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nuttx/drivers/contactless/mfrc522.c
Gregory Nutt dc8c814ca3 Squashed commit of the following: 
Fixed coding standard error in several files.  Use of while( is incorrect; a space is required between while and (.  Also ran tools/nxstyle and fix thoses complaints as well in most files.

    Changes to comply with coding standard.  Mostly focused on files with missing space after keyword in if(, switch(, and for(.  Offending files also got changes to comply with tools nxstyle.  If there were logs of nxstyle complaints, the file also got a taste of tools/indent.sh.  Still need to fix occurrences of while( with missing space.  There are a lot of them.
2019-02-27 08:41:08 -06:00

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/****************************************************************************
* drivers/contactless/mfrc522.c
*
* Copyright(C) 2016 Uniquix Ltda. All rights reserved.
* Author: Alan Carvalho de Assis <acassis@gmail.com>
*
* This driver is based on Arduino library for MFRC522 from Miguel
* Balboa released into the public domain:
* https://github.com/miguelbalboa/rfid/
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES(INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <assert.h>
#include <nuttx/kmalloc.h>
#include <nuttx/signal.h>
#include <nuttx/contactless/mfrc522.h>
#include "mfrc522.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifdef CONFIG_CL_MFRC522_DEBUG
# define mfrc522err _err
# define mfrc522info _info
#else
# ifdef CONFIG_CPP_HAVE_VARARGS
# define mfrc522err(x...)
# define mfrc522info(x...)
# else
# define mfrc522err (void)
# define mfrc522info (void)
# endif
#endif
#ifdef CONFIG_CL_MFRC522_DEBUG_TX
# define tracetx errdumpbuffer
#else
# define tracetx(x...)
#endif
#ifdef CONFIG_CL_MFRC522_DEBUG_RX
# define tracerx errdumpbuffer
#else
# define tracerx(x...)
#endif
#define FRAME_SIZE(f) (sizeof(struct mfrc522_frame) + f->len + 2)
#define FRAME_POSTAMBLE(f) (f->data[f->len + 1])
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static inline void mfrc522_configspi(FAR struct spi_dev_s *spi);
static void mfrc522_lock(FAR struct spi_dev_s *spi);
static void mfrc522_unlock(FAR struct spi_dev_s *spi);
/* Character driver methods */
static int mfrc522_open(FAR struct file *filep);
static int mfrc522_close(FAR struct file *filep);
static ssize_t mfrc522_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t mfrc522_write(FAR struct file *filep,
FAR const char *buffer, size_t buflen);
static int mfrc522_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
uint8_t mfrc522_readu8(FAR struct mfrc522_dev_s *dev, uint8_t regaddr);
void mfrc522_writeu8(FAR struct mfrc522_dev_s *dev, uint8_t regaddr,
FAR uint8_t regval);
void mfrc522_writeblk(FAR struct mfrc522_dev_s *dev, uint8_t regaddr,
uint8_t *regval, int length);
void mfrc522_readblk(FAR struct mfrc522_dev_s *dev, uint8_t regaddr,
FAR uint8_t *regval, int length, uint8_t rxalign);
void mfrc522_softreset(FAR struct mfrc522_dev_s *dev);
int mfrc522_picc_select(FAR struct mfrc522_dev_s *dev,
FAR struct picc_uid_s *uid, uint8_t validbits);
#if 0 /* TODO */
/* IRQ Handling */
static int mfrc522_irqhandler(FAR int irq, FAR void *context, FAR void *dev);
static inline int mfrc522_attachirq(FAR struct mfrc522_dev_s *dev,
xcpt_t isr);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_mfrc522fops =
{
mfrc522_open,
mfrc522_close,
mfrc522_read,
mfrc522_write,
0,
mfrc522_ioctl
#ifndef CONFIG_DISABLE_POLL
, 0
#endif
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, 0
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
static void mfrc522_lock(FAR struct spi_dev_s *spi)
{
(void)SPI_LOCK(spi, true);
SPI_SETMODE(spi, SPIDEV_MODE0);
SPI_SETBITS(spi, 8);
(void)SPI_HWFEATURES(spi, 0);
(void)SPI_SETFREQUENCY(spi, CONFIG_MFRC522_SPI_FREQ);
}
static void mfrc522_unlock(FAR struct spi_dev_s *spi)
{
(void)SPI_LOCK(spi, false);
}
static inline void mfrc522_configspi(FAR struct spi_dev_s *spi)
{
/* Configure SPI for the MFRC522 module. */
SPI_SETMODE(spi, SPIDEV_MODE0);
SPI_SETBITS(spi, 8);
(void)SPI_HWFEATURES(spi, 0);
(void)SPI_SETFREQUENCY(spi, CONFIG_MFRC522_SPI_FREQ);
}
static inline void mfrc522_select(struct mfrc522_dev_s *dev)
{
SPI_SELECT(dev->spi, SPIDEV_CONTACTLESS(0), true);
}
static inline void mfrc522_deselect(struct mfrc522_dev_s *dev)
{
SPI_SELECT(dev->spi, SPIDEV_CONTACTLESS(0), false);
}
/****************************************************************************
* Name: mfrc522_readu8
*
* Description:
* Read a byte from a register address.
