@@ -22,6 +22,7 @@ USB support
misc_usbsevseg
mtouchusb
ohci
+ raw-gadget
usbip_protocol
usbmon
usb-serial
new file mode 100644
@@ -0,0 +1,61 @@
+==============
+USB Raw Gadget
+==============
+
+USB Raw Gadget is a kernel module that provides a userspace interface for
+the USB Gadget subsystem. Essentially it allows to emulate USB devices
+from userspace. Enabled with CONFIG_USB_RAW_GADGET. Raw Gadget is
+currently a strictly debugging feature and shouldn't be used in
+production, use GadgetFS instead.
+
+Comparison to GadgetFS
+~~~~~~~~~~~~~~~~~~~~~~
+
+Raw Gadget is similar to GadgetFS, but provides a more low-level and
+direct access to the USB Gadget layer for the userspace. The key
+differences are:
+
+1. Every USB request is passed to the userspace to get a response, while
+ GadgetFS responds to some USB requests internally based on the provided
+ descriptors. However note, that the UDC driver might respond to some
+ requests on its own and never forward them to the Gadget layer.
+
+2. GadgetFS performs some sanity checks on the provided USB descriptors,
+ while Raw Gadget allows you to provide arbitrary data as responses to
+ USB requests.
+
+3. Raw Gadget provides a way to select a UDC device/driver to bind to,
+ while GadgetFS currently binds to the first available UDC.
+
+4. Raw Gadget uses predictable endpoint names (handles) across different
+ UDCs (as long as UDCs have enough endpoints of each required transfer
+ type).
+
+5. Raw Gadget has ioctl-based interface instead of a filesystem-based one.
+
+Userspace interface
+~~~~~~~~~~~~~~~~~~~
+
+To create a Raw Gadget instance open /dev/raw-gadget. Multiple raw-gadget
+instances (bound to different UDCs) can be used at the same time. The
+interaction with the opened file happens through the ioctl() calls, see
+comments in include/uapi/linux/usb/raw_gadget.h for details.
+
+The typical usage of Raw Gadget looks like:
+
+1. Open Raw Gadget instance via /dev/raw-gadget.
+2. Initialize the instance via USB_RAW_IOCTL_INIT.
+3. Launch the instance with USB_RAW_IOCTL_RUN.
+4. In a loop issue USB_RAW_IOCTL_EVENT_FETCH calls to receive events from
+ Raw Gadget and react to those depending on what kind of USB device
+ needs to be emulated.
+
+Potential future improvements
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- Implement ioctl's for setting/clearing halt status on endpoints.
+
+- Reporting more events (suspend, resume, etc.) through
+ USB_RAW_IOCTL_EVENT_FETCH.
+
+- Support O_NONBLOCK I/O.
@@ -516,4 +516,15 @@ config USB_G_WEBCAM
Say "y" to link the driver statically, or "m" to build a
dynamically linked module called "g_webcam".
+config USB_RAW_GADGET
+ tristate "USB Raw Gadget"
+ help
+ USB Raw Gadget is a kernel module that provides a userspace interface
+ for the USB Gadget subsystem. Essentially it allows to emulate USB
+ devices from userspace. See Documentation/usb/raw-gadget.rst for
+ details.
+
+ Say "y" to link the driver statically, or "m" to build a
+ dynamically linked module called "raw_gadget".
+
endchoice
@@ -43,3 +43,4 @@ obj-$(CONFIG_USB_G_WEBCAM) += g_webcam.o
obj-$(CONFIG_USB_G_NCM) += g_ncm.o
obj-$(CONFIG_USB_G_ACM_MS) += g_acm_ms.o
obj-$(CONFIG_USB_GADGET_TARGET) += tcm_usb_gadget.o
+obj-$(CONFIG_USB_RAW_GADGET) += raw_gadget.o
new file mode 100644
@@ -0,0 +1,1078 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB Raw Gadget driver.
+ * See Documentation/usb/raw-gadget.rst for more details.
