@@ -9,6 +9,7 @@ Description:
c_srate capture sampling rate
c_ssize capture sample size (bytes)
c_sync capture synchronization type (async/adaptive)
+ fb_max maximum extra bandwidth in async mode
p_chmask playback channel mask
p_srate playback sampling rate
p_ssize playback sample size (bytes)
@@ -729,6 +729,7 @@ The uac2 function provides these attributes in its function directory:
c_srate capture sampling rate
c_ssize capture sample size (bytes)
c_sync capture synchronization type (async/adaptive)
+ fb_max maximum extra bandwidth in async mode
p_chmask playback channel mask
p_srate playback sampling rate
p_ssize playback sample size (bytes)
@@ -584,8 +584,11 @@ static int set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
ssize = uac2_opts->c_ssize;
}
+ if (!is_playback && (uac2_opts->c_sync == USB_ENDPOINT_SYNC_ASYNC))
+ srate = srate * (1000 + uac2_opts->fb_max) / 1000;
+
max_size_bw = num_channels(chmask) * ssize *
- ((srate / (factor / (1 << (ep_desc->bInterval - 1)))) + 1);
+ DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1)));
ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_size_bw,
max_size_ep));
@@ -957,6 +960,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->params.c_srate = uac2_opts->c_srate;
agdev->params.c_ssize = uac2_opts->c_ssize;
agdev->params.req_number = uac2_opts->req_number;
+ agdev->params.fb_max = uac2_opts->fb_max;
ret = g_audio_setup(agdev, "UAC2 PCM", "UAC2_Gadget");
if (ret)
goto err_free_descs;
@@ -1329,6 +1333,7 @@ UAC2_ATTRIBUTE(c_srate);
UAC2_ATTRIBUTE_SYNC(c_sync);
UAC2_ATTRIBUTE(c_ssize);
UAC2_ATTRIBUTE(req_number);
+UAC2_ATTRIBUTE(fb_max);
static struct configfs_attribute *f_uac2_attrs[] = {
&f_uac2_opts_attr_p_chmask,
@@ -1339,6 +1344,7 @@ static struct configfs_attribute *f_uac2_attrs[] = {
&f_uac2_opts_attr_c_ssize,
&f_uac2_opts_attr_c_sync,
&f_uac2_opts_attr_req_number,
+ &f_uac2_opts_attr_fb_max,
NULL,
};
@@ -1378,6 +1384,7 @@ static struct usb_function_instance *afunc_alloc_inst(void)
opts->c_ssize = UAC2_DEF_CSSIZE;
opts->c_sync = UAC2_DEF_CSYNC;
opts->req_number = UAC2_DEF_REQ_NUM;
+ opts->fb_max = UAC2_DEF_FB_MAX;
return &opts->func_inst;
}
@@ -16,6 +16,7 @@
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
+#include <sound/control.h>
#include "u_audio.h"
@@ -35,12 +36,12 @@ struct uac_rtd_params {
void *rbuf;
+ unsigned int pitch; /* Stream pitch ratio to 1000000 */
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 */
};
@@ -75,18 +76,29 @@ static const struct snd_pcm_hardware uac_pcm_hardware = {
};
static void u_audio_set_fback_frequency(enum usb_device_speed speed,
- unsigned int freq, void *buf)
+ unsigned long long freq,
+ unsigned int pitch,
+ void *buf)
{
u32 ff = 0;
+ /*
+ * Because the pitch base is 1000000, the final divider here
+ * will be 1000 * 1000000 = 1953125 << 9
+ *
+ * Instead of dealing with big numbers lets fold this 9 left shift
+ */
+
if (speed == USB_SPEED_FULL) {
/*
* Full-speed feedback endpoints report frequency
- * in samples/microframe
+ * in samples/frame
* Format is encoded in Q10.10 left-justified in the 24 bits,
* so that it has a Q10.14 format.
