diff options
| -rw-r--r-- | openpcd/firmware/src/picc/tc_fdt.c | 51 | ||||
| -rw-r--r-- | openpcd/firmware/src/picc/tc_fdt.h | 9 |
2 files changed, 60 insertions, 0 deletions
diff --git a/openpcd/firmware/src/picc/tc_fdt.c b/openpcd/firmware/src/picc/tc_fdt.c new file mode 100644 index 0000000..cc7729a --- /dev/null +++ b/openpcd/firmware/src/picc/tc_fdt.c @@ -0,0 +1,51 @@ +/* OpenPC TC (Timer / Clock) support code + * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de> + * + * This idea of this code is to feed the 13.56MHz carrier clock of RC632 + * into TCLK1, which is routed to XC1. Then configure TC0 to divide this + * clock by a configurable divider. + * + * PICC Simulator Side: + * In order to support responding to synchronous frames (REQA/WUPA/ANTICOL), + * we need a second Timer/Counter (TC1). This unit is reset by an external + * event (rising edge of modulation pause PCD->PICC) 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 <lib_AT91SAM7.h> +#include <AT91SAM7.h> +#include <os/dbgu.h> + +#include "../openpcd.h" +#include <os/tc_cdiv.h> +#include <picc/tc_fdt.h> + +void tc_fdt_set(u_int16_t count) +{ + tcb->TCB_TC2.TC_RA = count; +} + +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)); + /* Clock XC1, Wave Mode, No automatic reset on RC comp + * TIOA2 in RA comp = set, TIOA2 on RC comp = clear, + * TIOB2 as input, EEVT = TIOB2, Reset/Trigger on EEVT */ + tcb->TCB_TC2.TC_CMR = AT91C_TC_CLKS_XC1 | AT91C_TC_WAVE | + AT91C_TC_WAVESEL_UP | + AT91C_TC_ACPA_SET | AT91C_TC_ACPC_CLEAR | + AT91C_TC_BEEVT_NONE | AT91C_TC_BCPB_NONE | + AT91C_TC_EEVT_TIOB | AT91C_TC_ETRGEDG_RISING | + AT91C_TC_ENETRG ; + + /* Reset to start timers */ + tcb->TCB_BCR = 1; +} + diff --git a/openpcd/firmware/src/picc/tc_fdt.h b/openpcd/firmware/src/picc/tc_fdt.h new file mode 100644 index 0000000..b39b935 --- /dev/null +++ b/openpcd/firmware/src/picc/tc_fdt.h @@ -0,0 +1,9 @@ +#ifndef _TC_FDT_H +#define _TC_FDT_H + +#include <sys/types.h> + +extern void tc_fdt_init(void); +extern void tc_fdt_set(u_int16_t count); + +#endif |