+ *
+ * Andrey Konovalov <andreyknvl@gmail.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/kref.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/semaphore.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/wait.h>
+
+#include <linux/usb.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/ch11.h>
+#include <linux/usb/gadget.h>
+
+#include <uapi/linux/usb/raw_gadget.h>
+
+#define DRIVER_DESC "USB Raw Gadget"
+#define DRIVER_NAME "raw-gadget"
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Andrey Konovalov");
+MODULE_LICENSE("GPL");
+
+/*----------------------------------------------------------------------*/
+
+#define RAW_EVENT_QUEUE_SIZE 16
+
+struct raw_event_queue {
+ /* See the comment in raw_event_queue_fetch() for locking details. */
+ spinlock_t lock;
+ struct semaphore sema;
+ struct usb_raw_event *events[RAW_EVENT_QUEUE_SIZE];
+ int size;
+};
+
+static void raw_event_queue_init(struct raw_event_queue *queue)
+{
+ spin_lock_init(&queue->lock);
+ sema_init(&queue->sema, 0);
+ queue->size = 0;
+}
+
+static int raw_event_queue_add(struct raw_event_queue *queue,
+ enum usb_raw_event_type type, size_t length, const void *data)
+{
+ unsigned long flags;
+ struct usb_raw_event *event;
+
+ spin_lock_irqsave(&queue->lock, flags);
+ if (WARN_ON(queue->size >= RAW_EVENT_QUEUE_SIZE)) {
+ spin_unlock_irqrestore(&queue->lock, flags);
+ return -ENOMEM;
+ }
+ event = kmalloc(sizeof(*event) + length, GFP_ATOMIC);
+ if (!event) {
+ spin_unlock_irqrestore(&queue->lock, flags);
+ return -ENOMEM;
+ }
+ event->type = type;
+ event->length = length;
+ if (event->length)
+ memcpy(&event->data[0], data, length);
+ queue->events[queue->size] = event;
+ queue->size++;
+ up(&queue->sema);
+ spin_unlock_irqrestore(&queue->lock, flags);
+ return 0;
+}
+
+static struct usb_raw_event *raw_event_queue_fetch(
+ struct raw_event_queue *queue)
+{
+ unsigned long flags;
+ struct usb_raw_event *event;
+
+ /*
+ * This function can be called concurrently. We first check that
+ * there's at least one event queued by decrementing the semaphore,
+ * and then take the lock to protect queue struct fields.
+ */
+ if (down_interruptible(&queue->sema))
+ return NULL;
+ spin_lock_irqsave(&queue->lock, flags);
+ if (WARN_ON(!queue->size))
+ return NULL;
+ event = queue->events[0];
+ queue->size--;
+ memmove(&queue->events[0], &queue->events[1],
+ queue->size * sizeof(queue->events[0]));
+ spin_unlock_irqrestore(&queue->lock, flags);
+ return event;
+}
+
+static void raw_event_queue_destroy(struct raw_event_queue *queue)
+{
+ int i;
+
+ for (i = 0; i < queue->size; i++)
+ kfree(queue->events[i]);
+ queue->size = 0;
+}
+
+/*----------------------------------------------------------------------*/
+
+struct raw_dev;
+
+#define USB_RAW_MAX_ENDPOINTS 32
+
+enum ep_state {
+ STATE_EP_DISABLED,
+ STATE_EP_ENABLED,
+};
+
+struct raw_ep {
+ struct raw_dev *dev;
+ enum ep_state state;
+ struct usb_ep *ep;
+ struct usb_request *req;
+ bool urb_queued;
+ bool disabling;
+ ssize_t status;
+};
+
+enum dev_state {
+ STATE_DEV_INVALID = 0,
+ STATE_DEV_OPENED,
+ STATE_DEV_INITIALIZED,
+ STATE_DEV_RUNNING,
+ STATE_DEV_CLOSED,
+ STATE_DEV_FAILED
+};
+
+struct raw_dev {
+ struct kref count;
+ spinlock_t lock;
+
+ const char *udc_name;
+ struct usb_gadget_driver driver;
+
+ /* Reference to misc device: */
+ struct device *dev;
+
+ /* Protected by lock: */
+ enum dev_state state;
+ bool gadget_registered;
+ struct usb_gadget *gadget;
+ struct usb_request *req;
+ bool ep0_in_pending;
+ bool ep0_out_pending;
+ bool ep0_urb_queued;
+ ssize_t ep0_status;
+ struct raw_ep eps[USB_RAW_MAX_ENDPOINTS];
+
+ struct completion ep0_done;
+ struct raw_event_queue queue;
+};
+
+static struct raw_dev *dev_new(void)
+{
+ struct raw_dev *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return NULL;
+ /* Matches kref_put() in raw_release(). */
+ kref_init(&dev->count);
+ spin_lock_init(&dev->lock);
+ init_completion(&dev->ep0_done);
+ raw_event_queue_init(&dev->queue);
+ return dev;
+}
+
+static void dev_free(struct kref *kref)
+{
+ struct raw_dev *dev = container_of(kref, struct raw_dev, count);
+ int i;
+
+ kfree(dev->udc_name);
+ kfree(dev->driver.udc_name);
+ if (dev->req) {
+ if (dev->ep0_urb_queued)
+ usb_ep_dequeue(dev->gadget->ep0, dev->req);
+ usb_ep_free_request(dev->gadget->ep0, dev->req);
+ }
+ raw_event_queue_destroy(&dev->queue);
+ for (i = 0; i < USB_RAW_MAX_ENDPOINTS; i++) {
+ if (dev->eps[i].state != STATE_EP_ENABLED)
+ continue;
+ usb_ep_disable(dev->eps[i].ep);
+ usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
+ kfree(dev->eps[i].ep->desc);
+ dev->eps[i].state = STATE_EP_DISABLED;
+ }
+ kfree(dev);
+}
+
+/*----------------------------------------------------------------------*/
+
+static int raw_queue_event(struct raw_dev *dev,
+ enum usb_raw_event_type type, size_t length, const void *data)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ ret = raw_event_queue_add(&dev->queue, type, length, data);
+ if (ret < 0) {
+ spin_lock_irqsave(&dev->lock, flags);
+ dev->state = STATE_DEV_FAILED;
+ spin_unlock_irqrestore(&dev->lock, flags);
+ }
+ return ret;
+}
+
+static void gadget_ep0_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct raw_dev *dev = req->context;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (req->status)
+ dev->ep0_status = req->status;
+ else
+ dev->ep0_status = req->actual;
+ if (dev->ep0_in_pending)
+ dev->ep0_in_pending = false;
+ else
+ dev->ep0_out_pending = false;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ complete(&dev->ep0_done);
+}
+
+static int gadget_bind(struct usb_gadget *gadget,
+ struct usb_gadget_driver *driver)
+{
+ int ret = 0;
+ struct raw_dev *dev = container_of(driver, struct raw_dev, driver);
+ struct usb_request *req;
+ unsigned long flags;
+
+ if (strcmp(gadget->name, dev->udc_name) != 0)
+ return -ENODEV;
+
+ set_gadget_data(gadget, dev);
+ req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
+ if (!req) {
+ dev_err(&gadget->dev, "usb_ep_alloc_request failed\n");
+ set_gadget_data(gadget, NULL);
+ return -ENOMEM;
+ }
+
+ spin_lock_irqsave(&dev->lock, flags);
+ dev->req = req;
+ dev->req->context = dev;
+ dev->req->complete = gadget_ep0_complete;
+ dev->gadget = gadget;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ /* Matches kref_put() in gadget_unbind(). */
+ kref_get(&dev->count);
+
+ ret = raw_queue_event(dev, USB_RAW_EVENT_CONNECT, 0, NULL);
+ if (ret < 0)
+ dev_err(&gadget->dev, "failed to queue event\n");
+
+ return ret;
+}
+
+static void gadget_unbind(struct usb_gadget *gadget)
+{
+ struct raw_dev *dev = get_gadget_data(gadget);
+
+ set_gadget_data(gadget, NULL);
+ /* Matches kref_get() in gadget_bind(). */
+ kref_put(&dev->count, dev_free);
+}
+
+static int gadget_setup(struct usb_gadget *gadget,
+ const struct usb_ctrlrequest *ctrl)
+{
+ int ret = 0;
+ struct raw_dev *dev = get_gadget_data(gadget);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_err(&gadget->dev, "ignoring, device is not running\n");
+ ret = -ENODEV;
+ goto out_unlock;
+ }
+ if (dev->ep0_in_pending || dev->ep0_out_pending) {
+ dev_dbg(&gadget->dev, "stalling, request already pending\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if ((ctrl->bRequestType & USB_DIR_IN) && ctrl->wLength)
+ dev->ep0_in_pending = true;
+ else
+ dev->ep0_out_pending = true;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ ret = raw_queue_event(dev, USB_RAW_EVENT_CONTROL, sizeof(*ctrl), ctrl);
+ if (ret < 0)
+ dev_err(&gadget->dev, "failed to queue event\n");
+ goto out;
+
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+out:
+ return ret;
+}
+
+/* These are currently unused but present in case UDC driver requires them. */
+static void gadget_disconnect(struct usb_gadget *gadget) { }
+static void gadget_suspend(struct usb_gadget *gadget) { }
+static void gadget_resume(struct usb_gadget *gadget) { }
+static void gadget_reset(struct usb_gadget *gadget) { }
+
+/*----------------------------------------------------------------------*/
+
+static struct miscdevice raw_misc_device;
+
+static int raw_open(struct inode *inode, struct file *fd)
+{
+ struct raw_dev *dev;
+
+ /* Nonblocking I/O is not supported yet. */
+ if (fd->f_flags & O_NONBLOCK)
+ return -EINVAL;
+
+ dev = dev_new();
+ if (!dev)
+ return -ENOMEM;
+ fd->private_data = dev;
+ dev->state = STATE_DEV_OPENED;
+ dev->dev = raw_misc_device.this_device;
+ return 0;
+}
+
+static int raw_release(struct inode *inode, struct file *fd)
+{
+ int ret = 0;
+ struct raw_dev *dev = fd->private_data;
+ unsigned long flags;
+ bool unregister = false;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ dev->state = STATE_DEV_CLOSED;
+ if (!dev->gadget) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ goto out_put;
+ }
+ if (dev->gadget_registered)
+ unregister = true;
+ dev->gadget_registered = false;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ if (unregister) {
+ ret = usb_gadget_unregister_driver(&dev->driver);
+ if (ret != 0)
+ dev_err(dev->dev,
+ "usb_gadget_unregister_driver() failed with %d\n",
