ANDROID: USB: gadget: Add ACCESSORY_SET_AUDIO_MODE control request and ioctl
The control request will be used by the host to enable/disable USB audio
and the ioctl will be used by userspace to read the audio mode
Change-Id: I81c38611b588451e80eacdccc417ca6e11c60cab
Signed-off-by: Mike Lockwood <lockwood@google.com>
diff --git a/drivers/usb/gadget/f_accessory.c b/drivers/usb/gadget/f_accessory.c
index 04ceb09..07c29d9 100644
--- a/drivers/usb/gadget/f_accessory.c
+++ b/drivers/usb/gadget/f_accessory.c
@@ -40,7 +40,7 @@
#define BULK_BUFFER_SIZE 16384
#define ACC_STRING_SIZE 256
-#define PROTOCOL_VERSION 1
+#define PROTOCOL_VERSION 2
/* String IDs */
#define INTERFACE_STRING_INDEX 0
@@ -78,6 +78,8 @@
/* set to 1 if we have a pending start request */
int start_requested;
+ int audio_mode;
+
/* synchronize access to our device file */
atomic_t open_excl;
@@ -510,6 +512,8 @@
break;
case ACCESSORY_IS_START_REQUESTED:
return dev->start_requested;
+ case ACCESSORY_GET_AUDIO_MODE:
+ return dev->audio_mode;
}
if (!src)
return -EINVAL;
@@ -586,6 +590,10 @@
cdev->gadget->ep0->driver_data = dev;
cdev->req->complete = acc_complete_set_string;
value = w_length;
+ } else if (b_request == ACCESSORY_SET_AUDIO_MODE &&
+ w_index == 0 && w_length == 0) {
+ dev->audio_mode = w_value;
+ value = 0;
}
} else if (b_requestType == (USB_DIR_IN | USB_TYPE_VENDOR)) {
if (b_request == ACCESSORY_GET_PROTOCOL) {
@@ -600,6 +608,7 @@
memset(dev->uri, 0, sizeof(dev->uri));
memset(dev->serial, 0, sizeof(dev->serial));
dev->start_requested = 0;
+ dev->audio_mode = 0;
}
}
diff --git a/include/linux/usb/f_accessory.h b/include/linux/usb/f_accessory.h
index 5b2dcf9..ddb2fd0 100644
--- a/include/linux/usb/f_accessory.h
+++ b/include/linux/usb/f_accessory.h
@@ -36,13 +36,15 @@
#define ACCESSORY_STRING_URI 4
#define ACCESSORY_STRING_SERIAL 5
-/* Control request for retrieving device's protocol version (currently 1)
+/* Control request for retrieving device's protocol version
*
* requestType: USB_DIR_IN | USB_TYPE_VENDOR
* request: ACCESSORY_GET_PROTOCOL
* value: 0
* index: 0
* data version number (16 bits little endian)
+ * 1 for original accessory support
+ * 2 adds device to host audio support
*/
#define ACCESSORY_GET_PROTOCOL 51
@@ -70,6 +72,17 @@
*/
#define ACCESSORY_START 53
+/* Control request for setting the audio mode.
+ *
+ * requestType: USB_DIR_OUT | USB_TYPE_VENDOR
+ * request: ACCESSORY_SET_AUDIO_MODE
+ * value: 0 - no audio
+ * 1 - device to host, 44100 16-bit stereo PCM
+ * index: 0
+ * data none
+ */
+#define ACCESSORY_SET_AUDIO_MODE 58
+
/* ioctls for retrieving strings set by the host */
#define ACCESSORY_GET_STRING_MANUFACTURER _IOW('M', 1, char[256])
#define ACCESSORY_GET_STRING_MODEL _IOW('M', 2, char[256])
@@ -79,5 +92,7 @@
#define ACCESSORY_GET_STRING_SERIAL _IOW('M', 6, char[256])
/* returns 1 if there is a start request pending */
#define ACCESSORY_IS_START_REQUESTED _IO('M', 7)
+/* returns audio mode (set via the ACCESSORY_SET_AUDIO_MODE control request) */
+#define ACCESSORY_GET_AUDIO_MODE _IO('M', 8)
#endif /* __LINUX_USB_F_ACCESSORY_H */