/* Zipit sleep control. 
 * (c) 2005 Chris Studholme
 * GPL
 */

#include <stdio.h>
#include <stdlib.h>
#include <strings.h> 
#include <sys/time.h>
#include <time.h>
#include <unistd.h>

#include "hardware.h"

volatile unsigned char* pbdr = (unsigned char*)(CLPS7111_VIRT_BASE+PBDR);
volatile unsigned char* pbddr = (unsigned char*)(CLPS7111_VIRT_BASE+PBDDR);
volatile unsigned char* pddr = (unsigned char*)(CLPS7111_VIRT_BASE+PDDR);
volatile unsigned char* ledflsh = (unsigned char*)(CLPS7111_VIRT_BASE+LEDFLSH);

volatile unsigned int* rtc = (unsigned int*)(CLPS7111_VIRT_BASE+RTCDR);
volatile unsigned int* rtcmr = (unsigned int*)(CLPS7111_VIRT_BASE+RTCMR);
volatile unsigned int* stdby = (unsigned int*)(CLPS7111_VIRT_BASE+STDBY);
volatile unsigned int* intmr1 = (unsigned int*)(CLPS7111_VIRT_BASE+INTMR1);
volatile unsigned int* intmr2 = (unsigned int*)(CLPS7111_VIRT_BASE+INTMR2);
volatile unsigned int* intmr3 = (unsigned int*)(CLPS7111_VIRT_BASE+INTMR3);
volatile unsigned int* rtceoi = (unsigned int*)(CLPS7111_VIRT_BASE+RTCEOI);
volatile unsigned int* kbdeoi = (unsigned int*)(CLPS7111_VIRT_BASE+KBDEOI);
volatile unsigned int* syscon1 = (unsigned int*)(CLPS7111_VIRT_BASE+SYSCON1);
volatile unsigned int* syscon2 = (unsigned int*)(CLPS7111_VIRT_BASE+SYSCON2);
volatile unsigned int* syscon3 = (unsigned int*)(CLPS7111_VIRT_BASE+SYSCON3);


/* Put processor to sleep.  
 *
 * If sync is non-zero, busy waits are added before and after sleep to sync
 * with RTC and ensure kernel clock can be accurately updated.
 *
 * If timeout>0, auto wakeup in timeout seconds.
 *
 * If wol is non-zero, incoming network packets will cause wakeup.
 * 
 * The following functions are performed:
 *   - green LED is forced off
 *   - orange LED blinks briefly once every 4 seconds
 *   - LCD is shut down
 *   - timer interrupt is disabled
 *   - keyboard wakeup is enabled:
 *     a. if lid is closed, any key including lid will wake
 *     b. if lid is open, any key except Enter/BS/;/L/lid will wake
 *   - actual sleep
 *
 * On wakeup all hardware is restored to previous state and kernel clock
 * is updated to account for slept time.  If sync is zero, the kernel can
 * gain or lose up to one second per sleep.
 */
static void do_sleep(int sync, int timeout, int wol) {

  // turn off green LED
  unsigned char pbddr_save = *pbddr;
  *pbddr |= 2;
  unsigned char pbdr_save = *pbdr;
  *pbdr &= ~2;

  // setup orange/yellow LED to flash
  unsigned char pddr_save = *pddr;
  *ledflsh = 64 + 4 + 3;

  // save syscon and intmr registers
  unsigned int syscon1_save = *syscon1;
  unsigned int syscon2_save = *syscon2;
  unsigned int intmr1_save = *intmr1;
  unsigned int intmr2_save = *intmr2;

  // disable LCD
  *pddr &= ~(1<<5);
  *syscon1 &= ~(1<<12);

  // turn off DAI???  Is this audio?  What do I do?

  // wait for rtc edge
  if (sync) {
    unsigned int now = *rtc;
    while (now==*rtc) ;
  }
  unsigned int start = *rtc;

  // disable timer interrupt
  *intmr1 &= ~(1<<9);

  // disable net interrupt if !wol
  if (!wol)
    *intmr1 &= ~(1<<5);  // disable external interrupt 1

  // keyboard interrupt
  if (*pbdr&8) {  
    // lid open; we'll miss wakeup on Enter/BS/;/L/lid
    *syscon2 = syscon2_save|2;  // only use first 6 port A bits
    *syscon1 &= ~15;  // scan entire keyboard
    *kbdeoi = 0xff;  // clear pending interrupt
    *intmr2 |= 1; // enable keyboard interrupt
  }
  else {  
    // lid closed; wake on any keyboard activity
    *syscon2 = syscon2_save|8;
  }

  if (timeout>0) {
    if (sync && timeout>1)
      --timeout;  // we busy wait one of these seconds after wakeup
    *rtcmr = start+timeout;
    *rtceoi = 0xff;
    *intmr1 |= (1<<10);
  }


  // ******** actually sleep ********
  *stdby = 0xAA;
  // ********   sleep done   ********


  // wait for rtc edge
  if (sync) {
    unsigned int now = *rtc;
    while (now==*rtc) ;
  }
  unsigned int end = *rtc;

  // update kernel clock
  struct timeval tv;
  gettimeofday(&tv,0);
  tv.tv_sec += end-start;
  settimeofday(&tv,0);

  // restore interrupts
  *syscon2 = syscon2_save;
  *intmr2 = intmr2_save;
  *intmr1 = intmr1_save;

  // turn on DAI
  // probably something I should do?

  // restore LCD
  *syscon1 = syscon1_save;
  // pddr is restored below

  // restore orange/yellow LED
  *ledflsh = 0;
  *pddr = pddr_save;

  // restore green LED
  *pbdr = pbdr_save;
  *pbddr = pbddr_save;
}


int main(int argc, char **argv) {

  int timeout=0;
  int wol=0;
  int sync=1;

  if (argc>=2)
    timeout = atoi(argv[1]);

  if (argc>=3)
    wol = atoi(argv[2]);

  do_sleep(sync,timeout,wol);

  return 0;
}