+ ret);
+ /* Matches kref_get() in raw_ioctl_run(). */
+ kref_put(&dev->count, dev_free);
+ }
+
+out_put:
+ /* Matches dev_new() in raw_open(). */
+ kref_put(&dev->count, dev_free);
+ return ret;
+}
+
+/*----------------------------------------------------------------------*/
+
+static int raw_ioctl_init(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ struct usb_raw_init arg;
+ char *udc_driver_name;
+ char *udc_device_name;
+ unsigned long flags;
+
+ ret = copy_from_user(&arg, (void __user *)value, sizeof(arg));
+ if (ret)
+ return ret;
+
+ switch (arg.speed) {
+ case USB_SPEED_UNKNOWN:
+ arg.speed = USB_SPEED_HIGH;
+ break;
+ case USB_SPEED_LOW:
+ case USB_SPEED_FULL:
+ case USB_SPEED_HIGH:
+ case USB_SPEED_SUPER:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ udc_driver_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
+ if (!udc_driver_name)
+ return -ENOMEM;
+ ret = strscpy(udc_driver_name, &arg.driver_name[0],
+ UDC_NAME_LENGTH_MAX);
+ if (ret < 0) {
+ kfree(udc_driver_name);
+ return ret;
+ }
+ ret = 0;
+
+ udc_device_name = kmalloc(UDC_NAME_LENGTH_MAX, GFP_KERNEL);
+ if (!udc_device_name) {
+ kfree(udc_driver_name);
+ return -ENOMEM;
+ }
+ ret = strscpy(udc_device_name, &arg.device_name[0],
+ UDC_NAME_LENGTH_MAX);
+ if (ret < 0) {
+ kfree(udc_driver_name);
+ kfree(udc_device_name);
+ return ret;
+ }
+ ret = 0;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_OPENED) {
+ dev_dbg(dev->dev, "fail, device is not opened\n");
+ kfree(udc_driver_name);
+ kfree(udc_device_name);
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ dev->udc_name = udc_driver_name;
+
+ dev->driver.function = DRIVER_DESC;
+ dev->driver.max_speed = arg.speed;
+ dev->driver.setup = gadget_setup;
+ dev->driver.disconnect = gadget_disconnect;
+ dev->driver.bind = gadget_bind;
+ dev->driver.unbind = gadget_unbind;
+ dev->driver.suspend = gadget_suspend;
+ dev->driver.resume = gadget_resume;
+ dev->driver.reset = gadget_reset;
+ dev->driver.driver.name = DRIVER_NAME;
+ dev->driver.udc_name = udc_device_name;
+ dev->driver.match_existing_only = 1;
+
+ dev->state = STATE_DEV_INITIALIZED;
+
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static int raw_ioctl_run(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ if (value)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_INITIALIZED) {
+ dev_dbg(dev->dev, "fail, device is not initialized\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ ret = usb_gadget_probe_driver(&dev->driver);
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (ret) {
+ dev_err(dev->dev,
+ "fail, usb_gadget_probe_driver returned %d\n", ret);
+ dev->state = STATE_DEV_FAILED;
+ goto out_unlock;
+ }
+ dev->gadget_registered = true;
+ dev->state = STATE_DEV_RUNNING;
+ /* Matches kref_put() in raw_release(). */
+ kref_get(&dev->count);
+
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static int raw_ioctl_event_fetch(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ struct usb_raw_event arg;
+ unsigned long flags;
+ struct usb_raw_event *event;
+ uint32_t length;
+
+ ret = copy_from_user(&arg, (void __user *)value, sizeof(arg));
+ if (ret)
+ return ret;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_dbg(dev->dev, "fail, device is not running\n");
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return -EINVAL;
+ }
+ if (!dev->gadget) {
+ dev_dbg(dev->dev, "fail, gadget is not bound\n");
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return -EBUSY;
+ }
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ event = raw_event_queue_fetch(&dev->queue);
+ if (!event) {
+ dev_dbg(&dev->gadget->dev, "event fetching interrupted\n");
+ return -EINTR;
+ }
+ length = min(arg.length, event->length);
+ ret = copy_to_user((void __user *)value, event,
+ sizeof(*event) + length);
+ return ret;
+}
+
+static void *raw_alloc_io_data(struct usb_raw_ep_io *io, void __user *ptr,
+ bool get_from_user)
+{
+ int ret;
+ void *data;
+
+ ret = copy_from_user(io, ptr, sizeof(*io));
+ if (ret)
+ return ERR_PTR(ret);
+ if (io->ep >= USB_RAW_MAX_ENDPOINTS)
+ return ERR_PTR(-EINVAL);
+ if (!usb_raw_io_flags_valid(io->flags))
+ return ERR_PTR(-EINVAL);
+ if (io->length > PAGE_SIZE)
+ return ERR_PTR(-EINVAL);
+ if (get_from_user)
+ data = memdup_user(ptr + sizeof(*io), io->length);
+ else {
+ data = kmalloc(io->length, GFP_KERNEL);
+ if (!data)
+ data = ERR_PTR(-ENOMEM);
+ }
+ return data;
+}
+
+static int raw_process_ep0_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
