Software calibration API

Collaboration diagram for Software calibration API:

Functions
int	a4l_read_calibration_file (char *name, struct a4l_calibration_data *data)
	Read the analogy generated calibration file. More...
int	a4l_get_softcal_converter (struct a4l_polynomial *converter, int subd, int chan, int range, struct a4l_calibration_data *data)
	Get the polynomial that will be use for the software calibration. More...
int	a4l_rawtodcal (a4l_chinfo_t *chan, double *dst, void *src, int cnt, struct a4l_polynomial *converter)
	Convert raw data (from the driver) to calibrated double units. More...
int	a4l_dcaltoraw (a4l_chinfo_t *chan, void *dst, double *src, int cnt, struct a4l_polynomial *converter)
	Convert double values to raw calibrated data using polynomials. More...

Detailed Description

Function Documentation

a4l_dcaltoraw()

int a4l_dcaltoraw	(	a4l_chinfo_t *	chan,
		void *	dst,
		double *	src,
		int	cnt,
		struct a4l_polynomial *	converter
	)

Convert double values to raw calibrated data using polynomials.

Parameters

[in]	chan	Channel descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of conversion to perform
[in]	converter	Conversion polynomial

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_dcaltoraw()

a4l_get_softcal_converter()

int a4l_get_softcal_converter	(	struct a4l_polynomial *	converter,
		int	subd,
		int	chan,
		int	range,
		struct a4l_calibration_data *	data
	)

Get the polynomial that will be use for the software calibration.

Parameters

[out]	converter	Polynomial to be used on the software calibration
[in]	subd	Subdevice index
[in]	chan	Channel
[in]	range	Range
[in]	data	Calibration data read from the calibration file

Returns

-1 on error

a4l_rawtodcal()

int a4l_rawtodcal	(	a4l_chinfo_t *	chan,
		double *	dst,
		void *	src,
		int	cnt,
		struct a4l_polynomial *	converter
	)

Convert raw data (from the driver) to calibrated double units.

Parameters

[in]	chan	Channel descriptor
[out]	dst	Ouput buffer
[in]	src	Input buffer
[in]	cnt	Count of conversion to perform
[in]	converter	Conversion polynomial

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_rawtodcal()

a4l_read_calibration_file()

int a4l_read_calibration_file	(	char *	name,
		struct a4l_calibration_data *	data
	)

Read the analogy generated calibration file.

Parameters

[in]	name	Name of the calibration file
[out]	data	Pointer to the calibration file contents