From: Julian Scheel <julian@xxxxxxxx>
Implement support for multiple sampling rates in u_audio part of the
audio gadget. The currently configured rates are exposed through
read-only amixer controls 'Capture Rate' and 'Playback Rate'.
Signed-off-by: Julian Scheel <julian@xxxxxxxx>
Signed-off-by: Pavel Hofman <pavel.hofman@xxxxxxxxxxx>
---
drivers/usb/gadget/function/f_uac1.c | 2 +
drivers/usb/gadget/function/f_uac2.c | 2 +
drivers/usb/gadget/function/u_audio.c | 135 +++++++++++++++++++++++
drivers/usb/gadget/function/u_audio.h | 10 +-
drivers/usb/gadget/function/uac_common.h | 9 ++
5 files changed, 156 insertions(+), 2 deletions(-)
create mode 100644 drivers/usb/gadget/function/uac_common.h
diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c
index 03f50643fbba..ccb0e4f41e5d 100644
--- a/drivers/usb/gadget/function/f_uac1.c
+++ b/drivers/usb/gadget/function/f_uac1.c
@@ -1298,6 +1298,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
audio->in_ep_maxpsize = le16_to_cpu(as_in_ep_desc.wMaxPacketSize);
audio->params.c_chmask = audio_opts->c_chmask;
audio->params.c_srate = audio_opts->c_srate;
+ audio->params.c_srates[0] = audio_opts->c_srate;
audio->params.c_ssize = audio_opts->c_ssize;
if (FUIN_EN(audio_opts)) {
audio->params.p_fu.id = USB_IN_FU_ID;
@@ -1310,6 +1311,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
}
audio->params.p_chmask = audio_opts->p_chmask;
audio->params.p_srate = audio_opts->p_srate;
+ audio->params.p_srates[0] = audio_opts->p_srate;
audio->params.p_ssize = audio_opts->p_ssize;
if (FUOUT_EN(audio_opts)) {
audio->params.c_fu.id = USB_OUT_FU_ID;
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index f8c1f406f19b..1d6e426e5078 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -1210,6 +1210,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
agdev->params.p_chmask = uac2_opts->p_chmask;
agdev->params.p_srate = uac2_opts->p_srate;
+ agdev->params.p_srates[0] = uac2_opts->p_srate;
agdev->params.p_ssize = uac2_opts->p_ssize;
if (FUIN_EN(uac2_opts)) {
agdev->params.p_fu.id = USB_IN_FU_ID;
@@ -1221,6 +1222,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
}
agdev->params.c_chmask = uac2_opts->c_chmask;
agdev->params.c_srate = uac2_opts->c_srate;
+ agdev->params.c_srates[0] = uac2_opts->c_srate;
agdev->params.c_ssize = uac2_opts->c_ssize;
if (FUOUT_EN(uac2_opts)) {
agdev->params.c_fu.id = USB_OUT_FU_ID;
diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index 4f6c0049c534..e737a104156d 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -32,6 +32,7 @@ enum {
UAC_P_PITCH_CTRL,
UAC_MUTE_CTRL,
UAC_VOLUME_CTRL,
+ UAC_RATE_CTRL,
};
/* Runtime data params for one stream */
@@ -62,6 +63,8 @@ struct uac_rtd_params {
s16 volume;
int mute;
+ struct snd_kcontrol *snd_kctl_rate; /* read-only current rate */
+
spinlock_t lock; /* lock for control transfers */
};
@@ -490,6 +493,48 @@ static inline void free_ep_fback(struct uac_rtd_params *prm, struct usb_ep *ep)
dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);
}
+int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate)
+{
+ struct uac_params *params = &audio_dev->params;
+ struct snd_uac_chip *uac = audio_dev->uac;
+ struct uac_rtd_params *prm = &uac->c_prm;
+ int i;
+
+ dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);
+ for (i = 0; i < UAC_MAX_RATES; i++) {
+ if (params->c_srates[i] == srate) {
+ params->c_srate = srate;
+ return 0;
+ }
+ if (params->c_srates[i] == 0)
+ break;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_capture_srate);
+
+int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate)
+{
+ struct snd_uac_chip *uac = audio_dev->uac;
+ struct uac_rtd_params *prm = &uac->p_prm;
+ struct uac_params *params = &audio_dev->params;
+ int i;
+
+ dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);
+ for (i = 0; i < UAC_MAX_RATES; i++) {
+ if (params->p_srates[i] == srate) {
+ params->p_srate = srate;
+ return 0;
+ }
+ if (params->p_srates[i] == 0)
+ break;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_playback_srate);
+
int u_audio_start_capture(struct g_audio *audio_dev)
{
struct snd_uac_chip *uac = audio_dev->uac;
@@ -501,6 +546,7 @@ int u_audio_start_capture(struct g_audio *audio_dev)
struct uac_params *params = &audio_dev->params;
int req_len, i;
+ dev_dbg(dev, "start capture with rate %d\n", params->c_srate);
ep = audio_dev->out_ep;
prm = &uac->c_prm;
config_ep_by_speed(gadget, &audio_dev->func, ep);
