target/linux/s3c24xx/files-2.6.31/include/linux/touchscreen/ts_filter.h

   1 #ifndef __TS_FILTER_H__
   2 #define __TS_FILTER_H__
   3
   4 /*
   5  * Touchscreen filter.
   6  *
   7  * (c) 2008,2009 Andy Green <andy@openmoko.com>
   8  */
   9
  10 #include <linux/platform_device.h>
  11
  12 #define MAX_TS_FILTER_COORDS            3  /* X, Y and Z (pressure). */
  13
  14 struct ts_filter;
  15 struct ts_filter_configuration;
  16
  17 /* Operations that a filter can perform. */
  18
  19 struct ts_filter_api {
  20         /* Create the filter - mandatory. */
  21         struct ts_filter * (*create)(
  22                 struct platform_device *pdev,
  23                 const struct ts_filter_configuration *config,
  24                 int count_coords);
  25         /* Destroy the filter - mandatory. */
  26         void (*destroy)(struct ts_filter *filter);
  27         /* Clear the filter - optional. */
  28         void (*clear)(struct ts_filter *filter);
  29
  30
  31         /*
  32          * The next three API functions only make sense if all of them are
  33          * set for a filter. If a filter has the next three methods then
  34          * it can propagate coordinates in the chain.
  35          */
  36
  37         /*
  38          * Process the filter.
  39          * It returns non-zero if the filter reaches an error.
  40          */
  41         int (*process)(struct ts_filter *filter, int *coords);
  42         /*
  43          * Is the filter ready to return a point?
  44          * Please do not code side effects in this function.
  45          */
  46         int (*haspoint)(struct ts_filter *filter);
  47         /*
  48          * Get a point.
  49          * Do not call unless the filter actually has a point to deliver.
  50          */
  51         void (*getpoint)(struct ts_filter *filter, int *coords);
  52
  53         /*
  54          * Scale the points - optional.
  55          * A filter could only scale coordinates.
  56          */
  57         void (*scale)(struct ts_filter *filter, int *coords);
  58 };
  59
  60 /*
  61  * Generic filter configuration. Actual configurations have this structure
  62  * as a member.
  63  */
  64 struct ts_filter_configuration {
  65 };
  66
  67 struct ts_filter {
  68         /* Operations for this filter. */
  69         const struct ts_filter_api *api;
  70         /* Number of coordinates to process. */
  71         int count_coords;
  72 };
  73
  74 #endif