linux/drivers/usb/gadget/f_uvc.c
Laurent Pinchart cdda479f15 USB gadget: video class function driver
This USB video class function driver implements a video capture device from the
host's point of view. It creates a V4L2 output device on the gadget's side to
transfer data from a userspace application over USB.

The UVC-specific descriptors are passed by the gadget driver to the UVC
function driver, making them completely configurable without any modification
to the function's driver code.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:41 -07:00

662 lines
17 KiB
C

/*
* uvc_gadget.c -- USB Video Class Gadget driver
*
* Copyright (C) 2009-2010
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/video.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-event.h>
#include "uvc.h"
unsigned int uvc_trace_param;
/* --------------------------------------------------------------------------
* Function descriptors
*/
/* string IDs are assigned dynamically */
#define UVC_STRING_ASSOCIATION_IDX 0
#define UVC_STRING_CONTROL_IDX 1
#define UVC_STRING_STREAMING_IDX 2
static struct usb_string uvc_en_us_strings[] = {
[UVC_STRING_ASSOCIATION_IDX].s = "UVC Camera",
[UVC_STRING_CONTROL_IDX].s = "Video Control",
[UVC_STRING_STREAMING_IDX].s = "Video Streaming",
{ }
};
static struct usb_gadget_strings uvc_stringtab = {
.language = 0x0409, /* en-us */
.strings = uvc_en_us_strings,
};
static struct usb_gadget_strings *uvc_function_strings[] = {
&uvc_stringtab,
NULL,
};
#define UVC_INTF_VIDEO_CONTROL 0
#define UVC_INTF_VIDEO_STREAMING 1
static struct usb_interface_assoc_descriptor uvc_iad __initdata = {
.bLength = USB_DT_INTERFACE_ASSOCIATION_SIZE,
.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
.bFirstInterface = 0,
.bInterfaceCount = 2,
.bFunctionClass = USB_CLASS_VIDEO,
.bFunctionSubClass = 0x03,
.bFunctionProtocol = 0x00,
.iFunction = 0,
};
static struct usb_interface_descriptor uvc_control_intf __initdata = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
.bInterfaceNumber = UVC_INTF_VIDEO_CONTROL,
.bAlternateSetting = 0,
.bNumEndpoints = 1,
.bInterfaceClass = USB_CLASS_VIDEO,
.bInterfaceSubClass = 0x01,
.bInterfaceProtocol = 0x00,
.iInterface = 0,
};
static struct usb_endpoint_descriptor uvc_control_ep __initdata = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_INT,
.wMaxPacketSize = cpu_to_le16(16),
.bInterval = 8,
};
static struct uvc_control_endpoint_descriptor uvc_control_cs_ep __initdata = {
.bLength = UVC_DT_CONTROL_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_CS_ENDPOINT,
.bDescriptorSubType = UVC_EP_INTERRUPT,
.wMaxTransferSize = cpu_to_le16(16),
};
static struct usb_interface_descriptor uvc_streaming_intf_alt0 __initdata = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
.bInterfaceNumber = UVC_INTF_VIDEO_STREAMING,
.bAlternateSetting = 0,
.bNumEndpoints = 0,
.bInterfaceClass = USB_CLASS_VIDEO,
.bInterfaceSubClass = 0x02,
.bInterfaceProtocol = 0x00,
.iInterface = 0,
};
static struct usb_interface_descriptor uvc_streaming_intf_alt1 __initdata = {
.bLength = USB_DT_INTERFACE_SIZE,
.bDescriptorType = USB_DT_INTERFACE,
.bInterfaceNumber = UVC_INTF_VIDEO_STREAMING,
.bAlternateSetting = 1,
.bNumEndpoints = 1,
.bInterfaceClass = USB_CLASS_VIDEO,
.bInterfaceSubClass = 0x02,
.bInterfaceProtocol = 0x00,
.iInterface = 0,
};
static struct usb_endpoint_descriptor uvc_streaming_ep = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_ISOC,