@@ -593,6 +639,7 @@ int u_audio_start_playback(struct g_audio *audio_dev)
int req_len, i;
unsigned int p_interval, p_pktsize;
+ dev_dbg(dev, "start playback with rate %d\n", params->p_srate);
ep = audio_dev->in_ep;
prm = &uac->p_prm;
config_ep_by_speed(gadget, &audio_dev->func, ep);
@@ -941,6 +988,68 @@ static int u_audio_volume_put(struct snd_kcontrol *kcontrol,
return change;
}
+static int get_max_srate(const int *srates)
+{
+ int i, max_srate = 0;
+
+ for (i = 0; i < UAC_MAX_RATES; i++) {
+ if (srates[i] == 0)
+ break;
+ if (srates[i] > max_srate)
+ max_srate = srates[i];
+ }
+ return max_srate;
+}
+
+static int get_min_srate(const int *srates)
+{
+ int i, min_srate = INT_MAX;
+
+ for (i = 0; i < UAC_MAX_RATES; i++) {
+ if (srates[i] == 0)
+ break;
+ if (srates[i] < min_srate)
+ min_srate = srates[i];
+ }
+ return min_srate;
+}
+
+static int uac_pcm_rate_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ const int *srates;
+ 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;
+
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+
+ if (prm == &uac->c_prm)
+ srates = params->c_srates;
+ else
+ srates = params->p_srates;
+ uinfo->value.integer.min = get_min_srate(srates);
+ uinfo->value.integer.max = get_max_srate(srates);
+ return 0;
+}
+
+static int uac_pcm_rate_get(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;
+
+ if (prm == &uac->c_prm)
+ ucontrol->value.integer.value[0] = params->c_srate;
+ else
+ ucontrol->value.integer.value[0] = params->p_srate;
+
+ return 0;
+}
static struct snd_kcontrol_new u_audio_controls[] = {
[UAC_FBACK_CTRL] {
@@ -971,6 +1080,13 @@ static struct snd_kcontrol_new u_audio_controls[] = {
.get = u_audio_volume_get,
.put = u_audio_volume_put,
},
+ [UAC_RATE_CTRL] {
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = "", /* will be filled later */
+ .access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+ .info = uac_pcm_rate_info,
+ .get = uac_pcm_rate_get,
+ },
};
int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
@@ -1184,6 +1300,25 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
prm->volume_min = fu->volume_min;
prm->volume_res = fu->volume_res;
}
+
+ /* Add rate control */
+ snprintf(ctrl_name, sizeof(ctrl_name),
+ "%s Rate", direction);
+ u_audio_controls[UAC_RATE_CTRL].name = ctrl_name;
+
+ kctl = snd_ctl_new1(&u_audio_controls[UAC_RATE_CTRL], 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;
+ prm->snd_kctl_rate = kctl;
}
strscpy(card->driver, card_name, sizeof(card->driver));
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h
index 8dfdae1721cd..76b5b8169444 100644
--- a/drivers/usb/gadget/function/u_audio.h
+++ b/drivers/usb/gadget/function/u_audio.h
@@ -10,6 +10,7 @@
#define __U_AUDIO_H
#include <linux/usb/composite.h>
+#include "uac_common.h"
/*
* Same maximum frequency deviation on the slower side as in
@@ -40,13 +41,15 @@ struct uac_fu_params {
struct uac_params {
/* playback */
int p_chmask; /* channel mask */
- int p_srate; /* rate in Hz */
+ int p_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */
+ int p_srate; /* selected rate in Hz */
int p_ssize; /* sample size */
struct uac_fu_params p_fu; /* Feature Unit parameters */
/* capture */
int c_chmask; /* channel mask */
- int c_srate; /* rate in Hz */
+ int c_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */
+ int c_srate; /* selected rate in Hz */
int c_ssize; /* sample size */
struct uac_fu_params c_fu; /* Feature Unit parameters */
@@ -117,6 +120,9 @@ void u_audio_stop_capture(struct g_audio *g_audio);
int u_audio_start_playback(struct g_audio *g_audio);
void u_audio_stop_playback(struct g_audio *g_audio);
+int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate);
+int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate);
+
int u_audio_get_volume(struct g_audio *g_audio, int playback, s16 *val);
int u_audio_set_volume(struct g_audio *g_audio, int playback, s16 val);
int u_audio_get_mute(struct g_audio *g_audio, int playback, int *val);
diff --git a/drivers/usb/gadget/function/uac_common.h b/drivers/usb/gadget/function/uac_common.h
new file mode 100644
index 000000000000..3ecf89d6e814
--- /dev/null
+++ b/drivers/usb/gadget/function/uac_common.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ */
+
+#ifndef UAC_COMMON_H
+#define UAC_COMMON_H
+
+#define UAC_MAX_RATES 10 /* maximum number of rates configurable by f_uac1/2 */
+#endif
--
2.25.1
