/*-
* Free/Libre Near Field Communication (NFC) library
*
* Libnfc historical contributors:
* Copyright (C) 2009 Roel Verdult
* Copyright (C) 2009-2013 Romuald Conty
* Copyright (C) 2010-2012 Romain Tarti?re
* Copyright (C) 2010-2013 Philippe Teuwen
* Copyright (C) 2012-2013 Ludovic Rousseau
* See AUTHORS file for a more comprehensive list of contributors.
* Additional contributors of this file:
* Copyright (C) 2013 Laurent Latil
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation, either version 3 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 Lesser General Public License
* along with this program. If not, see
*/
/**
* @file pn532_i2c.c
* @brief PN532 driver using I2C bus.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif // HAVE_CONFIG_H
#include "pn532_i2c.h"
#include
#include
#include
#include
#include
#include
#include
#include "drivers.h"
#include "nfc-internal.h"
#include "chips/pn53x.h"
#include "chips/pn53x-internal.h"
#include "buses/i2c.h"
#define PN532_I2C_DRIVER_NAME "pn532_i2c"
#define LOG_CATEGORY "libnfc.driver.pn532_i2c"
#define LOG_GROUP NFC_LOG_GROUP_DRIVER
// I2C address of the PN532 chip.
#define PN532_I2C_ADDR 0x24
/*
* When sending lots of data, the pn532 occasionally fails to respond in time.
* Since it happens so rarely, lets try to fix it by re-sending the data. This
* define allows for fine tuning the number of retries.
*/
#define PN532_SEND_RETRIES 3
// Internal data structs
const struct pn53x_io pn532_i2c_io;
struct pn532_i2c_data {
i2c_device dev;
volatile bool abort_flag;
};
/* preamble and start bytes, see pn532-internal.h for details */
const uint8_t pn53x_preamble_and_start[] = { 0x00, 0x00, 0xff };
#define PN53X_PREAMBLE_AND_START_LEN (sizeof(pn53x_preamble_and_start) / sizeof(pn53x_preamble_and_start[0]))
/* Private Functions Prototypes */
static nfc_device *pn532_i2c_open(const nfc_context *context, const nfc_connstring connstring);
static void pn532_i2c_close(nfc_device *pnd);
static int pn532_i2c_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, int timeout);
static int pn532_i2c_ack(nfc_device *pnd);
static int pn532_i2c_abort_command(nfc_device *pnd);
static int pn532_i2c_wakeup(nfc_device *pnd);
static int pn532_i2c_wait_rdyframe(nfc_device *pnd, uint8_t *pbtData, const size_t szDataLen, int timeout);
static size_t pn532_i2c_scan(const nfc_context *context, nfc_connstring connstrings[], const size_t connstrings_len);
#define DRIVER_DATA(pnd) ((struct pn532_i2c_data*)(pnd->driver_data))
/*
* Bus free time (in ms) between a STOP condition and START condition. See
* tBuf in the PN532 data sheet, section 12.25: Timing for the I2C interface,
* table 320. I2C timing specification, page 211, rev. 3.2 - 2007-12-07.
*/
#define PN532_BUS_FREE_TIME 5
static struct timespec __transaction_stop;
/**
* @brief Wrapper around i2c_read to ensure proper timing by respecting the
* minimal free bus time between a STOP condition and a START condition.
*
* @note This is not thread safe, but since libnfc is single threaded
* this should be okay.
*
* @param id I2C device
* @param buf pointer on buffer used to store data
* @param len length of the buffer
* @return length (in bytes) of read data, or driver error code (negative value)
*/
static ssize_t pn532_i2c_read(const i2c_device id,
uint8_t *buf, const size_t len)
{
struct timespec transaction_start, bus_free_time = { 0, 0 };
ssize_t ret;
clock_gettime(CLOCK_MONOTONIC, &transaction_start);
bus_free_time.tv_nsec = (PN532_BUS_FREE_TIME * 1000 * 1000) -
(transaction_start.tv_nsec - __transaction_stop.tv_nsec);
nanosleep(&bus_free_time, NULL);
ret = i2c_read(id, buf, len);
clock_gettime(CLOCK_MONOTONIC, &__transaction_stop);
return ret;
}
/**
* @brief Wrapper around i2c_write to ensure proper timing by respecting the
* minimal free bus time between a STOP condition and a START condition.
*
* @note This is not thread safe, but since libnfc is single threaded
* this should be okay.
