irq_router.c

#include "main-header.h"
#include "irq_router.h"
#define MAX_IRQS 15
 
// set this bit to trigger irq
#define IRQ_STATUS_DUE 0
 
typedef struct softirq_registration {
  MCULIB_HANDLE handle;
  int           pin;
  softirq *     callback;
  void *        opaque;
  byte          status;
} softirq_registration_t;
 
static struct softirq_registration registrations[MAX_IRQS];
/*
 * \brief register a softirq on a pin.
 *
 * caller must set up pin for input and provide call back function.
 * softirq will be called during mainloop (it will not interrupt mainloop)
 */
int register_softirq(MCULIB_HANDLE handle, int pin, softirq *callback, void *opaque) {
  int i;
  struct softirq_registration *sf = NULL;
  struct softirq_registration *usf = NULL;
 
  for (i = 0; i < MAX_IRQS; i++) {
    sf = &registrations[i];
    if (sf->callback == NULL) {
      if (usf == NULL) {
        usf = sf;
      }
      continue;
    }
    if (sf->pin == pin) {
      usf = sf;
      break;
    }
  }
  if (usf == NULL) {
    printf("Not enough softirqs available\r\n");
    return 1;
  }
  usf->pin = pin;
  usf->handle = handle;
  usf->callback = callback;
  usf->opaque = opaque;
  return 0;
}
void release_irq_by_handle(MCULIB_HANDLE handle) {
  int i;
  struct softirq_registration *sf = NULL;
 
  for (i = 0; i < MAX_IRQS; i++) {
    sf = &registrations[i];
    if ((sf->callback != NULL) && (sf->handle == handle)) {
      sf->callback = NULL;
    }
  }
}
 
static struct softirq_registration *get_by_pin(int pin) {
  int i;
  struct softirq_registration *sf = NULL;
 
  for (i = 0; i < MAX_IRQS; i++) {
    sf = &registrations[i];
    if ((sf->callback != NULL) && (sf->pin == pin)) {
      return sf;
    }
  }
  return NULL;
}
 
void process_irqs() {
  int i;
  struct softirq_registration *sf = NULL;
 
  for (i = 0; i < MAX_IRQS; i++) {
    sf = &registrations[i];
    if ((sf->callback != NULL) && (sf->status & (1 << IRQ_STATUS_DUE))) {
      sf->status = sf->status & ~(1 << IRQ_STATUS_DUE);
      //      printf("IRQ-router: SoftIRQ on pin %i\r\n",sf->pin);
      sf->callback(sf->pin, sf->opaque);
      sf->status = sf->status & ~(1 << IRQ_STATUS_DUE); // clear the irq a second time, so to avoid spurious IRQs. this certainly can't be the right thing to do
    }
  }
}
 
static void pinirq(int pin)   __attribute__((no_instrument_function));
// the *REAL* irq
// mark the fact that "real" IRQ occured on this pin
static void pinirq(int pin) {
  struct softirq_registration *sf = get_by_pin(pin);
 
  if (sf == NULL) {
    return;
  }
  sf->status = sf->status | (1 << IRQ_STATUS_DUE);
}
 
void irq_router_init() {
  memset(&registrations, sizeof(registrations), 0);
  mculib_pin_in_callback(MAIN_MCULIBHANDLE, &pinirq); // for ti1101
}