[RFC,v2,1/3] usb: gadget: f_uac2/u_audio: add feedback endpoint support

Message ID	20210430142625.357152-2-jbrunet@baylibre.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <linux-usb-owner@kernel.org> From: Jerome Brunet <jbrunet@baylibre.com> To: Ruslan Bilovol <ruslan.bilovol@gmail.com>, balbi@kernel.org Cc: linux-usb@vger.kernel.org, gschmottlach@gmail.com, Jerome Brunet <jbrunet@baylibre.com> Subject: [RFC PATCH v2 1/3] usb: gadget: f_uac2/u_audio: add feedback endpoint support Date: Fri, 30 Apr 2021 16:26:23 +0200 Message-Id: <20210430142625.357152-2-jbrunet@baylibre.com> In-Reply-To: <20210430142625.357152-1-jbrunet@baylibre.com> References: <20210430142625.357152-1-jbrunet@baylibre.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	UAC2 Gadget: feedback endpoint support \| expand [RFC,v2,0/3] UAC2 Gadget: feedback endpoint support [RFC,v2,1/3] usb: gadget: f_uac2/u_audio: add feedback endpoint support [RFC,v2,2/3] usb: gadget: f_uac2: add adaptive sync support for capture [RFC,v2,3/3] usb: gadget: u_audio: add real feedback implementation

diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c index 7aa4c8bc5a1a..5d63244ba319 100644 --- a/drivers/usb/gadget/function/f_uac2.c +++ b/drivers/usb/gadget/function/f_uac2.c @@ -240,7 +240,7 @@ static struct usb_interface_descriptor std_as_out_if1_desc = { .bDescriptorType = USB_DT_INTERFACE, .bAlternateSetting = 1, - .bNumEndpoints = 1, + .bNumEndpoints = 2, .bInterfaceClass = USB_CLASS_AUDIO, .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING, .bInterfaceProtocol = UAC_VERSION_2, @@ -317,6 +317,37 @@ static struct uac2_iso_endpoint_descriptor as_iso_out_desc = { .wLockDelay = 0, }; +/* STD AS ISO IN Feedback Endpoint */ +static struct usb_endpoint_descriptor fs_epin_fback_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 usb_endpoint_descriptor hs_epin_fback_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_USAGE_FEEDBACK, + .wMaxPacketSize = cpu_to_le16(4), + .bInterval = 4, +}; + +static struct usb_endpoint_descriptor ss_epin_fback_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(4), + .bInterval = 4, +}; + + /* Audio Streaming IN Interface - Alt0 */ static struct usb_interface_descriptor std_as_in_if0_desc = { .bLength = sizeof std_as_in_if0_desc, @@ -431,6 +462,7 @@ static struct usb_descriptor_header *fs_audio_desc[] = { (struct usb_descriptor_header *)&as_out_fmt1_desc, (struct usb_descriptor_header *)&fs_epout_desc, (struct usb_descriptor_header *)&as_iso_out_desc, + (struct usb_descriptor_header *)&fs_epin_fback_desc, (struct usb_descriptor_header *)&std_as_in_if0_desc, (struct usb_descriptor_header *)&std_as_in_if1_desc, @@ -461,6 +493,7 @@ static struct usb_descriptor_header *hs_audio_desc[] = { (struct usb_descriptor_header *)&as_out_fmt1_desc, (struct usb_descriptor_header *)&hs_epout_desc, (struct usb_descriptor_header *)&as_iso_out_desc, + (struct usb_descriptor_header *)&hs_epin_fback_desc, (struct usb_descriptor_header *)&std_as_in_if0_desc, (struct usb_descriptor_header *)&std_as_in_if1_desc, @@ -492,6 +525,7 @@ static struct usb_descriptor_header *ss_audio_desc[] = { (struct usb_descriptor_header *)&ss_epout_desc, (struct usb_descriptor_header *)&ss_epout_desc_comp, (struct usb_descriptor_header *)&as_iso_out_desc, + (struct usb_descriptor_header *)&ss_epin_fback_desc, (struct usb_descriptor_header *)&std_as_in_if0_desc, (struct usb_descriptor_header *)&std_as_in_if1_desc, @@ -568,22 +602,26 @@ static void setup_headers(struct f_uac2_opts *opts, struct usb_ss_ep_comp_descriptor *epin_desc_comp = NULL; struct usb_endpoint_descriptor *epout_desc; struct usb_endpoint_descriptor *epin_desc; + struct usb_endpoint_descriptor *epin_fback_desc; int i; switch (speed) { case USB_SPEED_FULL: epout_desc = &fs_epout_desc; epin_desc = &fs_epin_desc; + epin_fback_desc = &fs_epin_fback_desc; break; case USB_SPEED_HIGH: epout_desc = &hs_epout_desc; epin_desc = &hs_epin_desc; + epin_fback_desc = &hs_epin_fback_desc; break; default: epout_desc = &ss_epout_desc; epin_desc = &ss_epin_desc; epout_desc_comp = &ss_epout_desc_comp; epin_desc_comp = &ss_epin_desc_comp; + epin_fback_desc = &ss_epin_fback_desc; } i = 0; @@ -611,6 +649,7 @@ 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 (EPIN_EN(opts)) { headers[i++] = USBDHDR(&std_as_in_if0_desc); @@ -844,6 +883,12 @@ 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, + &fs_epin_fback_desc); + if (!agdev->in_ep_fback) { + dev_err(dev, "%s:%d Error!\n", __func__, __LINE__); + return -ENODEV; + } } if (EPIN_EN(uac2_opts)) { @@ -867,8 +912,10 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn) le16_to_cpu(ss_epout_desc.wMaxPacketSize)); hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress; + hs_epin_fback_desc.bEndpointAddress = fs_epin_fback_desc.bEndpointAddress; hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress; ss_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress; + ss_epin_fback_desc.bEndpointAddress = fs_epin_fback_desc.bEndpointAddress; ss_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress; setup_descriptor(uac2_opts); diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c index 5fbceee897a3..f637ebec80b0 100644 --- a/drivers/usb/gadget/function/u_audio.c +++ b/drivers/usb/gadget/function/u_audio.c @@ -38,6 +38,10 @@ struct uac_rtd_params { unsigned int max_psize; /* MaxPacketSize of endpoint */ struct usb_request **reqs; + + struct usb_request *req_fback; /* Feedback endpoint request */ + unsigned int ffback; /* Real frequency reported by feedback endpoint */ + bool fb_ep_enabled; /* if the ep is enabled */ }; struct snd_uac_chip { @@ -70,6 +74,32 @@ static const struct snd_pcm_hardware uac_pcm_hardware = { .periods_min = MIN_PERIODS, }; +static void u_audio_set_fback_frequency(enum usb_device_speed speed, + unsigned int freq, void *buf) +{ + u32 ff = 0; + + if (speed == USB_SPEED_FULL) { + /* + * Full-speed feedback endpoints report frequency + * in samples/microframe + * Format is encoded in Q10.10 left-justified in the 24 bits, + * so that it has a Q10.14 format. + */ + ff = DIV_ROUND_UP((freq << 14), 1000); + } else { + /* + * High-speed feedback endpoints report frequency + * in samples/microframe. + * Format is encoded in Q12.13 fitted into four bytes so that + * the binary point is located between the second and the third + * byte fromat (that is Q16.16) + */ + ff = DIV_ROUND_UP((freq << 13), 1000); + } + *(__le32 *)buf = cpu_to_le32(ff); +} + static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req) { unsigned int pending; @@ -173,6 +203,34 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req) dev_err(uac->card->dev, "%d Error!\n", __LINE__); } +static void u_audio_iso_fback_complete(struct usb_ep *ep, + struct usb_request *req) +{ + struct uac_rtd_params *prm = req->context; + struct snd_uac_chip *uac = prm->uac; + struct g_audio *audio_dev = uac->audio_dev; + int status = req->status; + unsigned long flags; + + /* i/f shutting down */ + if (!prm->fb_ep_enabled || req->status == -ESHUTDOWN) + return; + + /* + * We can't really do much about bad xfers. + * Afterall, the ISOCH xfers could fail legitimately. + */ + if (status) + pr_debug("%s: iso_complete status(%d) %d/%d\n", + __func__, status, req->actual, req->length); + + u_audio_set_fback_frequency(audio_dev->gadget->speed, + prm->ffback, req->buf); + + if (usb_ep_queue(ep, req, GFP_ATOMIC)) + dev_err(uac->card->dev, "%d Error!