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>
This commit is contained in:
Bryan Wu 2009-06-03 09:17:58 -04:00 committed by Greg Kroah-Hartman
parent c47d7b0989
commit c6994e6f06
6 changed files with 1400 additions and 0 deletions

View File

@ -580,6 +580,20 @@ config USB_ZERO_HNPTEST
the "B-Peripheral" role, that device will use HNP to let this
one serve as the USB host instead (in the "B-Host" role).
config USB_AUDIO
tristate "Audio Gadget (EXPERIMENTAL)"
depends on SND
help
Gadget Audio is compatible with USB Audio Class specification 1.0.
It will include at least one AudioControl interface, zero or more
AudioStream interface and zero or more MIDIStream interface.
Gadget Audio will use on-board ALSA (CONFIG_SND) audio card to
playback or capture audio stream.
Say "y" to link the driver statically, or "m" to build a
dynamically linked module called "g_audio".
config USB_ETH
tristate "Ethernet Gadget (with CDC Ethernet support)"
depends on NET

View File

@ -31,6 +31,7 @@ obj-$(CONFIG_USB_S3C_HSOTG) += s3c-hsotg.o
# USB gadget drivers
#
g_zero-objs := zero.o
g_audio-objs := audio.o
g_ether-objs := ether.o
g_serial-objs := serial.o
g_midi-objs := gmidi.o
@ -40,6 +41,7 @@ g_printer-objs := printer.o
g_cdc-objs := cdc2.o
obj-$(CONFIG_USB_ZERO) += g_zero.o
obj-$(CONFIG_USB_AUDIO) += g_audio.o
obj-$(CONFIG_USB_ETH) += g_ether.o
obj-$(CONFIG_USB_GADGETFS) += gadgetfs.o
obj-$(CONFIG_USB_FILE_STORAGE) += g_file_storage.o

302
drivers/usb/gadget/audio.c Normal file
View File

@ -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");

View File

@ -0,0 +1,707 @@
/*
* f_audio.c -- USB Audio class function 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.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <asm/atomic.h>
#include "u_audio.h"
#define OUT_EP_MAX_PACKET_SIZE 200
static int req_buf_size = OUT_EP_MAX_PACKET_SIZE;
module_param(req_buf_size, int, S_IRUGO);
MODULE_PARM_DESC(req_buf_size, "ISO OUT endpoint request buffer size");
static int req_count = 256;
module_param(req_count, int, S_IRUGO);
MODULE_PARM_DESC(req_count, "ISO OUT endpoint request count");
static int audio_buf_size = 48000;
module_param(audio_buf_size, int, S_IRUGO);
MODULE_PARM_DESC(audio_buf_size, "Audio buffer size");
/*
* DESCRIPTORS ... most are static, but strings and full
* configuration descriptors are built on demand.
*/
/*
* We have two interfaces- AudioControl and AudioStreaming
* TODO: only supcard playback currently
*/
#define F_AUDIO_AC_INTERFACE 0
#define F_AUDIO_AS_INTERFACE 1
#define F_AUDIO_NUM_INTERFACES 2
/* B.3.1 Standard AC Interface Descriptor */
static struct usb_interface_descriptor ac_interface_desc __initdata = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
.bNumEndpoints = 0,
.bInterfaceClass = USB_CLASS_AUDIO,
.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
};
DECLARE_USB_AC_HEADER_DESCRIPTOR(2);
#define USB_DT_AC_HEADER_LENGH USB_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
/* B.3.2 Class-Specific AC Interface Descriptor */
static struct usb_ac_header_descriptor_2 ac_header_desc = {
.bLength = USB_DT_AC_HEADER_LENGH,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = HEADER,
.bcdADC = __constant_cpu_to_le16(0x0100),
.wTotalLength = __constant_cpu_to_le16(USB_DT_AC_HEADER_LENGH),
.bInCollection = F_AUDIO_NUM_INTERFACES,
.baInterfaceNr = {
[0] = F_AUDIO_AC_INTERFACE,
[1] = F_AUDIO_AS_INTERFACE,
}
};
#define INPUT_TERMINAL_ID 1