.wMaxPacketSize = cpu_to_le16(512),
.bInterval = 1,
};
static const struct usb_descriptor_header * const uvc_fs_streaming[] = {
(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
(struct usb_descriptor_header *) &uvc_streaming_ep,
NULL,
};
static const struct usb_descriptor_header * const uvc_hs_streaming[] = {
(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
(struct usb_descriptor_header *) &uvc_streaming_ep,
NULL,
};
/* --------------------------------------------------------------------------
* Control requests
*/
static void
uvc_function_ep0_complete(struct usb_ep *ep, struct usb_request *req)
{
struct uvc_device *uvc = req->context;
struct v4l2_event v4l2_event;
struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
if (uvc->event_setup_out) {
uvc->event_setup_out = 0;
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_DATA;
uvc_event->data.length = req->actual;
memcpy(&uvc_event->data.data, req->buf, req->actual);
v4l2_event_queue(uvc->vdev, &v4l2_event);
}
}
static int
uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
{
struct uvc_device *uvc = to_uvc(f);
struct v4l2_event v4l2_event;
struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
/* printk(KERN_INFO "setup request %02x %02x value %04x index %04x %04x\n",
* ctrl->bRequestType, ctrl->bRequest, le16_to_cpu(ctrl->wValue),
* le16_to_cpu(ctrl->wIndex), le16_to_cpu(ctrl->wLength));
*/
if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS) {
INFO(f->config->cdev, "invalid request type\n");
return -EINVAL;
}
/* Stall too big requests. */
if (le16_to_cpu(ctrl->wLength) > UVC_MAX_REQUEST_SIZE)
return -EINVAL;
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_SETUP;
memcpy(&uvc_event->req, ctrl, sizeof(uvc_event->req));
v4l2_event_queue(uvc->vdev, &v4l2_event);
return 0;
}
static int
uvc_function_get_alt(struct usb_function *f, unsigned interface)
{
struct uvc_device *uvc = to_uvc(f);
INFO(f->config->cdev, "uvc_function_get_alt(%u)\n", interface);
if (interface == uvc->control_intf)
return 0;
else if (interface != uvc->streaming_intf)
return -EINVAL;
else
return uvc->state == UVC_STATE_STREAMING ? 1 : 0;
}
static int
uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
{
struct uvc_device *uvc = to_uvc(f);
struct v4l2_event v4l2_event;
struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
INFO(f->config->cdev, "uvc_function_set_alt(%u, %u)\n", interface, alt);
if (interface == uvc->control_intf) {
if (alt)
return -EINVAL;
if (uvc->state == UVC_STATE_DISCONNECTED) {
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_CONNECT;
uvc_event->speed = f->config->cdev->gadget->speed;
v4l2_event_queue(uvc->vdev, &v4l2_event);
uvc->state = UVC_STATE_CONNECTED;
}
return 0;
}
if (interface != uvc->streaming_intf)
return -EINVAL;
/* TODO
if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
return alt ? -EINVAL : 0;
*/
switch (alt) {
case 0:
if (uvc->state != UVC_STATE_STREAMING)
return 0;
if (uvc->video.ep)
usb_ep_disable(uvc->video.ep);
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_STREAMOFF;
v4l2_event_queue(uvc->vdev, &v4l2_event);
uvc->state = UVC_STATE_CONNECTED;
break;
case 1:
if (uvc->state != UVC_STATE_CONNECTED)
return 0;
if (uvc->video.ep)
usb_ep_enable(uvc->video.ep, &uvc_streaming_ep);
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_STREAMON;
v4l2_event_queue(uvc->vdev, &v4l2_event);
uvc->state = UVC_STATE_STREAMING;
break;
default:
return -EINVAL;