*
* Input Parameters:
*
* Returned Value: the read byte from the register
*
****************************************************************************/
uint8_t mfrc522_readu8(FAR struct mfrc522_dev_s *dev, uint8_t regaddr)
{
uint8_t regval;
uint8_t address = (0x80 | (regaddr & 0x7E));
mfrc522_lock(dev->spi);
mfrc522_select(dev);
SPI_SEND(dev->spi, address);
regval = SPI_SEND(dev->spi, 0);
mfrc522_deselect(dev);
mfrc522_unlock(dev->spi);
tracerx("read", regval, 1);
return regval;
}
/****************************************************************************
* Name: mfrc522_write8
*
* Description:
* Write a byte to a register address.
*
* Input Parameters:
*
* Returned Value:
*
****************************************************************************/
void mfrc522_writeu8(FAR struct mfrc522_dev_s *dev, uint8_t regaddr,
FAR uint8_t regval)
{
mfrc522_lock(dev->spi);
mfrc522_select(dev);
SPI_SEND(dev->spi, regaddr & 0x7E);
SPI_SEND(dev->spi, regval);
mfrc522_deselect(dev);
mfrc522_unlock(dev->spi);
tracerx("write", &regval, 1);
}
/****************************************************************************
* Name: mfrc522_readblk
*
* Description:
* Read a block of bytes from a register address. Align the bit positions of
* regval[0] from rxalign..7.
*
* Input Parameters:
*
* Returned Value: none
*
****************************************************************************/
void mfrc522_readblk(FAR struct mfrc522_dev_s *dev, uint8_t regaddr,
FAR uint8_t *regval, int length, uint8_t rxalign)
{
uint8_t i = 0;
uint8_t address = (0x80 | (regaddr & 0x7E));
mfrc522_lock(dev->spi);
mfrc522_select(dev);
/* Inform the MFRC522 the address we want to read */
SPI_SEND(dev->spi, address);
while (i < length)
{
if (i == 0 && rxalign)
{
uint8_t mask = 0;
uint8_t value;
uint8_t j;
for (j = rxalign; j <= 7; j++)
{
mask |= (1 << j);
}
/* Read the first byte */
value = SPI_SEND(dev->spi, address);
/* Apply mask to current regval[0] with the read value */
regval[0] = (regval[0] & ~mask) | (value & mask);
}
else
{
/* Read the remaining bytes */
regval[i] = SPI_SEND(dev->spi, address);
}
i++;
}
/* Read the last byte. Send 0 to stop reading (it maybe wrong, 1 byte out) */
regval[i] = SPI_SEND(dev->spi, 0);
mfrc522_deselect(dev);
mfrc522_unlock(dev->spi);
tracerx("readblk", regval, size);
}
/****************************************************************************
* Name: mfrc522_writeblk
*
* Description:
* Write a block of bytes to a register address.
*
* Input Parameters:
*
* Returned Value: none
*
****************************************************************************/
void mfrc522_writeblk(FAR struct mfrc522_dev_s *dev, uint8_t regaddr,
uint8_t *regval, int length)
{
uint8_t address = (regaddr & 0x7E);
mfrc522_lock(dev->spi);
mfrc522_select(dev);
/* Inform the MFRC522 the address we want write to */
SPI_SEND(dev->spi, address);
/* Send the block of bytes */
SPI_SNDBLOCK(dev->spi, regval, length);
mfrc522_deselect(dev);
mfrc522_unlock(dev->spi);
tracerx("writeblk", regval, size);
}
/****************************************************************************
* Name: mfrc522_calc_crc
*
* Description:
* Use the CRC coprocessor in the MFRC522 to calculate a CRC_A.
