Startup / Shutdown
[EDT DMA Library]

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Detailed Description

These functions are used to open and close the EDT device.

Functions
EdtDev *	edt_open (char *device_name, int unit)
	Opens the specified EDT Product and sets up the device handle.
EdtDev *	edt_open_quiet (char *device_name, int unit)
	Just a version of edt_open that does so quietly, so we can try opening the device just to see if it's there without a lot of printfs coming out.
EdtDev *	edt_open_channel (char *device_name, int unit, int channel)
	Opens a specific DMA channel on the specified EDT Product, when multiple channels are supported by the Xilinx firmware, and sets up the device handle.
int	edt_close (EdtDev *edt_p)
	Shuts down all pending I/O operations, closes the device or channel and frees all driver resources associated with the device handle.

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Function Documentation

EdtDev* edt_open	(	char *	device_name,
		int	unit
	)

Opens the specified EDT Product and sets up the device handle.

Once opened, the device handle may be used to perform I/O using edt_read, edt_write, edt_configure_ring_buffers, and other input-output library calls. When finished, use edt_close to release any resources allocated during use.

Parameters:

	device_name	a string with the name of the EDT Product board; for example, "pcd". EDT_INTERFACE can also be used; it is defined as the name of the board type in edtdef.h.
	unit	Unit number of the device (if multiple devices). The first unit is always 0.

Returns:

A pointer to the EdtDev structure if successful. This data structure holds information about the device which is needed by library functions. User applications should avoid accessing structure elements directly. NULL is returned if unsuccessful, and the global variable errno is set. Use edt_perror to print an error message.

Definition at line 565 of file libedt.c.

EdtDev* edt_open_quiet	(	char *	device_name,
		int	unit
	)

Just a version of edt_open that does so quietly, so we can try opening the device just to see if it's there without a lot of printfs coming out.

Parameters:

	device_name	a string with the name of the EDT Product board; for example, "pcd". EDT_INTERFACE can also be used; it is defined as the name of the board type in edtdef.h.
	unit	Unit number of the device (if multiple devices). The first unit is always 0.

Returns:

Pointer to EdtDev struct, or NULL if error.

Definition at line 586 of file libedt.c.

EdtDev* edt_open_channel	(	char *	device_name,
		int	unit,
		int	channel
	)

Opens a specific DMA channel on the specified EDT Product, when multiple channels are supported by the Xilinx firmware, and sets up the device handle.

Use edt_close to close the channel.

To open a device with only one channel, just use edt_open.

Once opened, the device handle may be used to perform I/O using edt_read, edt_write, edt_configure_ring_buffers, and other input-output library calls. When finished, use edt_close to release any resources allocated during use.

Parameters:

	device_name	a string with the name of the EDT Product board; for example, "pcd". EDT_INTERFACE can also be used; it is defined as the name of the board type in edtdef.h.
	unit	Unit number of the device (if multiple devices). The first unit is always 0.
	channel	specifies DMA channel number (counting from zero).

Returns:

A pointer to the EdtDev structure if successful. This data structure holds information about the device which is needed by library functions. User applications should avoid accessing structure elements directly. NULL is returned if unsuccessful, and the global variable errno is set. Use edt_perror to print an error message.

Definition at line 619 of file libedt.c.

int edt_close

(

EdtDev *

edt_p

)

Shuts down all pending I/O operations, closes the device or channel and frees all driver resources associated with the device handle.

Parameters:

edt_p

pointer to edt device structure returned by edt_open

Returns:

0 on success, -1 on failure. If an error occurs, call edt_perror to get the system error message.

Definition at line 713 of file libedt.c.

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