}
return 0;
}
static void
uvc_function_disable(struct usb_function *f)
{
struct uvc_device *uvc = to_uvc(f);
struct v4l2_event v4l2_event;
INFO(f->config->cdev, "uvc_function_disable\n");
memset(&v4l2_event, 0, sizeof(v4l2_event));
v4l2_event.type = UVC_EVENT_DISCONNECT;
v4l2_event_queue(uvc->vdev, &v4l2_event);
uvc->state = UVC_STATE_DISCONNECTED;
}
/* --------------------------------------------------------------------------
* Connection / disconnection
*/
void
uvc_function_connect(struct uvc_device *uvc)
{
struct usb_composite_dev *cdev = uvc->func.config->cdev;
int ret;
if ((ret = usb_function_activate(&uvc->func)) < 0)
INFO(cdev, "UVC connect failed with %d\n", ret);
}
void
uvc_function_disconnect(struct uvc_device *uvc)
{
struct usb_composite_dev *cdev = uvc->func.config->cdev;
int ret;
if ((ret = usb_function_deactivate(&uvc->func)) < 0)
INFO(cdev, "UVC disconnect failed with %d\n", ret);
}
/* --------------------------------------------------------------------------
* USB probe and disconnect
*/
static int
uvc_register_video(struct uvc_device *uvc)
{
struct usb_composite_dev *cdev = uvc->func.config->cdev;
struct video_device *video;
/* TODO reference counting. */
video = video_device_alloc();
if (video == NULL)
return -ENOMEM;
video->parent = &cdev->gadget->dev;
video->minor = -1;
video->fops = &uvc_v4l2_fops;
video->release = video_device_release;
strncpy(video->name, cdev->gadget->name, sizeof(video->name));
uvc->vdev = video;
video_set_drvdata(video, uvc);
return video_register_device(video, VFL_TYPE_GRABBER, -1);
}
#define UVC_COPY_DESCRIPTOR(mem, dst, desc) \
do { \
memcpy(mem, desc, (desc)->bLength); \
*(dst)++ = mem; \
mem += (desc)->bLength; \
} while (0);
#define UVC_COPY_DESCRIPTORS(mem, dst, src) \
do { \
const struct usb_descriptor_header * const *__src; \
for (__src = src; *__src; ++__src) { \
memcpy(mem, *__src, (*__src)->bLength); \
*dst++ = mem; \
mem += (*__src)->bLength; \
} \
} while (0)
static struct usb_descriptor_header ** __init
uvc_copy_descriptors(struct uvc_device *uvc, enum usb_device_speed speed)
{
struct uvc_input_header_descriptor *uvc_streaming_header;
struct uvc_header_descriptor *uvc_control_header;
const struct uvc_descriptor_header * const *uvc_streaming_cls;
const struct usb_descriptor_header * const *uvc_streaming_std;
const struct usb_descriptor_header * const *src;
struct usb_descriptor_header **dst;
struct usb_descriptor_header **hdr;
unsigned int control_size;
unsigned int streaming_size;
unsigned int n_desc;
unsigned int bytes;
void *mem;
uvc_streaming_cls = (speed == USB_SPEED_FULL)
? uvc->desc.fs_streaming : uvc->desc.hs_streaming;
uvc_streaming_std = (speed == USB_SPEED_FULL)
? uvc_fs_streaming : uvc_hs_streaming;
/* Descriptors layout
*
* uvc_iad
* uvc_control_intf
* Class-specific UVC control descriptors
* uvc_control_ep
* uvc_control_cs_ep
* uvc_streaming_intf_alt0
* Class-specific UVC streaming descriptors
* uvc_{fs|hs}_streaming
*/
/* Count descriptors and compute their size. */
control_size = 0;
streaming_size = 0;
bytes = uvc_iad.bLength + uvc_control_intf.bLength
+ uvc_control_ep.bLength + uvc_control_cs_ep.bLength
+ uvc_streaming_intf_alt0.bLength;
n_desc = 5;
for (src = (const struct usb_descriptor_header**)uvc->desc.control; *src; ++src) {
control_size += (*src)->bLength;
bytes += (*src)->bLength;
n_desc++;
}
for (src = (const struct usb_descriptor_header**)uvc_streaming_cls; *src; ++src) {
