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authorBryan Wu <cooloney@kernel.org>2009-06-03 09:17:58 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2009-06-15 21:44:47 -0700
commitc6994e6f067cf0fc4c6cca3d164018b1150916f8 (patch)
treed971c529cbd4684e5c1c5fcb67f3f09d1cca4295 /drivers/usb/gadget/audio.c
parentc47d7b09891abb4f8b222317c89c7469bed8db3a (diff)
downloadop-kernel-dev-c6994e6f067cf0fc4c6cca3d164018b1150916f8.zip
op-kernel-dev-c6994e6f067cf0fc4c6cca3d164018b1150916f8.tar.gz
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>
Diffstat (limited to 'drivers/usb/gadget/audio.c')
-rw-r--r--drivers/usb/gadget/audio.c302
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/usb/gadget/audio.c b/drivers/usb/gadget/audio.c
new file mode 100644
index 0000000..94de7e8
--- /dev/null
+++ b/drivers/usb/gadget/audio.c
@@ -0,0 +1,302 @@
+/*
+ * audio.c -- Audio gadget driver
+ *
+ * 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.
+ */
+
+/* #define VERBOSE_DEBUG */
+
+#include <linux/kernel.h>
+#include <linux/utsname.h>
+
+#include "u_audio.h"
+
+#define DRIVER_DESC "Linux USB Audio Gadget"
+#define DRIVER_VERSION "Dec 18, 2008"
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Kbuild is not very cooperative with respect to linking separately
+ * compiled library objects into one module. So for now we won't use
+ * separate compilation ... ensuring init/exit sections work to shrink
+ * the runtime footprint, and giving us at least some parts of what
+ * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
+ */
+#include "composite.c"
+#include "usbstring.c"
+#include "config.c"
+#include "epautoconf.c"
+
+#include "u_audio.c"
+#include "f_audio.c"
+
+/*-------------------------------------------------------------------------*/
+
+/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
+ * Instead: allocate your own, using normal USB-IF procedures.
+ */
+
+/* Thanks to NetChip Technologies for donating this product ID. */
+#define AUDIO_VENDOR_NUM 0x0525 /* NetChip */
+#define AUDIO_PRODUCT_NUM 0xa4a1 /* Linux-USB Audio Gadget */
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_device_descriptor device_desc = {
+ .bLength = sizeof device_desc,
+ .bDescriptorType = USB_DT_DEVICE,
+
+ .bcdUSB = __constant_cpu_to_le16(0x200),
+
+ .bDeviceClass = USB_CLASS_PER_INTERFACE,
+ .bDeviceSubClass = 0,
+ .bDeviceProtocol = 0,
+ /* .bMaxPacketSize0 = f(hardware) */
+
+ /* Vendor and product id defaults change according to what configs
+ * we support. (As does bNumConfigurations.) These values can
+ * also be overridden by module parameters.
+ */
+ .idVendor = __constant_cpu_to_le16(AUDIO_VENDOR_NUM),
+ .idProduct = __constant_cpu_to_le16(AUDIO_PRODUCT_NUM),
+ /* .bcdDevice = f(hardware) */
+ /* .iManufacturer = DYNAMIC */
+ /* .iProduct = DYNAMIC */
+ /* NO SERIAL NUMBER */
+ .bNumConfigurations = 1,
+};
+
+static struct usb_otg_descriptor otg_descriptor = {
+ .bLength = sizeof otg_descriptor,
+ .bDescriptorType = USB_DT_OTG,
+
+ /* REVISIT SRP-only hardware is possible, although
+ * it would not be called "OTG" ...
