On 10/17/23 15:00, Wesley Cheng wrote:
> The QC ADSP is able to support USB playback endpoints, so that the main
playback only?
> application processor can be placed into lower CPU power modes. This adds
> the required AFE port configurations and port start command to start an
> audio session.
>
> Specifically, the QC ADSP can support all potential endpoints that are
> exposed by the audio data interface. This includes, feedback endpoints
> (both implicit and explicit) as well as the isochronous (data) endpoints.
implicit feedback means support for capture. This is confusing...
> +static int q6usb_hw_params(struct snd_pcm_substream *substream,
> + struct snd_pcm_hw_params *params,
> + struct snd_soc_dai *dai)
> +{
> + struct q6afe_dai_data *dai_data = dev_get_drvdata(dai->dev);
> + int channels = params_channels(params);
> + int rate = params_rate(params);
> + struct q6afe_usb_cfg *usb = &dai_data->port_config[dai->id].usb_audio;
> +
> + usb->sample_rate = rate;
> + usb->num_channels = channels;
> +
> + switch (params_format(params)) {
> + case SNDRV_PCM_FORMAT_U16_LE:
> + case SNDRV_PCM_FORMAT_S16_LE:
> + case SNDRV_PCM_FORMAT_SPECIAL:
what does FORMAT_SPECIAL mean? the only other reference I see to this is
related to SLIMbus, not sure how this is related?
> + usb->bit_width = 16;
> + break;
> + case SNDRV_PCM_FORMAT_S24_LE:
> + case SNDRV_PCM_FORMAT_S24_3LE:
> + usb->bit_width = 24;
> + break;
> + case SNDRV_PCM_FORMAT_S32_LE:
> + usb->bit_width = 32;
> + break;
> + default:
> + dev_err(dai->dev, "%s: invalid format %d\n",
> + __func__, params_format(params));
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> @@ -617,6 +655,9 @@ static const struct snd_soc_dapm_route q6afe_dapm_routes[] = {
> {"TX_CODEC_DMA_TX_5", NULL, "TX_CODEC_DMA_TX_5 Capture"},
> {"RX_CODEC_DMA_RX_6 Playback", NULL, "RX_CODEC_DMA_RX_6"},
> {"RX_CODEC_DMA_RX_7 Playback", NULL, "RX_CODEC_DMA_RX_7"},
> +
> + /* USB playback AFE port receives data for playback, hence use the RX port */
> + {"USB Playback", NULL, "USB_RX"},
Capture for implicit feedback?
> };
>
> static int msm_dai_q6_dai_probe(struct snd_soc_dai *dai)
> @@ -644,6 +685,18 @@ static int msm_dai_q6_dai_remove(struct snd_soc_dai *dai)
> return 0;
> }
>
> +static const struct snd_soc_dai_ops q6usb_ops = {
> + .probe = msm_dai_q6_dai_probe,
> + .prepare = q6afe_dai_prepare,
> + .hw_params = q6usb_hw_params,
this is rather confusing with two different layers used for hw_params
and prepare? Additional comments or explanations wouldn't hurt.
> + .shutdown = q6afe_dai_shutdown,
> + /*
> + * Startup callback not needed, as AFE port start command passes the PCM
> + * parameters within the AFE command, which is provided by the PCM core
> + * during the prepare() stage.
This doesn't really explain why you need a shutdown?
> + * struct afe_param_id_usb_audio_dev_latency_mode
> + * @cfg_minor_version: Minor version used for tracking USB audio device
> + * configuration.
> + * Supported values:
> + * AFE_API_MINOR_VERSION_USB_AUDIO_LATENCY_MODE
> + * @mode: latency mode for the USB audio device
what are the different latency modes? and is this related to the latency
reporting that was added in the USB2 audio class IIRC?
> +static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
> +{
> + union afe_port_config *pcfg = &port->port_cfg;
> + struct afe_param_id_usb_audio_dev_params usb_dev;
> + struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
> + struct afe_param_id_usb_audio_svc_interval svc_int;
> + int ret = 0;
useless init overridden...
> +
> + if (!pcfg) {
> + dev_err(port->afe->dev, "%s: Error, no configuration data\n", __func__);
> + ret = -EINVAL;
> + goto exit;
> + }
> +
> + memset(&usb_dev, 0, sizeof(usb_dev));
> + memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
> + memset(&svc_int, 0, sizeof(svc_int));
> +
> + usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> + ret = q6afe_port_set_param_v2(port, &usb_dev,
.... here
> + AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
> + AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
> + if (ret) {
> + dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
> + __func__, ret);
> + goto exit;
> + }
> +
> + lpcm_fmt.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> + lpcm_fmt.endian = pcfg->usb_cfg.endian;
> + ret = q6afe_port_set_param_v2(port, &lpcm_fmt,
> + AFE_PARAM_ID_USB_AUDIO_DEV_LPCM_FMT,
> + AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(lpcm_fmt));
> + if (ret) {
> + dev_err(port->afe->dev, "%s: AFE device param cmd LPCM_FMT failed %d\n",
> + __func__, ret);
> + goto exit;
> + }
> +
> + svc_int.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> + svc_int.svc_interval = pcfg->usb_cfg.service_interval;
> + ret = q6afe_port_set_param_v2(port, &svc_int,
> + AFE_PARAM_ID_USB_AUDIO_SVC_INTERVAL,
> + AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(svc_int));
> + if (ret)
> + dev_err(port->afe->dev, "%s: AFE device param cmd svc_interval failed %d\n",
> + __func__, ret);
> +
> +exit:
> + return ret;
> +}
> -#define AFE_PORT_MAX 129
> +#define AFE_PORT_MAX 137
does this mean 8 ports are reserved for USB?
Or is this 137 just a random index coming from the AFE design?
