@@ -8,6 +8,7 @@ Description:
c_chmask capture channel mask
c_srate capture sampling rate
c_ssize capture sample size (bytes)
+ c_sync capture synchronization type (async/adaptive)
p_chmask playback channel mask
p_srate playback sampling rate
p_ssize playback sample size (bytes)
@@ -728,6 +728,7 @@ The uac2 function provides these attributes in its function directory:
c_chmask capture channel mask
c_srate capture sampling rate
c_ssize capture sample size (bytes)
+ c_sync capture synchronization type (async/adaptive)
p_chmask playback channel mask
p_srate playback sampling rate
p_ssize playback sample size (bytes)
@@ -44,6 +44,7 @@
#define EPIN_EN(_opts) ((_opts)->p_chmask != 0)
#define EPOUT_EN(_opts) ((_opts)->c_chmask != 0)
+#define EPOUT_FBACK_IN_EN(_opts) ((_opts)->c_sync == USB_ENDPOINT_SYNC_ASYNC)
struct f_uac2 {
struct g_audio g_audio;
@@ -240,7 +241,7 @@ enum {
.bDescriptorType = USB_DT_INTERFACE,
.bAlternateSetting = 1,
- .bNumEndpoints = 2,
+ /* .bNumEndpoints = DYNAMIC */
.bInterfaceClass = USB_CLASS_AUDIO,
.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
.bInterfaceProtocol = UAC_VERSION_2,
@@ -273,7 +274,7 @@ enum {
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
- .bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
+ /* .bmAttributes = = DYNAMIC */
/* .wMaxPacketSize = DYNAMIC */
.bInterval = 1,
};
@@ -282,7 +283,7 @@ enum {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
- .bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
+ /* .bmAttributes = = DYNAMIC */
/* .wMaxPacketSize = DYNAMIC */
.bInterval = 1,
};
@@ -544,6 +545,8 @@ static void setup_descriptor(struct f_uac2_opts *opts)
iad_desc.bInterfaceCount = 1;
ac_hdr_desc.wTotalLength = cpu_to_le16(sizeof(ac_hdr_desc));
+ std_as_out_if1_desc.bNumEndpoints = 1;
+
if (EPIN_EN(opts)) {
u16 len = le16_to_cpu(ac_hdr_desc.wTotalLength);
@@ -561,6 +564,19 @@ static void setup_descriptor(struct f_uac2_opts *opts)
len += sizeof(io_out_ot_desc);
ac_hdr_desc.wTotalLength = cpu_to_le16(len);
iad_desc.bInterfaceCount++;
+
+ fs_epout_desc.bmAttributes = USB_ENDPOINT_XFER_ISOC;
+ hs_epout_desc.bmAttributes = USB_ENDPOINT_XFER_ISOC;
+ if (EPOUT_FBACK_IN_EN(opts)) {
+ fs_epout_desc.bmAttributes |= USB_ENDPOINT_SYNC_ASYNC;
+ hs_epout_desc.bmAttributes |= USB_ENDPOINT_SYNC_ASYNC;
+ std_as_out_if1_desc.bNumEndpoints++;
+ } else {
+ fs_epout_desc.bmAttributes |=
+ USB_ENDPOINT_SYNC_ADAPTIVE;
+ hs_epout_desc.bmAttributes |=
+ USB_ENDPOINT_SYNC_ADAPTIVE;
+ }
}
i = 0;
@@ -585,7 +601,8 @@ static void setup_descriptor(struct f_uac2_opts *opts)
fs_audio_desc[i++] = USBDHDR(&as_out_fmt1_desc);
fs_audio_desc[i++] = USBDHDR(&fs_epout_desc);
fs_audio_desc[i++] = USBDHDR(&as_iso_out_desc);
- fs_audio_desc[i++] = USBDHDR(&fs_epin_fback_desc);
+ if (EPOUT_FBACK_IN_EN(opts))
+ fs_audio_desc[i++] = USBDHDR(&fs_epin_fback_desc);
}
if (EPIN_EN(opts)) {
fs_audio_desc[i++] = USBDHDR(&std_as_in_if0_desc);
@@ -619,7 +636,8 @@ static void setup_descriptor(struct f_uac2_opts *opts)
hs_audio_desc[i++] = USBDHDR(&as_out_fmt1_desc);
hs_audio_desc[i++] = USBDHDR(&hs_epout_desc);
hs_audio_desc[i++] = USBDHDR(&as_iso_out_desc);
- hs_audio_desc[i++] = USBDHDR(&hs_epin_fback_desc);
+ if (EPOUT_FBACK_IN_EN(opts))
+ hs_audio_desc[i++] = USBDHDR(&hs_epin_fback_desc);
}
if (EPIN_EN(opts)) {
hs_audio_desc[i++] = USBDHDR(&std_as_in_if0_desc);
@@ -776,17 +794,22 @@ static int afunc_validate_opts(struct g_audio *agdev, struct device *dev)
return ret;
}
+ setup_descriptor(uac2_opts);
+
if (EPOUT_EN(uac2_opts)) {
agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
if (!agdev->out_ep) {
dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
return -ENODEV;
}
- agdev->in_ep_fback = usb_ep_autoconfig(gadget,
+ if (EPOUT_FBACK_IN_EN(uac2_opts)) {
+ agdev->in_ep_fback = usb_ep_autoconfig(gadget,
&fs_epin_fback_desc);
- if (!agdev->in_ep_fback) {
- dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
- return -ENODEV;
+ if (!agdev->in_ep_fback) {
+ dev_err(dev, "%s:%d Error!\n",
+ __func__, __LINE__);
+ return -ENODEV;
+ }
}
}
@@ -809,8 +832,6 @@ static int afunc_validate_opts(struct g_audio *agdev, struct device *dev)
hs_epin_fback_desc.bEndpointAddress = fs_epin_fback_desc.bEndpointAddress;
hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
- setup_descriptor(uac2_opts);
-
ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL,
NULL);
if (ret)
@@ -1133,11 +1154,68 @@ static void f_uac2_attr_release(struct config_item *item)
\
CONFIGFS_ATTR(f_uac2_opts_, name)
+#define UAC2_ATTRIBUTE_SYNC(name) \
+static ssize_t f_uac2_opts_##name##_show(struct config_item *item, \
+ char *page) \
+{ \
+ struct f_uac2_opts *opts = to_f_uac2_opts(item); \
+ int result; \
+ char *str; \
+ \
+ mutex_lock(&opts->lock); \
+ switch (opts->name) { \
+ case USB_ENDPOINT_SYNC_ASYNC: \
+ str = "async"; \
+ break; \
+ case USB_ENDPOINT_SYNC_ADAPTIVE: \
+ str = "adaptive"; \
+ break; \
+ default: \
+ str = "unknown"; \
+ break; \
+ } \
+ result = sprintf(page, "%s\n", str); \
+ mutex_unlock(&opts->lock); \
+ \
+ return result; \
+} \
+ \
+static ssize_t f_uac2_opts_##name##_store(struct config_item *item, \
+ const char *page, size_t len) \
+{ \
+ struct f_uac2_opts *opts = to_f_uac2_opts(item); \
+ int ret = 0; \
+ \
+ mutex_lock(&opts->lock); \
+ if (opts->refcnt) { \
+ ret = -EBUSY; \
+ goto end; \
+ } \
+ \
+ if (!strncmp(page, "async", 5)) \
+ opts->name = USB_ENDPOINT_SYNC_ASYNC; \
+ else if (!strncmp(page, "adaptive", 8)) \
+ opts->name = USB_ENDPOINT_SYNC_ADAPTIVE; \
+ else { \
+ ret = -EINVAL; \
+ goto end; \
+ } \
+ \
+ ret = len; \
+ \
+end: \
+ mutex_unlock(&opts->lock); \
+ return ret; \
+} \
+ \
+CONFIGFS_ATTR(f_uac2_opts_, name)
+
UAC2_ATTRIBUTE(p_chmask);
UAC2_ATTRIBUTE(p_srate);
UAC2_ATTRIBUTE(p_ssize);
UAC2_ATTRIBUTE(c_chmask);
UAC2_ATTRIBUTE(c_srate);
+UAC2_ATTRIBUTE_SYNC(c_sync);
UAC2_ATTRIBUTE(c_ssize);
UAC2_ATTRIBUTE(req_number);
@@ -1148,6 +1226,7 @@ static void f_uac2_attr_release(struct config_item *item)
&f_uac2_opts_attr_c_chmask,
&f_uac2_opts_attr_c_srate,
&f_uac2_opts_attr_c_ssize,
+ &f_uac2_opts_attr_c_sync,
&f_uac2_opts_attr_req_number,
NULL,
};
@@ -1186,6 +1265,7 @@ static struct usb_function_instance *afunc_alloc_inst(void)
opts->c_chmask = UAC2_DEF_CCHMASK;
opts->c_srate = UAC2_DEF_CSRATE;
opts->c_ssize = UAC2_DEF_CSSIZE;
+ opts->c_sync = UAC2_DEF_CSYNC;
opts->req_number = UAC2_DEF_REQ_NUM;
return &opts->func_inst;
}
@@ -21,6 +21,7 @@
#define UAC2_DEF_CCHMASK 0x3
#define UAC2_DEF_CSRATE 64000
#define UAC2_DEF_CSSIZE 2
+#define UAC2_DEF_CSYNC USB_ENDPOINT_SYNC_ASYNC
#define UAC2_DEF_REQ_NUM 2
struct f_uac2_opts {
@@ -31,6 +32,7 @@ struct f_uac2_opts {
int c_chmask;
int c_srate;
int c_ssize;
+ int c_sync;
int req_number;
bool bound;
Current f_uac2 USB OUT (aka 'capture') synchronization implements 'ASYNC' scenario which means USB Gadget 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 USB gadget to prevent overruns/underruns In case if Gadget can has no it's internal clock and can consume audio samples at any rate (for example, on the Gadget side someone records audio directly to a file, or audio samples are played through an external DAC as soon as they arrive), UAC2 spec suggests 'ADAPTIVE' synchronization type. Change UAC2 driver to make it configurable through additional 'c_sync' configfs file. Default remains 'asynchronous' with possibility to switch it to 'adaptive' Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com> --- Documentation/ABI/testing/configfs-usb-gadget-uac2 | 1 + Documentation/usb/gadget-testing.rst | 1 + drivers/usb/gadget/function/f_uac2.c | 102 ++++++++++++++++++--- drivers/usb/gadget/function/u_uac2.h | 2 + 4 files changed, 95 insertions(+), 11 deletions(-)