+ */
+ .bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
+};
+
+static const struct usb_descriptor_header *otg_desc[] = {
+ (struct usb_descriptor_header *) &otg_descriptor,
+ NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+/**
+ * Handle USB audio endpoint set/get command in setup class request
+ */
+
+static int audio_set_endpoint_req(struct usb_configuration *c,
+ const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ int value = -EOPNOTSUPP;
+ u16 ep = le16_to_cpu(ctrl->wIndex);
+ u16 len = le16_to_cpu(ctrl->wLength);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+
+ DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
+ ctrl->bRequest, w_value, len, ep);
+
+ switch (ctrl->bRequest) {
+ case SET_CUR:
+ value = 0;
+ break;
+
+ case SET_MIN:
+ break;
+
+ case SET_MAX:
+ break;
+
+ case SET_RES:
+ break;
+
+ case SET_MEM:
+ break;
+
+ default:
+ break;
+ }
+
+ return value;
+}
+
+static int audio_get_endpoint_req(struct usb_configuration *c,
+ const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ int value = -EOPNOTSUPP;
+ u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
+ u16 len = le16_to_cpu(ctrl->wLength);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+
+ DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
+ ctrl->bRequest, w_value, len, ep);
+
+ switch (ctrl->bRequest) {
+ case GET_CUR:
+ case GET_MIN:
+ case GET_MAX:
+ case GET_RES:
+ value = 3;
+ break;
+ case GET_MEM:
+ break;
+ default:
+ break;
+ }
+
+ return value;
+}
+
+static int
+audio_setup(struct usb_configuration *c, const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ struct usb_request *req = cdev->req;
+ int value = -EOPNOTSUPP;
+ u16 w_index = le16_to_cpu(ctrl->wIndex);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+
+ /* composite driver infrastructure handles everything except
+ * Audio class messages; interface activation uses set_alt().
+ */
+ switch (ctrl->bRequestType) {
+ case USB_AUDIO_SET_ENDPOINT:
+ value = audio_set_endpoint_req(c, ctrl);
+ break;
+
+ case USB_AUDIO_GET_ENDPOINT:
+ value = audio_get_endpoint_req(c, ctrl);
+ break;
+
+ default:
+ ERROR(cdev, "Invalid control req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ }
+
+ /* respond with data transfer or status phase? */
+ if (value >= 0) {
+ DBG(cdev, "Audio req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ req->zero = 0;
+ req->length = value;
+ value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+ if (value < 0)
+ ERROR(cdev, "Audio response on err %d\n", value);
+ }
+
+ /* device either stalls (value < 0) or reports success */
+ return value;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int __init audio_do_config(struct usb_configuration *c)
+{
+ /* FIXME alloc iConfiguration string, set it in c->strings */
+
+ if (gadget_is_otg(c->cdev->gadget)) {
+ c->descriptors = otg_desc;
+ c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+ }
+
+ audio_bind_config(c);
+
+ return 0;
+}
+
+static struct usb_configuration audio_config_driver = {
+ .label = DRIVER_DESC,
+ .bind = audio_do_config,
+ .setup = audio_setup,
+ .bConfigurationValue = 1,
+ /* .iConfiguration = DYNAMIC */
+ .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int __init audio_bind(struct usb_composite_dev *cdev)
+{
+ int gcnum;
+ int status;
+
+ gcnum = usb_gadget_controller_number(cdev->gadget);
+ if (gcnum >= 0)
+ device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
+ else {
+ ERROR(cdev, "controller '%s' not recognized; trying %s\n",
+ cdev->gadget->name,
+ audio_config_driver.label);
+ device_desc.bcdDevice =
+ __constant_cpu_to_le16(0x0300 | 0x0099);
+ }
+
+ /* device descriptor strings: manufacturer, product */
+ snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
+ init_utsname()->sysname, init_utsname()->release,
+ cdev->gadget->name);
+ status = usb_string_id(cdev);
+ if (status < 0)
+ goto fail;
+ strings_dev[STRING_MANUFACTURER_IDX].id = status;
+ device_desc.iManufacturer = status;
+
+ status = usb_string_id(cdev);
+ if (status < 0)
+ goto fail;
+ strings_dev[STRING_PRODUCT_IDX].id = status;
+ device_desc.iProduct = status;
+
+ status = usb_add_config(cdev, &audio_config_driver);
+ if (status < 0)
+ goto fail;
+
+ INFO(cdev, "%s, version: %s\n", DRIVER_DESC, DRIVER_VERSION);
+ return 0;
+
+fail:
+ return status;
+}
+
+static int __exit audio_unbind(struct usb_composite_dev *cdev)
+{
+ return 0;
+}
+
+static struct usb_composite_driver audio_driver = {
+ .name = "g_audio",
+ .dev = &device_desc,
+ .strings = audio_strings,
+ .bind = audio_bind,
+ .unbind = __exit_p(audio_unbind),
+};
+
+static int __init init(void)
+{
+ return usb_composite_register(&audio_driver);
+}
+module_init(init);
+
+static void __exit cleanup(void)
+{
+ usb_composite_unregister(&audio_driver);
+}
+module_exit(cleanup);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
+MODULE_LICENSE("GPL");
+
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