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