git.zerfleddert.de Git - rsbs2/blob - bmc/chassis.c

   1 #include <avr/io.h>
   2 #include <avr/interrupt.h>
   3 #include <stdio.h>
   4
   5 #include "chassis.h"
   6
   7 #ifdef __AVR_ATmega16__
   8 #define CHASSISPORT B
   9 #define POWER_PIN 0
  10 #define RESET_PIN 1
  11 #define ACTIVE_LOW
  12 #else
  13 #error "Please add chassis power/reset-PIN information for this chip"
  14 #endif
  15
  16 #define __CPORT(port) PORT##port
  17 #define _CPORT(port) __CPORT(port)
  18 #define CPORT _CPORT(CHASSISPORT)
  19
  20 #define __CDDR(port) DDR##port
  21 #define _CDDR(port) __CDDR(port)
  22 #define CDDR _CDDR(CHASSISPORT)
  23
  24 static volatile int power_cnt = 0;
  25 static volatile int reset_cnt = 0;
  26
  27 static void chassis_set_pins(uint8_t pins, uint8_t state);
  28
  29 void chassis_init()
  30 {
  31         chassis_set_pins((1<<POWER_PIN) | (1<<RESET_PIN), 0);
  32         CDDR |= ((1<<POWER_PIN) | (1<<RESET_PIN));
  33
  34         /* About 1ms */
  35         OCR0 = ((F_CPU/256)/1000)-1;
  36
  37         TCCR0 = ((1<<WGM01) | (1<<CS02)); /* CTC, Prescaler 256 */
  38         TIMSK |= (1<<OCIE0);
  39
  40 }
  41
  42 static void chassis_set_pins(uint8_t pins, uint8_t state)
  43 {
  44 #ifdef ACTIVE_LOW
  45         state = !state;
  46 #endif
  47
  48         if(state) {
  49                 CPORT |= pins;
  50         } else {
  51                 CPORT &= ~pins;
  52         }
  53 }
  54
  55 static void chassis_power(int msec)
  56 {
  57         uint8_t old_SREG = SREG;
  58
  59         chassis_set_pins((1<<POWER_PIN), 1);
  60
  61         cli();
  62         if (!power_cnt)
  63                 power_cnt = msec;
  64         SREG = old_SREG;
  65 }
  66
  67 static void chassis_reset(int msec)
  68 {
  69         uint8_t old_SREG = SREG;
  70
  71         chassis_set_pins((1<<RESET_PIN), 1);
  72
  73         cli();
  74         if (!reset_cnt)
  75                 reset_cnt = msec;
  76         SREG = old_SREG;
  77 }
  78
  79 void chassis_control(unsigned char action)
  80 {
  81 #ifdef DEBUG
  82         printf("Chassis control 0x%02x\n", action);
  83 #endif
  84
  85         switch(action) {
  86                 case CHASSIS_ACTION_POWER_DOWN:
  87                         chassis_power(5000);
  88                         break;
  89
  90                 case CHASSIS_ACTION_POWER_UP:
  91                         chassis_power(500);
  92                         break;
  93
  94                 case CHASSIS_ACTION_HARD_RESET:
  95                         chassis_reset(500);
  96                         break;
  97
  98                 default:
  99 #ifdef DEBUG
 100                         printf("Unimplemented chassis action 0x%02x\n", action);
 101 #endif
 102                         break;
 103         }
 104 }
 105
 106 ISR(TIMER0_COMP_vect)
 107 {
 108         if (power_cnt) {
 109                 power_cnt--;
 110
 111                 if (!power_cnt)
 112                         chassis_set_pins((1<<POWER_PIN), 0);
 113         }
 114         if (reset_cnt) {
 115                 reset_cnt--;
 116
 117                 if (!reset_cnt)
 118                         chassis_set_pins((1<<RESET_PIN), 0);
 119         }
 120 }