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 "config.h"
   6 #include "chassis.h"
   7
   8 #ifdef __AVR_ATmega16__
   9 #define CHASSISPORT B
  10 #define POWER_PIN 0
  11 #define RESET_PIN 1
  12 #define ACTIVE_LOW
  13 #else
  14 #error "Please add chassis power/reset-PIN information for this chip"
  15 #endif
  16
  17 #define __CPORT(port) PORT##port
  18 #define _CPORT(port) __CPORT(port)
  19 #define CPORT _CPORT(CHASSISPORT)
  20
  21 #define __CDDR(port) DDR##port
  22 #define _CDDR(port) __CDDR(port)
  23 #define CDDR _CDDR(CHASSISPORT)
  24
  25 static volatile int power_cnt = 0;
  26 static volatile int reset_cnt = 0;
  27 static volatile int power_cycle = 0;
  28
  29 static void chassis_set_pins(uint8_t pins, uint8_t state);
  30
  31 void chassis_init()
  32 {
  33         chassis_set_pins((1<<POWER_PIN) | (1<<RESET_PIN), 0);
  34
  35         /* About 1ms */
  36         OCR0 = ((F_CPU/64)/1000) - 1;
  37
  38         TCCR0 = ((1<<WGM01) | (1<<CS01) | (1<<CS00)); /* CTC, Prescaler 64 */
  39         TIMSK |= (1<<OCIE0);
  40
  41 }
  42
  43 /* gracefully transition between tri-state and active */
  44 static void chassis_set_pins(uint8_t pins, uint8_t state)
  45 {
  46         if(state) {
  47                 /* active */
  48 #ifndef ACTIVE_LOW
  49                 /* Pull UPs for a short moment... */
  50                 CPORT |= pins;
  51 #endif
  52                 CDDR |= pins;
  53 #ifdef ACTIVE_LOW
  54                 CPORT &= ~pins;
  55 #endif
  56         } else {
  57 #ifdef ACTIVE_LOW
  58                 CPORT &= ~pins; /* NoOp... */
  59 #endif
  60                 CDDR &= ~pins;
  61 #ifndef ACTIVE_LOW
  62                 CPORT &= ~pins;
  63 #endif
  64         }
  65 }
  66
  67 static void chassis_power(int msec)
  68 {
  69         uint8_t old_SREG = SREG;
  70
  71         chassis_set_pins((1<<POWER_PIN), 1);
  72
  73         cli();
  74         if (!power_cnt)
  75                 power_cnt = msec;
  76         SREG = old_SREG;
  77 }
  78
  79 static void chassis_reset(int msec)
  80 {
  81         uint8_t old_SREG = SREG;
  82
  83         chassis_set_pins((1<<RESET_PIN), 1);
  84
  85         cli();
  86         if (!reset_cnt)
  87                 reset_cnt = msec;
  88         SREG = old_SREG;
  89 }
  90
  91 void chassis_control(unsigned char action)
  92 {
  93         uint8_t old_SREG = SREG;
  94
  95 #ifdef DEBUG
  96         printf("Chassis control 0x%02x\n", action);
  97 #endif
  98
  99         switch(action) {
 100                 case CHASSIS_ACTION_POWER_DOWN:
 101                         chassis_power(POWERDOWN_TIME_MS);
 102                         break;
 103
 104                 case CHASSIS_ACTION_POWER_UP:
 105                         chassis_power(POWERUP_TIME_MS);
 106                         break;
 107
 108                 case CHASSIS_ACTION_HARD_RESET:
 109                         chassis_reset(RESET_TIME_MS);
 110                         break;
 111
 112                 case CHASSIS_ACTION_POWER_CYCLE:
 113                         cli();
 114                         power_cycle = POWER_CYCLE_PAUSE_MS;
 115                         SREG = old_SREG;
 116                         chassis_power(POWERDOWN_TIME_MS);
 117
 118                 default:
 119 #ifdef DEBUG
 120                         printf("Unimplemented chassis action 0x%02x\n", action);
 121 #endif
 122                         break;
 123         }
 124 }
 125
 126 ISR(TIMER0_COMP_vect)
 127 {
 128         if (power_cnt) {
 129                 power_cnt--;
 130
 131                 if (!power_cnt)
 132                         chassis_set_pins((1<<POWER_PIN), 0);
 133         } else if (power_cycle) {
 134                 power_cycle--;
 135
 136                 if (!power_cycle) {
 137                         chassis_set_pins((1<<POWER_PIN), 1);
 138                         power_cnt = POWERUP_TIME_MS;
 139                 }
 140         }
 141         if (reset_cnt) {
 142                 reset_cnt--;
 143
 144                 if (!reset_cnt)
 145                         chassis_set_pins((1<<RESET_PIN), 0);
 146         }
 147 }