of "too early"
|
||||||
|
*/
|
||||||
|
ctx->rel_sof_offset = (SAMPLES_PER_SOF * CLKS_PER_SAMPLE) / 2;
|
||||||
|
/* If there are more than 2 I2S TX blocks queued, use feedback regulator
|
||||||
|
* to correct the situation.
|
||||||
|
*/
|
||||||
|
ctx->base_sof_offset = (i2s_blocks_queued - 2) *
|
||||||
|
(SAMPLES_PER_SOF * CLKS_PER_SAMPLE);
|
||||||
|
}
|
||||||
|
|
||||||
|
int feedback_samples_offset(struct feedback_ctx *ctx)
|
||||||
|
{
|
||||||
|
int32_t offset = ctx->rel_sof_offset + ctx->base_sof_offset;
|
||||||
|
|
||||||
|
return offset / CLKS_PER_SAMPLE;
|
||||||
|
}
|
||||||
570
samples/subsys/usb/uac2_implicit_feedback/src/main.c
Normal file
570
samples/subsys/usb/uac2_implicit_feedback/src/main.c
Normal file
|
|
@ -0,0 +1,570 @@
|
||||||
|
/*
|
||||||
|
* Copyright (c) 2023-2024 Nordic Semiconductor ASA
|
||||||
|
*
|
||||||
|
* SPDX-License-Identifier: Apache-2.0
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include <stdint.h>
|
||||||
|
#include <stdlib.h>
|
||||||
|
|
||||||
|
#include <sample_usbd.h>
|
||||||
|
#include "feedback.h"
|
||||||
|
|
||||||
|
#include <zephyr/cache.h>
|
||||||
|
#include <zephyr/device.h>
|
||||||
|
#include <zephyr/usb/usbd.h>
|
||||||
|
#include <zephyr/usb/class/usbd_uac2.h>
|
||||||
|
#include <zephyr/drivers/i2s.h>
|
||||||
|
#include <zephyr/logging/log.h>
|
||||||
|
|
||||||
|
LOG_MODULE_REGISTER(uac2_sample, LOG_LEVEL_INF);
|
||||||
|
|
||||||
|
#define HEADPHONES_OUT_TERMINAL_ID UAC2_ENTITY_ID(DT_NODELABEL(out_terminal))
|
||||||
|
#define MICROPHONE_IN_TERMINAL_ID UAC2_ENTITY_ID(DT_NODELABEL(in_terminal))
|
||||||
|
|
||||||
|
#define SAMPLES_PER_SOF 48
|
||||||
|
#define SAMPLE_FREQUENCY (SAMPLES_PER_SOF * 1000)
|
||||||
|
#define SAMPLE_BIT_WIDTH 16
|
||||||
|
#define NUMBER_OF_CHANNELS 2
|
||||||
|
#define BYTES_PER_SAMPLE DIV_ROUND_UP(SAMPLE_BIT_WIDTH, 8)
|
||||||
|
#define BYTES_PER_SLOT (BYTES_PER_SAMPLE * NUMBER_OF_CHANNELS)
|
||||||
|
#define MIN_BLOCK_SIZE ((SAMPLES_PER_SOF - 1) * BYTES_PER_SLOT)
|
||||||
|
#define BLOCK_SIZE (SAMPLES_PER_SOF * BYTES_PER_SLOT)
|
||||||
|
#define MAX_BLOCK_SIZE ((SAMPLES_PER_SOF + 1) * BYTES_PER_SLOT)
|
||||||
|
|
||||||
|
/* Absolute minimum is 5 TX buffers (1 actively consumed by I2S, 2nd queued as
|
||||||
|
* next buffer, 3rd acquired by USB stack to receive data to, and 2 to handle
|
||||||
|
* SOF/I2S offset errors), but add 2 additional buffers to prevent out of memory
|
||||||
|
* errors when USB host decides to perform rapid terminal enable/disable cycles.
