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nest-open-source / nest-detect / 1.0 / openthread / 3d661cc102eeba35ebfa1f188cb333740870660f / . / tools / spi-hdlc-adapter / spi-hdlc-adapter.c
blob: 20b762c37625a7268ae2e1571a53fa5bc4274bfe [file] [log] [blame]
/*
* Copyright (c) 2017, The OpenThread Authors.
* All rights reserved.
*
* 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 of the copyright holder 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 HOLDER 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.
*/
#define _GNU_SOURCE 1
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <syslog.h>
#include <getopt.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/select.h>
#include <sys/ucontext.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <linux/spi/spidev.h>
#if HAVE_EXECINFO_H
#include <execinfo.h>
#endif
#if HAVE_PTY_H
#include <pty.h>
#endif
#if HAVE_UTIL_H
#include <util.h>
#endif
/* ------------------------------------------------------------------------- */
/* MARK: Macros and Constants */
#define SPI_HDLC_VERSION "0.06"
#define MAX_FRAME_SIZE 2048
#define HEADER_LEN 5
#define SPI_HEADER_RESET_FLAG 0x80
#define SPI_HEADER_CRC_FLAG 0x40
#define SPI_HEADER_PATTERN_VALUE 0x02
#define SPI_HEADER_PATTERN_MASK 0x03
#define EXIT_QUIT 65535
#ifndef MSEC_PER_SEC
#define MSEC_PER_SEC 1000
#endif
#ifndef USEC_PER_MSEC
#define USEC_PER_MSEC 1000
#endif
#ifndef USEC_PER_SEC
#define USEC_PER_SEC (USEC_PER_MSEC * MSEC_PER_SEC)
#endif
#define SPI_POLL_PERIOD_MSEC (MSEC_PER_SEC/30)
#define GPIO_INT_ASSERT_STATE 0 // I̅N̅T̅ is asserted low
#define GPIO_RES_ASSERT_STATE 0 // R̅E̅S̅ is asserted low
#define SPI_RX_ALIGN_ALLOWANCE_MAX 6
#define SOCKET_DEBUG_BYTES_PER_LINE 16
#ifndef AUTO_PRINT_BACKTRACE
#define AUTO_PRINT_BACKTRACE (HAVE_EXECINFO_H)
#endif
#define AUTO_PRINT_BACKTRACE_STACK_DEPTH 20
static const uint8_t kHdlcResetSignal[] = { 0x7E, 0x13, 0x11, 0x7E };
static const uint16_t kHdlcCrcCheckValue = 0xf0b8;
static const uint16_t kHdlcCrcResetValue = 0xffff;
enum {
MODE_STDIO = 0,
MODE_PTY = 1,
};
// Ignores return value from function 's'
#define IGNORE_RETURN_VALUE(s) do { if (s){} } while (0)
/* ------------------------------------------------------------------------- */
/* MARK: Global State */
#if HAVE_OPENPTY
static int sMode = MODE_PTY;
#else
static int sMode = MODE_STDIO;
#endif
static const char* sSpiDevPath = NULL;
static const char* sIntGpioDevPath = NULL;
static const char* sResGpioDevPath = NULL;
static int sVerbose = LOG_NOTICE;
static int sSpiDevFd = -1;
static int sResGpioValueFd = -1;
static int sIntGpioValueFd = -1;
static int sHdlcInputFd = -1;
static int sHdlcOutputFd = -1;
static int sSpiSpeed = 1000000; // in Hz (default: 1MHz)
static uint8_t sSpiMode = 0;
static int sSpiCsDelay = 20; // in microseconds
static uint16_t sSpiRxPayloadSize;
static uint8_t sSpiRxFrameBuffer[MAX_FRAME_SIZE + SPI_RX_ALIGN_ALLOWANCE_MAX];
static uint16_t sSpiTxPayloadSize;
static bool sSpiTxIsReady = false;
static int sSpiTxRefusedCount = 0;
static uint8_t sSpiTxFrameBuffer[MAX_FRAME_SIZE + SPI_RX_ALIGN_ALLOWANCE_MAX];
static int sSpiRxAlignAllowance = 0;
static int sSpiSmallPacketSize = 32; // in bytes
static bool sSlaveDidReset = false;
// If sUseRawFrames is set to true, HDLC encoding/encoding
// is skipped and the raw frames are read-from/written-to
// the sHdlcInputFd/sHdlcOutputFd whole. See `--raw`.