+ void *data, bool in)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_dbg(dev->dev, "fail, device is not running\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (!dev->gadget) {
+ dev_dbg(dev->dev, "fail, gadget is not bound\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if (dev->ep0_urb_queued) {
+ dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if ((in && !dev->ep0_in_pending) ||
+ (!in && !dev->ep0_out_pending)) {
+ dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if (WARN_ON(in && dev->ep0_out_pending)) {
+ ret = -ENODEV;
+ dev->state = STATE_DEV_FAILED;
+ goto out_done;
+ }
+ if (WARN_ON(!in && dev->ep0_in_pending)) {
+ ret = -ENODEV;
+ dev->state = STATE_DEV_FAILED;
+ goto out_done;
+ }
+
+ dev->req->buf = data;
+ dev->req->length = io->length;
+ dev->req->zero = usb_raw_io_flags_zero(io->flags);
+ dev->ep0_urb_queued = true;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ ret = usb_ep_queue(dev->gadget->ep0, dev->req, GFP_KERNEL);
+ if (ret) {
+ dev_err(&dev->gadget->dev,
+ "fail, usb_ep_queue returned %d\n", ret);
+ spin_lock_irqsave(&dev->lock, flags);
+ dev->state = STATE_DEV_FAILED;
+ goto out_done;
+ }
+
+ ret = wait_for_completion_interruptible(&dev->ep0_done);
+ if (ret) {
+ dev_dbg(&dev->gadget->dev, "wait interrupted\n");
+ usb_ep_dequeue(dev->gadget->ep0, dev->req);
+ wait_for_completion(&dev->ep0_done);
+ spin_lock_irqsave(&dev->lock, flags);
+ goto out_done;
+ }
+
+ spin_lock_irqsave(&dev->lock, flags);
+ ret = dev->ep0_status;
+
+out_done:
+ dev->ep0_urb_queued = false;
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static int raw_ioctl_ep0_write(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ void *data;
+ struct usb_raw_ep_io io;
+
+ data = raw_alloc_io_data(&io, (void __user *)value, true);
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+ ret = raw_process_ep0_io(dev, &io, data, true);
+ kfree(data);
+ return ret;
+}
+
+static int raw_ioctl_ep0_read(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ void *data;
+ struct usb_raw_ep_io io;
+ unsigned int length;
+
+ data = raw_alloc_io_data(&io, (void __user *)value, false);
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+ ret = raw_process_ep0_io(dev, &io, data, false);
+ if (ret < 0) {
+ kfree(data);
+ return ret;
+ }
+ length = min(io.length, (unsigned int)ret);
+ ret = copy_to_user((void __user *)(value + sizeof(io)), data, length);
+ kfree(data);
+ return ret;
+}
+
+static bool check_ep_caps(struct usb_ep *ep,
+ struct usb_endpoint_descriptor *desc)
+{
+ switch (usb_endpoint_type(desc)) {
+ case USB_ENDPOINT_XFER_ISOC:
+ if (!ep->caps.type_iso)
+ return false;
+ break;
+ case USB_ENDPOINT_XFER_BULK:
+ if (!ep->caps.type_bulk)
+ return false;
+ break;
+ case USB_ENDPOINT_XFER_INT:
+ if (!ep->caps.type_int)
+ return false;
+ break;
+ default:
+ return false;
+ }
+
+ if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
+ return false;
+ if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out)
+ return false;
+
+ return true;
+}
+
+static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0, i;
+ unsigned long flags;
+ struct usb_endpoint_descriptor *desc;
+ struct usb_ep *ep = NULL;
+
+ desc = memdup_user((void __user *)value, sizeof(*desc));
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ /*
+ * Endpoints with a maxpacket length of 0 can cause crashes in UDC
+ * drivers.
+ */
+ if (usb_endpoint_maxp(desc) == 0) {
+ dev_dbg(dev->dev, "fail, bad endpoint maxpacket\n");
+ kfree(desc);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_dbg(dev->dev, "fail, device is not running\n");
+ ret = -EINVAL;
+ goto out_free;
+ }
+ if (!dev->gadget) {
+ dev_dbg(dev->dev, "fail, gadget is not bound\n");
+ ret = -EBUSY;
+ goto out_free;
+ }
+
+ for (i = 0; i < USB_RAW_MAX_ENDPOINTS; i++) {
+ if (dev->eps[i].state == STATE_EP_ENABLED)
+ continue;
+ break;
+ }
+ if (i == USB_RAW_MAX_ENDPOINTS) {
+ dev_dbg(&dev->gadget->dev,
+ "fail, no device endpoints available\n");
+ ret = -EBUSY;
+ goto out_free;
+ }
+
+ gadget_for_each_ep(ep, dev->gadget) {
+ if (ep->enabled)
+ continue;
+ if (!check_ep_caps(ep, desc))
+ continue;
+ ep->desc = desc;
+ ret = usb_ep_enable(ep);
+ if (ret < 0) {
+ dev_err(&dev->gadget->dev,
+ "fail, usb_ep_enable returned %d\n", ret);
+ goto out_free;
+ }
+ dev->eps[i].req = usb_ep_alloc_request(ep, GFP_ATOMIC);
+ if (!dev->eps[i].req) {
+ dev_err(&dev->gadget->dev,
+ "fail, usb_ep_alloc_request failed\n");
+ usb_ep_disable(ep);
+ ret = -ENOMEM;
+ goto out_free;
+ }
+ dev->eps[i].ep = ep;
+ dev->eps[i].state = STATE_EP_ENABLED;
