USB: gadget: add USB Audio Gadget driver
Funtions added:
- setup all the USB audio class device descriptors
- handle class specific setup request
- receive data from USB host by ISO transfer
- play audio data by ALSA sound card
- open and setup playback PCM interface
- set default playback PCM parameters
- provide playback functions for USB audio driver
- provide PCM parameters set/get functions
Test on:
- Host: Ubuntu 8.10, kernel 2.6.27
- Gadget: EZKIT-BF548 with ASoC AD1980 codec
Todo:
- add real Mute control code
- add real Volume control code
- maybe find another way to replace dynamic buffer handling
with static buffer allocation
- test on Windows system
- provide control interface to handle mute/volume control
- provide capture interface in the future
- test on BF527, other USB device controler and other audio codec
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/u_audio.h b/drivers/usb/gadget/u_audio.h
new file mode 100644
index 0000000..cc8d159
--- /dev/null
+++ b/drivers/usb/gadget/u_audio.h
@@ -0,0 +1,56 @@
+/*
+ * u_audio.h -- interface to USB gadget "ALSA AUDIO" utilities
+ *
+ * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
+ * Copyright (C) 2008 Analog Devices, Inc
+ *
+ * Enter bugs at http://blackfin.uclinux.org/
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __U_AUDIO_H
+#define __U_AUDIO_H
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/composite.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#include "gadget_chips.h"
+
+/*
+ * This represents the USB side of an audio card device, managed by a USB
+ * function which provides control and stream interfaces.
+ */
+
+struct gaudio_snd_dev {
+ struct gaudio *card;
+ struct file *filp;
+ struct snd_pcm_substream *substream;
+ int access;
+ int format;
+ int channels;
+ int rate;
+};
+
+struct gaudio {
+ struct usb_function func;
+ struct usb_gadget *gadget;
+
+ /* ALSA sound device interfaces */
+ struct gaudio_snd_dev control;
+ struct gaudio_snd_dev playback;
+ struct gaudio_snd_dev capture;
+
+ /* TODO */
+};
+
+int gaudio_setup(struct gaudio *card);
+void gaudio_cleanup(struct gaudio *card);
+
+#endif /* __U_AUDIO_H */