static struct usb_input_terminal_descriptor input_terminal_desc = {
.bLength = USB_DT_AC_INPUT_TERMINAL_SIZE,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = INPUT_TERMINAL,
.bTerminalID = INPUT_TERMINAL_ID,
.wTerminalType = USB_AC_TERMINAL_STREAMING,
.bAssocTerminal = 0,
.wChannelConfig = 0x3,
};
DECLARE_USB_AC_FEATURE_UNIT_DESCRIPTOR(0);
#define FEATURE_UNIT_ID 2
static struct usb_ac_feature_unit_descriptor_0 feature_unit_desc = {
.bLength = USB_DT_AC_FEATURE_UNIT_SIZE(0),
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = FEATURE_UNIT,
.bUnitID = FEATURE_UNIT_ID,
.bSourceID = INPUT_TERMINAL_ID,
.bControlSize = 2,
.bmaControls[0] = (FU_MUTE | FU_VOLUME),
};
static struct usb_audio_control mute_control = {
.list = LIST_HEAD_INIT(mute_control.list),
.name = "Mute Control",
.type = MUTE_CONTROL,
/* Todo: add real Mute control code */
.set = generic_set_cmd,
.get = generic_get_cmd,
};
static struct usb_audio_control volume_control = {
.list = LIST_HEAD_INIT(volume_control.list),
.name = "Volume Control",
.type = VOLUME_CONTROL,
/* Todo: add real Volume control code */
.set = generic_set_cmd,
.get = generic_get_cmd,
};
static struct usb_audio_control_selector feature_unit = {
.list = LIST_HEAD_INIT(feature_unit.list),
.id = FEATURE_UNIT_ID,
.name = "Mute & Volume Control",
.type = FEATURE_UNIT,
.desc = (struct usb_descriptor_header *)&feature_unit_desc,
};
#define OUTPUT_TERMINAL_ID 3
static struct usb_output_terminal_descriptor output_terminal_desc = {
.bLength = USB_DT_AC_OUTPUT_TERMINAL_SIZE,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = OUTPUT_TERMINAL,
.bTerminalID = OUTPUT_TERMINAL_ID,
.wTerminalType = USB_AC_OUTPUT_TERMINAL_SPEAKER,
.bAssocTerminal = FEATURE_UNIT_ID,
.bSourceID = FEATURE_UNIT_ID,
};
/* B.4.1 Standard AS Interface Descriptor */
static struct usb_interface_descriptor as_interface_alt_0_desc = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
.bAlternateSetting = 0,
.bNumEndpoints = 0,
.bInterfaceClass = USB_CLASS_AUDIO,
.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
};
static struct usb_interface_descriptor as_interface_alt_1_desc = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
.bAlternateSetting = 1,
.bNumEndpoints = 1,
.bInterfaceClass = USB_CLASS_AUDIO,
.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
};
/* B.4.2 Class-Specific AS Interface Descriptor */
static struct usb_as_header_descriptor as_header_desc = {
.bLength = USB_DT_AS_HEADER_SIZE,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = AS_GENERAL,
.bTerminalLink = INPUT_TERMINAL_ID,
.bDelay = 1,
.wFormatTag = USB_AS_AUDIO_FORMAT_TYPE_I_PCM,
};
DECLARE_USB_AS_FORMAT_TYPE_I_DISCRETE_DESC(1);
static struct usb_as_formate_type_i_discrete_descriptor_1 as_type_i_desc = {
.bLength = USB_AS_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubtype = FORMAT_TYPE,
.bFormatType = USB_AS_FORMAT_TYPE_I,
.bSubframeSize = 2,
.bBitResolution = 16,
.bSamFreqType = 1,
};
/* Standard ISO OUT Endpoint Descriptor */
static struct usb_endpoint_descriptor as_out_ep_desc __initdata = {
.bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_AS_ENDPOINT_ADAPTIVE
| USB_ENDPOINT_XFER_ISOC,
.wMaxPacketSize = __constant_cpu_to_le16(OUT_EP_MAX_PACKET_SIZE),
.bInterval = 4,
};
/* Class-specific AS ISO OUT Endpoint Descriptor */
static struct usb_as_iso_endpoint_descriptor as_iso_out_desc __initdata = {
.bLength = USB_AS_ISO_ENDPOINT_DESC_SIZE,
.bDescriptorType = USB_DT_CS_ENDPOINT,
.bDescriptorSubtype = EP_GENERAL,
