USB device controller (UDC) driver API
The USB device controller driver API is described in
include/zephyr/drivers/usb/udc.h and referred to
as the UDC driver API.
UDC driver API is experimental and is subject to change without notice. It is a replacement for USB device controller driver API. If you wish to port an existing driver to UDC driver API, or add a new driver, please use drivers/usb/udc/udc_skeleton.c as a starting point.
API reference
- group udc_api
New USB device controller (UDC) driver API.
Functions
-
static inline bool udc_is_initialized(const struct device *dev)
Checks whether the controller is initialized.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Returns:
true if controller is initialized, false otherwise
-
static inline bool udc_is_enabled(const struct device *dev)
Checks whether the controller is enabled.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Returns:
true if controller is enabled, false otherwise
-
static inline bool udc_is_suspended(const struct device *dev)
Checks whether the controller is suspended.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Returns:
true if controller is suspended, false otherwise
-
int udc_init(const struct device *dev, udc_event_cb_t event_cb)
Initialize USB device controller.
Initialize USB device controller and control IN/OUT endpoint. After initialization controller driver should be able to detect power state of the bus and signal power state changes.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
event_cb – [in] Event callback from the higher layer (USB device stack)
- Return values:
-EINVAL – on parameter error (no callback is passed)
-EALREADY – already initialized
- Returns:
0 on success, all other values should be treated as error.
-
int udc_enable(const struct device *dev)
Enable USB device controller.
Enable powered USB device controller and allow host to recognize and enumerate the device.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Return values:
-EPERM – controller is not initialized
-EALREADY – already enabled
- Returns:
0 on success, all other values should be treated as error.
-
int udc_disable(const struct device *dev)
Disable USB device controller.
Disable enabled USB device controller. The driver should continue to detect power state changes.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Return values:
-EALREADY – already disabled
- Returns:
0 on success, all other values should be treated as error.
-
int udc_shutdown(const struct device *dev)
Poweroff USB device controller.
Shut down the controller completely to reduce energy consumption or to change the role of the controller.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Return values:
-EALREADY – controller is not initialized
- Returns:
0 on success, all other values should be treated as error.
-
static inline struct udc_device_caps udc_caps(const struct device *dev)
Get USB device controller capabilities.
Obtain the capabilities of the controller such as full speed (FS), high speed (HS), and more.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Returns:
USB device controller capabilities.
-
enum udc_bus_speed udc_device_speed(const struct device *dev)
Get actual USB device speed.
The function should be called after the reset event to determine the actual bus speed.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Returns:
USB device controller capabilities.
-
static inline int udc_set_address(const struct device *dev, const uint8_t addr)
Set USB device address.
Set address of enabled USB device.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
addr – [in] USB device address
- Return values:
-EPERM – controller is not enabled (or not initialized)
- Returns:
0 on success, all other values should be treated as error.
-
static inline int udc_host_wakeup(const struct device *dev)
Initiate host wakeup procedure.
Initiate host wakeup. Only possible when the bus is suspended.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
- Return values:
-EPERM – controller is not enabled (or not initialized)
- Returns:
0 on success, all other values should be treated as error.
-
int udc_ep_try_config(const struct device *dev, const uint8_t ep, const uint8_t attributes, uint16_t *const mps, const uint8_t interval)
Try an endpoint configuration.
Try an endpoint configuration based on endpoint descriptor. This function may modify wMaxPacketSize descriptor fields of the endpoint. All properties of the descriptor, such as direction, and transfer type, should be set correctly. If wMaxPacketSize value is zero, it will be updated to maximum buffer size of the endpoint.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
ep – [in] Endpoint address (same as bEndpointAddress)
attributes – [in] Endpoint attributes (same as bmAttributes)
mps – [in] Maximum packet size (same as wMaxPacketSize)
interval – [in] Polling interval (same as bInterval)
- Return values:
-EINVAL – on wrong parameter
-ENOTSUP – endpoint configuration not supported
-ENODEV – no endpoints available
- Returns:
0 on success, all other values should be treated as error.
