[proxmark3-svn] / armsrc / ticks.c

//-----------------------------------------------------------------------------
// Jonathan Westhues, Sept 2005
// Iceman, Sept 2016
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Timers, Clocks functions used in LF or Legic where you would need detailed time.
//-----------------------------------------------------------------------------

#include "ticks.h"

// attempt at high resolution microsecond timer
// beware: timer counts in 21.3uS increments (1024/48Mhz)
void SpinDelayUs(int us) {
        int ticks = (48 * us) >> 10;

        // Borrow a PWM unit for my real-time clock
        AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0);
        
        // 48 MHz / 1024 gives 46.875 kHz
        AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10);
        AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0;
        AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff;

        uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;

        for(;;) {
                uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;
                if (now == (uint16_t)(start + ticks))
                        return;

                WDT_HIT();
        }
}

void SpinDelay(int ms) {
  // convert to uS and call microsecond delay function
        SpinDelayUs(ms*1000);
}
//  -------------------------------------------------------------------------
//  timer lib
//  -------------------------------------------------------------------------
//  test procedure:
//
//      ti = GetTickCount();
//      SpinDelay(1000);
//      ti = GetTickCount() - ti;
//      Dbprintf("timer(1s): %d t=%d", ti, GetTickCount());
void StartTickCount() {
        // This timer is based on the slow clock. The slow clock frequency is between 22kHz and 40kHz.
        // We can determine the actual slow clock frequency by looking at the Main Clock Frequency Register.
    uint16_t mainf = AT91C_BASE_PMC->PMC_MCFR & 0xffff;         // = 16 * main clock frequency (16MHz) / slow clock frequency
        // set RealTimeCounter divider to count at 1kHz:
        AT91C_BASE_RTTC->RTTC_RTMR = AT91C_RTTC_RTTRST | ((256000 + (mainf/2)) / mainf);
        // note: worst case precision is approx 2.5%
}

/*
* Get the current count.
*/
uint32_t RAMFUNC GetTickCount(){
        return AT91C_BASE_RTTC->RTTC_RTVR;// was * 2;
}

//  -------------------------------------------------------------------------
//  microseconds timer 
//  -------------------------------------------------------------------------
void StartCountUS() {
        AT91C_BASE_PMC->PMC_PCER |= (1 << 12) | (1 << 13) | (1 << 14);
        AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;

        // fast clock
        // tick=1.5mks
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
        AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz) / 32 
                                                                AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR |
                                                                AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET;
        AT91C_BASE_TC0->TC_RA = 1;
        AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000
        
        AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // timer disable  
        AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // from timer 0
        
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        AT91C_BASE_TCB->TCB_BCR = 1;
        
        while (AT91C_BASE_TC1->TC_CV > 1);
}

uint32_t RAMFUNC GetCountUS(){
        //return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV / 15) * 10);
        //  By suggestion from PwPiwi, http://www.proxmark.org/forum/viewtopic.php?pid=17548#p17548
        return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV * 2) / 3); 
}
void ResetUSClock(void) {       
        //enable clock of timer and software trigger
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        while (AT91C_BASE_TC1->TC_CV > 1);
}

//  -------------------------------------------------------------------------
//  Timer for iso14443 commands. Uses ssp_clk from FPGA 
//  -------------------------------------------------------------------------
void StartCountSspClk() {
        AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0) | (1 << AT91C_ID_TC1) | (1 << AT91C_ID_TC2);  // Enable Clock to all timers
        AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_TIOA1               // XC0 Clock = TIOA1
                                                        | AT91C_TCB_TC1XC1S_NONE                // XC1 Clock = none
                                                        | AT91C_TCB_TC2XC2S_TIOA0;              // XC2 Clock = TIOA0

        // configure TC1 to create a short pulse on TIOA1 when a rising edge on TIOB1 (= ssp_clk from FPGA) occurs:
        AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;                               // disable TC1
        AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK // TC1 Clock = MCK(48MHz)/2 = 24MHz
                                                        | AT91C_TC_CPCSTOP                              // Stop clock on RC compare
                                                        | AT91C_TC_EEVTEDG_RISING               // Trigger on rising edge of Event
                                                        | AT91C_TC_EEVT_TIOB                    // Event-Source: TIOB1 (= ssp_clk from FPGA = 13,56MHz/16)
                                                        | AT91C_TC_ENETRG                               // Enable external trigger event
                                                        | AT91C_TC_WAVESEL_UP                   // Upmode without automatic trigger on RC compare
                                                        | AT91C_TC_WAVE                                 // Waveform Mode
                                                        | AT91C_TC_AEEVT_SET                    // Set TIOA1 on external event
                                                        | AT91C_TC_ACPC_CLEAR;                  // Clear TIOA1 on RC Compare
        AT91C_BASE_TC1->TC_RC = 0x04;                                                   // RC Compare value = 0x04