|
||||||
|
*/
|
||||||
|
#define I2S_BLOCKS 7
|
||||||
|
K_MEM_SLAB_DEFINE_STATIC(i2s_tx_slab, MAX_BLOCK_SIZE, I2S_BLOCKS, 4);
|
||||||
|
K_MEM_SLAB_DEFINE_STATIC(i2s_rx_slab, MAX_BLOCK_SIZE, I2S_BLOCKS, 4);
|
||||||
|
|
||||||
|
struct usb_i2s_ctx {
|
||||||
|
const struct device *i2s_dev;
|
||||||
|
bool headphones_enabled;
|
||||||
|
bool microphone_enabled;
|
||||||
|
bool i2s_started;
|
||||||
|
bool rx_started;
|
||||||
|
bool usb_data_received;
|
||||||
|
/* Counter used to determine when to start I2S and then when to start
|
||||||
|
* sending RX packets to host. Overflows are not a problem because this
|
||||||
|
* variable is not necessary after both I2S and RX is started.
|
||||||
|
*/
|
||||||
|
uint8_t i2s_counter;
|
||||||
|
struct feedback_ctx *fb;
|
||||||
|
|
||||||
|
/* Leftover samples from I2S receive buffer, already compacted to mono,
|
||||||
|
* that were not sent to host. The buffer, if not NULL, is allocated
|
||||||
|
* from I2S RX slab.
|
||||||
|
*/
|
||||||
|
uint8_t *pending_mic_buf;
|
||||||
|
uint8_t pending_mic_samples;
|
||||||
|
|
||||||
|
/* Rolling bit buffers for tracking nominal + 1 and nominal - 1 samples
|
||||||
|
* sent. Bits are mutually exclusive, i.e.:
|
||||||
|
* plus_ones | minus_ones = plus_ones ^ minus_ones
|
||||||
|
*
|
||||||
|
* Used to avoid overcompensation in feedback regulator. LSBs indicate
|
||||||
|
* latest write size.
|
||||||
|
*/
|
||||||
|
uint8_t plus_ones;
|
||||||
|
uint8_t minus_ones;
|
||||||
|
};
|
||||||
|
|
||||||
|
static void uac2_terminal_update_cb(const struct device *dev, uint8_t terminal,
|
||||||
|
bool enabled, bool microframes,
|
||||||
|
void *user_data)
|
||||||
|
{
|
||||||
|
struct usb_i2s_ctx *ctx = user_data;
|
||||||
|
|
||||||
|
/* This sample is for Full-Speed only devices. */
|
||||||
|
__ASSERT_NO_MSG(microframes == false);
|
||||||
|
|
||||||
|
if (terminal == HEADPHONES_OUT_TERMINAL_ID) {
|
||||||
|
ctx->headphones_enabled = enabled;
|
||||||
|
} else if (terminal == MICROPHONE_IN_TERMINAL_ID) {
|
||||||
|
ctx->microphone_enabled = enabled;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (ctx->i2s_started && !ctx->headphones_enabled &&
|
||||||
|
!ctx->microphone_enabled) {
|
||||||
|
i2s_trigger(ctx->i2s_dev, I2S_DIR_BOTH, I2S_TRIGGER_DROP);
|
||||||
|
ctx->i2s_started = false;
|
||||||
|
ctx->i2s_counter = 0;
|
||||||
|
ctx->plus_ones = ctx->minus_ones = 0;
|
||||||
|
if (ctx->pending_mic_samples) {
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, ctx->pending_mic_buf);
|
||||||
|
ctx->pending_mic_buf = NULL;
|
||||||
|
ctx->pending_mic_samples = 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void *uac2_get_recv_buf(const struct device *dev, uint8_t terminal,
|
||||||
|
uint16_t size, void *user_data)
|
||||||
|
{
|
||||||
|
ARG_UNUSED(dev);
|
||||||
|
struct usb_i2s_ctx *ctx = user_data;
|
||||||
|
void *buf = NULL;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
if (terminal == HEADPHONES_OUT_TERMINAL_ID) {
|
||||||
|
__ASSERT_NO_MSG(size <= MAX_BLOCK_SIZE);
|
||||||
|
|
||||||
|
if (!ctx->headphones_enabled) {
|
||||||
|
LOG_ERR("Buffer request on disabled terminal");
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
ret = k_mem_slab_alloc(&i2s_tx_slab, &buf, K_NO_WAIT);
|
||||||
|
if (ret != 0) {
|
||||||
|
buf = NULL;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
return buf;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void uac2_data_recv_cb(const struct device *dev, uint8_t terminal,
|
||||||
|
void *buf, uint16_t size, void *user_data)
|
||||||
|
{
|
||||||
|
struct usb_i2s_ctx *ctx = user_data;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
ctx->usb_data_received = true;
|
||||||
|
|
||||||
|
if (!ctx->headphones_enabled && !ctx->microphone_enabled) {
|
||||||
|
k_mem_slab_free(&i2s_tx_slab, buf);
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (!size) {
|
||||||
|
/* This code path is expected when host only records microphone
|
||||||
|
* data and is not streaming any audio to the headphones. Simply
|
||||||
|
* transmit as many zero-filled samples were last sent to allow
|
||||||
|
* the feedback regulator to work.
