betty/buttons.c

   1 /*
   2  * buttons.c - button api
   3  *
   4  * author: hackbard@hackdaworld.org
   5  *
   6  */
   7
   8 #include "buttons.h"
   9
  10 #define BUTTON_RESET \
  11         IOSET2=((1<<18)|(1<<19)|(1<<20)|(1<<21)|(1<<22)|(1<<23)|(1<<24))
  12
  13 #define BUTTON_UNSET \
  14         IOCLR2=((1<<18)|(1<<19)|(1<<20)|(1<<21)|(1<<22)|(1<<23)|(1<<24))
  15
  16 #define COUNT_AND_CHECK         cnt++; \
  17                                 if(cnt==BUTTON_MAX) \
  18                                         break
  19
  20 void button_init(t_button *button) {
  21
  22         /*
  23          * input:
  24          *  - p0.30 : interrupt! wtf is the 'vw 3 p9'? a transistor?
  25          *  - p0.28, p0.27, p3.21, p3.20, p0.22, p0.13 : the columns
  26          *
  27          * output:
  28          *  - p2.18-p2.24 : the rows
  29          */
  30
  31         /* poll / interrupt mode */
  32         if(button->mode&BUTTON_INT)
  33                 BUTTON_UNSET;
  34         else if(button->mode&BUTTON_POLL)
  35                 BUTTON_RESET;
  36 }
  37
  38 void button_set_retries(t_button *button,int retries) {
  39
  40         button->retries=retries;
  41 }
  42
  43 void button_select_row(u8 row) {
  44
  45         BUTTON_RESET;
  46         if(row>6)
  47                 return;
  48         IOCLR2=(1<<(18+row));
  49 }
  50
  51 u8 button_get_event(t_button *button) {
  52
  53         u8 row;
  54         u8 offset;
  55         u8 cnt;
  56         u32 port0,port3;
  57         u8 tries;
  58
  59         cnt=0;
  60         tries=button->retries+1;
  61
  62         while(tries--) {
  63                 /* rest offset counter */
  64                 offset=0;
  65                 /* rows */
  66                 for(row=0;row<7;row++) {
  67                         /* select the row */
  68                         button_select_row(row);
  69                         /* scan the columns 6 */
  70                         port0=IOPIN0;
  71                         port3=IOPIN3;
  72                         if(!(port0&(1<<28))) {
  73                                 button->key[cnt]=offset+0;
  74                                 COUNT_AND_CHECK;
  75                         }
  76                         if(!(port0&(1<<27))) {
  77                                 button->key[cnt]=offset+1;
  78                                 COUNT_AND_CHECK;
  79                         }
  80                         if(!(port0&(1<<22))) {
  81                                 button->key[cnt]=offset+2;
  82                                 COUNT_AND_CHECK;
  83                         }
  84                         if(!(port0&(1<<13))) {
  85                                 button->key[cnt]=offset+3;
  86                                 COUNT_AND_CHECK;
  87                         }
  88                         if(!(port3&(1<<21))) {
  89                                 button->key[cnt]=offset+4;
  90                                 COUNT_AND_CHECK;
  91                         }
  92                         if(!(port3&(1<<20))) {
  93                                 button->key[cnt]=offset+5;
  94                                 COUNT_AND_CHECK;
  95                         }
  96                         offset+=6;
  97                 }
  98                 if(cnt)
  99                         break;
 100         }
 101
 102         if(button->mode&BUTTON_INT)
 103                 BUTTON_UNSET;
 104         else if(button->mode&BUTTON_POLL)
 105                 BUTTON_RESET;
 106
 107         return cnt;
 108 }
 109