streaming_size += (*src)->bLength;
bytes += (*src)->bLength;
n_desc++;
}
for (src = uvc_streaming_std; *src; ++src) {
bytes += (*src)->bLength;
n_desc++;
}
mem = kmalloc((n_desc + 1) * sizeof(*src) + bytes, GFP_KERNEL);
if (mem == NULL)
return NULL;
hdr = mem;
dst = mem;
mem += (n_desc + 1) * sizeof(*src);
/* Copy the descriptors. */
UVC_COPY_DESCRIPTOR(mem, dst, &uvc_iad);
UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_intf);
uvc_control_header = mem;
UVC_COPY_DESCRIPTORS(mem, dst,
(const struct usb_descriptor_header**)uvc->desc.control);
uvc_control_header->wTotalLength = cpu_to_le16(control_size);
uvc_control_header->bInCollection = 1;
uvc_control_header->baInterfaceNr[0] = uvc->streaming_intf;
UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_ep);
UVC_COPY_DESCRIPTOR(mem, dst, &uvc_control_cs_ep);
UVC_COPY_DESCRIPTOR(mem, dst, &uvc_streaming_intf_alt0);
uvc_streaming_header = mem;
UVC_COPY_DESCRIPTORS(mem, dst,
(const struct usb_descriptor_header**)uvc_streaming_cls);
uvc_streaming_header->wTotalLength = cpu_to_le16(streaming_size);
uvc_streaming_header->bEndpointAddress = uvc_streaming_ep.bEndpointAddress;
UVC_COPY_DESCRIPTORS(mem, dst, uvc_streaming_std);
*dst = NULL;
return hdr;
}
static void
uvc_function_unbind(struct usb_configuration *c, struct usb_function *f)
{
struct usb_composite_dev *cdev = c->cdev;
struct uvc_device *uvc = to_uvc(f);
INFO(cdev, "uvc_function_unbind\n");
if (uvc->vdev) {
if (uvc->vdev->minor == -1)
video_device_release(uvc->vdev);
else
video_unregister_device(uvc->vdev);
uvc->vdev = NULL;
}
if (uvc->control_ep)
uvc->control_ep->driver_data = NULL;
if (uvc->video.ep)
uvc->video.ep->driver_data = NULL;
if (uvc->control_req) {
usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
kfree(uvc->control_buf);
}
kfree(f->descriptors);
kfree(f->hs_descriptors);
kfree(uvc);
}
static int __init
uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
{
struct usb_composite_dev *cdev = c->cdev;
struct uvc_device *uvc = to_uvc(f);
struct usb_ep *ep;
int ret = -EINVAL;
INFO(cdev, "uvc_function_bind\n");
/* Allocate endpoints. */
ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
if (!ep) {
INFO(cdev, "Unable to allocate control EP\n");
goto error;
}
uvc->control_ep = ep;
ep->driver_data = uvc;
ep = usb_ep_autoconfig(cdev->gadget, &uvc_streaming_ep);
if (!ep) {
INFO(cdev, "Unable to allocate streaming EP\n");
goto error;
}
uvc->video.ep = ep;
ep->driver_data = uvc;
/* Allocate interface IDs. */
if ((ret = usb_interface_id(c, f)) < 0)
goto error;
uvc_iad.bFirstInterface = ret;
uvc_control_intf.bInterfaceNumber = ret;
uvc->control_intf = ret;
if ((ret = usb_interface_id(c, f)) < 0)
goto error;
uvc_streaming_intf_alt0.bInterfaceNumber = ret;
uvc_streaming_intf_alt1.bInterfaceNumber = ret;
uvc->streaming_intf = ret;
/* Copy descriptors. */
f->descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
f->hs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_HIGH);
/* Preallocate control endpoint request. */
uvc->control_req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
uvc->control_buf = kmalloc(UVC_MAX_REQUEST_SIZE, GFP_KERNEL);
if (uvc->control_req == NULL || uvc->control_buf == NULL) {
ret = -ENOMEM;
goto error;
}
uvc->control_req->buf = uvc->control_buf;
uvc->control_req->complete = uvc_function_ep0_complete;
uvc->control_req->context = uvc;
/* Avoid letting this gadget enumerate until the userspace server is
* active.
