avr/main.c

   1 /*
   2  */
   3
   4
   5 #include "common.h"
   6
   7 #include <util/delay.h>
   8 #include <avr/interrupt.h>
   9 #include <stdlib.h>
  10 #include <stdio.h>
  11
  12 #include "config.h"
  13 #include "debug.h"
  14 #include "z80-if.h"
  15 #include "i2c.h"
  16 #include "con-utils.h"
  17 #include "serial.h"
  18 #include "timer.h"
  19 #include "cli.h"
  20 #include "env.h"
  21
  22 #define udelay(n)  _delay_us(n)
  23
  24 static uint8_t mcusr;
  25
  26 /*--------------------------------------------------------------------------*/
  27 #if DEBUG
  28
  29 __attribute__ ((naked)) __attribute__ ((section (".init3")))
  30 void preset_ram (void)
  31 {
  32         for (uint8_t *p = RAMSTART; p <= (uint8_t *) RAMEND; p++)
  33                 *p = 0xdd;
  34
  35 }
  36
  37 static const FLASH char * const FLASH rreasons[] = {
  38                         FSTR("Power on"),
  39                         FSTR("External"),
  40                         FSTR("Brown out"),
  41                         FSTR("Watchdog"),
  42                         FSTR("JTAG"),
  43                 };
  44
  45 static
  46 void print_reset_reason(void)
  47 {
  48         uint8_t r = mcusr & 0x1f;
  49         const FLASH char * const FLASH *p = rreasons;
  50
  51         printf_P(PSTR("### Reset reason(s): %s"), r ? "" : "none");
  52         for ( ; r; p++, r >>= 1) {
  53                 if (r & 1) {
  54                         my_puts_P(*p);
  55                         if (r & ~1)
  56                                 printf_P(PSTR(", "));
  57                 }
  58         }
  59         printf_P(PSTR(".\n"));
  60 }
  61
  62 #endif
  63
  64 ISR(INT5_vect)
  65 {
  66         Stat |= S_MSG_PENDING;
  67 }
  68
  69 static
  70 void setup_avr(void)
  71 {
  72         /* save and clear reset reason(s) */
  73         /* TODO: move to init section? */
  74         mcusr = MCUSR;
  75         MCUSR = 0;
  76
  77         /* WD */
  78
  79         /* CPU */
  80
  81         /* Disable JTAG Interface regardless of the JTAGEN fuse setting. */
  82         MCUCR = _BV(JTD);
  83         MCUCR = _BV(JTD);
  84
  85         /* Disable peripherals. Enable individually in respective init function. */
  86         PRR0 = _BV(PRTWI) |
  87                 _BV(PRTIM2) | _BV(PRTIM0) | _BV(PRTIM1) |
  88                 _BV(PRSPI) | _BV(PRUSART0) | _BV(PRADC);
  89
  90         PRR1 = _BV(PRTIM5) | _BV(PRTIM4) | _BV(PRTIM3) |
  91                 _BV(PRUSART3) | _BV(PRUSART2) | _BV(PRUSART1);
  92
  93
  94         /* disable analog comparator */
  95         ACSR = _BV(ACD);
  96         /* Ports */
  97
  98         /* Clock */
  99         CLKPR = _BV(CLKPCE);
 100         CLKPR = 0;
 101
 102         /* Timer */
 103         PRR1 &= ~_BV(PRTIM3);
 104         OCR3A = F_CPU / 1000 - 1;       /* Timer3: 1000Hz interval (OC3A) */
 105         TCCR3B = (0b01<<WGM32)|(0b001<<CS30); /* CTC Mode, Prescaler 1 */
 106         TIMSK3 = _BV(OCIE3A);           /* Enable TC2.oca interrupt */
 107
 108         /* INT5 falling edge */
 109         EICRB = (EICRB & ~(0b11 << ISC50)) | 0b10 << ISC50;
 110         /* Enable INT5 */
 111         EIMSK |= _BV(INT5);
 112 }
 113
 114 static
 115 int reset_reason_is_power_on(void)
 116 {
 117         return (mcusr & _BV(PORF)) != 0;
 118 }
 119
 120 /*--------------------------------------------------------------------------*/
 121
 122 /* Stored value of bootdelay, used by autoboot_command() */
 123 static int  stored_bootdelay;
 124
 125
 126 /***************************************************************************
 127  * Watch for 'delay' seconds for autoboot stop.
