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_timed() fcts: allow 32b cycles counter & prescaler!=0
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@doegox
doegox committed May 11, 2011
1 parent 520e64c commit 53f1acf
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Showing 5 changed files with 35 additions and 24 deletions.
4 changes: 2 additions & 2 deletions include/nfc/nfc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -77,8 +77,8 @@ extern "C" {
NFC_EXPORT bool nfc_initiator_deselect_target (nfc_device_t * pnd);
NFC_EXPORT bool nfc_initiator_transceive_bytes (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx, size_t * pszRx);
NFC_EXPORT bool nfc_initiator_transceive_bits (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits, const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar);
NFC_EXPORT bool nfc_initiator_transceive_bytes_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx, size_t * pszRx, uint16_t * cycles);
NFC_EXPORT bool nfc_initiator_transceive_bits_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits, const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint16_t * cycles);
NFC_EXPORT bool nfc_initiator_transceive_bytes_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx, size_t * pszRx, uint32_t * cycles);
NFC_EXPORT bool nfc_initiator_transceive_bits_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits, const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint32_t * cycles);

/* NFC target: act as tag (i.e. MIFARE Classic) or NFC target device. */
NFC_EXPORT bool nfc_target_init (nfc_device_t * pnd, nfc_target_t * pnt, byte_t * pbtRx, size_t * pszRx);
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43 changes: 27 additions & 16 deletions libnfc/chips/pn53x.c
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Expand Up @@ -1085,22 +1085,30 @@ pn53x_initiator_transceive_bytes (nfc_device_t * pnd, const byte_t * pbtTx, cons
return true;
}

// For _timer() functions, the prescaler will dictate what will
// be the precision and the largest delay to measure before saturation
// prescaler = 0 => precision: ~73ns timer saturates at ~5ms
// prescaler = 1 => precision: ~221ns timer saturates at ~15ms
// prescaler = 2 => precision: ~369ns timer saturates at ~25ms
// prescaler = 10 => precision: ~1.5us timer saturates at ~100ms
static uint16_t __timer_prescaler = 0;

void __pn53x_init_timer(nfc_device_t * pnd)
{
uint16_t prescaler = 0;
uint16_t reloadval = 0xFFFF;
// Initialize timer
pn53x_write_register (pnd, PN53X_REG_CIU_TMode, 0xFF, SYMBOL_TAUTO | ((prescaler >> 8) & SYMBOL_TPRESCALERHI));
pn53x_write_register (pnd, PN53X_REG_CIU_TPrescaler, 0xFF, (prescaler & SYMBOL_TPRESCALERLO));
pn53x_write_register (pnd, PN53X_REG_CIU_TMode, 0xFF, SYMBOL_TAUTO | ((__timer_prescaler >> 8) & SYMBOL_TPRESCALERHI));
pn53x_write_register (pnd, PN53X_REG_CIU_TPrescaler, 0xFF, (__timer_prescaler & SYMBOL_TPRESCALERLO));
pn53x_write_register (pnd, PN53X_REG_CIU_TReloadVal_hi, 0xFF, (reloadval >> 8) & 0xFF);
pn53x_write_register (pnd, PN53X_REG_CIU_TReloadVal_lo, 0xFF, reloadval & 0xFF);
}

uint16_t __pn53x_get_timer(nfc_device_t * pnd, const uint8_t last_cmd_byte)
uint32_t __pn53x_get_timer(nfc_device_t * pnd, const uint8_t last_cmd_byte)
{
uint8_t parity;
uint8_t counter_hi, counter_lo;
uint16_t counter, cycles;
uint16_t counter, u16cycles;
uint32_t u32cycles;
size_t off = 0;
if (CHIP_DATA(pnd)->type == PN533) {
// PN533 prepends its answer by a status byte
Expand All @@ -1125,15 +1133,18 @@ uint16_t __pn53x_get_timer(nfc_device_t * pnd, const uint8_t last_cmd_byte)
counter = (counter << 8) + counter_lo;
if (counter == 0) {
// counter saturated
cycles = 0xFFFF;
u32cycles = 0xFFFFFFFF;
} else {
cycles = 0xFFFF - counter + 1;
u16cycles = 0xFFFF - counter;
u32cycles = u16cycles;
u32cycles *= (__timer_prescaler * 2 + 1);
u32cycles++;
// Correction depending on PN53x Rx detection handling:
// timer stops after 5 (or 2 for PN531) bits are received
if(CHIP_DATA(pnd)->type == PN531) {
cycles -= (2 * 128);
u32cycles -= (2 * 128);
} else {
cycles -= (5 * 128);
u32cycles -= (5 * 128);
}
// Correction depending on last parity bit sent
parity = (last_cmd_byte >> 7) ^ ((last_cmd_byte >> 6) & 1) ^
Expand All @@ -1144,17 +1155,17 @@ uint16_t __pn53x_get_timer(nfc_device_t * pnd, const uint8_t last_cmd_byte)
// When sent ...YY (cmd ends with logical 1, so when last parity bit is 1):
if (parity) {
// it finishes 64us sooner than a ...ZY signal
cycles += 64;
u32cycles += 64;
}
// Correction depending on device design
cycles += CHIP_DATA(pnd)->timer_correction;
u32cycles += CHIP_DATA(pnd)->timer_correction;
}
return cycles;
return u32cycles;
}