*
* Input Parameters:
*
* Returned Value: OK or -ETIMEDOUT
*
****************************************************************************/
int mfrc522_calc_crc(FAR struct mfrc522_dev_s *dev, uint8_t *buffer,
int length, uint8_t *result)
{
struct timespec tstart;
struct timespec tend;
/* Stop any command in execution */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_IDLE_CMD);
/* Clear the CRCIRq interrupt request bit */
mfrc522_writeu8(dev, MFRC522_DIV_IRQ_REG, MFRC522_CRC_IRQ);
/* Flush all bytes in the FIFO */
mfrc522_writeu8(dev, MFRC522_FIFO_LEVEL_REG, MFRC522_FLUSH_BUFFER);
/* Write data to the FIFO */
mfrc522_writeblk(dev, MFRC522_FIFO_DATA_REG, buffer, length);
/* Start the calculation */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_CALC_CRC_CMD);
/* Wait for CRC completion or 200ms time-out */
clock_gettime(CLOCK_REALTIME, &tstart);
tstart.tv_nsec += 200000;
if (tstart.tv_nsec >= 1000 * 1000 * 1000)
{
tstart.tv_sec++;
tstart.tv_nsec -= 1000 * 1000 * 1000;
}
while (1)
{
uint8_t irqreg;
irqreg = mfrc522_readu8(dev, MFRC522_DIV_IRQ_REG);
if (irqreg & MFRC522_CRC_IRQ)
{
break;
}
/* Get time now */
clock_gettime(CLOCK_REALTIME, &tend);
if ((tend.tv_sec > tstart.tv_sec) && (tend.tv_nsec > tstart.tv_nsec))
{
return -ETIMEDOUT;
}
}
/* Stop calculating CRC for new content of FIFO */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_IDLE_CMD);
result[0] = mfrc522_readu8(dev, MFRC522_CRC_RESULT_REGL);
result[1] = mfrc522_readu8(dev, MFRC522_CRC_RESULT_REGH);
return OK;
}
/****************************************************************************
* Name: mfrc522_comm_picc
*
* Description:
* Transfers data to the MFRC522 FIFO, executes a command, waits for
* completion and transfers data back from the FIFO.
* CRC validation can only be done if back_data and back_len are specified.
*
* Input Parameters:
*
* Returned Value: OK or -ETIMEDOUT
*
****************************************************************************/
int mfrc522_comm_picc(FAR struct mfrc522_dev_s *dev, uint8_t command,
uint8_t waitirq, uint8_t *send_data, uint8_t send_len,
uint8_t *back_data, uint8_t *back_len,
uint8_t *validbits, uint8_t rxalign, bool checkcrc)
{
int ret;
uint8_t errors;
uint8_t vbits;
uint8_t value;
struct timespec tstart;
struct timespec tend;
/* Prepare values for BitFramingReg */
uint8_t txlastbits = validbits ? *validbits : 0;
uint8_t bitframing = (rxalign << 4) + txlastbits;
/* Stop any active command */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_IDLE_CMD);
/* Clear all seven interrupt request bits */
value = mfrc522_readu8(dev, MFRC522_COM_IRQ_REG);
mfrc522_writeu8(dev, MFRC522_COM_IRQ_REG, value | MFRC522_COM_IRQ_MASK);
/* Flush all bytes in the FIFO */
mfrc522_writeu8(dev, MFRC522_FIFO_LEVEL_REG, MFRC522_FLUSH_BUFFER);
/* Write data to FIFO */
mfrc522_writeblk(dev, MFRC522_FIFO_DATA_REG, send_data, send_len);
/* Bit adjustments */
mfrc522_writeu8(dev, MFRC522_BIT_FRAMING_REG, bitframing);
/* Execute command */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, command);
/* We setup the TAuto flag in the mfrc522_init() then we could use the
* internal MFC522 Timer to detect timeout, but because there could be some
* hardware fault, let us to use a NuttX timeout as well.
*/
clock_gettime(CLOCK_REALTIME, &tstart);
tstart.tv_nsec += 200000;
if (tstart.tv_nsec >= 1000 * 1000 * 1000)
{
tstart.tv_sec++;
tstart.tv_nsec -= 1000 * 1000 * 1000;
}
/* If it is a Transceive command, then start transmittion */
if (command == MFRC522_TRANSCV_CMD)
{
value = mfrc522_readu8(dev, MFRC522_BIT_FRAMING_REG);
mfrc522_writeu8(dev, MFRC522_BIT_FRAMING_REG,
value | MFRC522_START_SEND);
}
/* Wait for the command to complete */
while (1)
{
uint8_t irqsreg;
irqsreg = mfrc522_readu8(dev, MFRC522_COM_IRQ_REG);
/* If at least an of selected IRQ happened */
if (irqsreg & waitirq)
{
break;
}
/* Timer expired */
if (irqsreg & MFRC522_TIMER_IRQ)
{
return -ETIMEDOUT;
}
/* Get time now */
clock_gettime(CLOCK_REALTIME, &tend);
if ((tend.tv_sec > tstart.tv_sec) && (tend.tv_nsec > tstart.tv_nsec))
{
return -ETIMEDOUT;
}
}
/* Read error register to verify if there are any issue */
errors = mfrc522_readu8(dev, MFRC522_ERROR_REG);
/* Check for Protocol error */
if (errors & (MFRC522_PROTO_ERR))
{
return -EPROTO;
}
/* Check for Parity and Buffer Overflow errors */