|
||||||
|
*
|
||||||
|
* When host is streaming audio, this can be a transient error.
|
||||||
|
* While the "feedback regulator delay" is likely to differ,
|
||||||
|
* it is still probably best to just zero-fill last sent number
|
||||||
|
* of samples. If we overcompensate as a result, the situation
|
||||||
|
* will stabilize after a while anyway.
|
||||||
|
*
|
||||||
|
* In either case, we have to keep I2S going and the only way
|
||||||
|
* we can control the SOF to I2S offset is by varying the number
|
||||||
|
* of samples sent.
|
||||||
|
*/
|
||||||
|
if (ctx->plus_ones & 1) {
|
||||||
|
size = (SAMPLES_PER_SOF + 1) * BYTES_PER_SLOT;
|
||||||
|
} else if (ctx->minus_ones & 1) {
|
||||||
|
size = (SAMPLES_PER_SOF - 1) * BYTES_PER_SLOT;
|
||||||
|
} else {
|
||||||
|
size = SAMPLES_PER_SOF * BYTES_PER_SLOT;
|
||||||
|
}
|
||||||
|
memset(buf, 0, size);
|
||||||
|
sys_cache_data_flush_range(buf, size);
|
||||||
|
}
|
||||||
|
|
||||||
|
LOG_DBG("Received %d data to input terminal %d", size, terminal);
|
||||||
|
|
||||||
|
ret = i2s_write(ctx->i2s_dev, buf, size);
|
||||||
|
if (ret < 0) {
|
||||||
|
ctx->i2s_started = false;
|
||||||
|
ctx->i2s_counter = 0;
|
||||||
|
ctx->plus_ones = ctx->minus_ones = 0;
|
||||||
|
if (ctx->pending_mic_samples) {
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, ctx->pending_mic_buf);
|
||||||
|
ctx->pending_mic_buf = NULL;
|
||||||
|
ctx->pending_mic_samples = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Most likely underrun occurred, prepare I2S restart */
|
||||||
|
i2s_trigger(ctx->i2s_dev, I2S_DIR_BOTH, I2S_TRIGGER_PREPARE);
|
||||||
|
|
||||||
|
ret = i2s_write(ctx->i2s_dev, buf, size);
|
||||||
|
if (ret < 0) {
|
||||||
|
/* Drop data block, will try again on next frame */
|
||||||
|
k_mem_slab_free(&i2s_tx_slab, buf);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
if (ret == 0) {
|
||||||
|
ctx->i2s_counter++;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void uac2_buf_release_cb(const struct device *dev, uint8_t terminal,
|
||||||
|
void *buf, void *user_data)
|
||||||
|
{
|
||||||
|
if (terminal == MICROPHONE_IN_TERMINAL_ID) {
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, buf);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Determine next number of samples to send, called at most once every SOF */
|
||||||
|
static int next_mic_num_samples(struct usb_i2s_ctx *ctx)
|
||||||
|
{
|
||||||
|
int offset = feedback_samples_offset(ctx->fb);
|
||||||
|
|
||||||
|
/* The rolling buffers essentially handle controller dead time, i.e.
|
||||||
|
* the buffers are used to prevent overcompensating on feedback offset.
|
||||||
|
* Remove the oldest entry by shifting the values by one bit.
|
||||||
|
*/
|
||||||
|
ctx->plus_ones <<= 1;
|
||||||
|
ctx->minus_ones <<= 1;
|
||||||
|
|
||||||
|
if ((offset < 0) && (POPCOUNT(ctx->plus_ones) < -offset)) {
|
||||||
|
/* I2S buffer starts at least 1 sample before SOF, send nominal
|
||||||
|
* + 1 samples to host in order to shift offset towards 0.
