betty/buttons.c

   1 /*
   2  * buttons.c - button api
   3  *
   4  * author: hackbard@hackdaworld.org
   5  *
   6  */
   7
   8 #include "buttons.h"
   9
  10 void button_init(void) {
  11
  12         /*
  13          * select as input the following pins
  14          *  - p0.30 : interrupt, wtf is the 'vw 3 p9'?
  15          *  - p0.28, p0.27, p3.21, p3.20, p0.22, p0.13 : column select
  16          *
  17          *  select as output
  18          *  - p2.18-p2.24 : the rows
  19          */
  20
  21         // gpio, as is: p3.20, p3.21
  22         PINSEL1&=~((1<<29)|(1<<28));    // p0.30
  23         PINSEL1&=~((1<<25)|(1<<24));    // p0.28
  24         PINSEL1&=~((1<<23)|(1<<22));    // p0.27
  25         PINSEL1&=~((1<<13)|(1<<12));    // p0.22
  26         PINSEL0&=~((1<<27)|(1<<26));    // p0.13
  27         // ctrl databus for p2.18 - p2.24
  28         PINSEL2&=(PINSEL2&(~((1<<5)|(1<<4))))|(1<<4);
  29         // input
  30         IODIR0&=~((1<<30)|(1<<28)|(1<<27)|(1<<22)|(1<<13));
  31         IODIR3&=~((1<<21)|(1<<20));
  32         // output + pull them high
  33         IODIR2|=((1<<18)|(1<<19)|(1<<20)|(1<<21)|(1<<22)|(1<<23)|(1<<24));
  34         IOSET2=((1<<18)|(1<<19)|(1<<20)|(1<<21)|(1<<22)|(1<<23)|(1<<24));
  35 }
  36
  37 void button_select_row(u8 row) {
  38
  39         IOSET2=((1<<18)|(1<<19)|(1<<20)|(1<<21)|(1<<22)|(1<<23)|(1<<24));
  40         if(row>6)
  41                 return;
  42         IOCLR2=(1<<(18+row));
  43 }
  44
  45 u8 button_get_event(u64 *keys,int retries) {
  46
  47         u8 row;
  48         u8 offset;
  49         u8 cnt;
  50         u32 port0,port3;
  51
  52         *keys=0;
  53         cnt=0;
  54
  55         while(retries--) {
  56                 /* rest counter */
  57                 offset=0;
  58                 /* rows */
  59                 for(row=0;row<7;row++) {
  60                         /* select the row */
  61                         button_select_row(row);
  62                         /* scan the columns 6 */
  63                         port0=IOPIN0;
  64                         port3=IOPIN2;
  65                         if(!(port0&(1<<28))) {
  66                                 *keys|=(1<<(offset+0));
  67                                 cnt+=1;
  68                         }
  69                         if(!(port0&(1<<27))) {
  70                                 *keys|=(1<<(offset+1));
  71                                 cnt+=1;
  72                         }
  73                         if(!(port0&(1<<22))) {
  74                                 *keys|=(1<<(offset+2));
  75                                 cnt+=1;
  76                         }
  77                         if(!(port0&(1<<13))) {
  78                                 *keys|=(1<<(offset+3));
  79                                 cnt+=1;
  80                         }
  81                         if(!(port3&(1<<21))) {
  82                                 *keys|=(1<<(offset+4));
  83                                 cnt+=1;
  84                         }
  85                         if(!(port3&(1<<20))) {
  86                                 *keys|=(1<<(offset+5));
  87                                 cnt+=1;
  88                         }
  89                         offset+=6;
  90                 }
  91                 if(*keys)
  92                         break;
  93         }
  94
  95         return cnt;
  96 }
  97