if (errors & (MFRC522_PARITY_ERR | MFRC522_BUF_OVFL_ERR))
{
return -EIO;
}
/* Check collision error */
if (errors & MFRC522_COLL_ERR)
{
return -EBUSY; /* should it be EAGAIN ? */
}
/* If the caller wants data back, get it from the MFRC522 */
if (back_data && back_len)
{
uint8_t nbytes;
/* Number of bytes in the FIFO */
nbytes = mfrc522_readu8(dev, MFRC522_FIFO_LEVEL_REG);
/* Returned more bytes than the expected */
if (nbytes > *back_len)
{
return -ENOMEM;
}
*back_len = nbytes;
/* Read the data from FIFO */
mfrc522_readblk(dev, MFRC522_FIFO_DATA_REG, back_data, nbytes, rxalign);
/* RxLastBits[2:0] indicates the number of valid bits received */
vbits = mfrc522_readu8(dev, MFRC522_CONTROL_REG)
& MFRC522_RX_LAST_BITS_MASK;
if (validbits)
{
*validbits = vbits;
}
}
/* Perform CRC_A validation if requested */
if (back_data && back_len && checkcrc)
{
uint8_t ctrlbuf[2];
/* In this case a MIFARE Classic NAK is not OK */
if (*back_len == 1 && vbits == 4)
{
return -EACCES;
}
/* We need the CRC_A value or all 8 bits of the last byte */
if (*back_len < 2 || vbits != 0)
{
return -EPERM;
}
/* Verify CRC_A */
ret = mfrc522_calc_crc(dev, &back_data[0], *back_len - 2, &ctrlbuf[0]);
if (ret != OK)
{
return ret;
}
if ((back_data[*back_len - 2] != ctrlbuf[0]) ||
(back_data[*back_len - 1] != ctrlbuf[1]))
{
return -EFAULT;
}
}
return OK;
}
/****************************************************************************
* Name: mfrc522_transcv_data
*
* Description:
* Executes the Transceive command
*
* Input Parameters:
*
* Returned Value: OK or -ETIMEDOUT
*
****************************************************************************/
int mfrc522_transcv_data(FAR struct mfrc522_dev_s *dev, uint8_t *senddata,
uint8_t sendlen, uint8_t *backdata, uint8_t *backlen,
uint8_t *validbits, uint8_t rxalign, bool check_crc)
{
uint8_t waitirq = MFRC522_RX_IRQ | MFRC522_IDLE_IRQ;
return mfrc522_comm_picc(dev, MFRC522_TRANSCV_CMD, waitirq, senddata,
sendlen, backdata, backlen, validbits, rxalign,
check_crc);
}
/****************************************************************************
* Name: mfrc522_picc_reqa_wupa
*
* Description:
* Transmits REQA or WUPA commands
*
* Input Parameters:
*
* Returned Value: OK or -ETIMEDOUT
*
****************************************************************************/
int mfrc522_picc_reqa_wupa(FAR struct mfrc522_dev_s *dev, uint8_t command,
uint8_t *buffer, uint8_t length)
{
uint8_t validbits;
uint8_t value;
int status;
if (!buffer || length < 2)
{
return -EINVAL;
}
/* Force clear of received bits if a collision is detected */
value = mfrc522_readu8(dev, MFRC522_COLL_REG);
mfrc522_writeu8(dev, MFRC522_COLL_REG, value & MFRC522_VALUES_AFTER_COLL);
validbits = 7;
status = mfrc522_transcv_data(dev, &command, 1, buffer, &length, &validbits,
0, false);
/* For REQA and WUPA we need to transmit only 7 bits */
if (status != OK)
{
return status;
}
/* ATQA must be exactly 16 bits */
if (length != 2 || validbits != 0)
{
return -EAGAIN;
}
mfrc522info("buffer[0]=0x%02X | buffer[1]=0x%02X\n", buffer[0], buffer[1]);
return OK;
}
/****************************************************************************
* Name: mfrc522_picc_request_a
*
* Description:
* Transmits a REQuest command, Type A. Invites PICCs in state IDLE to go to
* READY and prepare for anticollision or selection.
*
* Input Parameters:
*
* Returned Value: OK or -ETIMEDOUT
*
****************************************************************************/
int mfrc522_picc_request_a(FAR struct mfrc522_dev_s *dev, uint8_t *buffer,
uint8_t length)
{
return mfrc522_picc_reqa_wupa(dev, PICC_CMD_REQA, buffer, length);
}
/****************************************************************************
* Name: mfrc522_picc_detect
*
* Description:
* Detects if a Contactless Card is near
*
* Input Parameters:
*
* Returned Value: OK or -ETIMEDOUT
*
****************************************************************************/
int mfrc522_picc_detect(FAR struct mfrc522_dev_s *dev)
{
int ret;
uint8_t buffer_atqa[2];
uint8_t length = sizeof(buffer_atqa);
/* Send a REQA command */
ret = mfrc522_picc_request_a(dev, buffer_atqa, length);
return (ret == OK || ret == -EBUSY);
}
/****************************************************************************
* Name: mfrc522_picc_select
*
* Description:
* Selects a near Card and read its UID.
