On Wed, Oct 18, 2023 at 12:39:07PM +0800, Charles Yi wrote:
> UAC1 has it's own freerunning clock and can update Host about
> real clock frequency through feedback endpoint so Host can align
> number of samples sent to the UAC1 to prevent overruns/underruns.
>
> Change UAC1 driver to make it configurable through additional
> 'c_sync' configfs file.
>
> Default remains 'asynchronous' with possibility to switch it
> to 'adaptive'.
>
> Signed-off-by: Charles Yi <be286@xxxxxxx>
> ---
> drivers/usb/gadget/function/f_uac1.c | 30 ++++++++++++++++++++++++++++
> drivers/usb/gadget/function/u_uac1.h | 2 ++
> 2 files changed, 32 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c
> index 6f0e1d803dc2..7a6fcb40bb46 100644
> --- a/drivers/usb/gadget/function/f_uac1.c
> +++ b/drivers/usb/gadget/function/f_uac1.c
> @@ -33,6 +33,8 @@
> #define FUOUT_EN(_opts) ((_opts)->c_mute_present \
> || (_opts)->c_volume_present)
>
> +#define EPOUT_FBACK_IN_EN(_opts) ((_opts)->c_sync == USB_ENDPOINT_SYNC_ASYNC)
> +
> struct f_uac1 {
> struct g_audio g_audio;
> u8 ac_intf, as_in_intf, as_out_intf;
> @@ -227,6 +229,16 @@ static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
> .wLockDelay = cpu_to_le16(1),
> };
>
> +static struct usb_endpoint_descriptor as_fback_ep_desc = {
> + .bLength = USB_DT_ENDPOINT_SIZE,
> + .bDescriptorType = USB_DT_ENDPOINT,
> +
> + .bEndpointAddress = USB_DIR_IN,
> + .bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_USAGE_FEEDBACK,
> + .wMaxPacketSize = cpu_to_le16(3),
> + .bInterval = 1,
> +};
> +
> static struct uac_format_type_i_discrete_descriptor as_in_type_i_desc = {
> .bLength = 0, /* filled on rate setup */
> .bDescriptorType = USB_DT_CS_INTERFACE,
> @@ -280,6 +292,7 @@ static struct usb_descriptor_header *f_audio_desc[] = {
>
> (struct usb_descriptor_header *)&as_out_ep_desc,
> (struct usb_descriptor_header *)&as_iso_out_desc,
> + (struct usb_descriptor_header *)&as_fback_ep_desc,
>
> (struct usb_descriptor_header *)&as_in_interface_alt_0_desc,
> (struct usb_descriptor_header *)&as_in_interface_alt_1_desc,
> @@ -1107,6 +1120,9 @@ static void setup_descriptor(struct f_uac1_opts *opts)
> f_audio_desc[i++] = USBDHDR(&as_out_type_i_desc);
> f_audio_desc[i++] = USBDHDR(&as_out_ep_desc);
> f_audio_desc[i++] = USBDHDR(&as_iso_out_desc);
> + if (EPOUT_FBACK_IN_EN(opts)) {
> + f_audio_desc[i++] = USBDHDR(&as_fback_ep_desc);
> + }
> }
> if (EPIN_EN(opts)) {
> f_audio_desc[i++] = USBDHDR(&as_in_interface_alt_0_desc);
> @@ -1317,6 +1333,12 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
> ac_header_desc->baInterfaceNr[ba_iface_id++] = status;
> uac1->as_out_intf = status;
> uac1->as_out_alt = 0;
> +
> + if (EPOUT_FBACK_IN_EN(audio_opts)) {
> + as_out_ep_desc.bmAttributes =
> + USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC;
> + as_out_interface_alt_1_desc.bNumEndpoints++;
> + }
> }
>
> if (EPIN_EN(audio_opts)) {
> @@ -1354,6 +1376,12 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
> goto err_free_fu;
> audio->out_ep = ep;
> audio->out_ep->desc = &as_out_ep_desc;
> + if (EPOUT_FBACK_IN_EN(audio_opts)) {
> + audio->in_ep_fback = usb_ep_autoconfig(gadget, &as_fback_ep_desc);
> + if (!audio->in_ep_fback) {
> + goto err_free_fu;
> + }
> + }
> }
>
> if (EPIN_EN(audio_opts)) {
> @@ -1685,6 +1713,8 @@ static struct usb_function_instance *f_audio_alloc_inst(void)
>
> opts->req_number = UAC1_DEF_REQ_NUM;
>
> + opts->c_sync = UAC1_DEF_CSYNC;
> +
> snprintf(opts->function_name, sizeof(opts->function_name), "AC Interface");
>
> return &opts->func_inst;
> diff --git a/drivers/usb/gadget/function/u_uac1.h b/drivers/usb/gadget/function/u_uac1.h
> index f7a616760e31..c6e2271e8cdd 100644
> --- a/drivers/usb/gadget/function/u_uac1.h
> +++ b/drivers/usb/gadget/function/u_uac1.h
> @@ -27,6 +27,7 @@
> #define UAC1_DEF_MAX_DB 0 /* 0 dB */
> #define UAC1_DEF_RES_DB (1*256) /* 1 dB */
>
> +#define UAC1_DEF_CSYNC USB_ENDPOINT_SYNC_ASYNC
>
> struct f_uac1_opts {
> struct usb_function_instance func_inst;
> @@ -56,6 +57,7 @@ struct f_uac1_opts {
>
> struct mutex lock;
> int refcnt;
> + int c_sync;
> };
>
> #endif /* __U_UAC1_H */
> --
> 2.34.1
>
>
Hi,
This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him
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