.bmAttributes = 1,
.bLockDelayUnits = 1,
.wLockDelay = __constant_cpu_to_le16(1),
};
static struct usb_descriptor_header *f_audio_desc[] __initdata = {
(struct usb_descriptor_header *)&ac_interface_desc,
(struct usb_descriptor_header *)&ac_header_desc,
(struct usb_descriptor_header *)&input_terminal_desc,
(struct usb_descriptor_header *)&output_terminal_desc,
(struct usb_descriptor_header *)&feature_unit_desc,
(struct usb_descriptor_header *)&as_interface_alt_0_desc,
(struct usb_descriptor_header *)&as_interface_alt_1_desc,
(struct usb_descriptor_header *)&as_header_desc,
(struct usb_descriptor_header *)&as_type_i_desc,
(struct usb_descriptor_header *)&as_out_ep_desc,
(struct usb_descriptor_header *)&as_iso_out_desc,
NULL,
};
/* string IDs are assigned dynamically */
#define STRING_MANUFACTURER_IDX 0
#define STRING_PRODUCT_IDX 1
static char manufacturer[50];
static struct usb_string strings_dev[] = {
[STRING_MANUFACTURER_IDX].s = manufacturer,
[STRING_PRODUCT_IDX].s = DRIVER_DESC,
{ } /* end of list */
};
static struct usb_gadget_strings stringtab_dev = {
.language = 0x0409, /* en-us */
.strings = strings_dev,
};
static struct usb_gadget_strings *audio_strings[] = {
&stringtab_dev,
NULL,
};
/*
* This function is an ALSA sound card following USB Audio Class Spec 1.0.
*/
/*-------------------------------------------------------------------------*/
struct f_audio_buf {
u8 *buf;
int actual;
struct list_head list;
};
static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
{
struct f_audio_buf *copy_buf;
copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
if (!copy_buf)
return (struct f_audio_buf *)-ENOMEM;
copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
if (!copy_buf->buf) {
kfree(copy_buf);
return (struct f_audio_buf *)-ENOMEM;
}
return copy_buf;
}
static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
{
kfree(audio_buf->buf);
kfree(audio_buf);
}
/*-------------------------------------------------------------------------*/
struct f_audio {
struct gaudio card;
/* endpoints handle full and/or high speeds */
struct usb_ep *out_ep;
struct usb_endpoint_descriptor *out_desc;
spinlock_t lock;
struct f_audio_buf *copy_buf;
struct work_struct playback_work;
struct list_head play_queue;
/* Control Set command */
struct list_head cs;
u8 set_cmd;
struct usb_audio_control *set_con;
};
static inline struct f_audio *func_to_audio(struct usb_function *f)
{
return container_of(f, struct f_audio, card.func);
}
/*-------------------------------------------------------------------------*/
static void f_audio_playback_work(struct work_struct *data)
{
struct f_audio *audio = container_of(data, struct f_audio,
playback_work);
struct f_audio_buf *play_buf;
spin_lock_irq(&audio->lock);
if (list_empty(&audio->play_queue)) {
spin_unlock_irq(&audio->lock);
return;
}
play_buf = list_first_entry(&audio->play_queue,
struct f_audio_buf, list);
list_del(&play_buf->list);
spin_unlock_irq(&audio->lock);
u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
f_audio_buffer_free(play_buf);
return;
}
static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
{
struct f_audio *audio = req->context;
struct usb_composite_dev *cdev = audio->card.func.config->cdev;
struct f_audio_buf *copy_buf = audio->copy_buf;
int err;
if (!copy_buf)
return -EINVAL;
/* Copy buffer is full, add it to the play_queue */
if (audio_buf_size - copy_buf->actual < req->actual) {
list_add_tail(&copy_buf->list, &audio->play_queue);