*
* Input Parameters:
*
* Returned Value: OK or -ETIMEDOUT
*
****************************************************************************/
int mfrc522_picc_select(FAR struct mfrc522_dev_s *dev,
FAR struct picc_uid_s *uid, uint8_t validbits)
{
bool uid_complete;
bool select_done;
bool use_cascade_tag;
uint8_t cascade_level = 1;
int result;
uint8_t i;
uint8_t value;
uint8_t count;
/* The first index in uid->data[] that is used in the current Cascade Level */
uint8_t uid_index;
/* The number of known UID bits in the current Cascade Level. */
uint8_t curr_level_known_bits;
/* The SELECT/ANTICOLLISION uses a 7 byte standard frame + 2 bytes CRC_A */
uint8_t buffer[9];
/* The number of bytes used in the buffer, number bytes on FIFO */
uint8_t buffer_used;
/* Used to defines the bit position for the first bit received */
uint8_t rxalign;
/* The number of valid bits in the last transmitted byte. */
uint8_t txlastbits;
uint8_t *resp_buf;
uint8_t resp_len;
/* Sanity check */
if (validbits > 80)
{
return -EINVAL;
}
/* Force clear of received bits if a collision is detected */
value = mfrc522_readu8(dev, MFRC522_COLL_REG);
mfrc522_writeu8(dev, MFRC522_COLL_REG, value & MFRC522_VALUES_AFTER_COLL);
/* Repeat cascade level loop until we have a complete UID */
uid_complete = false;
while (!uid_complete)
{
uint8_t bytes_to_copy;
/* Set the Cascade Level in the SEL byte, find out if we need to use the
* Cascade Tag in byte 2.
*/
switch (cascade_level)
{
case 1:
buffer[0] = PICC_CMD_SEL_CL1;
uid_index = 0;
/* When we know that the UID has more than 4 bytes */
use_cascade_tag = validbits && (uid->size > 4);
break;
case 2:
buffer[0] = PICC_CMD_SEL_CL2;
uid_index = 3;
/* When we know that the UID has more than 7 bytes */
use_cascade_tag = validbits && (uid->size > 7);
break;
case 3:
buffer[0] = PICC_CMD_SEL_CL3;
uid_index = 6;
use_cascade_tag = false;
break;
default:
return -EIO; /* Internal error */
}
/* How many UID bits are known in this Cascade Level? */
curr_level_known_bits = validbits - (8 * uid_index);
if (curr_level_known_bits < 0)
{
curr_level_known_bits = 0;
}
/* Copy the known bits from uid->uid_data[] to buffer[] */
i = 2; /* destination index in buffer[] */
if (use_cascade_tag)
{
buffer[i++] = PICC_CMD_CT;
}
/* Number of bytes needed to represent the known bits for this level */
bytes_to_copy = curr_level_known_bits / 8 +
(curr_level_known_bits % 8 ? 1 : 0);
if (bytes_to_copy)
{
/* Max 4 bytes in each Cascade Level. Only 3 left if we use the
* Cascade Tag.
*/
uint8_t max_bytes = use_cascade_tag ? 3 : 4;
if (bytes_to_copy > max_bytes)
{
bytes_to_copy = max_bytes;
}
for (count = 0; count < bytes_to_copy; count++)
{
buffer[i++] = uid->uid_data[uid_index + count];
}
}
/* Now that the data has been copied we need to include the 8 bits in CT
* in curr_level_known_bits.
*/
if (use_cascade_tag)
{
curr_level_known_bits += 8;
}
/* Repeat anti collision loop until we can transmit all UID bits + BCC
* and receive a SAK - max 32 iterations.
*/
select_done = false;
while (!select_done)
{
/* Find out how many bits and bytes to send and receive. */
if (curr_level_known_bits >= 32)
{
/* All UID bits in this Cascade Level are known. This is a
* SELECT.
*/
/* NVB - Number of Valid Bits: Seven whole bytes */
buffer[1] = 0x70;
/* Calculate BCC - Block Check Character */
buffer[6] = buffer[2] ^ buffer[3] ^ buffer[4] ^ buffer[5];
/* Calculate CRC_A */
result = mfrc522_calc_crc(dev, buffer, 7, &buffer[7]);
if (result != OK)
{
return result;
}
txlastbits = 0; /* 0 => All 8 bits are valid. */
buffer_used = 9;
/* Store response in the last 3 bytes of buffer (BCC and CRC_A -
* not needed after tx).