bool
pn53x_initiator_transceive_bits_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits,
const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint16_t * cycles)
const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint32_t * cycles)
{
// TODO Do something with these bytes...
(void) pbtTxPar;
Expand Down Expand Up @@ -1214,7 +1225,7 @@ pn53x_initiator_transceive_bits_timed (nfc_device_t * pnd, const byte_t * pbtTx,
// our PN53x timer saturates after 4.8ms so this function shouldn't be used for
// responses coming very late anyway.
// Ideally we should implement a real timer here too but looping a few times is good enough.
for (i=0; i<4; i++) {
for (i=0; i<(3 *(__timer_prescaler * 2 + 1)); i++) {
pn53x_read_register (pnd, PN53X_REG_CIU_FIFOLevel, &sz);
if (sz > 0)
break;
Expand Down Expand Up @@ -1257,7 +1268,7 @@ pn53x_initiator_transceive_bits_timed (nfc_device_t * pnd, const byte_t * pbtTx,

bool
pn53x_initiator_transceive_bytes_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx,
size_t * pszRx, uint16_t * cycles)
size_t * pszRx, uint32_t * cycles)
{
unsigned int i;
uint8_t sz;
Expand Down Expand Up @@ -1309,7 +1320,7 @@ pn53x_initiator_transceive_bytes_timed (nfc_device_t * pnd, const byte_t * pbtTx
// our PN53x timer saturates after 4.8ms so this function shouldn't be used for
// responses coming very late anyway.
// Ideally we should implement a real timer here too but looping a few times is good enough.
for (i=0; i<4; i++) {
for (i=0; i<(3 *(__timer_prescaler * 2 + 1)); i++) {
pn53x_read_register (pnd, PN53X_REG_CIU_FIFOLevel, &sz);
if (sz > 0)
break;
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4 changes: 2 additions & 2 deletions libnfc/chips/pn53x.h
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Original file line number Diff line number Diff line change
Expand Up @@ -288,9 +288,9 @@ bool pn53x_initiator_transceive_bytes (nfc_device_t * pnd, const byte_t * pbt
byte_t * pbtRx, size_t * pszRx);
bool pn53x_initiator_transceive_bits_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits,
const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits,
byte_t * pbtRxPar, uint16_t * cycles);
byte_t * pbtRxPar, uint32_t * cycles);
bool pn53x_initiator_transceive_bytes_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx,
byte_t * pbtRx, size_t * pszRx, uint16_t * cycles);
byte_t * pbtRx, size_t * pszRx, uint32_t * cycles);
bool pn53x_initiator_deselect_target (nfc_device_t * pnd);

// NFC device as Target functions
Expand Down
4 changes: 2 additions & 2 deletions libnfc/nfc-internal.h
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Original file line number Diff line number Diff line change
Expand Up @@ -195,8 +195,8 @@ struct nfc_driver_t {
bool (*initiator_deselect_target) (nfc_device_t * pnd);
bool (*initiator_transceive_bytes) (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx, size_t * pszRx);
bool (*initiator_transceive_bits) (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits, const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar);
bool (*initiator_transceive_bytes_timed) (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx, size_t * pszRx, uint16_t * cycles);
bool (*initiator_transceive_bits_timed) (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits, const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint16_t * cycles);
bool (*initiator_transceive_bytes_timed) (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx, size_t * pszRx, uint32_t * cycles);
bool (*initiator_transceive_bits_timed) (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits, const byte_t * pbtTxPar, byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint32_t * cycles);

bool (*target_init) (nfc_device_t * pnd, nfc_target_t * pnt, byte_t * pbtRx, size_t * pszRx);
bool (*target_send_bytes) (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx);
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4 changes: 2 additions & 2 deletions libnfc/nfc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -565,7 +565,7 @@ nfc_initiator_transceive_bits (nfc_device_t * pnd, const byte_t * pbtTx, const s
*/
bool
nfc_initiator_transceive_bytes_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTx, byte_t * pbtRx,
size_t * pszRx, uint16_t * cycles)
size_t * pszRx, uint32_t * cycles)
{
HAL (initiator_transceive_bytes_timed, pnd, pbtTx, szTx, pbtRx, pszRx, cycles)
}
Expand All @@ -585,7 +585,7 @@ nfc_initiator_transceive_bytes_timed (nfc_device_t * pnd, const byte_t * pbtTx,
*/
bool
nfc_initiator_transceive_bits_timed (nfc_device_t * pnd, const byte_t * pbtTx, const size_t szTxBits, const byte_t * pbtTxPar,
byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint16_t * cycles)
byte_t * pbtRx, size_t * pszRxBits, byte_t * pbtRxPar, uint32_t * cycles)
{
HAL (initiator_transceive_bits_timed, pnd, pbtTx, szTxBits, pbtTxPar, pbtRx, pszRxBits, pbtRxPar, cycles);
}
Expand Down

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