From 40c73b30546e759bedcec607fedc2d4be954508f Mon Sep 17 00:00:00 2001 From: Ruslan Bilovol Date: Fri, 4 Jun 2021 00:01:03 +0200 Subject: [PATCH] usb: gadget: f_uac2: add adaptive sync support for capture 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 Signed-off-by: Jerome Brunet Link: https://lore.kernel.org/r/20210603220104.1216001-3-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/configfs-usb-gadget-uac2 | 1 + Documentation/usb/gadget-testing.rst | 1 + drivers/usb/gadget/function/f_uac2.c | 100 +++++++++++++++++++-- drivers/usb/gadget/function/u_uac2.h | 2 + 4 files changed, 95 insertions(+), 9 deletions(-) diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uac2 b/Documentation/ABI/testing/configfs-usb-gadget-uac2 index d4356c8..e7e59d7 100644 --- a/Documentation/ABI/testing/configfs-usb-gadget-uac2 +++ b/Documentation/ABI/testing/configfs-usb-gadget-uac2 @@ -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) diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst index 2085e7b..f5a1266 100644 --- a/Documentation/usb/gadget-testing.rst +++ b/Documentation/usb/gadget-testing.rst @@ -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) diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c index 5d63244..321e6c0 100644 --- a/drivers/usb/gadget/function/f_uac2.c +++ b/drivers/usb/gadget/function/f_uac2.c @@ -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 @@ static struct usb_interface_descriptor std_as_out_if1_desc = { .bDescriptorType = USB_DT_INTERFACE, .bAlternateSetting = 1, - .bNumEndpoints = 2, + .bNumEndpoints = 1, .bInterfaceClass = USB_CLASS_AUDIO, .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING, .bInterfaceProtocol = UAC_VERSION_2, @@ -273,7 +274,7 @@ static struct usb_endpoint_descriptor fs_epout_desc = { .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 @@ static struct usb_endpoint_descriptor hs_epout_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, - .bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC, + /* .bmAttributes = DYNAMIC */ /* .wMaxPacketSize = DYNAMIC */ .bInterval = 4, }; @@ -292,7 +293,7 @@ static struct usb_endpoint_descriptor ss_epout_desc = { .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, - .bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC, + /* .bmAttributes = DYNAMIC */ /* .wMaxPacketSize = DYNAMIC */ .bInterval = 4, }; @@ -649,7 +650,9 @@ static void setup_headers(struct f_uac2_opts *opts, headers[i++] = USBDHDR(epout_desc_comp); headers[i++] = USBDHDR(&as_iso_out_desc); - headers[i++] = USBDHDR(epin_fback_desc); + + if (EPOUT_FBACK_IN_EN(opts)) + headers[i++] = USBDHDR(epin_fback_desc); } if (EPIN_EN(opts)) { headers[i++] = USBDHDR(&std_as_in_if0_desc); @@ -820,6 +823,23 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn) std_as_out_if1_desc.bInterfaceNumber = ret; uac2->as_out_intf = ret; uac2->as_out_alt = 0; + + if (EPOUT_FBACK_IN_EN(uac2_opts)) { + fs_epout_desc.bmAttributes = + USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC; + hs_epout_desc.bmAttributes = + USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC; + ss_epout_desc.bmAttributes = + USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC; + std_as_out_if1_desc.bNumEndpoints++; + } else { + fs_epout_desc.bmAttributes = + USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ADAPTIVE; + hs_epout_desc.bmAttributes = + USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ADAPTIVE; + ss_epout_desc.bmAttributes = + USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ADAPTIVE; + } } if (EPIN_EN(uac2_opts)) { @@ -883,11 +903,14 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn) 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; + } } } @@ -1242,11 +1265,68 @@ end: \ \ 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); @@ -1257,6 +1337,7 @@ static struct configfs_attribute *f_uac2_attrs[] = { &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, }; @@ -1295,6 +1376,7 @@ 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; } diff --git a/drivers/usb/gadget/function/u_uac2.h b/drivers/usb/gadget/function/u_uac2.h index b503571..13589c3 100644 --- a/drivers/usb/gadget/function/u_uac2.h +++ b/drivers/usb/gadget/function/u_uac2.h @@ -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; -- 2.7.4