\n", __LINE__); +} + static int uac_pcm_trigger(struct snd_pcm_substream *substream, int cmd) { struct snd_uac_chip *uac = snd_pcm_substream_chip(substream); @@ -335,14 +393,33 @@ static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep) dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__); } +static inline void free_ep_fback(struct uac_rtd_params *prm, struct usb_ep *ep) +{ + struct snd_uac_chip *uac = prm->uac; + + if (!prm->fb_ep_enabled) + return; + + prm->fb_ep_enabled = false; + + if (prm->req_fback) { + usb_ep_dequeue(ep, prm->req_fback); + kfree(prm->req_fback->buf); + usb_ep_free_request(ep, prm->req_fback); + prm->req_fback = NULL; + } + + if (usb_ep_disable(ep)) + dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__); +} int u_audio_start_capture(struct g_audio *audio_dev) { struct snd_uac_chip *uac = audio_dev->uac; struct usb_gadget *gadget = audio_dev->gadget; struct device *dev = &gadget->dev; - struct usb_request *req; - struct usb_ep *ep; + struct usb_request *req, *req_fback; + struct usb_ep *ep, *ep_fback; struct uac_rtd_params *prm; struct uac_params *params = &audio_dev->params; int req_len, i; @@ -374,6 +451,42 @@ int u_audio_start_capture(struct g_audio *audio_dev) dev_err(dev, "%s:%d Error!\n", __func__, __LINE__); } + ep_fback = audio_dev->in_ep_fback; + if (!ep_fback) + return 0; + + /* Setup feedback endpoint */ + config_ep_by_speed(gadget, &audio_dev->func, ep_fback); + prm->fb_ep_enabled = true; + usb_ep_enable(ep_fback); + req_len = ep_fback->maxpacket; + + req_fback = usb_ep_alloc_request(ep_fback, GFP_ATOMIC); + if (req_fback == NULL) + return -ENOMEM; + + prm->req_fback = req_fback; + req_fback->zero = 0; + req_fback->context = prm; + req_fback->length = req_len; + req_fback->complete = u_audio_iso_fback_complete; + + req_fback->buf = kzalloc(req_len, GFP_ATOMIC); + if (!req_fback->buf) + return -ENOMEM; + + /* + * Configure the feedback endpoint's reported frequency. + * Always start with original frequency since its deviation can't + * be meauserd at start of playback + */ + prm->ffback = params->c_srate; + u_audio_set_fback_frequency(audio_dev->gadget->speed, + prm->ffback, req_fback->buf); + + if (usb_ep_queue(ep_fback, req_fback, GFP_ATOMIC)) + dev_err(dev, "%s:%d Error!\n", __func__, __LINE__); + return 0; } EXPORT_SYMBOL_GPL(u_audio_start_capture); @@ -382,6 +495,8 @@ void u_audio_stop_capture(struct g_audio *audio_dev) { struct snd_uac_chip *uac = audio_dev->uac; + if (audio_dev->in_ep_fback) + free_ep_fback(&uac->c_prm, audio_dev->in_ep_fback); free_ep(&uac->c_prm, audio_dev->out_ep); } EXPORT_SYMBOL_GPL(u_audio_stop_capture); diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h index 5ea6b86f1fda..53e6baf55cbf 100644 --- a/drivers/usb/gadget/function/u_audio.h +++ b/drivers/usb/gadget/function/u_audio.h @@ -30,7 +30,10 @@ struct g_audio { struct usb_gadget *gadget; struct usb_ep *in_ep; + struct usb_ep *out_ep; + /* feedback IN endpoint corresponding to out_ep */ + struct usb_ep *in_ep_fback; /* Max packet size for all in_ep possible speeds */ unsigned int in_ep_maxpsize;

[RFC,v2,1/3] usb: gadget: f_uac2/u_audio: add feedback endpoint support

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