*
* @param id I2C device
* @param buf pointer on buffer containing data
* @param len length of the buffer
* @return NFC_SUCCESS on success, otherwise driver error code
*/
static ssize_t pn532_i2c_write(const i2c_device id,
const uint8_t *buf, const size_t len)
{
struct timespec transaction_start, bus_free_time = { 0, 0 };
ssize_t ret;
clock_gettime(CLOCK_MONOTONIC, &transaction_start);
bus_free_time.tv_nsec = (PN532_BUS_FREE_TIME * 1000 * 1000) -
(transaction_start.tv_nsec - __transaction_stop.tv_nsec);
nanosleep(&bus_free_time, NULL);
ret = i2c_write(id, buf, len);
clock_gettime(CLOCK_MONOTONIC, &__transaction_stop);
return ret;
}
/**
* @brief Scan all available I2C buses to find PN532 devices.
*
* @param context NFC context.
* @param connstrings array of 'nfc_connstring' buffer (allocated by caller). It is used to store the
* connection info strings of all I2C PN532 devices found.
* @param connstrings_len length of the connstrings array.
* @return number of PN532 devices found on all I2C buses.
*/
static size_t
pn532_i2c_scan(const nfc_context *context, nfc_connstring connstrings[], const size_t connstrings_len)
{
size_t device_found = 0;
i2c_device id;
char **i2cPorts = i2c_list_ports();
const char *i2cPort;
int iDevice = 0;
while ((i2cPort = i2cPorts[iDevice++])) {
id = i2c_open(i2cPort, PN532_I2C_ADDR);
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_DEBUG, "Trying to find PN532 device on I2C bus %s.", i2cPort);
if ((id != INVALID_I2C_ADDRESS) && (id != INVALID_I2C_BUS)) {
nfc_connstring connstring;
snprintf(connstring, sizeof(nfc_connstring), "%s:%s", PN532_I2C_DRIVER_NAME, i2cPort);
nfc_device *pnd = nfc_device_new(context, connstring);
if (!pnd) {
perror("malloc");
i2c_close(id);
iDevice = 0;
while ((i2cPort = i2cPorts[iDevice++])) {
free((void *)i2cPort);
}
free(i2cPorts);
return 0;
}
pnd->driver = &pn532_i2c_driver;
pnd->driver_data = malloc(sizeof(struct pn532_i2c_data));
if (!pnd->driver_data) {
perror("malloc");
i2c_close(id);
nfc_device_free(pnd);
iDevice = 0;
while ((i2cPort = i2cPorts[iDevice++])) {
free((void *)i2cPort);
}
free(i2cPorts);
return 0;
}
DRIVER_DATA(pnd)->dev = id;
// Alloc and init chip's data
if (pn53x_data_new(pnd, &pn532_i2c_io) == NULL) {
perror("malloc");
i2c_close(DRIVER_DATA(pnd)->dev);
nfc_device_free(pnd);
iDevice = 0;
while ((i2cPort = i2cPorts[iDevice++])) {
free((void *)i2cPort);
}
free(i2cPorts);
return 0;
}
// SAMConfiguration command if needed to wakeup the chip and pn53x_SAMConfiguration check if the chip is a PN532
CHIP_DATA(pnd)->type = PN532;
// This device starts in LowVBat power mode
CHIP_DATA(pnd)->power_mode = LOWVBAT;
DRIVER_DATA(pnd)->abort_flag = false;
// Check communication using "Diagnose" command, with "Communication test" (0x00)
int res = pn53x_check_communication(pnd);
i2c_close(DRIVER_DATA(pnd)->dev);
pn53x_data_free(pnd);
nfc_device_free(pnd);
if (res < 0) {
continue;
}
memcpy(connstrings[device_found], connstring, sizeof(nfc_connstring));
device_found++;
// Test if we reach the maximum "wanted" devices
if (device_found >= connstrings_len)
break;
}
}
iDevice = 0;
while ((i2cPort = i2cPorts[iDevice++])) {
free((void *)i2cPort);
}
free(i2cPorts);
return device_found;
}
/**
* @brief Close I2C connection to the PN532 device.
*
* @param pnd pointer on the device to close.
*/
static void
pn532_i2c_close(nfc_device *pnd)
{
pn53x_idle(pnd);
i2c_close(DRIVER_DATA(pnd)->dev);
pn53x_data_free(pnd);
nfc_device_free(pnd);
}
/**
* @brief Open an I2C connection to the PN532 device.
*
* @param context NFC context.
* @param connstring connection info to the device ( pn532_i2c: ).
* @return pointer to the device, or NULL in case of error.