+ *
+ * ff = (freq << 14) / 1000
*/
- ff = DIV_ROUND_UP((freq << 14), 1000);
+ freq <<= 5;
} else {
/*
* High-speed feedback endpoints report frequency
@@ -94,9 +106,14 @@ static void u_audio_set_fback_frequency(enum usb_device_speed speed,
* 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 = (freq << 16) / 8000
*/
- ff = DIV_ROUND_UP((freq << 13), 1000);
+ freq <<= 4;
}
+
+ ff = DIV_ROUND_CLOSEST_ULL((freq * pitch), 1953125);
+
*(__le32 *)buf = cpu_to_le32(ff);
}
@@ -209,8 +226,8 @@ static void u_audio_iso_fback_complete(struct usb_ep *ep,
struct uac_rtd_params *prm = req->context;
struct snd_uac_chip *uac = prm->uac;
struct g_audio *audio_dev = uac->audio_dev;
+ struct uac_params *params = &audio_dev->params;
int status = req->status;
- unsigned long flags;
/* i/f shutting down */
if (!prm->fb_ep_enabled || req->status == -ESHUTDOWN)
@@ -225,7 +242,8 @@ static void u_audio_iso_fback_complete(struct usb_ep *ep,
__func__, status, req->actual, req->length);
u_audio_set_fback_frequency(audio_dev->gadget->speed,
- prm->ffback, req->buf);
+ params->c_srate, prm->pitch,
+ req->buf);
if (usb_ep_queue(ep, req, GFP_ATOMIC))
dev_err(uac->card->dev, "%d Error!\n", __LINE__);
@@ -480,9 +498,10 @@ int u_audio_start_capture(struct g_audio *audio_dev)
* Always start with original frequency since its deviation can't
* be meauserd at start of playback
*/
- prm->ffback = params->c_srate;
+ prm->pitch = 1000000;
u_audio_set_fback_frequency(audio_dev->gadget->speed,
- prm->ffback, req_fback->buf);
+ params->c_srate, prm->pitch,
+ req_fback->buf);
if (usb_ep_queue(ep_fback, req_fback, GFP_ATOMIC))
dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
@@ -578,12 +597,82 @@ void u_audio_stop_playback(struct g_audio *audio_dev)
}
EXPORT_SYMBOL_GPL(u_audio_stop_playback);
+static int u_audio_pitch_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+ struct snd_uac_chip *uac = prm->uac;
+ struct g_audio *audio_dev = uac->audio_dev;
+ struct uac_params *params = &audio_dev->params;
+ unsigned int pitch_min, pitch_max;
+
+ pitch_min = (1000 - FBACK_SLOW_MAX) * 1000;
+ pitch_max = (1000 + params->fb_max) * 1000;
+
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = pitch_min;
+ uinfo->value.integer.max = pitch_max;
+ uinfo->value.integer.step = 1;
+ return 0;
+}
+
+static int u_audio_pitch_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+
+ ucontrol->value.integer.value[0] = prm->pitch;
+
+ return 0;
+}
+
+static int u_audio_pitch_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+ struct snd_uac_chip *uac = prm->uac;
+ struct g_audio *audio_dev = uac->audio_dev;
+ struct uac_params *params = &audio_dev->params;
+ unsigned int val;
+ unsigned int pitch_min, pitch_max;
+ int change = 0;
+
+ pitch_min = (1000 - FBACK_SLOW_MAX) * 1000;
+ pitch_max = (1000 + params->fb_max) * 1000;
+
+ val = ucontrol->value.integer.value[0];
+
+ if (val < pitch_min)
+ val = pitch_min;
+ if (val > pitch_max)
+ val = pitch_max;
+
+ if (prm->pitch != val) {
+ prm->pitch = val;
+ change = 1;
+ }
+
+ return change;
+}
+
+static const struct snd_kcontrol_new u_audio_controls[] = {
+{
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = "Capture Pitch 1000000",
+ .info = u_audio_pitch_info,
+ .get = u_audio_pitch_get,
+ .put = u_audio_pitch_put,
+},
+};
+
int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
const char *card_name)
{
struct snd_uac_chip *uac;
struct snd_card *card;
struct snd_pcm *pcm;
+ struct snd_kcontrol *kctl;
struct uac_params *params;
int p_chmask, c_chmask;
int err;
@@ -671,6 +760,23 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac_pcm_ops);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac_pcm_ops);
+ if (c_chmask && g_audio->in_ep_fback) {
+ strscpy(card->mixername, card_name, sizeof(card->driver));
+
+ kctl = snd_ctl_new1(&u_audio_controls[0], &uac->c_prm);
+ if (!kctl) {
+ err = -ENOMEM;
+ goto snd_fail;
+ }
+
+ kctl->id.device = pcm->device;
+ kctl->id.subdevice = 0;
+
+ err = snd_ctl_add(card, kctl);
+ if (err < 0)
+ goto snd_fail;
+ }
+
strscpy(card->driver, card_name, sizeof(card->driver));
strscpy(card->shortname, card_name, sizeof(card->shortname));
sprintf(card->longname, "%s %i", card_name, card->dev->id);
@@ -11,6 +11,14 @@
#include <linux/usb/composite.h>
+/*
+ * Same maximum frequency deviation on the slower side as in
+ * sound/usb/endpoint.c. Value is expressed in per-mil deviation.
+ * The maximum deviation on the faster side will be provided as
+ * parameter, as it impacts the endpoint required bandwidth.
+ */
+#define FBACK_SLOW_MAX 250
+
struct uac_params {
/* playback */
int p_chmask; /* channel mask */
@@ -23,6 +31,7 @@ struct uac_params {
int c_ssize; /* sample size */
int req_number; /* number of preallocated requests */
+ int fb_max; /* upper frequency drift feedback limit per-mil */
};
struct g_audio {
@@ -23,6 +23,7 @@
#define UAC2_DEF_CSSIZE 2
#define UAC2_DEF_CSYNC USB_ENDPOINT_SYNC_ASYNC
#define UAC2_DEF_REQ_NUM 2
+#define UAC2_DEF_FB_MAX 5
struct f_uac2_opts {
struct usb_function_instance func_inst;
@@ -34,6 +35,7 @@ struct f_uac2_opts {
int c_ssize;
int c_sync;
int req_number;
+ int fb_max;
bool bound;
struct mutex lock;