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         PRR1 &= ~_BV(PRTIM3);
  99         OCR3A = F_CPU / 1000 - 1;       /* Timer3: 1000Hz interval (OC3A) */
 100         TCCR3B = (0b01<<WGM32)|(0b001<<CS30); /* CTC Mode, Prescaler 1 */
 101         TIMSK3 = _BV(OCIE3A);           /* Enable TC2.oca interrupt */
 102 }
 103
 104 static
 105 int reset_reason_is_power_on(void)
 106 {
 107         return (mcusr & _BV(PORF)) != 0;
 108 }
 109
 110 /*--------------------------------------------------------------------------*/
 111
 112 /* Stored value of bootdelay, used by autoboot_command() */
 113 static int  stored_bootdelay;
 114
 115
 116 /***************************************************************************
 117  * Watch for 'delay' seconds for autoboot stop.
 118  * returns: 0 - no key, allow autoboot
 119  *          1 - got key, abort
 120  */
 121
 122 static int abortboot(int  bootdelay)
 123 {
 124         int abort = 0;
 125         uint32_t ts;
 126
 127         if (bootdelay >= 0)
 128                 printf_P(PSTR("Hit any key to stop autoboot: %2d "), bootdelay);
 129
 130 #if defined CONFIG_ZERO_BOOTDELAY_CHECK
 131         /*
 132          * Check if key already pressed
 133          * Don't check if bootdelay < 0
 134          */
 135         if (bootdelay >= 0) {
 136                 if (tstc()) {   /* we got a key press   */
 137                         (void) my_getchar();  /* consume input  */
 138                         my_puts_P(PSTR("\b\b\b 0"));
 139                         abort = 1;      /* don't auto boot      */
 140                 }
 141         }
 142 #endif
 143
 144         while ((bootdelay > 0) && (!abort)) {
 145                 --bootdelay;
 146                 /* delay 1000 ms */
 147                 ts = get_timer(0);
 148                 do {
 149                         if (tstc()) {   /* we got a key press   */
 150                                 abort  = 1;     /* don't auto boot      */
 151                                 bootdelay = 0;  /* no more delay        */
 152                                 break;
 153                         }
 154                         udelay(10000);
 155                 } while (!abort && get_timer(ts) < 1000);
 156
 157                 printf_P(PSTR("\b\b\b%2d "), bootdelay);
 158         }
 159
 160         putchar('\n');
 161
 162         return abort;
 163 }
 164
 165 static
 166 const char *bootdelay_process(void)
 167 {
 168         char *s;
 169         int bootdelay;
 170
 171         bootdelay = (int) getenv_ulong(PSTR(ENV_BOOTDELAY), 10, CONFIG_BOOTDELAY);
 172
 173
 174         debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
 175         _delay_ms(20);
 176
 177         s = getenv(PSTR(ENV_BOOTCMD));
 178         stored_bootdelay = bootdelay;
 179         return s;
 180 }
 181
 182 static
 183 void autoboot_command(const char *s)
 184 {
 185         debug("### main_loop: bootcmd=\"%s\"\n", s ? s : PSTR("<UNDEFINED>"));
 186         _delay_ms(20);
 187
 188         if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
 189                 run_command_list(s, -1);
 190         }
 191 }
 192
 193
 194 static
 195 void main_loop(void)
 196 {
 197         const char *s;
 198
 199         s = bootdelay_process();
 200         autoboot_command(s);
 201         cli_loop();
 202 }
 203
 204 int main(void)
 205 {
 206
 207         setup_avr();
 208         z80_setup_bus();
 209
 210         env_init();
 211
 212         if (reset_reason_is_power_on())
 213                 _delay_ms(CONFIG_PWRON_DELAY);
 214
 215         serial_setup(getenv_ulong(PSTR(ENV_BAUDRATE), 10, CONFIG_BAUDRATE));
 216         sei();
 217
 218 #if DEBUG
 219         debug("\n=========================<  (RE)START DEBUG  >=========================\n");
 220         print_reset_reason();
 221 #endif
 222
 223 #if DEBUG
 224         unsigned long i_speed = getenv_ulong(PSTR("i2c_clock"), 10, CONFIG_SYS_I2C_CLOCK);
 225         debug("### Setting I2C clock Frequency to %lu Hz.\n", i_speed);
 226         i2c_init(i_speed);
 227 #else
 228         i2c_init(CONFIG_SYS_I2C_CLOCK);
 229 #endif
 230
 231         printf_P(PSTR("\nATMEGA1281+Z8S180 Stamp Monitor\n\n"));
 232
 233
 234         main_loop();
 235 }