        // use TC0 to count TIOA1 pulses
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;                               // disable TC0
        AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_XC0                              // TC0 clock = XC0 clock = TIOA1
                                                        | AT91C_TC_WAVE                                 // Waveform Mode
                                                        | AT91C_TC_WAVESEL_UP                   // just count
                                                        | AT91C_TC_ACPA_CLEAR                   // Clear TIOA0 on RA Compare
                                                        | AT91C_TC_ACPC_SET;                    // Set TIOA0 on RC Compare
        AT91C_BASE_TC0->TC_RA = 1;                                                              // RA Compare value = 1; pulse width to TC2
        AT91C_BASE_TC0->TC_RC = 0;                                                              // RC Compare value = 0; increment TC2 on overflow

        // use TC2 to count TIOA0 pulses (giving us a 32bit counter (TC0/TC2) clocked by ssp_clk)
        AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKDIS;                               // disable TC2  
        AT91C_BASE_TC2->TC_CMR = AT91C_TC_CLKS_XC2                              // TC2 clock = XC2 clock = TIOA0
                                                        | AT91C_TC_WAVE                                 // Waveform Mode
                                                        | AT91C_TC_WAVESEL_UP;                  // just count

        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;                               // enable and reset TC0
        AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;                               // enable and reset TC1
        AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;                               // enable and reset TC2

        // synchronize the counter with the ssp_frame signal. 
        // Note: FPGA must be in any iso14443 mode, otherwise the frame signal would not be present 
        while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME));   // wait for ssp_frame to go high (start of frame)
        while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME);              // wait for ssp_frame to be low
        while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK));     // wait for ssp_clk to go high

        // note: up to now two ssp_clk rising edges have passed since the rising edge of ssp_frame
        // it is now safe to assert a sync signal. This sets all timers to 0 on next active clock edge
        AT91C_BASE_TCB->TCB_BCR = 1;                                                    // assert Sync (set all timers to 0 on next active clock edge)
        // at the next (3rd) ssp_clk rising edge, TC1 will be reset (and not generate a clock signal to TC0)
        // at the next (4th) ssp_clk rising edge, TC0 (the low word of our counter) will be reset. From now on,
        // whenever the last three bits of our counter go 0, we can be sure to be in the middle of a frame transfer.
        // (just started with the transfer of the 4th Bit).

        // The high word of the counter (TC2) will not reset until the low word (TC0) overflows. 
        // Therefore need to wait quite some time before we can use the counter.
        while (AT91C_BASE_TC2->TC_CV > 1);
}
void ResetSspClk(void) {        
        //enable clock of timer and software trigger
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
}

uint32_t RAMFUNC GetCountSspClk(){

        uint32_t tmp_count = (AT91C_BASE_TC2->TC_CV << 16) | AT91C_BASE_TC0->TC_CV;
        if ((tmp_count & 0x0000ffff) == 0)  //small chance that we may have missed an increment in TC2
                return (AT91C_BASE_TC2->TC_CV << 16);
        return tmp_count;
}


//  -------------------------------------------------------------------------
//  Timer for bitbanging,  or LF stuff when you need a very precis timer
//  1us = 1.5ticks
//  -------------------------------------------------------------------------
void StartTicks(void){
        //initialization of the timer
        AT91C_BASE_PMC->PMC_PCER |= (1 << 12) | (1 << 13) | (1 << 14);
        AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
        AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK;  //clock at 48/32 MHz
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        AT91C_BASE_TCB->TCB_BCR = 1;
        // wait until timer becomes zero.
        while (AT91C_BASE_TC0->TC_CV > 1);
}
// Wait - Spindelay in ticks.
// if called with a high number, this will trigger the WDT...
void WaitTicks(uint32_t ticks){
        if ( ticks == 0 ) return;
        ticks += GET_TICKS;     
        while (GET_TICKS < ticks);
}
// Wait / Spindelay in us (microseconds) 
// 1us = 1.5ticks.
void WaitUS(uint16_t us){
        if ( us == 0 ) return;
        WaitTicks(  (uint32_t)(us * 1.5) );
}
void WaitMS(uint16_t ms){
        if (ms == 0) return;
        WaitTicks( (uint32_t)(ms * 1500) );
}
// Starts Clock and waits until its reset
void ResetTicks(){
        ResetTimer(AT91C_BASE_TC0);
}
void ResetTimer(AT91PS_TC timer){
        timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
        while(timer->TC_CV > 1) ;
}