Collaboration diagram for Range / conversion API:

Functions
int	a4l_sizeof_chan (a4l_chinfo_t *chan)
	Get the size in memory of an acquired element. More...

int	a4l_sizeof_subd (a4l_sbinfo_t *subd)
	Get the size in memory of a digital acquired element. More...

int	a4l_find_range (a4l_desc_t dsc, unsigned int idx_subd, unsigned int idx_chan, unsigned long unit, double min, double max, a4l_rnginfo_t *rng)
	Find the must suitable range. More...

int	a4l_rawtoul (a4l_chinfo_t chan, unsigned long dst, void *src, int cnt)
	Unpack raw data (from the driver) into unsigned long values. More...

int	a4l_rawtof (a4l_chinfo_t chan, a4l_rnginfo_t rng, float dst, void src, int cnt)
	Convert raw data (from the driver) to float-typed samples. More...

int	a4l_rawtod (a4l_chinfo_t chan, a4l_rnginfo_t rng, double dst, void src, int cnt)
	Convert raw data (from the driver) to double-typed samples. More...

int	a4l_ultoraw (a4l_chinfo_t chan, void dst, unsigned long *src, int cnt)
	Pack unsigned long values into raw data (for the driver) More...

int	a4l_ftoraw (a4l_chinfo_t chan, a4l_rnginfo_t rng, void dst, float src, int cnt)
	Convert float-typed samples to raw data (for the driver) More...

int	a4l_dtoraw (a4l_chinfo_t chan, a4l_rnginfo_t rng, void dst, double src, int cnt)
	Convert double-typed samples to raw data (for the driver) More...

Detailed Description

Function Documentation

int a4l_dtoraw	(	a4l_chinfo_t *	chan,
		a4l_rnginfo_t *	rng,
		void *	dst,
		double *	src,
		int	cnt
	)

Convert double-typed samples to raw data (for the driver)

Parameters

[in]	chan	Channel descriptor
[in]	rng	Range descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of conversion to perform

Returns: the count of conversion performed, otherwise a negative error code:

-EINVAL is returned if some argument is missing or wrong; chan, rng and the pointers should be checked; check also the kernel log ("dmesg"); WARNING: a4l_fill_desc() should be called before using a4l_dtoraw()

References A4L_RNG_FACTOR, and a4l_sizeof_chan().

int a4l_find_range	(	a4l_desc_t *	dsc,
		unsigned int	idx_subd,
		unsigned int	idx_chan,
		unsigned long	unit,
		double	min,
		double	max,
		a4l_rnginfo_t **	rng
	)

Find the must suitable range.

Parameters

[in]	dsc	Device descriptor filled by a4l_open() and a4l_fill_desc()
[in]	idx_subd	Index of the concerned subdevice
[in]	idx_chan	Index of the concerned channel
[in]	unit	Unit type used in the range
[in]	min	Minimal limit value
[in]	max	Maximal limit value
[out]	rng	Found range

Returns: The index of the most suitable range on success. Otherwise:

-ENOENT is returned if a suitable range is not found.
-EINVAL is returned if some argument is missing or wrong; idx_subd, idx_chan and the dsc pointer should be checked; check also the kernel log ("dmesg"); WARNING: a4l_fill_desc() should be called before using a4l_find_range()

References a4l_get_chinfo(), a4l_get_rnginfo(), A4L_RNG_FACTOR, A4L_RNG_UNIT, and a4l_descriptor::magic.

int a4l_ftoraw	(	a4l_chinfo_t *	chan,
		a4l_rnginfo_t *	rng,
		void *	dst,
		float *	src,
		int	cnt
	)

Convert float-typed samples to raw data (for the driver)

Parameters

[in]	chan	Channel descriptor
[in]	rng	Range descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of conversion to perform

Returns: the count of conversion performed, otherwise a negative error code:

-EINVAL is returned if some argument is missing or wrong; chan, rng and the pointers should be checked; check also the kernel log ("dmesg"); WARNING: a4l_fill_desc() should be called before using a4l_ftoraw()

References A4L_RNG_FACTOR, and a4l_sizeof_chan().

int a4l_rawtod	(	a4l_chinfo_t *	chan,
		a4l_rnginfo_t *	rng,
		double *	dst,
		void *	src,
		int	cnt
	)

Convert raw data (from the driver) to double-typed samples.