*/
if ((ret = usb_function_deactivate(f)) < 0)
goto error;
/* Initialise video. */
ret = uvc_video_init(&uvc->video);
if (ret < 0)
goto error;
/* Register a V4L2 device. */
ret = uvc_register_video(uvc);
if (ret < 0) {
printk(KERN_INFO "Unable to register video device\n");
goto error;
}
return 0;
error:
uvc_function_unbind(c, f);
return ret;
}
/* --------------------------------------------------------------------------
* USB gadget function
*/
/**
* uvc_bind_config - add a UVC function to a configuration
* @c: the configuration to support the UVC instance
* Context: single threaded during gadget setup
*
* Returns zero on success, else negative errno.
*
* Caller must have called @uvc_setup(). Caller is also responsible for
* calling @uvc_cleanup() before module unload.
*/
int __init
uvc_bind_config(struct usb_configuration *c,
const struct uvc_descriptor_header * const *control,
const struct uvc_descriptor_header * const *fs_streaming,
const struct uvc_descriptor_header * const *hs_streaming)
{
struct uvc_device *uvc;
int ret = 0;
/* TODO Check if the USB device controller supports the required
* features.
*/
if (!gadget_is_dualspeed(c->cdev->gadget))
return -EINVAL;
uvc = kzalloc(sizeof(*uvc), GFP_KERNEL);
if (uvc == NULL)
return -ENOMEM;
uvc->state = UVC_STATE_DISCONNECTED;
/* Validate the descriptors. */
if (control == NULL || control[0] == NULL ||
control[0]->bDescriptorSubType != UVC_DT_HEADER)
goto error;
if (fs_streaming == NULL || fs_streaming[0] == NULL ||
fs_streaming[0]->bDescriptorSubType != UVC_DT_INPUT_HEADER)
goto error;
if (hs_streaming == NULL || hs_streaming[0] == NULL ||
hs_streaming[0]->bDescriptorSubType != UVC_DT_INPUT_HEADER)
goto error;
uvc->desc.control = control;
uvc->desc.fs_streaming = fs_streaming;
uvc->desc.hs_streaming = hs_streaming;
/* Allocate string descriptor numbers. */
if ((ret = usb_string_id(c->cdev)) < 0)
goto error;
uvc_en_us_strings[UVC_STRING_ASSOCIATION_IDX].id = ret;
uvc_iad.iFunction = ret;
if ((ret = usb_string_id(c->cdev)) < 0)
goto error;
uvc_en_us_strings[UVC_STRING_CONTROL_IDX].id = ret;
uvc_control_intf.iInterface = ret;
if ((ret = usb_string_id(c->cdev)) < 0)
goto error;
uvc_en_us_strings[UVC_STRING_STREAMING_IDX].id = ret;
uvc_streaming_intf_alt0.iInterface = ret;
uvc_streaming_intf_alt1.iInterface = ret;
/* Register the function. */
uvc->func.name = "uvc";
uvc->func.strings = uvc_function_strings;
uvc->func.bind = uvc_function_bind;
uvc->func.unbind = uvc_function_unbind;
uvc->func.get_alt = uvc_function_get_alt;
uvc->func.set_alt = uvc_function_set_alt;
uvc->func.disable = uvc_function_disable;
uvc->func.setup = uvc_function_setup;
ret = usb_add_function(c, &uvc->func);
if (ret)
kfree(uvc);
return 0;
error:
kfree(uvc);
return ret;
}
module_param_named(trace, uvc_trace_param, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(trace, "Trace level bitmask");