schedule_work(&audio->playback_work);
copy_buf = f_audio_buffer_alloc(audio_buf_size);
if (copy_buf < 0)
return -ENOMEM;
}
memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
copy_buf->actual += req->actual;
audio->copy_buf = copy_buf;
err = usb_ep_queue(ep, req, GFP_ATOMIC);
if (err)
ERROR(cdev, "%s queue req: %d\n", ep->name, err);
return 0;
}
static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
{
struct f_audio *audio = req->context;
int status = req->status;
u32 data = 0;
struct usb_ep *out_ep = audio->out_ep;
switch (status) {
case 0: /* normal completion? */
if (ep == out_ep)
f_audio_out_ep_complete(ep, req);
else if (audio->set_con) {
memcpy(&data, req->buf, req->length);
audio->set_con->set(audio->set_con, audio->set_cmd,
le16_to_cpu(data));
audio->set_con = NULL;
}
break;
default:
break;
}
}
static int audio_set_intf_req(struct usb_function *f,
const struct usb_ctrlrequest *ctrl)
{
struct f_audio *audio = func_to_audio(f);
struct usb_composite_dev *cdev = f->config->cdev;
struct usb_request *req = cdev->req;
u8 id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
u16 len = le16_to_cpu(ctrl->wLength);
u16 w_value = le16_to_cpu(ctrl->wValue);
u8 con_sel = (w_value >> 8) & 0xFF;
u8 cmd = (ctrl->bRequest & 0x0F);
struct usb_audio_control_selector *cs;
struct usb_audio_control *con;
DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
ctrl->bRequest, w_value, len, id);
list_for_each_entry(cs, &audio->cs, list) {
if (cs->id == id) {
list_for_each_entry(con, &cs->control, list) {
if (con->type == con_sel) {
audio->set_con = con;
break;
}
}
break;
}
}
audio->set_cmd = cmd;
req->context = audio;
req->complete = f_audio_complete;
return len;
}
static int audio_get_intf_req(struct usb_function *f,
const struct usb_ctrlrequest *ctrl)
{
struct f_audio *audio = func_to_audio(f);
struct usb_composite_dev *cdev = f->config->cdev;
struct usb_request *req = cdev->req;
int value = -EOPNOTSUPP;
u8 id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
u16 len = le16_to_cpu(ctrl->wLength);
u16 w_value = le16_to_cpu(ctrl->wValue);
u8 con_sel = (w_value >> 8) & 0xFF;
u8 cmd = (ctrl->bRequest & 0x0F);
struct usb_audio_control_selector *cs;
struct usb_audio_control *con;
DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
ctrl->bRequest, w_value, len, id);
list_for_each_entry(cs, &audio->cs, list) {
if (cs->id == id) {
list_for_each_entry(con, &cs->control, list) {
if (con->type == con_sel && con->get) {
value = con->get(con, cmd);
break;
}
}
break;
}
}
req->context = audio;
req->complete = f_audio_complete;
memcpy(req->buf, &value, len);
return len;
}
static int
f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
{
struct usb_composite_dev *cdev = f->config->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_INTF:
value = audio_set_intf_req(f, ctrl);
break;
case USB_AUDIO_GET_INTF:
value = audio_get_intf_req(f, 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 f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
struct f_audio *audio = func_to_audio(f);
struct usb_composite_dev *cdev = f->config->cdev;
struct usb_ep *out_ep = audio->out_ep;
struct usb_request *req;
int i = 0, err = 0;
DBG(cdev, "intf %d, alt %d\n", intf, alt);
if (intf == 1) {
if (alt == 1) {
usb_ep_enable(out_ep, audio->out_desc);
out_ep->driver_data = audio;
audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
/*
* allocate a bunch of read buffers
* and queue them all at once.