Parameters

[in]	chan	Channel descriptor
[in]	rng	Range descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of conversion to perform

Returns: the count of conversion performed, otherwise a negative error code:

-EINVAL is returned if some argument is missing or wrong; chan, rng and the pointers should be checked; check also the kernel log ("dmesg"); WARNING: a4l_fill_desc() should be called before using a4l_rawtod()

References A4L_RNG_FACTOR, and a4l_sizeof_chan().

int a4l_rawtof	(	a4l_chinfo_t *	chan,
		a4l_rnginfo_t *	rng,
		float *	dst,
		void *	src,
		int	cnt
	)

Convert raw data (from the driver) to float-typed samples.

Parameters

[in]	chan	Channel descriptor
[in]	rng	Range descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of conversion to perform

Returns: the count of conversion performed, otherwise a negative error code:

-EINVAL is returned if some argument is missing or wrong; chan, rng and the pointers should be checked; check also the kernel log ("dmesg"); WARNING: a4l_fill_desc() should be called before using a4l_rawtod()

References A4L_RNG_FACTOR, and a4l_sizeof_chan().

int a4l_rawtoul	(	a4l_chinfo_t *	chan,
		unsigned long *	dst,
		void *	src,
		int	cnt
	)

Unpack raw data (from the driver) into unsigned long values.

This function takes as input driver-specific data and scatters each element into an entry of an unsigned long table. It is a convenience routine which performs no conversion, just copy.

Parameters

[in]	chan	Channel descriptor
[in]	rng	Range descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of transfer to copy

Returns: the count of copy performed, otherwise a negative error code:

-EINVAL is returned if some argument is missing or wrong; chan, rng and the pointers should be checked; check also the kernel log ("dmesg"); WARNING: a4l_fill_desc() should be called before using a4l_ultoraw()

References a4l_sizeof_chan().

int a4l_sizeof_chan ( a4l_chinfo_t * chan )

Get the size in memory of an acquired element.

According to the board, the channels have various acquisition widths. With values like 8, 16 or 32, there is no problem finding out the size in memory (1, 2, 4); however with widths like 12 or 24, this function might be helpful to guess the size needed in RAM for a single acquired element.

Parameters

[in] chan Channel descriptor

Returns: the size in memory of an acquired element, otherwise a negative error code:

-EINVAL is returned if the argument chan is NULL

Referenced by a4l_dtoraw(), a4l_ftoraw(), a4l_rawtod(), a4l_rawtof(), a4l_rawtoul(), and a4l_ultoraw().

int a4l_sizeof_subd ( a4l_sbinfo_t * subd )

Get the size in memory of a digital acquired element.

This function is only useful for DIO subdevices. Digital subdevices are a specific kind of subdevice on which channels are regarded as bits composing the subdevice's bitfield. During a DIO acquisition, all bits are sampled. Therefore, a4l_sizeof_chan() is useless in this case and we have to use a4l_sizeof_subd(). With bitfields which sizes are 8, 16 or 32, there is no problem finding out the size in memory (1, 2, 4); however with widths like 12 or 24, this function might be helpful to guess the size needed in RAM for a single acquired element.

Parameters

[in] subd Subdevice descriptor

Returns: the size in memory of an acquired element, otherwise a negative error code:

-EINVAL is returned if the argument chan is NULL or if the subdevice is not a digital subdevice

References A4L_SUBD_DI, A4L_SUBD_DIO, A4L_SUBD_DO, and A4L_SUBD_TYPES.

Referenced by a4l_sync_dio().

int a4l_ultoraw	(	a4l_chinfo_t *	chan,
		void *	dst,
		unsigned long *	src,
		int	cnt
	)

Pack unsigned long values into raw data (for the driver)

This function takes as input a table of unsigned long values and gather them according to the channel width. It is a convenience routine which performs no conversion, just formatting.

Parameters

[in]	chan	Channel descriptor
[in]	rng	Range descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of transfer to copy

Returns: the count of copy performed, otherwise a negative error code:

-EINVAL is returned if some argument is missing or wrong; chan, rng and the pointers should be checked; check also the kernel log ("dmesg"); WARNING: a4l_fill_desc() should be called before using a4l_ultoraw()

References a4l_sizeof_chan().

Functions

Detailed Description

Function Documentation