 128  * returns: 0 - no key, allow autoboot
 129  *          1 - got key, abort
 130  */
 131
 132 static int abortboot(int  bootdelay)
 133 {
 134         int abort = 0;
 135         uint32_t ts;
 136
 137         if (bootdelay >= 0)
 138                 printf_P(PSTR("Hit any key to stop autoboot: %2d "), bootdelay);
 139
 140 #if defined CONFIG_ZERO_BOOTDELAY_CHECK
 141         /*
 142          * Check if key already pressed
 143          * Don't check if bootdelay < 0
 144          */
 145         if (bootdelay >= 0) {
 146                 if (tstc()) {   /* we got a key press   */
 147                         (void) my_getchar(1);  /* consume input */
 148                         my_puts_P(PSTR("\b\b\b 0"));
 149                         abort = 1;      /* don't auto boot      */
 150                 }
 151         }
 152 #endif
 153
 154         while ((bootdelay > 0) && (!abort)) {
 155                 --bootdelay;
 156                 /* delay 1000 ms */
 157                 ts = get_timer(0);
 158                 do {
 159                         if (tstc()) {   /* we got a key press   */
 160                                 abort  = 1;     /* don't auto boot      */
 161                                 bootdelay = 0;  /* no more delay        */
 162                                 break;
 163                         }
 164                         udelay(10000);
 165                 } while (!abort && get_timer(ts) < 1000);
 166
 167                 printf_P(PSTR("\b\b\b%2d "), bootdelay);
 168         }
 169
 170         putchar('\n');
 171
 172         return abort;
 173 }
 174
 175 static
 176 const char *bootdelay_process(void)
 177 {
 178         char *s;
 179         int bootdelay;
 180
 181         bootdelay = (int) getenv_ulong(PSTR(ENV_BOOTDELAY), 10, CONFIG_BOOTDELAY);
 182
 183
 184         debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
 185         _delay_ms(20);
 186
 187         s = getenv(PSTR(ENV_BOOTCMD));
 188         stored_bootdelay = bootdelay;
 189         return s;
 190 }
 191
 192 static
 193 void autoboot_command(const char *s)
 194 {
 195         debug("### main_loop: bootcmd=\"%s\"\n", s ? s : PSTR("<UNDEFINED>"));
 196         _delay_ms(20);
 197
 198         if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
 199                 run_command_list(s, -1);
 200         }
 201 }
 202
 203
 204 static
 205 void main_loop(void)
 206 {
 207         const char *s;
 208
 209         s = bootdelay_process();
 210         autoboot_command(s);
 211         cli_loop();
 212 }
 213
 214 int main(void)
 215 {
 216
 217         setup_avr();
 218         z80_setup_bus();
 219
 220         env_init();
 221
 222         if (reset_reason_is_power_on())
 223                 _delay_ms(CONFIG_PWRON_DELAY);
 224
 225         serial_setup(getenv_ulong(PSTR(ENV_BAUDRATE), 10, CONFIG_BAUDRATE));
 226         sei();
 227
 228 #if DEBUG
 229         debug("\n=========================<  (RE)START DEBUG  >=========================\n");
 230         print_reset_reason();
 231 #endif
 232
 233 #if DEBUG
 234         unsigned long i_speed = getenv_ulong(PSTR("i2c_clock"), 10, CONFIG_SYS_I2C_CLOCK);
 235         debug("### Setting I2C clock Frequency to %lu Hz.\n", i_speed);
 236         i2c_init(i_speed);
 237 #else
 238         i2c_init(CONFIG_SYS_I2C_CLOCK);
 239 #endif
 240
 241         printf_P(PSTR("\nATMEGA1281+Z8S180 Stamp Monitor\n\n"));
 242
 243
 244         main_loop();
 245 }