*/
static nfc_device *
pn532_i2c_open(const nfc_context *context, const nfc_connstring connstring)
{
char *i2c_devname;
i2c_device i2c_dev;
nfc_device *pnd;
int connstring_decode_level = connstring_decode(connstring, PN532_I2C_DRIVER_NAME, NULL, &i2c_devname, NULL);
switch (connstring_decode_level) {
case 2:
break;
case 1:
break;
case 0:
return NULL;
}
i2c_dev = i2c_open(i2c_devname, PN532_I2C_ADDR);
if (i2c_dev == INVALID_I2C_BUS || i2c_dev == INVALID_I2C_ADDRESS) {
return NULL;
}
pnd = nfc_device_new(context, connstring);
if (!pnd) {
perror("malloc");
i2c_close(i2c_dev);
return NULL;
}
snprintf(pnd->name, sizeof(pnd->name), "%s:%s", PN532_I2C_DRIVER_NAME, i2c_devname);
pnd->driver_data = malloc(sizeof(struct pn532_i2c_data));
if (!pnd->driver_data) {
perror("malloc");
i2c_close(i2c_dev);
nfc_device_free(pnd);
return NULL;
}
DRIVER_DATA(pnd)->dev = i2c_dev;
// Alloc and init chip's data
if (pn53x_data_new(pnd, &pn532_i2c_io) == NULL) {
perror("malloc");
i2c_close(i2c_dev);
nfc_device_free(pnd);
return NULL;
}
// SAMConfiguration command if needed to wakeup the chip and pn53x_SAMConfiguration check if the chip is a PN532
CHIP_DATA(pnd)->type = PN532;
// This device starts in LowVBat mode
CHIP_DATA(pnd)->power_mode = LOWVBAT;
// empirical tuning
CHIP_DATA(pnd)->timer_correction = 48;
pnd->driver = &pn532_i2c_driver;
DRIVER_DATA(pnd)->abort_flag = false;
// Check communication using "Diagnose" command, with "Communication test" (0x00)
if (pn53x_check_communication(pnd) < 0) {
nfc_perror(pnd, "pn53x_check_communication");
pn532_i2c_close(pnd);
return NULL;
}
pn53x_init(pnd);
return pnd;
}
static int
pn532_i2c_wakeup(nfc_device *pnd)
{
/* No specific. PN532 holds SCL during wakeup time */
CHIP_DATA(pnd)->power_mode = NORMAL; // PN532 should now be awake
return NFC_SUCCESS;
}
#define PN532_BUFFER_LEN (PN53x_EXTENDED_FRAME__DATA_MAX_LEN + PN53x_EXTENDED_FRAME__OVERHEAD)
/**
* @brief Send data to the PN532 device.
*
* @param pnd pointer on the NFC device.
* @param pbtData buffer containing frame data.
* @param szData size of the buffer.
* @param timeout timeout before aborting the operation (in ms).
* @return NFC_SUCCESS if operation is successful, or error code.
*/
static int
pn532_i2c_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, int timeout)
{
int res = 0;
uint8_t retries;
// Discard any existing data ?
switch (CHIP_DATA(pnd)->power_mode) {
case LOWVBAT: {
/** PN532C106 wakeup. */
if ((res = pn532_i2c_wakeup(pnd)) < 0) {
return res;
}
// According to PN532 application note, C106 appendix: to go out Low Vbat mode and enter in normal mode we need to send a SAMConfiguration command
if ((res = pn532_SAMConfiguration(pnd, PSM_NORMAL, 1000)) < 0) {
return res;
}
}
break;
case POWERDOWN: {
if ((res = pn532_i2c_wakeup(pnd)) < 0) {
return res;
}
}
break;
case NORMAL:
// Nothing to do :)
break;
};
uint8_t abtFrame[PN532_BUFFER_LEN];
size_t szFrame = 0;
memcpy(abtFrame, pn53x_preamble_and_start, PN53X_PREAMBLE_AND_START_LEN); // Every packet must start with the preamble and start bytes.
if ((res = pn53x_build_frame(abtFrame, &szFrame, pbtData, szData)) < 0) {
pnd->last_error = res;
return pnd->last_error;
}
for (retries = PN532_SEND_RETRIES; retries > 0; retries--) {
res = pn532_i2c_write(DRIVER_DATA(pnd)->dev, abtFrame, szFrame);
if (res >= 0)
break;
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Failed to transmit data. Retries left: %d.", retries - 1);
}
if (res < 0) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "%s", "Unable to transmit data. (TX)");
pnd->last_error = res;
return pnd->last_error;
}
uint8_t abtRxBuf[PN53x_ACK_FRAME__LEN];
// Wait for the ACK frame
res = pn532_i2c_wait_rdyframe(pnd, abtRxBuf, sizeof(abtRxBuf), timeout);
if (res < 0) {
if (res == NFC_EOPABORTED) {
// Send an ACK frame from host to abort the command.
pn532_i2c_ack(pnd);
}
pnd->last_error = res;
return pnd->last_error;
}
if (pn53x_check_ack_frame(pnd, abtRxBuf, res) == 0) {
// The PN53x is running the sent command
} else {
return pnd->last_error;
}
return NFC_SUCCESS;
}
/**
* @brief Read data from the PN532 device until getting a frame with RDY bit set
*
* @param pnd pointer on the NFC device.
