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 static
  65 void setup_avr(void)
  66 {
  67         /* save and clear reset reason(s) */
  68         /* TODO: move to init section? */
  69         mcusr = MCUSR;
  70         MCUSR = 0;
  71
  72         /* WD */
  73
  74         /* CPU */
  75
  76         /* Disable JTAG Interface regardless of the JTAGEN fuse setting. */
  77         MCUCR = _BV(JTD);
  78         MCUCR = _BV(JTD);
  79
  80         /* Disable peripherals. Enable individually in respective init function. */
  81         PRR0 = _BV(PRTWI) |
  82                 _BV(PRTIM2) | _BV(PRTIM0) | _BV(PRTIM1) |
  83                 _BV(PRSPI) | _BV(PRUSART0) | _BV(PRADC);
  84
  85         PRR1 = _BV(PRTIM5) | _BV(PRTIM4) | _BV(PRTIM3) |
  86                 _BV(PRUSART3) | _BV(PRUSART2) | _BV(PRUSART1);
  87
  88
  89         /* disable analog comparator */
  90         ACSR = _BV(ACD);
  91         /* Ports */
  92
  93         /* Clock */
  94         CLKPR = _BV(CLKPCE);
  95         CLKPR = 0;
  96
  97         /* Timer */
  98         PRR0 &= ~_BV(PRTIM2);
  99         OCR2A = F_CPU / 256 / 1000 - 1; /* Timer2: 1000Hz interval (OC2A) */
 100         TCCR2A = (0b10 << WGM20);       /* CTC Mode */
 101         TCCR2B = (0b110 << CS20);       /* Prescaler 256 */
 102         TIMSK2 = _BV(OCIE2A);           /* Enable TC2.oca interrupt */
 103 }
 104
 105 static
 106 int reset_reason_is_power_on(void)
 107 {
 108         return (mcusr & _BV(PORF)) != 0;
 109 }
 110
 111 /*--------------------------------------------------------------------------*/
 112
 113 /* Stored value of bootdelay, used by autoboot_command() */
 114 static int  stored_bootdelay;
 115
 116
 117 /***************************************************************************
 118  * Watch for 'delay' seconds for autoboot stop.
 119  * returns: 0 - no key, allow autoboot
 120  *          1 - got key, abort
 121  */
 122
 123 static int abortboot(int  bootdelay)
 124 {
 125         int abort = 0;
 126         uint32_t ts;
 127
 128         if (bootdelay >= 0)
 129                 printf_P(PSTR("Hit any key to stop autoboot: %2d "), bootdelay);
 130
 131 #if defined CONFIG_ZERO_BOOTDELAY_CHECK
 132         /*
 133          * Check if key already pressed
 134          * Don't check if bootdelay < 0
 135          */
 136         if (bootdelay >= 0) {
 137                 if (tstc()) {   /* we got a key press   */
 138                         (void) my_getchar();  /* consume input  */
 139                         my_puts_P(PSTR("\b\b\b 0"));
 140                         abort = 1;      /* don't auto boot      */
 141                 }
 142         }
 143 #endif
 144
 145         while ((bootdelay > 0) && (!abort)) {
 146                 --bootdelay;
 147                 /* delay 1000 ms */
 148                 ts = get_timer(0);
 149                 do {
 150                         if (tstc()) {   /* we got a key press   */
 151                                 abort  = 1;     /* don't auto boot      */
 152                                 bootdelay = 0;  /* no more delay        */
 153                                 break;
 154                         }
 155                         udelay(10000);
 156                 } while (!abort && get_timer(ts) < 1000);
 157
 158                 printf_P(PSTR("\b\b\b%2d "), bootdelay);
 159         }
 160
 161         putchar('\n');
 162
 163         return abort;
 164 }
 165
 166 static
 167 const char *bootdelay_process(void)
 168 {
 169         char *s;
 170         int bootdelay;
 171
 172         bootdelay = (int) getenv_ulong(PSTR("bootdelay"), 10, CONFIG_BOOTDELAY);
 173
 174
 175         debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
 176         _delay_ms(20);
 177
 178         s = getenv(PSTR("bootcmd"));
 179         stored_bootdelay = bootdelay;
 180         return s;
 181 }
 182
 183 static
 184 void autoboot_command(const char *s)
 185 {
 186         debug("### main_loop: bootcmd=\"%s\"\n", s ? s : PSTR("<UNDEFINED>"));
 187         _delay_ms(20);
 188
 189         if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
 190                 run_command_list(s, -1);
 191         }
 192 }
 193
 194
 195 static
 196 void main_loop(void)
 197 {
 198         const char *s;
 199
 200         s = bootdelay_process();
 201         autoboot_command(s);
 202         cli_loop();
 203 }
 204
 205 int main(void)
 206 {
 207
 208         setup_avr();
 209         z80_setup_bus();
 210
 211         env_init();
 212
 213         if (reset_reason_is_power_on())
 214                 _delay_ms(CONFIG_PWRON_DELAY);
 215
 216         serial_setup(getenv_ulong(PSTR("baudrate"), 10, CONFIG_BAUDRATE));
 217         sei();
 218
 219 #if DEBUG
 220         debug("\n=========================<  (RE)START DEBUG  >=========================\n");
 221         print_reset_reason();
 222 #endif
 223
 224 #if DEBUG
 225         unsigned long i_speed = getenv_ulong(PSTR("i2c_clock"), 10, CONFIG_SYS_I2C_CLOCK);
 226         debug("### Setting I2C clock Frequency to %lu Hz.\n", i_speed);
 227         i2c_init(i_speed);
 228 #else
 229         i2c_init(CONFIG_SYS_I2C_CLOCK);
 230 #endif
 231
 232         printf_P(PSTR("\n(ATMEGA1281+HD64180)_stamp Tester\n"));
 233
 234
 235         main_loop();
 236 }