-
int udc_ep_enable(const struct device *dev, const uint8_t ep, const uint8_t attributes, const uint16_t mps, const uint8_t interval)
Configure and enable endpoint.
Configure and make an endpoint ready for use. Valid for all endpoints except control IN/OUT.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
ep – [in] Endpoint address (same as bEndpointAddress)
attributes – [in] Endpoint attributes (same as bmAttributes)
mps – [in] Maximum packet size (same as wMaxPacketSize)
interval – [in] Polling interval (same as bInterval)
- Return values:
-EINVAL – on wrong parameter (control IN/OUT endpoint)
-EPERM – controller is not initialized
-ENODEV – endpoint configuration not found
-EALREADY – endpoint is already enabled
- Returns:
0 on success, all other values should be treated as error.
-
int udc_ep_disable(const struct device *dev, const uint8_t ep)
Disable endpoint.
Valid for all endpoints except control IN/OUT.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
ep – [in] Endpoint address
- Return values:
-EINVAL – on wrong parameter (control IN/OUT endpoint)
-ENODEV – endpoint configuration not found
-EALREADY – endpoint is already disabled
-EPERM – controller is not initialized
- Returns:
0 on success, all other values should be treated as error.
-
int udc_ep_set_halt(const struct device *dev, const uint8_t ep)
Halt endpoint.
Valid for all endpoints.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
ep – [in] Endpoint address
- Return values:
-ENODEV – endpoint configuration not found
-ENOTSUP – not supported (e.g. isochronous endpoint)
-EPERM – controller is not enabled
- Returns:
0 on success, all other values should be treated as error.
-
int udc_ep_clear_halt(const struct device *dev, const uint8_t ep)
Clear endpoint halt.
Valid for all endpoints.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
ep – [in] Endpoint address
- Return values:
-ENODEV – endpoint configuration not found
-ENOTSUP – not supported (e.g. isochronous endpoint)
-EPERM – controller is not enabled
- Returns:
0 on success, all other values should be treated as error.
-
int udc_ep_enqueue(const struct device *dev, struct net_buf *const buf)
Queue USB device controller request.
Add request to the queue. If the queue is empty, the request buffer can be claimed by the controller immediately.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
buf – [in] Pointer to UDC request buffer
- Return values:
-ENODEV – endpoint configuration not found
-EACCES – endpoint is not enabled (TBD)
-EBUSY – request can not be queued
-EPERM – controller is not initialized
- Returns:
0 on success, all other values should be treated as error.
-
int udc_ep_dequeue(const struct device *dev, const uint8_t ep)
Remove all USB device controller requests from endpoint queue.
UDC_EVT_EP_REQUEST event will be generated when the driver releases claimed buffer, no new requests will be claimed, all requests in the queue will passed as chained list of the event variable buf. The endpoint queue is empty after that.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
ep – [in] Endpoint address
- Return values:
-ENODEV – endpoint configuration not found
-EACCES – endpoint is not disabled
-EPERM – controller is not initialized
- Returns:
0 on success, all other values should be treated as error.
-
struct net_buf *udc_ep_buf_alloc(const struct device *dev, const uint8_t ep, const size_t size)
Allocate UDC request buffer.
Allocate a new buffer from common request buffer pool.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
ep – [in] Endpoint address
size – [in] Size of the request buffer
- Returns:
pointer to allocated request or NULL on error.
-
int udc_ep_buf_free(const struct device *dev, struct net_buf *const buf)
Free UDC request buffer.
Put the buffer back into the request buffer pool.
- Parameters:
dev – [in] Pointer to device struct of the driver instance
buf – [in] Pointer to UDC request buffer
- Returns:
0 on success, all other values should be treated as error.
-
static inline bool udc_is_initialized(const struct device *dev)