static bool sUseRawFrames = false;
static int sMTU = MAX_FRAME_SIZE - HEADER_LEN;
static int sRet = 0;
static bool sDumpStats = false;
static sig_t sPreviousHandlerForSIGINT;
static sig_t sPreviousHandlerForSIGTERM;
/* ------------------------------------------------------------------------- */
/* MARK: Statistics */
static uint64_t sSlaveResetCount = 0;
static uint64_t sSpiFrameCount = 0;
static uint64_t sSpiValidFrameCount = 0;
static uint64_t sSpiGarbageFrameCount = 0;
static uint64_t sSpiDuplexFrameCount = 0;
static uint64_t sSpiUnresponsiveFrameCount = 0;
static uint64_t sHdlcRxFrameByteCount = 0;
static uint64_t sHdlcTxFrameByteCount = 0;
static uint64_t sHdlcRxFrameCount = 0;
static uint64_t sHdlcTxFrameCount = 0;
static uint64_t sHdlcRxBadCrcCount = 0;
/* ------------------------------------------------------------------------- */
/* MARK: Signal Handlers */
static void signal_SIGINT(int sig)
{
static const char message[] = "\nCaught SIGINT!\n";
sRet = EXIT_QUIT;
// Can't use syslog() because it isn't async signal safe.
// So we write to stderr
IGNORE_RETURN_VALUE(write(STDERR_FILENO, message, sizeof(message)-1));
// Restore the previous handler so that if we end up getting
// this signal again we perform the system default action.
signal(SIGINT, sPreviousHandlerForSIGINT);
sPreviousHandlerForSIGINT = NULL;
// Ignore signal argument.
(void)sig;
}
static void signal_SIGTERM(int sig)
{
static const char message[] = "\nCaught SIGTERM!\n";
sRet = EXIT_QUIT;
// Can't use syslog() because it isn't async signal safe.
// So we write to stderr
IGNORE_RETURN_VALUE(write(STDERR_FILENO, message, sizeof(message)-1));
// Restore the previous handler so that if we end up getting
// this signal again we perform the system default action.
signal(SIGTERM, sPreviousHandlerForSIGTERM);
sPreviousHandlerForSIGTERM = NULL;
// Ignore signal argument.
(void)sig;
}
static void signal_SIGHUP(int sig)
{
static const char message[] = "\nCaught SIGHUP!\n";
sRet = EXIT_FAILURE;
// Can't use syslog() because it isn't async signal safe.
// So we write to stderr
IGNORE_RETURN_VALUE(write(STDERR_FILENO, message, sizeof(message)-1));
// We don't restore the "previous handler"
// because we always want to let the main
// loop decide what to do for hangups.
// Ignore signal argument.
(void)sig;
}
static void signal_dumpstats(int sig)
{
sDumpStats = true;
// Ignore signal argument.
(void)sig;
}
static void signal_clearstats(int sig)
{
sDumpStats = true;
sSlaveResetCount = 0;
sSpiFrameCount = 0;
sSpiValidFrameCount = 0;
sSpiGarbageFrameCount = 0;
sSpiDuplexFrameCount = 0;
sSpiUnresponsiveFrameCount = 0;
sHdlcRxFrameByteCount = 0;
sHdlcTxFrameByteCount = 0;
sHdlcRxFrameCount = 0;
sHdlcTxFrameCount = 0;
sHdlcRxBadCrcCount = 0;
// Ignore signal argument.