*/
resp_buf = &buffer[6];
resp_len = 3;
}
else
{
/* This is an ANTICOLLISION */
txlastbits = curr_level_known_bits % 8;
/* Number of whole bytes in the UID part. */
count = curr_level_known_bits / 8;
i = 2 + count;
/* NVB - Number of Valid Bits */
buffer[1] = (i << 4) + txlastbits;
buffer_used = i + (txlastbits ? 1 : 0);
/* Store response in the unused part of buffer */
resp_buf = &buffer[i];
resp_len = sizeof(buffer) - i;
}
/* Set bit adjustments */
rxalign = txlastbits;
mfrc522_writeu8(dev, MFRC522_BIT_FRAMING_REG,
(rxalign << 4) + txlastbits);
/* Transmit the buffer and receive the response */
result = mfrc522_transcv_data(dev, buffer, buffer_used, resp_buf,
&resp_len, &txlastbits, rxalign,
false);
/* More than one PICC in the field => collision */
if (result == -EBUSY)
{
uint8_t coll_pos;
uint8_t coll_reg = mfrc522_readu8(dev, MFRC522_COLL_REG);
/* CollPosNotValid */
if (coll_reg & 0x20)
{
/* Without a valid collision position we cannot continue */
return -EBUSY;
}
coll_pos = coll_reg & 0x1F; /* Values 0-31, 0 means bit 32. */
if (coll_pos == 0)
{
coll_pos = 32;
}
if (coll_pos <= curr_level_known_bits)
{
/* No progress - should not happen */
return -EIO;
}
/* Choose the PICC with the bit set. */
curr_level_known_bits = coll_pos;
/* The bit to modify */
count = (curr_level_known_bits - 1) % 8;
/* First byte is index 0. */
i = 1 + (curr_level_known_bits / 8) + (count ? 1 : 0);
buffer[i] |= (1 << count);
}
else if (result != OK)
{
return result;
}
else /* OK */
{
/* This was a SELECT. */
if (curr_level_known_bits >= 32)
{
/* No more collision */
select_done = true;
}
else
{
/* This was an ANTICOLLISION. */
/* We have all 32 bits of the UID in this Cascade Level */
curr_level_known_bits = 32;
/* Run loop again to do the SELECT */
}
}
}
/* We do not check the CBB - it was constructed by us above. */
/* Copy the found UID bytes from buffer[] to uid->uid_data[] */
i = (buffer[2] == PICC_CMD_CT) ? 3 : 2; /* source index in buffer[] */
bytes_to_copy = (buffer[2] == PICC_CMD_CT) ? 3 : 4;
for (count = 0; count < bytes_to_copy; count++)
{
uid->uid_data[uid_index + count] = buffer[i++];
}
/* Check response SAK (Select Acknowledge) */
if (resp_len != 3 || txlastbits != 0)
{
/* SAK must be exactly 24 bits (1 byte + CRC_A). */
return -EIO;
}
/* Verify CRC_A - do our own calculation and store the control in
* buffer[2..3] - those bytes are not needed anymore.
*/
result = mfrc522_calc_crc(dev, resp_buf, 1, &buffer[2]);
if (result != OK)
{
return result;
}
/* Is it correct */
if ((buffer[2] != resp_buf[1]) || (buffer[3] != resp_buf[2]))
{
return -EINVAL;
}
/* Cascade bit set - UID not complete yes */
if (resp_buf[0] & 0x04)
{
cascade_level++;
}
else
{
uid_complete = true;
uid->sak = resp_buf[0];
}
}
/* Set correct uid->size */
uid->size = 3 * cascade_level + 1;
return OK;
}
/****************************************************************************
* Name: mfrc522_softreset
*
* Description:
* Send a software reset command
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: none
*
****************************************************************************/
void mfrc522_softreset(FAR struct mfrc522_dev_s *dev)
{
/* Send a software reset command */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_SOFTRST_CMD);
/* Wait the internal state machine to initialize */
nxsig_usleep(50000);
/* Wait for the PowerDown bit in COMMAND_REG to be cleared */
while (mfrc522_readu8(dev, MFRC522_COMMAND_REG) & MFRC522_POWER_DOWN);
}
/****************************************************************************
* Name: mfrc522_enableantenna
*
* Description:
* Turns the antenna on by enabling the pins TX1 and TX2
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: none
*
****************************************************************************/
void mfrc522_enableantenna(FAR struct mfrc522_dev_s *dev)
{
uint8_t value = mfrc522_readu8(dev, MFRC522_TX_CTRL_REG);
if ((value & (MFRC522_TX1_RF_EN | MFRC522_TX2_RF_EN)) != 0x03)
{
mfrc522_writeu8(dev, MFRC522_TX_CTRL_REG, value | 0x03);
}
}
/****************************************************************************
* Name: mfrc522_disableantenna
*
* Description:
* Turns the antenna off cutting the signals on TX1 and TX2
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: none
*
****************************************************************************/
void mfrc522_disableantenna(FAR struct mfrc522_dev_s *dev)
{
uint8_t value = mfrc522_readu8(dev, MFRC522_TX_CTRL_REG);
value &= ~(MFRC522_TX1_RF_EN | MFRC522_TX2_RF_EN);
mfrc522_writeu8(dev, MFRC522_TX_CTRL_REG, value);
}
/****************************************************************************
* Name: mfrc522_getfwversion
*
* Description:
* Read the MFRC522 firmware version.
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: the firmware version byte
*
****************************************************************************/
uint8_t mfrc522_getfwversion(FAR struct mfrc522_dev_s *dev)
{
return mfrc522_readu8(dev, MFRC522_VERSION_REG);
}
/****************************************************************************
* Name: mfrc522_getantennagain
*
* Description:
* Read the MFRC522 receiver gain (RxGain).
