#ifndef __TS_FILTER_H__
#define __TS_FILTER_H__

/*
 * touchscreen filter
 *
 * (c) 2008 Andy Green <andy@openmoko.com>
 */

#include <linux/platform_device.h>

#define MAX_TS_FILTER_CHAIN		4  /* max filters you can chain up */
#define MAX_TS_FILTER_COORDS		3  /* X, Y and Z (pressure) */

struct ts_filter;

/* operations that a filter can perform
 */
struct ts_filter_api {
	struct ts_filter * (*create)(struct platform_device *pdev, void *config,
				     int count_coords);
	void (*destroy)(struct platform_device *pdev, struct ts_filter *filter);
	void (*clear)(struct ts_filter *filter);
	int (*process)(struct ts_filter *filter, int *coords);
	void (*scale)(struct ts_filter *filter, int *coords);
};

/* this is the common part of all filters, the result
 * we use this type as an otherwise opaque handle on to
 * the actual filter.  Therefore you need one of these
 * at the start of your actual filter struct
 */

struct ts_filter {
	struct ts_filter *next; /* next in chain */
	struct ts_filter_api *api; /* operations to use for this object */
	int count_coords;
	int coords[MAX_TS_FILTER_COORDS];
};

/*
 * helper to create a filter chain from array of API pointers and
 * array of config ints... leaves pointers to created filters in list
 * array and fills in ->next pointers to create the chain
 */

extern int ts_filter_create_chain(struct platform_device *pdev,
				  struct ts_filter_api **api, void **config,
				  struct ts_filter **list, int count_coords);

/* helper to destroy a whole chain from the list of filter pointers */

extern void ts_filter_destroy_chain(struct platform_device *pdev,
				    struct ts_filter **list);

#endif