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/* OpenPICC TC (Timer / Clock) support code
* (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/* PICC Simulator Side:
* In order to support responding to synchronous frames (REQA/WUPA/ANTICOL),
* we need a second Timer/Counter (TC2). This unit is reset by an external
* event (rising edge of modulation pause PCD->PICC, falling edge of
* demodulated data) connected to TIOB2, and counts up to a configurable
* number of carrier clock cycles (RA). Once the RA value is reached, TIOA2
* will see a rising edge. This rising edge will be interconnected to TF (Tx
* Frame) of the SSC to start transmitting our synchronous response.
*
*/
#include <FreeRTOS.h>
#include <task.h>
#include <lib_AT91SAM7.h>
#include <AT91SAM7.h>
#include "dbgu.h"
#include "openpicc.h"
#include "led.h"
#include "tc_cdiv.h"
#include "tc_fdt.h"
static AT91PS_TC tcfdt = AT91C_BASE_TC2;
void tc_fdt_set(u_int16_t count)
{
tcfdt->TC_RA = count;
}
/* 'count' number of carrier cycles after the last modulation pause,
* we deem the frame to have ended */
void tc_frame_end_set(u_int16_t count)
{
tcfdt->TC_RB = count;
}
static void tc_fdt_irq_inner(void)
{
vLedSetGreen(1);
u_int32_t sr = tcfdt->TC_SR;
DEBUGP("tc_fdt_irq: TC2_SR=0x%08x TC2_CV=0x%08x ",
sr, tcfdt->TC_CV);
if (sr & AT91C_TC_ETRGS) {
DEBUGP("Ext_trigger ");
}
if (sr & AT91C_TC_CPAS) {
DEBUGP("FDT_expired ");
/* FIXME: if we are in anticol / sync mode,
* we could do software triggering of SSC TX,
* but IIRC the hardware does this by TF */
}
if (sr & AT91C_TC_CPBS) {
DEBUGP("Frame_end ");
/* FIXME: stop ssc (in continuous mode),
* take care of preparing synchronous response if
* we operate in anticol mode.*/
}
if (sr & AT91C_TC_CPCS) {
DEBUGP("Compare_C ");
}
DEBUGPCR("");
AT91F_AIC_AcknowledgeIt();
vLedSetGreen(0);
}
static void tc_fdt_irq_outer(void) __attribute__ ((naked));
static void tc_fdt_irq_outer(void) {
portSAVE_CONTEXT();
tc_fdt_irq_inner();
portRESTORE_CONTEXT();
}
void tc_fdt_print(void)
{
DEBUGP("TC2_CV=0x%08x ", tcfdt->TC_CV);
DEBUGP("TC2_CMR=0x%08x ", tcfdt->TC_CMR);
DEBUGP("TC2_SR=0x%08x ", tcfdt->TC_SR);
DEBUGP("TC2_RA=0x%04x, TC2_RB=0x%04x, TC2_RC=0x%04x",
tcfdt->TC_RA, tcfdt->TC_RB, tcfdt->TC_RC);
}
void tc_fdt_init(void)
{
AT91F_PIO_CfgPeriph(AT91C_BASE_PIOA, AT91C_PA15_TF,
AT91C_PA26_TIOA2 | AT91C_PA27_TIOB2);
AT91F_PMC_EnablePeriphClock(AT91C_BASE_PMC,
((unsigned int) 1 << AT91C_ID_TC2));
/* Enable Clock for TC2 */
tcfdt->TC_CCR = AT91C_TC_CLKEN;
tcfdt->TC_RC = 0xffff;
tc_frame_end_set(128*2);
/* Clock XC1, Wave Mode, No automatic reset on RC comp
* TIOA2 in RA comp = set, TIOA2 on RC comp = clear,
* TIOA2 on EEVT = clear
* TIOB2 as input, EEVT = TIOB2, Reset/Trigger on EEVT */
tcfdt->TC_CMR = AT91C_TC_CLKS_XC1 | AT91C_TC_WAVE |
AT91C_TC_WAVESEL_UP |
AT91C_TC_ACPA_SET | AT91C_TC_ACPC_CLEAR |
AT91C_TC_AEEVT_CLEAR |
AT91C_TC_BEEVT_NONE | AT91C_TC_BCPB_NONE |
AT91C_TC_EEVT_TIOB | AT91C_TC_ETRGEDG_FALLING |
AT91C_TC_ENETRG | AT91C_TC_CPCSTOP ;
/* Reset to start timers */
tcb->TCB_BCR = 1;
AT91F_AIC_ConfigureIt(AT91C_ID_TC2,
OPENPCD_IRQ_PRIO_TC_FDT,
AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, &tc_fdt_irq_outer);
AT91F_AIC_EnableIt(AT91C_ID_TC2);
tcfdt->TC_IER = AT91C_TC_CPAS | AT91C_TC_CPBS | AT91C_TC_CPCS |
AT91C_TC_ETRGS;
}
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