betty/pwm.c

   1 /*
   2  * pwm.c - arm pwm interface
   3  *
   4  * author: hackbard@hackdaworld.org
   5  *
   6  */
   7
   8 #include "pwm.h"
   9
  10 /*
  11  * functions
  12  */
  13
  14 void pwm_set_rate_and_prescaler(u32 rate,u32 prescaler) {
  15
  16         PWMMR0=rate;
  17         PWMPR=prescaler;
  18 }
  19
  20 int pwm_config(u8 pwmchan,u8 mode,u32 val1,u32 val2) {
  21
  22         u32 *addr;
  23
  24         addr=(u32 *)&PWMMR0;
  25
  26         if((pwmchan>6)|(pwmchan<1))
  27                 return PWM_INVALID_CHAN;
  28
  29         if(mode==PWM_DOUBLE_EDGE) {
  30                 if(pwmchan&0x01)
  31                         return PWM_STUPID;
  32                 *((volatile u32 *)addr+pwmchan)=val2;
  33                 *((volatile u32 *)addr+pwmchan-1)=val1;
  34         }
  35
  36         if(mode==PWM_SINGLE_EDGE)
  37                 *((volatile u32 *)addr+pwmchan)=val1;
  38
  39         PWMPCR=(PWMPCR&0x7e7c)|(mode<<(2+pwmchan))|(1<<(9+pwmchan));
  40
  41         return PWM_SET;
  42 }
  43
  44 int pwm_update_match(u8 pwmchan,u8 mode,u32 val1,u32 val2) {
  45
  46         u32 *addr;
  47
  48         addr=(u32 *)&PWMMR0;
  49
  50         if((pwmchan>6)|(pwmchan<1))
  51                 return PWM_INVALID_CHAN;
  52
  53         if(mode==PWM_DOUBLE_EDGE) {
  54                 if(pwmchan&0x01)
  55                         return PWM_STUPID;
  56                 *((volatile u32 *)addr+pwmchan)=val2;
  57                 *((volatile u32 *)addr+pwmchan-1)=val1;
  58         }
  59
  60         if(mode==PWM_SINGLE_EDGE)
  61                 *((volatile u32 *)addr+pwmchan)=val1;
  62
  63         return PWM_SET;
  64 }
  65
  66 void pwm_match_ctrl_config(u8 matchreg,u8 ctrl) {
  67
  68         PWMMCR=(PWMMCR&0x1fffff)|(ctrl<<(3*matchreg));
  69 }
  70