*/
for (i = 0; i < req_count && err == 0; i++) {
req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
if (req) {
req->buf = kzalloc(req_buf_size,
GFP_ATOMIC);
if (req->buf) {
req->length = req_buf_size;
req->context = audio;
req->complete =
f_audio_complete;
err = usb_ep_queue(out_ep,
req, GFP_ATOMIC);
if (err)
ERROR(cdev,
"%s queue req: %d\n",
out_ep->name, err);
} else
err = -ENOMEM;
} else
err = -ENOMEM;
}
} else {
struct f_audio_buf *copy_buf = audio->copy_buf;
if (copy_buf) {
list_add_tail(&copy_buf->list,
&audio->play_queue);
schedule_work(&audio->playback_work);
}
}
}
return err;
}
static void f_audio_disable(struct usb_function *f)
{
return;
}
/*-------------------------------------------------------------------------*/
static void f_audio_build_desc(struct f_audio *audio)
{
struct gaudio *card = &audio->card;
u8 *sam_freq;
int rate;
/* Set channel numbers */
input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
/* Set sample rates */
rate = u_audio_get_playback_rate(card);
sam_freq = as_type_i_desc.tSamFreq[0];
memcpy(sam_freq, &rate, 3);
/* Todo: Set Sample bits and other parameters */
return;
}
/* audio function driver setup/binding */
static int __init
f_audio_bind(struct usb_configuration *c, struct usb_function *f)
{
struct usb_composite_dev *cdev = c->cdev;
struct f_audio *audio = func_to_audio(f);
int status;
struct usb_ep *ep;
f_audio_build_desc(audio);
/* allocate instance-specific interface IDs, and patch descriptors */
status = usb_interface_id(c, f);
if (status < 0)
goto fail;
ac_interface_desc.bInterfaceNumber = status;
status = usb_interface_id(c, f);
if (status < 0)
goto fail;
as_interface_alt_0_desc.bInterfaceNumber = status;
as_interface_alt_1_desc.bInterfaceNumber = status;
status = -ENODEV;
/* allocate instance-specific endpoints */
ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
if (!ep)
goto fail;
audio->out_ep = ep;
ep->driver_data = cdev; /* claim */
status = -ENOMEM;
/* supcard all relevant hardware speeds... we expect that when
* hardware is dual speed, all bulk-capable endpoints work at
* both speeds
*/
/* copy descriptors, and track endpoint copies */
if (gadget_is_dualspeed(c->cdev->gadget)) {
c->highspeed = true;
f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
} else
f->descriptors = usb_copy_descriptors(f_audio_desc);
return 0;
fail:
return status;
}
static void
f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
{
struct f_audio *audio = func_to_audio(f);
usb_free_descriptors(f->descriptors);
kfree(audio);
}
/*-------------------------------------------------------------------------*/
/* Todo: add more control selecotor dynamically */
int __init control_selector_init(struct f_audio *audio)
{
INIT_LIST_HEAD(&audio->cs);
list_add(&feature_unit.list, &audio->cs);
INIT_LIST_HEAD(&feature_unit.control);
list_add(&mute_control.list, &feature_unit.control);
list_add(&volume_control.list, &feature_unit.control);
volume_control.data[_CUR] = 0xffc0;
volume_control.data[_MIN] = 0xe3a0;
volume_control.data[_MAX] = 0xfff0;
volume_control.data[_RES] = 0x0030;
return 0;
}
/**
* audio_bind_config - add USB audio fucntion to a configuration
* @c: the configuration to supcard the USB audio function
* Context: single threaded during gadget setup
*
* Returns zero on success, else negative errno.
*/
int __init audio_bind_config(struct usb_configuration *c)
{
struct f_audio *audio;
int status;
/* allocate and initialize one new instance */
audio = kzalloc(sizeof *audio, GFP_KERNEL);
if (!audio)
return -ENOMEM;
audio->card.func.name = "g_audio";
audio->card.gadget = c->cdev->gadget;
INIT_LIST_HEAD(&audio->play_queue);
spin_lock_init(&audio->lock);
/* set up ASLA audio devices */
status = gaudio_setup(&audio->card);
if (status < 0)
goto setup_fail;
audio->card.func.strings = audio_strings;
audio->card.func.bind = f_audio_bind;
audio->card.func.unbind = f_audio_unbind;
