On Wed, Mar 08, 2023 at 03:57:27PM -0800, Wesley Cheng wrote:
> Some platforms may have support for offloading USB audio devices to a
> dedicated audio DSP. Introduce a set of APIs that allow for management of
> USB sound card and PCM devices enumerated by the USB SND class driver.
> This allows for the ASoC components to be aware of what USB devices are
> available for offloading.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> ---
> include/sound/soc-usb.h | 35 ++++++++
> sound/soc/Makefile | 2 +-
> sound/soc/soc-usb.c | 180 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 216 insertions(+), 1 deletion(-)
> create mode 100644 include/sound/soc-usb.h
> create mode 100644 sound/soc/soc-usb.c
>
> diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
> new file mode 100644
> index 000000000000..378992ea07bd
> --- /dev/null
> +++ b/include/sound/soc-usb.h
> @@ -0,0 +1,35 @@
> +/* SPDX-License-Identifier: GPL-2.0
> + *
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef __LINUX_SND_SOC_USB_H
> +#define __LINUX_SND_SOC_USB_H
> +
> +/**
> + * struct snd_soc_usb
> + * @list - list head for SND SOC struct list
> + * @dev - USB backend device reference
> + * @component - reference to DAPM component
> + * @connection_status_cb - callback to notify connection events
> + * @priv_data - driver data
> + **/
> +struct snd_soc_usb {
> + struct list_head list;
> + struct device *dev;
If this is a USB device, then make it a pointer to the real structure,
not just struct device.
> + struct snd_soc_component *component;
> + int (*connection_status_cb)(struct snd_soc_usb *usb, int card_idx,
> + int connected);
> + void *priv_data;
> +};
> +
> +int snd_soc_usb_connect(struct device *usbdev, int card_idx);
> +int snd_soc_usb_disconnect(struct device *usbdev);
> +void snd_soc_usb_set_priv_data(struct device *dev, void *priv);
> +void *snd_soc_usb_get_priv_data(struct device *usbdev);
Same here, you mix "dev" and "usbdev" in the names, make them real USB
devices please.
> +
> +struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
And here.
> + int (*connection_cb)(struct snd_soc_usb *usb, int card_idx,
> + int connected));
> +int snd_soc_usb_remove_port(struct device *dev);
> +#endif
> diff --git a/sound/soc/Makefile b/sound/soc/Makefile
> index 507eaed1d6a1..3305ceb59d84 100644
> --- a/sound/soc/Makefile
> +++ b/sound/soc/Makefile
> @@ -1,5 +1,5 @@
> # SPDX-License-Identifier: GPL-2.0
> -snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-utils.o soc-dai.o soc-component.o
> +snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-usb.o soc-utils.o soc-dai.o soc-component.o
> snd-soc-core-objs += soc-pcm.o soc-devres.o soc-ops.o soc-link.o soc-card.o
> snd-soc-core-$(CONFIG_SND_SOC_COMPRESS) += soc-compress.o
>
> diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
> new file mode 100644
> index 000000000000..4293451cdd49
> --- /dev/null
> +++ b/sound/soc/soc-usb.c
> @@ -0,0 +1,180 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +#include <linux/of.h>
> +#include <linux/usb.h>
> +#include <sound/soc.h>
> +#include <sound/soc-usb.h>
> +#include "../usb/card.h"
> +
> +static DEFINE_MUTEX(ctx_mutex);
> +static LIST_HEAD(usb_ctx_list);
> +
> +static struct device_node *snd_soc_find_phandle(struct device *dev)
> +{
> + struct device_node *node;
> +
> + node = of_parse_phandle(dev->of_node, "usb-soc-be", 0);
> + if (!node)
> + return ERR_PTR(-ENODEV);
> +
> + return node;
> +}
> +
> +static struct snd_soc_usb *snd_soc_find_usb_ctx(struct device *dev)
> +{
> + struct device_node *node;
> + struct snd_soc_usb *ctx = NULL;
> +
> + node = snd_soc_find_phandle(dev);
> + if (IS_ERR(node))
> + return NULL;
> +
> + mutex_lock(&ctx_mutex);
> + list_for_each_entry(ctx, &usb_ctx_list, list) {
> + if (ctx->dev->of_node == node) {
> + of_node_put(node);
> + mutex_unlock(&ctx_mutex);
> + return ctx;
> + }
> + }
> + of_node_put(node);
> + mutex_unlock(&ctx_mutex);
> +
> + return NULL;
> +}
> +
> +/**
> + * snd_soc_usb_get_priv_data() - Retrieve private data stored
> + * @dev: device reference
> + *
> + * Fetch the private data stored in the USB SND SOC structure.
> + *
> + */
> +void *snd_soc_usb_get_priv_data(struct device *dev)
> +{
> + struct snd_soc_usb *ctx;
> +
> + ctx = snd_soc_find_usb_ctx(dev);
> + if (!ctx) {
> + /* Check if backend device */
> + list_for_each_entry(ctx, &usb_ctx_list, list) {
> + if (dev->of_node == ctx->dev->of_node)
> + goto out;
No locking for this list traversal?
thanks,
greg k-h
