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-rw-r--r--drivers/usb/gadget/function/u_audio.h135
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h
new file mode 100644
index 000000000..9512b8fcc
--- /dev/null
+++ b/drivers/usb/gadget/function/u_audio.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * u_audio.h -- interface to USB gadget "ALSA sound card" utilities
+ *
+ * Copyright (C) 2016
+ * Author: Ruslan Bilovol <ruslan.bilovol@gmail.com>
+ */
+
+#ifndef __U_AUDIO_H
+#define __U_AUDIO_H
+
+#include <linux/usb/composite.h>
+#include "uac_common.h"
+
+/*
+ * Same maximum frequency deviation on the slower side as in
+ * sound/usb/endpoint.c. Value is expressed in per-mil deviation.
+ */
+#define FBACK_SLOW_MAX 250
+
+/*
+ * Maximum frequency deviation on the faster side, default value for UAC1/2.
+ * Value is expressed in per-mil deviation.
+ * UAC2 provides the value as a parameter as it impacts the endpoint required
+ * bandwidth.
+ */
+#define FBACK_FAST_MAX 5
+
+/* Feature Unit parameters */
+struct uac_fu_params {
+ int id; /* Feature Unit ID */
+
+ bool mute_present; /* mute control enable */
+
+ bool volume_present; /* volume control enable */
+ s16 volume_min; /* min volume in 1/256 dB */
+ s16 volume_max; /* max volume in 1/256 dB */
+ s16 volume_res; /* volume resolution in 1/256 dB */
+};
+
+struct uac_params {
+ /* playback */
+ int p_chmask; /* channel mask */
+ int p_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */
+ int p_ssize; /* sample size */
+ struct uac_fu_params p_fu; /* Feature Unit parameters */
+
+ /* capture */
+ int c_chmask; /* channel mask */
+ int c_srates[UAC_MAX_RATES]; /* available rates in Hz (0 terminated list) */
+ int c_ssize; /* sample size */
+ struct uac_fu_params c_fu; /* Feature Unit parameters */
+
+ /* rates are dynamic, in uac_rtd_params */
+
+ int req_number; /* number of preallocated requests */
+ int fb_max; /* upper frequency drift feedback limit per-mil */
+};
+
+struct g_audio {
+ struct usb_function func;
+ 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;
+ /* Max packet size for all out_ep possible speeds */
+ unsigned int out_ep_maxpsize;
+
+ /* Notify UAC driver about control change */
+ int (*notify)(struct g_audio *g_audio, int unit_id, int cs);
+
+ /* The ALSA Sound Card it represents on the USB-Client side */
+ struct snd_uac_chip *uac;
+
+ struct uac_params params;
+};
+
+static inline struct g_audio *func_to_g_audio(struct usb_function *f)
+{
+ return container_of(f, struct g_audio, func);
+}
+
+static inline uint num_channels(uint chanmask)
+{
+ uint num = 0;
+
+ while (chanmask) {
+ num += (chanmask & 1);
+ chanmask >>= 1;
+ }
+
+ return num;
+}
+
+/*
+ * g_audio_setup - initialize one virtual ALSA sound card
+ * @g_audio: struct with filled params, in_ep_maxpsize, out_ep_maxpsize
+ * @pcm_name: the id string for a PCM instance of this sound card
+ * @card_name: name of this soundcard
+ *
+ * This sets up the single virtual ALSA sound card that may be exported by a
+ * gadget driver using this framework.
+ *
+ * Context: may sleep
+ *
+ * Returns zero on success, or a negative error on failure.
+ */
+int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
+ const char *card_name);
+void g_audio_cleanup(struct g_audio *g_audio);
+
+int u_audio_start_capture(struct g_audio *g_audio);
+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_get_capture_srate(struct g_audio *audio_dev, u32 *val);
+int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate);
+int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val);
+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);
+int u_audio_set_mute(struct g_audio *g_audio, int playback, int val);
+
+void u_audio_suspend(struct g_audio *g_audio);
+
+#endif /* __U_AUDIO_H */