(void)sig;
}
#if AUTO_PRINT_BACKTRACE
static void signal_critical(int sig, siginfo_t * info, void * ucontext)
{
// This is the last hurah for this process.
// We dump the stack, because that's all we can do.
void *stack_mem[AUTO_PRINT_BACKTRACE_STACK_DEPTH];
void **stack = stack_mem;
char **stack_symbols;
int stack_depth, i;
ucontext_t *uc = (ucontext_t*)ucontext;
// Shut up compiler warning.
(void)uc;
(void)info;
// We call some functions here which aren't async-signal-safe,
// but this function isn't really useful without those calls.
// Since we are making a gamble (and we deadlock if we loose),
// we are going to set up a two-second watchdog to make sure
// we end up terminating like we should. The choice of a two
// second timeout is entirely arbitrary, and may be changed
// if needs warrant.
alarm(2);
signal(SIGALRM, SIG_DFL);
fprintf(stderr, " *** FATAL ERROR: Caught signal %d (%s):\n", sig, strsignal(sig));
stack_depth = backtrace(stack, AUTO_PRINT_BACKTRACE_STACK_DEPTH);
// Here are are trying to update the pointer in the backtrace
// to be the actual location of the fault.
#if defined(__x86_64__)
stack[1] = (void *) uc->uc_mcontext.gregs[REG_RIP];
#elif defined(__i386__)
stack[1] = (void *) uc->uc_mcontext.gregs[REG_EIP];
#elif defined(__arm__)
stack[1] = (void *) uc->uc_mcontext.arm_ip;
#else
#warning TODO: Add this arch to signal_critical
#endif
// Now dump the symbols to stderr, in case syslog barfs.
backtrace_symbols_fd(stack, stack_depth, STDERR_FILENO);
// Load up the symbols individually, so we can output to syslog, too.
stack_symbols = backtrace_symbols(stack, stack_depth);
syslog(LOG_CRIT, " *** FATAL ERROR: Caught signal %d (%s):", sig, strsignal(sig));
for (i = 0; i != stack_depth; i++)
{
syslog(LOG_CRIT, "[BT] %2d: %s", i, stack_symbols[i]);
}
free(stack_symbols);
exit(EXIT_FAILURE);
}
#endif // if AUTO_PRINT_BACKTRACE
static void log_debug_buffer(const char* desc, const uint8_t* buffer_ptr, int buffer_len, bool force)
{
int i = 0;
if (!force && (sVerbose < LOG_DEBUG))
{
return;
}
while (i < buffer_len)
{
int j;
char dump_string[SOCKET_DEBUG_BYTES_PER_LINE*3+1];
for (j = 0; i < buffer_len && j < SOCKET_DEBUG_BYTES_PER_LINE; i++, j++)
{
sprintf(dump_string+j*3, "%02X ", buffer_ptr[i]);
}
syslog(force ? LOG_WARNING : LOG_DEBUG, "%s: %s%s", desc, dump_string, (i < buffer_len)?" ...":"");
}
}
/* ------------------------------------------------------------------------- */
/* MARK: SPI Transfer Functions */
static void spi_header_set_flag_byte(uint8_t *header, uint8_t value)
{
header[0] = value;
}
static void spi_header_set_accept_len(uint8_t *header, uint16_t len)
{
header[1] = ((len >> 0) & 0xFF);
header[2] = ((len >> 8) & 0xFF);
}
static void spi_header_set_data_len(uint8_t *header, uint16_t len)
{
header[3] = ((len >> 0) & 0xFF);
header[4] = ((len >> 8) & 0xFF);
}
static uint8_t spi_header_get_flag_byte(const uint8_t *header)
{
return header[0];
}
static uint16_t spi_header_get_accept_len(const uint8_t *header)
{
return ( header[1] + (uint16_t)(header[2] << 8) );
}
static uint16_t spi_header_get_data_len(const uint8_t *header)
{
return ( header[3] + (uint16_t)(header[4] << 8) );
}
static uint8_t* get_real_rx_frame_start(void)
{
uint8_t* ret = sSpiRxFrameBuffer;
int i = 0;
for (i = 0; i < sSpiRxAlignAllowance; i++)
{
if (ret[0] != 0xFF)
{
break;
}
ret++;
}
return ret;
}
static int do_spi_xfer(int len)
{
int ret;
struct spi_ioc_transfer xfer[2] =
{
{ // This part is the delay between C̅S̅ being
// asserted and the SPI clock starting. This
// is not supported by all Linux SPI drivers.