* @param pbtData buffer used to store the received frame data.
* @param szDataLen allocated size of buffer.
* @param timeout timeout delay before aborting the operation (in ms). Use 0 for no timeout.
* @return length (in bytes) of the received frame, or NFC_ETIMEOUT if timeout delay has expired,
* NFC_EOPABORTED if operation has been aborted, NFC_EIO in case of IO failure
*/
static int
pn532_i2c_wait_rdyframe(nfc_device *pnd, uint8_t *pbtData, const size_t szDataLen, int timeout)
{
bool done = false;
int res;
struct timeval start_tv, cur_tv;
long long duration;
// Actual I2C response frame includes an additional status byte,
// so we use a temporary buffer to read the I2C frame
uint8_t i2cRx[PN53x_EXTENDED_FRAME__DATA_MAX_LEN + 1];
if (timeout > 0) {
// If a timeout is specified, get current timestamp
gettimeofday(&start_tv, NULL);
}
do {
int recCount = pn532_i2c_read(DRIVER_DATA(pnd)->dev, i2cRx, szDataLen + 1);
if (DRIVER_DATA(pnd)->abort_flag) {
// Reset abort flag
DRIVER_DATA(pnd)->abort_flag = false;
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_DEBUG,
"Wait for a READY frame has been aborted.");
return NFC_EOPABORTED;
}
if (recCount <= 0) {
done = true;
res = NFC_EIO;
} else {
const uint8_t rdy = i2cRx[0];
if (rdy & 1) {
int copyLength;
done = true;
res = recCount - 1;
copyLength = MIN(res, (int)szDataLen);
memcpy(pbtData, &(i2cRx[1]), copyLength);
} else {
/* Not ready yet. Check for elapsed timeout. */
if (timeout > 0) {
gettimeofday(&cur_tv, NULL);
duration = (cur_tv.tv_sec - start_tv.tv_sec) * 1000000L
+ (cur_tv.tv_usec - start_tv.tv_usec);
if (duration / 1000 > timeout) {
res = NFC_ETIMEOUT;
done = true;
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_DEBUG,
"timeout reached with no READY frame.");
}
}
}
}
} while (!done);
return res;
}
/**
* @brief Read a response frame from the PN532 device.
*
* @param pnd pointer on the NFC device.
* @param pbtData buffer used to store the response frame data.
* @param szDataLen allocated size of buffer.
* @param timeout timeout delay before aborting the operation (in ms). Use 0 for no timeout.
* @return length (in bytes) of the response, or NFC_ETIMEOUT if timeout delay has expired,
* NFC_EOPABORTED if operation has been aborted, NFC_EIO in case of IO failure
*/
static int
pn532_i2c_receive(nfc_device *pnd, uint8_t *pbtData, const size_t szDataLen, int timeout)
{
uint8_t frameBuf[PN53x_EXTENDED_FRAME__DATA_MAX_LEN];
int frameLength;
int TFI_idx;
size_t len;
frameLength = pn532_i2c_wait_rdyframe(pnd, frameBuf, sizeof(frameBuf), timeout);
if (NFC_EOPABORTED == pnd->last_error) {
return pn532_i2c_ack(pnd);
}
if (frameLength < 0) {
goto error;
}
if (0 != (memcmp(frameBuf, pn53x_preamble_and_start, PN53X_PREAMBLE_AND_START_LEN))) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "%s", "Frame preamble+start code mismatch");
pnd->last_error = NFC_EIO;
goto error;
}
if ((0x01 == frameBuf[3]) && (0xff == frameBuf[4])) {
uint8_t errorCode = frameBuf[5];
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Application level error detected (%d)", errorCode);
pnd->last_error = NFC_EIO;
goto error;
} else if ((0xff == frameBuf[3]) && (0xff == frameBuf[4])) {
// Extended frame
len = (frameBuf[5] << 8) + frameBuf[6];
// Verify length checksum
if (((frameBuf[5] + frameBuf[6] + frameBuf[7]) % 256) != 0) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Length checksum mismatch");
pnd->last_error = NFC_EIO;
goto error;
}
TFI_idx = 8;
} else {
// Normal frame
len = frameBuf[3];
// Verify length checksum
if ((uint8_t)(frameBuf[3] + frameBuf[4])) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "%s", "Length checksum mismatch");