|
||||||
|
*/
|
||||||
|
ctx->plus_ones |= 1;
|
||||||
|
return SAMPLES_PER_SOF + 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
if ((offset > 0) && (POPCOUNT(ctx->minus_ones) < offset)) {
|
||||||
|
/* I2S buffer starts at least 1 sample after SOF, send nominal
|
||||||
|
* - 1 samples to host in order to shift offset towards 0
|
||||||
|
*/
|
||||||
|
ctx->minus_ones |= 1;
|
||||||
|
return SAMPLES_PER_SOF - 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* I2S is either spot on, or the offset is expected to correct soon */
|
||||||
|
return SAMPLES_PER_SOF;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void process_mic_data(const struct device *dev, struct usb_i2s_ctx *ctx)
|
||||||
|
{
|
||||||
|
size_t num_bytes;
|
||||||
|
uint8_t *dst, *src;
|
||||||
|
uint8_t *mic_buf;
|
||||||
|
void *rx_block;
|
||||||
|
int ret;
|
||||||
|
int samples_to_send, mic_samples, rx_samples, leftover_samples;
|
||||||
|
|
||||||
|
samples_to_send = next_mic_num_samples(ctx);
|
||||||
|
|
||||||
|
if (ctx->pending_mic_samples >= samples_to_send) {
|
||||||
|
/* No need to fetch new I2S samples, this happens shortly after
|
||||||
|
* we have "borrowed" samples from next buffer. This is expected
|
||||||
|
* and means that the streams have synchronized.
|
||||||
|
*/
|
||||||
|
rx_block = NULL;
|
||||||
|
rx_samples = 0;
|
||||||
|
} else {
|
||||||
|
ret = i2s_read(ctx->i2s_dev, &rx_block, &num_bytes);
|
||||||
|
if (ret) {
|
||||||
|
/* No data available, I2S will restart soon */
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
sys_cache_data_invd_range(rx_block, num_bytes);
|
||||||
|
|
||||||
|
/* I2S operates on 2 channels (stereo) */
|
||||||
|
rx_samples = num_bytes / (BYTES_PER_SAMPLE * 2);
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Prepare microphone data to send, use pending samples if any */
|
||||||
|
src = rx_block;
|
||||||
|
if (ctx->pending_mic_buf) {
|
||||||
|
mic_buf = ctx->pending_mic_buf;
|
||||||
|
mic_samples = ctx->pending_mic_samples;
|
||||||
|
dst = &ctx->pending_mic_buf[mic_samples * BYTES_PER_SAMPLE];
|
||||||
|
} else if (rx_samples >= 1) {
|
||||||
|
/* First sample is already in place */
|
||||||
|
mic_buf = rx_block;
|
||||||
|
dst = &mic_buf[BYTES_PER_SAMPLE];
|
||||||
|
src += 2 * BYTES_PER_SAMPLE;
|
||||||
|
mic_samples = 1;
|
||||||
|
rx_samples--;
|
||||||
|
} else {
|
||||||
|
/* Something went horribly wrong, free the buffer and leave */
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, rx_block);
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Copy as many samples as possible, stop if mic buffer is ready */
|
||||||
|
while ((mic_samples < samples_to_send) && (rx_samples > 0)) {
|
||||||
|
memcpy(dst, src, BYTES_PER_SAMPLE);
|
||||||
|
|
||||||
|
dst += BYTES_PER_SAMPLE;
|
||||||
|
src += 2 * BYTES_PER_SAMPLE;
|
||||||
|
|
||||||
|
mic_samples++;
|
||||||
|
rx_samples--;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Is mic buffer ready to go? */
|
||||||
|
if (mic_samples < samples_to_send) {
|
||||||
|
/* No, we have to borrow sample from next buffer. This can only
|
||||||
|
* happen if we fully drained current receive buffer.
