use CTC unit to generate correct timings for power/reset

diff --git a/bmc/chassis.c b/bmc/chassis.c
index 1b6822e876c4ab650f7e5b5737b36b9685e48c07..ed2406372eec028d197c7dec8b3825ecea31e444 100644 (file)
--- a/bmc/chassis.c
+++ b/bmc/chassis.c
@@ -1,4 +1,5 @@
 #include <avr/io.h>
+#include <avr/interrupt.h>
 #include <stdio.h>
 
 #include "chassis.h"
@@ -20,12 +21,22 @@
 #define _CDDR(port) __CDDR(port)
 #define CDDR _CDDR(CHASSISPORT)
 
+static volatile int power_cnt = 0;
+static volatile int reset_cnt = 0;
+
 static void chassis_set_pins(uint8_t pins, uint8_t state);
 
 void chassis_init()
 {
        chassis_set_pins((1<<POWER_PIN) | (1<<RESET_PIN), 0);
        CDDR |= ((1<<POWER_PIN) | (1<<RESET_PIN));
+
+       /* About 1ms */
+       OCR0 = ((F_CPU/256)/1000)-1;
+
+       TCCR0 = ((1<<WGM01) | (1<<CS02)); /* CTC, Prescaler 256 */
+       TIMSK |= (1<<OCIE0);
+
 }
 
 static void chassis_set_pins(uint8_t pins, uint8_t state)
@@ -43,26 +54,26 @@ static void chassis_set_pins(uint8_t pins, uint8_t state)
 
 static void chassis_power(int msec)
 {
-       volatile int i;
+       uint8_t old_SREG = SREG;
 
        chassis_set_pins((1<<POWER_PIN), 1);
 
-       /* FIXME */
-       for(i = 0; i < (msec<<2); i++);
-
-       chassis_set_pins((1<<POWER_PIN), 0);
+       cli();
+       if (!power_cnt)
+               power_cnt = msec;
+       SREG = old_SREG;
 }
 
 static void chassis_reset(int msec)
 {
-       volatile int i;
+       uint8_t old_SREG = SREG;
 
        chassis_set_pins((1<<RESET_PIN), 1);
 
-       /* FIXME */
-       for(i = 0; i < (msec<<2); i++);
-
-       chassis_set_pins((1<<RESET_PIN), 0);
+       cli();
+       if (!reset_cnt)
+               reset_cnt = msec;
+       SREG = old_SREG;
 }
 
 void chassis_control(unsigned char action)
@@ -91,3 +102,19 @@ void chassis_control(unsigned char action)
                        break;
        }
 }
+
+ISR(TIMER0_COMP_vect)
+{
+       if (power_cnt) {
+               power_cnt--;
+
+               if (!power_cnt)
+                       chassis_set_pins((1<<POWER_PIN), 0);
+       }
+       if (reset_cnt) {
+               reset_cnt--;
+
+               if (!reset_cnt)
+                       chassis_set_pins((1<<RESET_PIN), 0);
+       }
+}