drivers/input/touchscreen/ts_filter.h

   1 #ifndef __TS_FILTER_H__
   2 #define __TS_FILTER_H__
   3
   4 /*
   5  * Touchscreen filter.
   6  *
   7  * (c) 2008 Andy Green <andy@openmoko.com>
   8  */
   9
  10 #include <linux/platform_device.h>
  11
  12 #define MAX_TS_FILTER_CHAIN             8  /* Max. filters we can chain up. */
  13 #define MAX_TS_FILTER_COORDS            3  /* X, Y and Z (pressure). */
  14
  15 struct ts_filter;
  16
  17 /* Operations that a filter can perform. */
  18
  19 struct ts_filter_api {
  20         struct ts_filter * (*create)(struct platform_device *pdev, void *config,
  21                                      int count_coords);
  22         void (*destroy)(struct platform_device *pdev, struct ts_filter *filter);
  23         void (*clear)(struct ts_filter *filter);
  24         int (*process)(struct ts_filter *filter, int *coords);
  25         void (*scale)(struct ts_filter *filter, int *coords);
  26 };
  27
  28 /*
  29  * This is the common part of all filters.
  30  * We use this type as an otherwise opaque handle on to
  31  * the actual filter.  Therefore you need one of these
  32  * at the start of your actual filter struct.
  33  */
  34
  35 struct ts_filter {
  36         struct ts_filter *next;         /* Next in chain. */
  37         struct ts_filter_api *api;      /* Operations to use for this object. */
  38         int count_coords;
  39         int coords[MAX_TS_FILTER_COORDS];
  40 };
  41
  42 /*
  43  * Helper to create a filter chain from an array of API pointers and
  44  * array of config ints. Leaves pointers to created filters in arr
  45  * array and fills in ->next pointers to create the chain.
  46  */
  47
  48 #ifdef CONFIG_TOUCHSCREEN_FILTER
  49 extern int ts_filter_create_chain(struct platform_device *pdev,
  50                                   struct ts_filter_api **api, void **config,
  51                                   struct ts_filter **arr, int count_coords);
  52
  53 /* Helper to destroy a whole chain from the list of filter pointers. */
  54
  55 extern void ts_filter_destroy_chain(struct platform_device *pdev,
  56                                     struct ts_filter **arr);
  57 #else
  58 #define ts_filter_create_chain(pdev, api, config, arr, count_coords) (0)
  59 #define ts_filter_destroy_chain(pdev, arr) do { } while (0)
  60 #endif
  61
  62 #endif