|
||||||
|
*/
|
||||||
|
__ASSERT_NO_MSG(rx_samples == 0);
|
||||||
|
|
||||||
|
if (rx_block != mic_buf) {
|
||||||
|
/* RX buffer no longer needed, samples are in mic_buf */
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, rx_block);
|
||||||
|
}
|
||||||
|
|
||||||
|
ret = i2s_read(ctx->i2s_dev, &rx_block, &num_bytes);
|
||||||
|
if (ret) {
|
||||||
|
/* No data, I2S will likely restart due to error soon */
|
||||||
|
ctx->pending_mic_buf = mic_buf;
|
||||||
|
ctx->pending_mic_samples = mic_samples;
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
sys_cache_data_invd_range(rx_block, num_bytes);
|
||||||
|
|
||||||
|
src = rx_block;
|
||||||
|
rx_samples = num_bytes / (BYTES_PER_SAMPLE * 2);
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Copy remaining sample, under normal conditions (i.e. connected to
|
||||||
|
* non-malicious host) this is guaranteed to fully fill mic_buf.
|
||||||
|
*/
|
||||||
|
while ((mic_samples < samples_to_send) && (rx_samples > 0)) {
|
||||||
|
memcpy(dst, src, BYTES_PER_SAMPLE);
|
||||||
|
|
||||||
|
dst += BYTES_PER_SAMPLE;
|
||||||
|
src += 2 * BYTES_PER_SAMPLE;
|
||||||
|
|
||||||
|
mic_samples++;
|
||||||
|
rx_samples--;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Are we still short on samples? */
|
||||||
|
if (mic_samples < samples_to_send) {
|
||||||
|
/* The only possibility for this code to execute is that we were
|
||||||
|
* short on samples and the next block (pointed to by rx_block)
|
||||||
|
* did not contain enough samples to fill the gap.
|
||||||
|
*/
|
||||||
|
__ASSERT_NO_MSG(rx_block != mic_buf);
|
||||||
|
|
||||||
|
/* Bailing out at this point likely leads to faster recovery.
|
||||||
|
* Note that this should never happen during normal operation.
|
||||||
|
*/
|
||||||
|
ctx->pending_mic_buf = mic_buf;
|
||||||
|
ctx->pending_mic_samples = mic_samples;
|
||||||
|
|
||||||
|
/* RX buffer is no longer needed */
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, rx_block);
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Handle any potential leftover, start by sanitizing length */
|
||||||
|
leftover_samples = mic_samples - samples_to_send + rx_samples;
|
||||||
|
if (leftover_samples > (MAX_BLOCK_SIZE / BYTES_PER_SAMPLE)) {
|
||||||
|
size_t dropped_samples =
|
||||||
|
leftover_samples - (MAX_BLOCK_SIZE / BYTES_PER_SAMPLE);
|
||||||
|
|
||||||
|
LOG_WRN("Too many leftover samples, dropping %d samples",
|
||||||
|
dropped_samples);
|
||||||
|
if (rx_samples >= dropped_samples) {
|
||||||
|
rx_samples -= dropped_samples;
|
||||||
|
} else {
|
||||||
|
mic_samples -= (dropped_samples - rx_samples);
|
||||||
|
rx_samples = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
leftover_samples = (MAX_BLOCK_SIZE / BYTES_PER_SAMPLE);
|
||||||
|
}
|
||||||
|
|
||||||
|
if (leftover_samples == 0) {
|
||||||
|
/* No leftover samples */
|
||||||
|
if ((rx_block != NULL) && (rx_block != mic_buf)) {
|
||||||
|
/* All samples were copied, free source buffer */
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, rx_block);
|
||||||
|
}
|
||||||
|
rx_block = NULL;
|
||||||
|
} else if ((mic_samples > samples_to_send) ||
|
||||||
|
((rx_samples > 0) && (rx_block == mic_buf))) {
|
||||||
|
/* Leftover samples have to be copied to new buffer */
|
||||||
|
ret = k_mem_slab_alloc(&i2s_rx_slab, &rx_block, K_NO_WAIT);
|
||||||
|
if (ret != 0) {
|
||||||
|
LOG_WRN("Out of memory dropping %d samples",
|
||||||
|
leftover_samples);
|
||||||
|
mic_samples = samples_to_send;
|
||||||
|
rx_samples = 0;
|
||||||
|
rx_block = NULL;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/* At this point rx_block is either
|
||||||
|
* * NULL if there are no leftover samples, OR
|
||||||
|
* * src buffer if leftover data can be copied from back to front, OR
|
||||||
|
* * brand new buffer if there is leftover data in mic buffer.