* See 9.3.3.6 / table 98 in MFRC522 datasheet.
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: none
*
****************************************************************************/
uint8_t mfrc522_getantennagain(FAR struct mfrc522_dev_s *dev)
{
return mfrc522_readu8(dev, MFRC522_RF_CFG_REG) & MFRC522_RX_GAIN_MASK;
}
/****************************************************************************
* Name: mfrc522_setantennagain
*
* Description:
* Set the MFRC522 receiver gain (RxGain) to value value specified in mask.
* See 9.3.3.6 / table 98 in MFRC522 datasheet.
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: none
*
****************************************************************************/
void mfrc522_setantennagain(FAR struct mfrc522_dev_s *dev, uint8_t mask)
{
uint8_t value;
if ((value = mfrc522_getantennagain(dev)) != mask)
{
mfrc522_writeu8(dev, MFRC522_RF_CFG_REG, value & ~MFRC522_RX_GAIN_MASK);
mfrc522_writeu8(dev, MFRC522_RF_CFG_REG, mask & MFRC522_RX_GAIN_MASK);
}
}
/****************************************************************************
* Name: mfrc522_init
*
* Description:
* Initializes the MFRC522 chip
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: none
*
****************************************************************************/
void mfrc522_init(FAR struct mfrc522_dev_s *dev)
{
/* Force a reset */
mfrc522_softreset(dev);
/* We need a timeout if something when communicating with a TAG case
* something goes wrong. f_timer = 13.56 MHz / (2*TPreScaler+1) where:
* TPreScaler = [TPrescaler_Hi:Tprescaler_Lo]. Tprescaler_Hi are the four
* low bits in TmodeReg. Tprescaler_Lo is on TPrescalerReg.
*
* TAuto=1; timer starts automatically at the end of the transmission in
* all communication modes at all speeds.
*/
mfrc522_writeu8(dev, MFRC522_TMODE_REG, MFRC522_TAUTO);
/* TPreScaler = TModeReg[3..0]:TPrescalerReg, ie: 0x0A9 = 169 =>
* f_timer=40kHz, then the timer period will be 25us.
*/
mfrc522_writeu8(dev, MFRC522_TPRESCALER_REG, 0xA9);
/* Reload timer with 0x3E8 = 1000, ie 25ms before timeout. */
mfrc522_writeu8(dev, MFRC522_TRELOAD_REGH, 0x06);
mfrc522_writeu8(dev, MFRC522_TRELOAD_REGL, 0xE8);
/* Force 100% ASK modulation independent of the ModGsPReg setting */
mfrc522_writeu8(dev, MFRC522_TX_ASK_REG, MFRC522_FORCE_100ASK);
/* Set the preset value for the CRC to 0x6363 (ISO 14443-3 part 6.2.4) */
mfrc522_writeu8(dev, MFRC522_MODE_REG, 0x3D);
/* Enable the Antenna pins */
mfrc522_enableantenna(dev);
}
/****************************************************************************
* Name: mfrc522_selftest
*
* Description:
* Executes a self-test of the MFRC522 chip
*
* See 16.1.1 in the MFRC522 datasheet
*
* Input Parameters: a pointer to mfrc522_dev_s structure
*
* Returned Value: none
*
****************************************************************************/
int mfrc522_selftest(FAR struct mfrc522_dev_s *dev)
{
uint8_t zeros[25] =
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0
};
char outbuf[3 * 8 + 1];
uint8_t result[64];
int i;
int j;
int k;
/* Execute a software reset */
mfrc522_softreset(dev);
/* Flush the FIFO buffer */
mfrc522_writeu8(dev, MFRC522_FIFO_LEVEL_REG, MFRC522_FLUSH_BUFFER);
/* Clear the internal buffer by writing 25 bytes 0x00 */
mfrc522_writeblk(dev, MFRC522_FIFO_DATA_REG, zeros, 25);
/* Transfer to internal buffer */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_MEM_CMD);
/* Enable self-test */
mfrc522_writeu8(dev, MFRC522_AUTOTEST_REG, MFRC522_SELFTEST_EN);
/* Write 0x00 to FIFO buffer */
mfrc522_writeu8(dev, MFRC522_FIFO_DATA_REG, 0x00);
/* Start self-test by issuing the CalcCRC command */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_CALC_CRC_CMD);
/* Wait for self-test to complete */
for (i = 0; i < 255; i++)
{
uint8_t n;
n = mfrc522_readu8(dev, MFRC522_DIV_IRQ_REG);
if (n & MFRC522_CRC_IRQ)
{
break;
}
}
/* Stop calculating CRC for new content in the FIFO */
mfrc522_writeu8(dev, MFRC522_COMMAND_REG, MFRC522_IDLE_CMD);
/* Read out the 64 bytes result from the FIFO buffer */
mfrc522_readblk(dev, MFRC522_FIFO_DATA_REG, result, 64, 0);
/* Self-test done. Reset AutoTestReg register to normal operation */
mfrc522_writeu8(dev, MFRC522_AUTOTEST_REG, 0x00);
mfrc522info("Self Test Result:\n");
for (i = 0; i < 64; i += 8)
{
for (j = 0, k = 0; j < 8; j++, k += 3)
{
(void)sprintf(&outbuf[k], " %02x", result[i + j]);
}
mfrc522info(" %02x:%s\n", i, outbuf);
}
mfrc522info("Done!\n");
return OK;
}
/****************************************************************************
* Name: mfrc522_open
*
* Description:
* This function is called whenever the MFRC522 device is opened.