audio->card.func.set_alt = f_audio_set_alt;
audio->card.func.setup = f_audio_setup;
audio->card.func.disable = f_audio_disable;
audio->out_desc = &as_out_ep_desc;
control_selector_init(audio);
INIT_WORK(&audio->playback_work, f_audio_playback_work);
status = usb_add_function(c, &audio->card.func);
if (status)
goto add_fail;
INFO(c->cdev, "audio_buf_size %d, req_buf_size %d, req_count %d\n",
audio_buf_size, req_buf_size, req_count);
return status;
add_fail:
gaudio_cleanup(&audio->card);
setup_fail:
kfree(audio);
return status;
}

View File

@ -0,0 +1,319 @@
/*
* u_audio.c -- ALSA audio utilities for Gadget stack
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/utsname.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/ctype.h>
#include <linux/random.h>
#include <linux/syscalls.h>
#include "u_audio.h"
/*
* This component encapsulates the ALSA devices for USB audio gadget
*/
#define FILE_PCM_PLAYBACK "/dev/snd/pcmC0D0p"
#define FILE_PCM_CAPTURE "/dev/snd/pcmC0D0c"
#define FILE_CONTROL "/dev/snd/controlC0"
static char *fn_play = FILE_PCM_PLAYBACK;
module_param(fn_play, charp, S_IRUGO);
MODULE_PARM_DESC(fn_play, "Playback PCM device file name");
static char *fn_cap = FILE_PCM_CAPTURE;
module_param(fn_cap, charp, S_IRUGO);
MODULE_PARM_DESC(fn_cap, "Capture PCM device file name");
static char *fn_cntl = FILE_CONTROL;
module_param(fn_cntl, charp, S_IRUGO);
MODULE_PARM_DESC(fn_cntl, "Control device file name");
/*-------------------------------------------------------------------------*/
/**
* Some ALSA internal helper functions
*/
static int snd_interval_refine_set(struct snd_interval *i, unsigned int val)
{
struct snd_interval t;
t.empty = 0;
t.min = t.max = val;
t.openmin = t.openmax = 0;
t.integer = 1;
return snd_interval_refine(i, &t);
}
static int _snd_pcm_hw_param_set(struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var, unsigned int val,
int dir)
{
int changed;
if (hw_is_mask(var)) {
struct snd_mask *m = hw_param_mask(params, var);
if (val == 0 && dir < 0) {
changed = -EINVAL;
snd_mask_none(m);
} else {
if (dir > 0)
val++;
else if (dir < 0)
val--;
changed = snd_mask_refine_set(
hw_param_mask(params, var), val);
}
} else if (hw_is_interval(var)) {
struct snd_interval *i = hw_param_interval(params, var);
if (val == 0 && dir < 0) {
changed = -EINVAL;
snd_interval_none(i);
} else if (dir == 0)
changed = snd_interval_refine_set(i, val);
else {
struct snd_interval t;
t.openmin = 1;
t.openmax = 1;
t.empty = 0;
t.integer = 0;
if (dir < 0) {
t.min = val - 1;
t.max = val;
} else {
t.min = val;
t.max = val+1;
}
changed = snd_interval_refine(i, &t);
}
} else
return -EINVAL;
if (changed) {
params->cmask |= 1 << var;
params->rmask |= 1 << var;
}
return changed;
}
/*-------------------------------------------------------------------------*/
/**
* Set default hardware params
*/
static int playback_default_hw_params(struct gaudio_snd_dev *snd)
{
struct snd_pcm_substream *substream = snd->substream;
struct snd_pcm_hw_params *params;
snd_pcm_sframes_t result;
/*
* SNDRV_PCM_ACCESS_RW_INTERLEAVED,
* SNDRV_PCM_FORMAT_S16_LE
* CHANNELS: 2
* RATE: 48000
*/
snd->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
snd->format = SNDRV_PCM_FORMAT_S16_LE;
snd->channels = 2;
snd->rate = 48000;
params = kzalloc(sizeof(*params), GFP_KERNEL);
if (!params)
return -ENOMEM;
_snd_pcm_hw_params_any(params);
_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_ACCESS,
snd->access, 0);
_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_FORMAT,
snd->format, 0);
_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_CHANNELS,
snd->channels, 0);
_snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_RATE,
snd->rate, 0);
snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_HW_PARAMS, params);
result = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_PREPARE, NULL);
if (result < 0) {
ERROR(snd->card,