|
||||||
|
*/
|
||||||
|
ctx->pending_mic_buf = rx_block;
|
||||||
|
ctx->pending_mic_samples = 0;
|
||||||
|
|
||||||
|
/* Copy excess samples from pending mic buf, if any */
|
||||||
|
if (mic_samples > samples_to_send) {
|
||||||
|
size_t bytes;
|
||||||
|
|
||||||
|
/* Samples in mic buffer are already compacted */
|
||||||
|
bytes = (mic_samples - samples_to_send) * BYTES_PER_SAMPLE;
|
||||||
|
memcpy(ctx->pending_mic_buf, &mic_buf[mic_samples], bytes);
|
||||||
|
|
||||||
|
ctx->pending_mic_samples = mic_samples - samples_to_send;
|
||||||
|
dst = &ctx->pending_mic_buf[bytes];
|
||||||
|
} else {
|
||||||
|
dst = ctx->pending_mic_buf;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Copy excess samples from src buffer, so we don't lose any */
|
||||||
|
while (rx_samples > 0) {
|
||||||
|
memcpy(dst, src, BYTES_PER_SAMPLE);
|
||||||
|
|
||||||
|
dst += BYTES_PER_SAMPLE;
|
||||||
|
src += 2 * BYTES_PER_SAMPLE;
|
||||||
|
|
||||||
|
ctx->pending_mic_samples++;
|
||||||
|
rx_samples--;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Finally send the microphone samples to host */
|
||||||
|
sys_cache_data_flush_range(mic_buf, mic_samples * BYTES_PER_SAMPLE);
|
||||||
|
if (usbd_uac2_send(dev, MICROPHONE_IN_TERMINAL_ID,
|
||||||
|
mic_buf, mic_samples * BYTES_PER_SAMPLE) < 0) {
|
||||||
|
k_mem_slab_free(&i2s_rx_slab, mic_buf);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void uac2_sof(const struct device *dev, void *user_data)
|
||||||
|
{
|
||||||
|
ARG_UNUSED(dev);
|
||||||
|
struct usb_i2s_ctx *ctx = user_data;
|
||||||
|
|
||||||
|
if (ctx->i2s_started) {
|
||||||
|
feedback_process(ctx->fb);
|
||||||
|
}
|
||||||
|
|
||||||
|
/* If we didn't receive data since last SOF but either terminal is
|
||||||
|
* enabled, then we have to come up with the buffer ourself to keep
|
||||||
|
* I2S going.
|
||||||
|
*/
|
||||||
|
if (!ctx->usb_data_received &&
|
||||||
|
(ctx->microphone_enabled || ctx->headphones_enabled)) {
|
||||||
|
/* No data received since last SOF but we have to keep going */
|
||||||
|
void *buf;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
ret = k_mem_slab_alloc(&i2s_tx_slab, &buf, K_NO_WAIT);
|
||||||
|
if (ret != 0) {
|
||||||
|
buf = NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (buf) {
|
||||||
|
/* Use size 0 to utilize zero-fill functionality */
|
||||||
|
uac2_data_recv_cb(dev, HEADPHONES_OUT_TERMINAL_ID,
|
||||||
|
buf, 0, user_data);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
ctx->usb_data_received = false;
|
||||||
|
|
||||||
|
/* We want to maintain 3 SOFs delay, i.e. samples received from host
|
||||||
|
* during SOF n should be transmitted on I2S during SOF n+3. This
|
||||||
|
* provides enough wiggle room for software scheduling that effectively
|
||||||
|
* eliminates "buffers not provided in time" problem.