*
****************************************************************************/
static int mfrc522_open(FAR struct file *filep)
{
FAR struct inode *inode;
FAR struct mfrc522_dev_s *dev;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
dev = inode->i_private;
mfrc522_configspi(dev->spi);
nxsig_usleep(10000);
mfrc522_getfwversion(dev);
dev->state = MFRC522_STATE_IDLE;
return OK;
}
/****************************************************************************
* Name: mfrc522_close
*
* Description:
* This routine is called when the MFRC522 device is closed.
*
****************************************************************************/
static int mfrc522_close(FAR struct file *filep)
{
FAR struct inode *inode;
FAR struct mfrc522_dev_s *dev;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
dev = inode->i_private;
dev->state = MFRC522_STATE_NOT_INIT;
return OK;
}
/****************************************************************************
* Name: mfrc522_read
*
* Description:
* This routine is called when the device is read.
*
* Returns TAG id as string to buffer.
* or -EIO if no TAG found
*
****************************************************************************/
static ssize_t mfrc522_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct inode *inode;
FAR struct mfrc522_dev_s *dev;
FAR struct picc_uid_s uid;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
dev = inode->i_private;
/* Is a card near? */
if (!mfrc522_picc_detect(dev))
{
mfrc522err("Card is not present!\n");
return -EAGAIN;
}
/* Now read the UID */
mfrc522_picc_select(dev, &uid, 0);
if (uid.sak != 0)
{
if (buffer)
{
snprintf(buffer, buflen, "0x%02X%02X%02X%02X",
uid.uid_data[0], uid.uid_data[1],
uid.uid_data[2], uid.uid_data[3]);
return buflen;
}
}
return OK;
}
/****************************************************************************
* Name: mfrc522_write
****************************************************************************/
static ssize_t mfrc522_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
FAR struct inode *inode;
FAR struct mfrc522_dev_s *dev;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
dev = inode->i_private;
(void)dev;
return -ENOSYS;
}
/****************************************************************************
* Name: mfrc522_ioctl
****************************************************************************/
static int mfrc522_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode;
FAR struct mfrc522_dev_s *dev;
int ret = OK;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
dev = inode->i_private;
switch (cmd)
{
case MFRC522IOC_GET_PICC_UID:
{
struct picc_uid_s *uid = (struct picc_uid_s *)arg;
/* Is a card near? */
if (mfrc522_picc_detect(dev))
{
ret = mfrc522_picc_select(dev, uid, 0);
}
}
break;
case MFRC522IOC_GET_STATE:
ret = dev->state;
break;
default:
mfrc522err("ERROR: Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mfrc522_register
*
* Description:
* Register the MFRC522 character device as 'devpath'
*
* Input Parameters:
* devpath - The full path to the driver to register.
* E.g., "/dev/rfid0"
* spi - An instance of the SPI interface to use to communicate with
* MFRC522.
* config - chip config
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int mfrc522_register(FAR const char *devpath, FAR struct spi_dev_s *spi)
{
FAR struct mfrc522_dev_s *dev;
uint8_t fwver;
int ret = 0;
/* Initialize the MFRC522 device structure */
dev = (FAR struct mfrc522_dev_s *)kmm_malloc(sizeof(struct mfrc522_dev_s));
if (!dev)
{
mfrc522err("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
dev->spi = spi;
/* Device is not initialized yet */
dev->state = MFRC522_STATE_NOT_INIT;
#if defined CONFIG_PM
dev->pm_level = PM_IDLE;
#endif
/* mfrc522_attachirq(dev, mfrc522_irqhandler); */
/* Initialize the MFRC522 */
mfrc522_init(dev);
/* Device initialized and idle */
dev->state = MFRC522_STATE_IDLE;
/* Read the Firmware Version */
fwver = mfrc522_getfwversion(dev);
mfrc522info("MFRC522 Firmware Version: 0x%02X!\n", fwver);
/* If returned firmware version is unknown don't register the device */
if (fwver != 0x90 && fwver != 0x91 && fwver != 0x92 && fwver != 0x88)
{
mfrc522err("None supported device detected!\n");
goto firmware_error;
}
/* Register the character driver */
ret = register_driver(devpath, &g_mfrc522fops, 0666, dev);
if (ret < 0)
{
mfrc522err("ERROR: Failed to register driver: %d\n", ret);
kmm_free(dev);
}
return ret;
firmware_error:
kmm_free(dev);
return -ENODEV;
}
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