app/smotor/pwm.c

   1 #include "pwm.h"
   2
   3 int PWM_PINSEL[] = {
   4   /*nothing*/ 1, /*PWM1*/ 1, 15, 3, 17, /*PWM5*/ 11, /*PWM6*/ 19
   5 };
   6
   7 uint32_t *PWM_MR[] = {
   8   (uint32_t*)&(PWMMR0),
   9   (uint32_t*)&(PWMMR1),
  10   (uint32_t*)&(PWMMR2),
  11   (uint32_t*)&(PWMMR3),
  12   (uint32_t*)&(PWMMR4),
  13   (uint32_t*)&(PWMMR5),
  14   (uint32_t*)&(PWMMR6)
  15 };
  16
  17 void pwm_channel(int n, int double_edge) {
  18   uint32_t bit;
  19
  20   PWMPCR |= (0x100 | (double_edge && n)) << n;
  21   if (n == 5) {
  22     PINSEL1 |= 0x00000400;
  23     PINSEL1 &= 0xfffff7ff;
  24   }
  25   else {
  26     bit = 1 << PWM_PINSEL[n];
  27     PINSEL0 |= bit;
  28     bit = ~(bit >> 1);
  29     PINSEL0 &= bit;
  30   }
  31 }
  32
  33 void pwm_set(int n, uint32_t when) {
  34   *PWM_MR[n] = when;
  35   PWMLER |= 1 << n;
  36 }
  37
  38 void pwm_set_double(int n, uint32_t from, uint32_t to) {
  39   *PWM_MR[n-1] = from;
  40   *PWM_MR[n] = to;
  41   PWMLER |= 0x3 << (n-1);
  42 }
  43
  44 void pwm_init(uint32_t prescale, uint32_t period) {
  45   PWMPR = prescale - 1;
  46   PWMMR0 = period - 1;
  47   PWMLER |= 0x1;
  48   PWMMCR |= 0x00000002;
  49   PWMTCR &= ~0x2;
  50   PWMTCR |= 0x9;
  51 }
  52