"Preparing sound card failed: %d\n", (int)result);
kfree(params);
return result;
}
/* Store the hardware parameters */
snd->access = params_access(params);
snd->format = params_format(params);
snd->channels = params_channels(params);
snd->rate = params_rate(params);
kfree(params);
INFO(snd->card,
"Hardware params: access %x, format %x, channels %d, rate %d\n",
snd->access, snd->format, snd->channels, snd->rate);
return 0;
}
/**
* Playback audio buffer data by ALSA PCM device
*/
static size_t u_audio_playback(struct gaudio *card, void *buf, size_t count)
{
struct gaudio_snd_dev *snd = &card->playback;
struct snd_pcm_substream *substream = snd->substream;
struct snd_pcm_runtime *runtime = substream->runtime;
mm_segment_t old_fs;
ssize_t result;
snd_pcm_sframes_t frames;
try_again:
if (runtime->status->state == SNDRV_PCM_STATE_XRUN ||
runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) {
result = snd_pcm_kernel_ioctl(substream,
SNDRV_PCM_IOCTL_PREPARE, NULL);
if (result < 0) {
ERROR(card, "Preparing sound card failed: %d\n",
(int)result);
return result;
}
}
frames = bytes_to_frames(runtime, count);
old_fs = get_fs();
set_fs(KERNEL_DS);
result = snd_pcm_lib_write(snd->substream, buf, frames);
if (result != frames) {
ERROR(card, "Playback error: %d\n", (int)result);
set_fs(old_fs);
goto try_again;
}
set_fs(old_fs);
return 0;
}
static int u_audio_get_playback_channels(struct gaudio *card)
{
return card->playback.channels;
}
static int u_audio_get_playback_rate(struct gaudio *card)
{
return card->playback.rate;
}
/**
* Open ALSA PCM and control device files
* Initial the PCM or control device
*/
static int gaudio_open_snd_dev(struct gaudio *card)
{
struct snd_pcm_file *pcm_file;
struct gaudio_snd_dev *snd;
if (!card)
return -ENODEV;
/* Open control device */
snd = &card->control;
snd->filp = filp_open(fn_cntl, O_RDWR, 0);
if (IS_ERR(snd->filp)) {
int ret = PTR_ERR(snd->filp);
ERROR(card, "unable to open sound control device file: %s\n",
fn_cntl);
snd->filp = NULL;
return ret;
}
snd->card = card;
/* Open PCM playback device and setup substream */
snd = &card->playback;
snd->filp = filp_open(fn_play, O_WRONLY, 0);
if (IS_ERR(snd->filp)) {
ERROR(card, "No such PCM playback device: %s\n", fn_play);
snd->filp = NULL;
}
pcm_file = snd->filp->private_data;
snd->substream = pcm_file->substream;
snd->card = card;
playback_default_hw_params(snd);
/* Open PCM capture device and setup substream */
snd = &card->capture;
snd->filp = filp_open(fn_cap, O_RDONLY, 0);
if (IS_ERR(snd->filp)) {
ERROR(card, "No such PCM capture device: %s\n", fn_cap);
snd->filp = NULL;
}
pcm_file = snd->filp->private_data;
snd->substream = pcm_file->substream;
snd->card = card;
return 0;
}
/**
* Close ALSA PCM and control device files
*/
static int gaudio_close_snd_dev(struct gaudio *gau)
{
struct gaudio_snd_dev *snd;
/* Close control device */
snd = &gau->control;
if (!IS_ERR(snd->filp))
filp_close(snd->filp, current->files);
/* Close PCM playback device and setup substream */
snd = &gau->playback;
if (!IS_ERR(snd->filp))
filp_close(snd->filp, current->files);
/* Close PCM capture device and setup substream */
snd = &gau->capture;
if (!IS_ERR(snd->filp))
filp_close(snd->filp, current->files);
return 0;
}
/**
* gaudio_setup - setup ALSA interface and preparing for USB transfer
*
* This sets up PCM, mixer or MIDI ALSA devices fore USB gadget using.
*
* Returns negative errno, or zero on success
*/
int __init gaudio_setup(struct gaudio *card)
{
int ret;
ret = gaudio_open_snd_dev(card);
if (ret)
ERROR(card, "we need at least one control device\n");
return ret;
}
/**
* gaudio_cleanup - remove ALSA device interface
*
* This is called to free all resources allocated by @gaudio_setup().
*/
void gaudio_cleanup(struct gaudio *card)
{
if (card)
gaudio_close_snd_dev(card);
}

View File

@ -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 */