+ ep->driver_data = &dev->eps[i];
+ ret = i;
+ goto out_unlock;
+ }
+
+ dev_dbg(&dev->gadget->dev, "fail, no gadget endpoints available\n");
+ ret = -EBUSY;
+
+out_free:
+ kfree(desc);
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static int raw_ioctl_ep_disable(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0, i = value;
+ unsigned long flags;
+ const void *desc;
+
+ if (i < 0 || i >= USB_RAW_MAX_ENDPOINTS)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_dbg(dev->dev, "fail, device is not running\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (!dev->gadget) {
+ dev_dbg(dev->dev, "fail, gadget is not bound\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if (dev->eps[i].state != STATE_EP_ENABLED) {
+ dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (dev->eps[i].disabling) {
+ dev_dbg(&dev->gadget->dev,
+ "fail, disable already in progress\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (dev->eps[i].urb_queued) {
+ dev_dbg(&dev->gadget->dev,
+ "fail, waiting for urb completion\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ dev->eps[i].disabling = true;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ usb_ep_disable(dev->eps[i].ep);
+
+ spin_lock_irqsave(&dev->lock, flags);
+ usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
+ desc = dev->eps[i].ep->desc;
+ dev->eps[i].ep = NULL;
+ dev->eps[i].state = STATE_EP_DISABLED;
+ kfree(desc);
+ dev->eps[i].disabling = false;
+
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static void gadget_ep_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct raw_ep *r_ep = (struct raw_ep *)ep->driver_data;
+ struct raw_dev *dev = r_ep->dev;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (req->status)
+ r_ep->status = req->status;
+ else
+ r_ep->status = req->actual;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ complete((struct completion *)req->context);
+}
+
+static int raw_process_ep_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
+ void *data, bool in)
+{
+ int ret = 0;
+ unsigned long flags;
+ struct raw_ep *ep = &dev->eps[io->ep];
+ DECLARE_COMPLETION_ONSTACK(done);
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_dbg(dev->dev, "fail, device is not running\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (!dev->gadget) {
+ dev_dbg(dev->dev, "fail, gadget is not bound\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if (ep->state != STATE_EP_ENABLED) {
+ dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if (ep->disabling) {
+ dev_dbg(&dev->gadget->dev,
+ "fail, endpoint is already being disabled\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if (ep->urb_queued) {
+ dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ if ((in && !ep->ep->caps.dir_in) || (!in && ep->ep->caps.dir_in)) {
+ dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ ep->dev = dev;
+ ep->req->context = &done;
+ ep->req->complete = gadget_ep_complete;
+ ep->req->buf = data;
+ ep->req->length = io->length;
+ ep->req->zero = usb_raw_io_flags_zero(io->flags);
+ ep->urb_queued = true;
+ spin_unlock_irqrestore(&dev->lock, flags);
+
+ ret = usb_ep_queue(ep->ep, ep->req, GFP_KERNEL);
+ if (ret) {
+ dev_err(&dev->gadget->dev,
+ "fail, usb_ep_queue returned %d\n", ret);
+ spin_lock_irqsave(&dev->lock, flags);
+ dev->state = STATE_DEV_FAILED;
+ goto out_done;
+ }
+
+ ret = wait_for_completion_interruptible(&done);
+ if (ret) {
+ dev_dbg(&dev->gadget->dev, "wait interrupted\n");
+ usb_ep_dequeue(ep->ep, ep->req);
+ wait_for_completion(&done);
+ spin_lock_irqsave(&dev->lock, flags);
+ goto out_done;
+ }
+
+ spin_lock_irqsave(&dev->lock, flags);
+ ret = ep->status;
+
+out_done:
+ ep->urb_queued = false;
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static int raw_ioctl_ep_write(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ char *data;
+ struct usb_raw_ep_io io;
+
+ data = raw_alloc_io_data(&io, (void __user *)value, true);
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+ ret = raw_process_ep_io(dev, &io, data, true);
+ kfree(data);
+ return ret;
+}
+
+static int raw_ioctl_ep_read(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ char *data;
+ struct usb_raw_ep_io io;
+ unsigned int length;
+
+ data = raw_alloc_io_data(&io, (void __user *)value, false);
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+ ret = raw_process_ep_io(dev, &io, data, false);
+ if (ret < 0) {
+ kfree(data);
+ return ret;
+ }
+ length = min(io.length, (unsigned int)ret);
+ ret = copy_to_user((void __user *)(value + sizeof(io)), data, length);
