On 8/29/24 21:40, Wesley Cheng wrote:
> Create a USB BE component that will register a new USB port to the ASoC USB
> framework. This will handle determination on if the requested audio
> profile is supported by the USB device currently selected.
>
> Check for if the PCM format is supported during the hw_params callback. If
> the profile is not supported then the userspace ALSA entity will receive an
> error, and can take further action.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> ---
> include/sound/q6usboffload.h | 20 +++
> sound/soc/qcom/Kconfig | 10 ++
> sound/soc/qcom/qdsp6/Makefile | 1 +
> sound/soc/qcom/qdsp6/q6usb.c | 246 ++++++++++++++++++++++++++++++++++
> 4 files changed, 277 insertions(+)
> create mode 100644 include/sound/q6usboffload.h
> create mode 100644 sound/soc/qcom/qdsp6/q6usb.c
>
> diff --git a/include/sound/q6usboffload.h b/include/sound/q6usboffload.h
> new file mode 100644
> index 000000000000..49ab2c34b84c
> --- /dev/null
> +++ b/include/sound/q6usboffload.h
> @@ -0,0 +1,20 @@
> +/* SPDX-License-Identifier: GPL-2.0
> + *
> + * linux/sound/q6usboffload.h -- QDSP6 USB offload
not sure about the linux/ prefix?
> + *
> + * Copyright (c) 2022-2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +/**
> + * struct q6usb_offload
> + * @dev - dev handle to usb be
> + * @sid - streamID for iommu
> + * @intr_num - usb interrupter number
> + * @domain - allocated iommu domain
> + **/
> +struct q6usb_offload {
> + struct device *dev;
> + long long sid;
> + u16 intr_num;
> + struct iommu_domain *domain;
> +};
consider reordering to avoid holes/alignment issues, e.g. all pointers
first, then long long then u16
> +static int q6usb_hw_params(struct snd_pcm_substream *substream,
> + struct snd_pcm_hw_params *params,
> + struct snd_soc_dai *dai)
> +{
> + struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
> + struct snd_soc_pcm_runtime *rtd = substream->private_data;
> + struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
> + int direction = substream->stream;
> + struct q6afe_port *q6usb_afe;
> + struct snd_soc_usb_device *sdev;
> + int ret = -EINVAL;
> +
> + mutex_lock(&data->mutex);
> +
> + /* No active chip index */
> + if (list_empty(&data->devices))
> + goto out;
-ENODEV for the default return value>?
> +
> + sdev = list_last_entry(&data->devices, struct snd_soc_usb_device, list);
> +
> + ret = snd_soc_usb_find_supported_format(sdev->chip_idx, params, direction);
> + if (ret < 0)
> + goto out;
> +
> + q6usb_afe = q6afe_port_get_from_id(cpu_dai->dev, USB_RX);
> + if (IS_ERR(q6usb_afe))
> + goto out;
> +
> + /* Notify audio DSP about the devices being offloaded */
> + ret = afe_port_send_usb_dev_param(q6usb_afe, sdev->card_idx,
> + sdev->ppcm_idx[sdev->num_playback - 1]);
don't you need a symmetrical notification upon hw_free()?
Also what happens if there are multiple calls to hw_params, which is
quite legit in ALSA/ASoC?
