use CTC unit to generate correct timings for power/reset

[rsbs2] / bmc / chassis.c

diff --git a/bmc/chassis.c b/bmc/chassis.c
index fd488663d7ec3735efebe70a3a71cb0bc9356b9a..ed2406372eec028d197c7dec8b3825ecea31e444 100644 (file)
--- a/bmc/chassis.c
+++ b/bmc/chassis.c
@@ -1,12 +1,79 @@
 #include <avr/io.h>
+#include <avr/interrupt.h>
 #include <stdio.h>
 
 #include "chassis.h"
 
+#ifdef __AVR_ATmega16__
+#define CHASSISPORT B
+#define POWER_PIN 0
+#define RESET_PIN 1
+#define ACTIVE_LOW
+#else
+#error "Please add chassis power/reset-PIN information for this chip"
+#endif
+
+#define __CPORT(port) PORT##port
+#define _CPORT(port) __CPORT(port)
+#define CPORT _CPORT(CHASSISPORT)
+
+#define __CDDR(port) DDR##port
+#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()
 {
-       DDRB = 0xff;
-       PORTB = 0xff;
+       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)
+{
+#ifdef ACTIVE_LOW
+       state = !state;
+#endif
+
+       if(state) {
+               CPORT |= pins;
+       } else {
+               CPORT &= ~pins;
+       }
+}
+
+static void chassis_power(int msec)
+{
+       uint8_t old_SREG = SREG;
+
+       chassis_set_pins((1<<POWER_PIN), 1);
+
+       cli();
+       if (!power_cnt)
+               power_cnt = msec;
+       SREG = old_SREG;
+}
+
+static void chassis_reset(int msec)
+{
+       uint8_t old_SREG = SREG;
+
+       chassis_set_pins((1<<RESET_PIN), 1);
+
+       cli();
+       if (!reset_cnt)
+               reset_cnt = msec;
+       SREG = old_SREG;
 }
 
 void chassis_control(unsigned char action)
@@ -17,15 +84,15 @@ void chassis_control(unsigned char action)
 
        switch(action) {
                case CHASSIS_ACTION_POWER_DOWN:
-                       PORTB=0xff;
+                       chassis_power(5000);
                        break;
 
                case CHASSIS_ACTION_POWER_UP:
-                       PORTB=0x00;
+                       chassis_power(500);
                        break;
 
                case CHASSIS_ACTION_HARD_RESET:
-                       PORTB=0x55;
+                       chassis_reset(500);
                        break;
 
                default:
@@ -35,3 +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);
+       }
+}