|
||||||
|
*
|
||||||
|
* ">= 2" translates into 3 SOFs delay because the timeline is:
|
||||||
|
* USB SOF n
|
||||||
|
* OUT DATA0 n received from host
|
||||||
|
* USB SOF n+1
|
||||||
|
* DATA0 n is available to UDC driver (See Universal Serial Bus
|
||||||
|
* Specification Revision 2.0 5.12.5 Data Prebuffering) and copied
|
||||||
|
* to I2S buffer before SOF n+2; i2s_counter = 1
|
||||||
|
* OUT DATA0 n+1 received from host
|
||||||
|
* USB SOF n+2
|
||||||
|
* DATA0 n+1 is copied; i2s_counter = 2
|
||||||
|
* OUT DATA0 n+2 received from host
|
||||||
|
* USB SOF n+3
|
||||||
|
* This function triggers I2S start
|
||||||
|
* DATA0 n+2 is copied; i2s_counter is no longer relevant
|
||||||
|
* OUT DATA0 n+3 received from host
|
||||||
|
*/
|
||||||
|
if (!ctx->i2s_started &&
|
||||||
|
(ctx->headphones_enabled || ctx->microphone_enabled) &&
|
||||||
|
ctx->i2s_counter >= 2) {
|
||||||
|
i2s_trigger(ctx->i2s_dev, I2S_DIR_BOTH, I2S_TRIGGER_START);
|
||||||
|
ctx->i2s_started = true;
|
||||||
|
feedback_start(ctx->fb, ctx->i2s_counter);
|
||||||
|
ctx->i2s_counter = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Start sending I2S RX data only when there are at least 3 buffers
|
||||||
|
* ready with data. This guarantees that there'll always be a buffer
|
||||||
|
* available from which sample can be borrowed.
|
||||||
|
*/
|
||||||
|
if (!ctx->rx_started && ctx->i2s_started && ctx->i2s_counter >= 3) {
|
||||||
|
ctx->rx_started = true;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (ctx->rx_started) {
|
||||||
|
process_mic_data(dev, ctx);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct uac2_ops usb_audio_ops = {
|
||||||
|
.sof_cb = uac2_sof,
|
||||||
|
.terminal_update_cb = uac2_terminal_update_cb,
|
||||||
|
.get_recv_buf = uac2_get_recv_buf,
|
||||||
|
.data_recv_cb = uac2_data_recv_cb,
|
||||||
|
.buf_release_cb = uac2_buf_release_cb,
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct usb_i2s_ctx main_ctx;
|
||||||
|
|
||||||
|
int main(void)
|
||||||
|
{
|
||||||
|
const struct device *dev = DEVICE_DT_GET(DT_NODELABEL(uac2_headset));
|
||||||
|
struct usbd_context *sample_usbd;
|
||||||
|
struct i2s_config config;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
main_ctx.i2s_dev = DEVICE_DT_GET(DT_NODELABEL(i2s_rxtx));
|
||||||
|
|
||||||
|
if (!device_is_ready(main_ctx.i2s_dev)) {
|
||||||
|
printk("%s is not ready\n", main_ctx.i2s_dev->name);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
config.word_size = SAMPLE_BIT_WIDTH;
|
||||||
|
config.channels = NUMBER_OF_CHANNELS;
|
||||||
|
config.format = I2S_FMT_DATA_FORMAT_I2S;
|
||||||
|
config.options = I2S_OPT_BIT_CLK_MASTER | I2S_OPT_FRAME_CLK_MASTER;
|
||||||
|
config.frame_clk_freq = SAMPLE_FREQUENCY;
|
||||||
|
config.mem_slab = &i2s_tx_slab;
|
||||||
|
config.block_size = MAX_BLOCK_SIZE;
|
||||||
|
config.timeout = 0;
|
||||||
|
|
||||||
|
ret = i2s_configure(main_ctx.i2s_dev, I2S_DIR_TX, &config);
|
||||||
|
if (ret < 0) {
|
||||||
|
printk("Failed to configure TX stream: %d\n", ret);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
config.mem_slab = &i2s_rx_slab;
|
||||||
|
ret = i2s_configure(main_ctx.i2s_dev, I2S_DIR_RX, &config);
|
||||||
|
if (ret < 0) {
|
||||||
|
printk("Failed to configure RX stream: %d\n", ret);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
main_ctx.fb = feedback_init();
|
||||||
|
|
||||||
|
usbd_uac2_set_ops(dev, &usb_audio_ops, &main_ctx);
|
||||||
|
|
||||||
|
sample_usbd = sample_usbd_init_device(NULL);
|
||||||
|
if (sample_usbd == NULL) {
|
||||||
|
return -ENODEV;
|
||||||
|
}
|
||||||
|
|
||||||
|
ret = usbd_enable(sample_usbd);
|
||||||
|
if (ret) {
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
Loading…
Add table
Add a link
Reference in a new issue