+ kfree(data);
+ return ret;
+}
+
+static int raw_ioctl_configure(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ if (value)
+ return -EINVAL;
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_dbg(dev->dev, "fail, device is not running\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (!dev->gadget) {
+ dev_dbg(dev->dev, "fail, gadget is not bound\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ usb_gadget_set_state(dev->gadget, USB_STATE_CONFIGURED);
+
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static int raw_ioctl_vbus_draw(struct raw_dev *dev, unsigned long value)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (dev->state != STATE_DEV_RUNNING) {
+ dev_dbg(dev->dev, "fail, device is not running\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+ if (!dev->gadget) {
+ dev_dbg(dev->dev, "fail, gadget is not bound\n");
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ usb_gadget_vbus_draw(dev->gadget, 2 * value);
+
+out_unlock:
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return ret;
+}
+
+static long raw_ioctl(struct file *fd, unsigned int cmd, unsigned long value)
+{
+ struct raw_dev *dev = fd->private_data;
+ int ret = 0;
+
+ if (!dev)
+ return -EBUSY;
+
+ switch (cmd) {
+ case USB_RAW_IOCTL_INIT:
+ ret = raw_ioctl_init(dev, value);
+ break;
+ case USB_RAW_IOCTL_RUN:
+ ret = raw_ioctl_run(dev, value);
+ break;
+ case USB_RAW_IOCTL_EVENT_FETCH:
+ ret = raw_ioctl_event_fetch(dev, value);
+ break;
+ case USB_RAW_IOCTL_EP0_WRITE:
+ ret = raw_ioctl_ep0_write(dev, value);
+ break;
+ case USB_RAW_IOCTL_EP0_READ:
+ ret = raw_ioctl_ep0_read(dev, value);
+ break;
+ case USB_RAW_IOCTL_EP_ENABLE:
+ ret = raw_ioctl_ep_enable(dev, value);
+ break;
+ case USB_RAW_IOCTL_EP_DISABLE:
+ ret = raw_ioctl_ep_disable(dev, value);
+ break;
+ case USB_RAW_IOCTL_EP_WRITE:
+ ret = raw_ioctl_ep_write(dev, value);
+ break;
+ case USB_RAW_IOCTL_EP_READ:
+ ret = raw_ioctl_ep_read(dev, value);
+ break;
+ case USB_RAW_IOCTL_CONFIGURE:
+ ret = raw_ioctl_configure(dev, value);
+ break;
+ case USB_RAW_IOCTL_VBUS_DRAW:
+ ret = raw_ioctl_vbus_draw(dev, value);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+/*----------------------------------------------------------------------*/
+
+static const struct file_operations raw_fops = {
+ .open = raw_open,
+ .unlocked_ioctl = raw_ioctl,
+ .compat_ioctl = raw_ioctl,
+ .release = raw_release,
+ .llseek = no_llseek,
+};
+
+static struct miscdevice raw_misc_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = DRIVER_NAME,
+ .fops = &raw_fops,
+};
+
+module_misc_device(raw_misc_device);
new file mode 100644
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * USB Raw Gadget driver.
+ *
+ * See Documentation/usb/raw-gadget.rst for more details.
+ */
+
+#ifndef _UAPI__LINUX_USB_RAW_GADGET_H
+#define _UAPI__LINUX_USB_RAW_GADGET_H
+
+#include <asm/ioctl.h>
+#include <linux/types.h>
+#include <linux/usb/ch9.h>
+
+/* Maximum length of driver_name/device_name in the usb_raw_init struct. */
+#define UDC_NAME_LENGTH_MAX 128
+
+/*
+ * struct usb_raw_init - argument for USB_RAW_IOCTL_INIT ioctl.
+ * @speed: The speed of the emulated USB device, takes the same values as
+ * the usb_device_speed enum: USB_SPEED_FULL, USB_SPEED_HIGH, etc.
+ * @driver_name: The name of the UDC driver.
+ * @device_name: The name of a UDC instance.
+ *
+ * The last two fields identify a UDC the gadget driver should bind to.
+ * For example, Dummy UDC has "dummy_udc" as its driver_name and "dummy_udc.N"
+ * as its device_name, where N in the index of the Dummy UDC instance.
+ * At the same time the dwc2 driver that is used on Raspberry Pi Zero, has
+ * "20980000.usb" as both driver_name and device_name.
+ */
+struct usb_raw_init {
+ __u8 driver_name[UDC_NAME_LENGTH_MAX];
+ __u8 device_name[UDC_NAME_LENGTH_MAX];
+ __u8 speed;
+};
+
+/* The type of event fetched with the USB_RAW_IOCTL_EVENT_FETCH ioctl. */
+enum usb_raw_event_type {
+ USB_RAW_EVENT_INVALID = 0,
+
+ /* This event is queued when the driver has bound to a UDC. */
+ USB_RAW_EVENT_CONNECT = 1,
+
+ /* This event is queued when a new control request arrived to ep0. */
+ USB_RAW_EVENT_CONTROL = 2,
+
+ /* The list might grow in the future. */
+};
+
+/*
+ * struct usb_raw_event - argument for USB_RAW_IOCTL_EVENT_FETCH ioctl.
+ * @type: The type of the fetched event.
+ * @length: Length of the data buffer. Updated by the driver and set to the
+ * actual length of the fetched event data.
+ * @data: A buffer to store the fetched event data.