pnd->last_error = NFC_EIO;
goto error;
}
TFI_idx = 5;
}
if ((len - 2) > szDataLen) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to receive data: buffer too small. (szDataLen: %" PRIuPTR ", len: %" PRIuPTR ")", szDataLen, len);
pnd->last_error = NFC_EIO;
goto error;
}
uint8_t TFI = frameBuf[TFI_idx];
if (TFI != 0xD5) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "%s", "TFI Mismatch");
pnd->last_error = NFC_EIO;
goto error;
}
if (frameBuf[TFI_idx + 1] != CHIP_DATA(pnd)->last_command + 1) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Command Code verification failed. (got %d, expected %d)",
frameBuf[TFI_idx + 1], CHIP_DATA(pnd)->last_command + 1);
pnd->last_error = NFC_EIO;
goto error;
}
uint8_t DCS = frameBuf[TFI_idx + len];
uint8_t btDCS = DCS;
// Compute data checksum
for (size_t i = 0; i < len; i++) {
btDCS += frameBuf[TFI_idx + i];
}
if (btDCS != 0) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Data checksum mismatch (DCS = %02x, btDCS = %d)", DCS, btDCS);
pnd->last_error = NFC_EIO;
goto error;
}
if (0x00 != frameBuf[TFI_idx + len + 1]) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Frame postamble mismatch (got %d)", frameBuf[frameLength - 1]);
pnd->last_error = NFC_EIO;
goto error;
}
memcpy(pbtData, &frameBuf[TFI_idx + 2], len - 2);
/* The PN53x command is done and we successfully received the reply */
return len - 2;
error:
return pnd->last_error;
}
/**
* @brief Send an ACK frame to the PN532 device.
*
* @param pnd pointer on the NFC device.
* @return NFC_SUCCESS on success, otherwise an error code
*/
int
pn532_i2c_ack(nfc_device *pnd)
{
return pn532_i2c_write(DRIVER_DATA(pnd)->dev, pn53x_ack_frame, sizeof(pn53x_ack_frame));
}
/**
* @brief Abort any pending operation
*
* @param pnd pointer on the NFC device.
* @return NFC_SUCCESS
*/
static int
pn532_i2c_abort_command(nfc_device *pnd)
{
if (pnd) {
DRIVER_DATA(pnd)->abort_flag = true;
}
return NFC_SUCCESS;
}
const struct pn53x_io pn532_i2c_io = {
.send = pn532_i2c_send,
.receive = pn532_i2c_receive,
};
const struct nfc_driver pn532_i2c_driver = {
.name = PN532_I2C_DRIVER_NAME,
.scan_type = INTRUSIVE,
.scan = pn532_i2c_scan,
.open = pn532_i2c_open,
.close = pn532_i2c_close,
.strerror = pn53x_strerror,
.initiator_init = pn53x_initiator_init,
.initiator_init_secure_element = pn532_initiator_init_secure_element,
.initiator_select_passive_target = pn53x_initiator_select_passive_target,
.initiator_poll_target = pn53x_initiator_poll_target,
.initiator_select_dep_target = pn53x_initiator_select_dep_target,
.initiator_deselect_target = pn53x_initiator_deselect_target,
.initiator_transceive_bytes = pn53x_initiator_transceive_bytes,
.initiator_transceive_bits = pn53x_initiator_transceive_bits,
.initiator_transceive_bytes_timed = pn53x_initiator_transceive_bytes_timed,
.initiator_transceive_bits_timed = pn53x_initiator_transceive_bits_timed,
.initiator_target_is_present = pn53x_initiator_target_is_present,
.target_init = pn53x_target_init,
.target_send_bytes = pn53x_target_send_bytes,
.target_receive_bytes = pn53x_target_receive_bytes,
.target_send_bits = pn53x_target_send_bits,
.target_receive_bits = pn53x_target_receive_bits,
.device_set_property_bool = pn53x_set_property_bool,
.device_set_property_int = pn53x_set_property_int,
.get_supported_modulation = pn53x_get_supported_modulation,
.get_supported_baud_rate = pn53x_get_supported_baud_rate,
.device_get_information_about = pn53x_get_information_about,
.abort_command = pn532_i2c_abort_command,
.idle = pn53x_idle,
.powerdown = pn53x_PowerDown,
};