app/spejbl_motor/pwm.c

   1 #include <cpu_def.h>
   2 #include "pwm.h"
   3
   4 int PWM_PINSEL[] = {
   5   /*nothing*/ 1, /*PWM1*/ 1, 15, 3, 17, /*PWM5*/ 11, /*PWM6*/ 19
   6 };
   7
   8 uint32_t *PWM_MR[] = {
   9   (uint32_t*)&(PWMMR0),
  10   (uint32_t*)&(PWMMR1),
  11   (uint32_t*)&(PWMMR2),
  12   (uint32_t*)&(PWMMR3),
  13   (uint32_t*)&(PWMMR4),
  14   (uint32_t*)&(PWMMR5),
  15   (uint32_t*)&(PWMMR6)
  16 };
  17
  18 void pwm_channel(int n, int double_edge) {
  19   uint32_t bit;
  20
  21   PWMPCR |= (0x100 | (double_edge && n)) << n;
  22   if (n == 5) {
  23     PINSEL1 |= 0x00000400;
  24     PINSEL1 &= 0xfffff7ff;
  25   }
  26   else {
  27     bit = 1 << PWM_PINSEL[n];
  28     PINSEL0 |= bit;
  29     bit = ~(bit >> 1);
  30     PINSEL0 &= bit;
  31   }
  32 }
  33
  34 void pwm_set(int n, uint32_t when) {
  35   *PWM_MR[n] = when;
  36   PWMLER |= 1 << n;
  37 }
  38
  39 void pwm_set_double(int n, uint32_t from, uint32_t to) {
  40   *PWM_MR[n-1] = from;
  41   *PWM_MR[n] = to;
  42   PWMLER |= 0x3 << (n-1);
  43 }
  44
  45 void pwm_init(uint32_t prescale, uint32_t period) {
  46   PWMPR = prescale - 1;
  47   PWMMR0 = period;
  48   PWMLER |= 0x1;
  49   PWMMCR |= 0x00000002;
  50   PWMTCR &= ~0x2;
  51   PWMTCR |= 0x9;
  52 }
  53
  54 void sync_pwm_timer(uint32_t *tc_addr) {
  55   cli();
  56   asm volatile
  57     (
  58      "mov  r2, %0       \n\t"
  59      "mov  r3, %1       \n\t"
  60      "ldr  r1, [r2]     \n\t"
  61      "add  r1, r1, #12  \n\t"
  62      "str  r1, [r3]     \n\t"
  63      : /* no output */ : "r" (tc_addr), "r" (&PWMTC)
  64      );
  65   sti();
  66 }