This API is used to perform synchronous operations.

Overview

A transfer is performed by single function call which returns after transfer was finished. Before transferring, you must select proper endpoint. Then you can perform transfer operations on it:

 int transferred;
 usb_host_cfg_h cfg;
 usb_host_interface_h iface;
 usb_host_endpoint_h ep;

 usb_host_device_get_config(dev, cfg_index, &cfg);
 usb_host_config_get_interface(cfg, interface_number, &iface);
 usb_host_interface_get_endpoint(iface, ep_number, &ep);

 ret = usb_host_transfer(ep, data, length, &transfered, 0);
 if (ret < 0)
     error();

In this example data buffer contains data received from device. Value of transfered is set to the number of received bytes.

Related Features

This API is related with the following features:

http://tizen.org/feature/usb.host It is recommended to design feature related codes in your application for reliability.
You can check if a device supports the related features for this API by using System Information, thereby controlling the procedure of your application.
To ensure your application is only running on the device with specific features, please define the features in your manifest file using the manifest editor in the SDK.
More details on featuring your application can be found from Feature Element.

Functions
int	usb_host_control_transfer (usb_host_device_h dev, uint8_t bm_request_type, uint8_t b_request, uint16_t w_value, uint16_t w_index, unsigned char data, uint16_t w_length, unsigned int timeout, int transferred)
	Performs USB control transfer.
int	usb_host_transfer (usb_host_endpoint_h ep, unsigned char data, int length, int transferred, unsigned int timeout)
	Performs transfer on given endpoint.

Function Documentation

int usb_host_control_transfer	(	usb_host_device_h	dev,
		uint8_t	bm_request_type,
		uint8_t	b_request,
		uint16_t	w_value,
		uint16_t	w_index,
		unsigned char *	data,
		uint16_t	w_length,
		unsigned int	timeout,
		int *	transferred
	)

Performs USB control transfer.

For more explanation about the values please refer to USB protocol specification

Since :: 3.0

Remarks:: The wValue, wIndex and wLength fields values should be given in host-endian byte order.

Parameters:

[in]	dev	Device handle
[in]	bm_request_type	bmRequestType type field for the setup packet
[in]	b_request	bRequest field for the setup packet
[in]	w_value	wValue field for the setup packet
[in]	w_index	wIndex field for the setup packet
[in]	data	Suitably-sized data buffer for either input or output (depending on direction bits within bmRequestType)
[in]	w_length	wLength field for the setup packet. The data buffer should be at least this size
[in]	timeout	Timeout (in milliseconds) that this function should wait before giving up due to no response being received. For an unlimited
[out]	transferred	Number of transferred bytes timeout, 0 value should be used

Returns:: 0 on success, otherwise a negative error value

Return values:

USB_HOST_ERROR_NONE	Successful
USB_HOST_ERROR_TIMED_OUT	Transfer timed out
USB_HOST_ERROR_BROKEN_PIPE	Control request was not supported by the device
USB_HOST_ERROR_NO_SUCH_DEVICE	The device has been disconnected
USB_HOST_ERROR_INVALID_PARAMETER	Invalid parameter was passed
USB_HOST_ERROR_NOT_SUPPORTED	Not supported
USB_HOST_ERROR_DEVICE_NOT_OPENED	The device was not opened
USB_HOST_ERROR_OVERFLOW	Device offered more data

Precondition:: dev must point to device opened by usb_host_device_open() or usb_host_device_open_with_vid_pid()

int usb_host_transfer	(	usb_host_endpoint_h	ep,
		unsigned char *	data,
		int	length,
		int *	transferred,
		unsigned int	timeout
	)

Performs transfer on given endpoint.

Performs a USB transfer on given endpoint. Direction of transfer is determined by the endpoint.

Since :: 3.0

Parameters:

[in]	ep	Endpoint handle
[in]	data	Suitably-sized data buffer for either input or output (depending on endpoint)
[in]	length	For writes, the number of bytes from data to be sent, for reads the maximum number of bytes to receive into the data buffer
[out]	transferred	number of bytes actually transferred
[in]	timeout	Timeout (in milliseconds) that this function should wait before giving up due to no response being received (for an unlimited timeout 0 value should be used)

Returns:: 0 on success (and populates transferred), negative error code on error

Return values:

USB_HOST_ERROR_NONE	Successful
USB_HOST_ERROR_TIMED_OUT	Transfer timed out
USB_HOST_ERROR_BROKEN_PIPE	Endpoint halted
USB_HOST_ERROR_OVERFLOW	Device offered more data
USB_HOST_ERROR_NO_SUCH_DEVICE	Device has been disconnected
USB_HOST_ERROR_INVALID_PARAMETER	Invalid parameter was passed
USB_HOST_ERROR_NOT_SUPPORTED	Not supported
USB_HOST_ERROR_DEVICE_NOT_OPENED	The device was not opened

Precondition:: ep must be a valid endpoint received from usb_host_interface_get_endpoint().; ep must be an endpoint of device opened by usb_host_device_open() or usb_host_device_open_with_vid_pid().

Overview

Related Features

Functions

Function Documentation