+ *
+ * Currently the fetched data buffer is empty for USB_RAW_EVENT_CONNECT,
+ * and contains struct usb_ctrlrequest for USB_RAW_EVENT_CONTROL.
+ */
+struct usb_raw_event {
+ __u32 type;
+ __u32 length;
+ __u8 data[0];
+};
+
+#define USB_RAW_IO_FLAGS_ZERO 0x0001
+#define USB_RAW_IO_FLAGS_MASK 0x0001
+
+static int usb_raw_io_flags_valid(__u16 flags)
+{
+ return (flags & ~USB_RAW_IO_FLAGS_MASK) == 0;
+}
+
+static int usb_raw_io_flags_zero(__u16 flags)
+{
+ return (flags & USB_RAW_IO_FLAGS_ZERO);
+}
+
+/*
+ * struct usb_raw_ep_io - argument for USB_RAW_IOCTL_EP0/EP_WRITE/READ ioctls.
+ * @ep: Endpoint handle as returned by USB_RAW_IOCTL_EP_ENABLE for
+ * USB_RAW_IOCTL_EP_WRITE/READ. Ignored for USB_RAW_IOCTL_EP0_WRITE/READ.
+ * @flags: When USB_RAW_IO_FLAGS_ZERO is specified, the zero flag is set on
+ * the submitted USB request, see include/linux/usb/gadget.h for details.
+ * @length: Length of data.
+ * @data: Data to send for USB_RAW_IOCTL_EP0/EP_WRITE. Buffer to store received
+ * data for USB_RAW_IOCTL_EP0/EP_READ.
+ */
+struct usb_raw_ep_io {
+ __u16 ep;
+ __u16 flags;
+ __u32 length;
+ __u8 data[0];
+};
+
+/*
+ * Initializes a Raw Gadget instance.
+ * Accepts a pointer to the usb_raw_init struct as an argument.
+ * Returns 0 on success or negative error code on failure.
+ */
+#define USB_RAW_IOCTL_INIT _IOW('U', 0, struct usb_raw_init)
+
+/*
+ * Instructs Raw Gadget to bind to a UDC and start emulating a USB device.
+ * Returns 0 on success or negative error code on failure.
+ */
+#define USB_RAW_IOCTL_RUN _IO('U', 1)
+
+/*
+ * A blocking ioctl that waits for an event and returns fetched event data to
+ * the user.
+ * Accepts a pointer to the usb_raw_event struct.
+ * Returns 0 on success or negative error code on failure.
+ */
+#define USB_RAW_IOCTL_EVENT_FETCH _IOR('U', 2, struct usb_raw_event)
+
+/*
+ * Queues an IN (OUT for READ) urb as a response to the last control request
+ * received on endpoint 0, provided that was an IN (OUT for READ) request and
+ * waits until the urb is completed. Copies received data to user for READ.
+ * Accepts a pointer to the usb_raw_ep_io struct as an argument.
+ * Returns length of trasferred data on success or negative error code on
+ * failure.
+ */
+#define USB_RAW_IOCTL_EP0_WRITE _IOW('U', 3, struct usb_raw_ep_io)
+#define USB_RAW_IOCTL_EP0_READ _IOWR('U', 4, struct usb_raw_ep_io)
+
+/*
+ * Finds an endpoint that supports the transfer type specified in the
+ * descriptor and enables it.
+ * Accepts a pointer to the usb_endpoint_descriptor struct as an argument.
+ * Returns enabled endpoint handle on success or negative error code on failure.
+ */
+#define USB_RAW_IOCTL_EP_ENABLE _IOW('U', 5, struct usb_endpoint_descriptor)
+
+/* Disables specified endpoint.
+ * Accepts endpoint handle as an argument.
+ * Returns 0 on success or negative error code on failure.
+ */
+#define USB_RAW_IOCTL_EP_DISABLE _IOW('U', 6, __u32)
+
+/*
+ * Queues an IN (OUT for READ) urb as a response to the last control request
+ * received on endpoint usb_raw_ep_io.ep, provided that was an IN (OUT for READ)
+ * request and waits until the urb is completed. Copies received data to user
+ * for READ.
+ * Accepts a pointer to the usb_raw_ep_io struct as an argument.
+ * Returns length of trasferred data on success or negative error code on
+ * failure.
+ */
+#define USB_RAW_IOCTL_EP_WRITE _IOW('U', 7, struct usb_raw_ep_io)
+#define USB_RAW_IOCTL_EP_READ _IOWR('U', 8, struct usb_raw_ep_io)
+
+/*
+ * Switches the gadget into the configured state.
+ * Returns 0 on success or negative error code on failure.
+ */
+#define USB_RAW_IOCTL_CONFIGURE _IO('U', 9)
+
+/*
+ * Constrains UDC VBUS power usage.
+ * Accepts current limit in 2 mA units as an argument.
+ * Returns 0 on success or negative error code on failure.
+ */
+#define USB_RAW_IOCTL_VBUS_DRAW _IOW('U', 10, __u32)
+
+#endif /* _UAPI__LINUX_USB_RAW_GADGET_H */