.tx_buf = 0,
.rx_buf = 0,
.len = 0,
.delay_usecs = (uint16_t)sSpiCsDelay,
.speed_hz = (uint32_t)sSpiSpeed,
.bits_per_word = 8,
.cs_change = false,
},
{ // This part is the actual SPI transfer.
.tx_buf = (unsigned long)sSpiTxFrameBuffer,
.rx_buf = (unsigned long)sSpiRxFrameBuffer,
.len = (uint32_t)(len + HEADER_LEN + sSpiRxAlignAllowance),
.delay_usecs = 0,
.speed_hz = (uint32_t)sSpiSpeed,
.bits_per_word = 8,
.cs_change = false,
}
};
if (sSpiCsDelay > 0)
{
// A C̅S̅ delay has been specified. Start transactions
// with both parts.
ret = ioctl(sSpiDevFd, SPI_IOC_MESSAGE(2), &xfer[0]);
}
else
{
// No C̅S̅ delay has been specified, so we skip the first
// part because it causes some SPI drivers to croak.
ret = ioctl(sSpiDevFd, SPI_IOC_MESSAGE(1), &xfer[1]);
}
if (ret != -1)
{
log_debug_buffer("SPI-TX", sSpiTxFrameBuffer, (int)xfer[1].len, false);
log_debug_buffer("SPI-RX", sSpiRxFrameBuffer, (int)xfer[1].len, false);
sSpiFrameCount++;
}
return ret;
}
static void debug_spi_header(const char* hint, bool force)
{
if (force || (sVerbose >= LOG_DEBUG))
{
const uint8_t* spiRxFrameBuffer = get_real_rx_frame_start();
syslog(force ? LOG_WARNING : LOG_DEBUG, "%s-TX: H:%02X ACCEPT:%d DATA:%0d\n",
hint,
spi_header_get_flag_byte(sSpiTxFrameBuffer),
spi_header_get_accept_len(sSpiTxFrameBuffer),
spi_header_get_data_len(sSpiTxFrameBuffer)
);
syslog(force ? LOG_WARNING : LOG_DEBUG, "%s-RX: H:%02X ACCEPT:%d DATA:%0d\n",
hint,
spi_header_get_flag_byte(spiRxFrameBuffer),
spi_header_get_accept_len(spiRxFrameBuffer),
spi_header_get_data_len(spiRxFrameBuffer)
);
}
}
static int push_pull_spi(void)
{
int ret;
uint16_t spi_xfer_bytes = 0;
const uint8_t* spiRxFrameBuffer = NULL;
uint8_t slave_header;
uint16_t slave_max_rx;
int successful_exchanges = 0;
static uint16_t slave_data_len;
// For now, sSpiRxPayloadSize must be zero
// when entering this function. This may change
// at some point, for now this makes things
// much easier.
assert(sSpiRxPayloadSize == 0);
if (sSpiValidFrameCount == 0)
{
// Set the reset flag to indicate to our slave that we
// are coming up from scratch.
spi_header_set_flag_byte(sSpiTxFrameBuffer, SPI_HEADER_RESET_FLAG|SPI_HEADER_PATTERN_VALUE);
}
else
{
spi_header_set_flag_byte(sSpiTxFrameBuffer, SPI_HEADER_PATTERN_VALUE);
}
// Zero out our rx_accept and our data_len for now.
spi_header_set_accept_len(sSpiTxFrameBuffer, 0);
spi_header_set_data_len(sSpiTxFrameBuffer, 0);
// Sanity check.
if (slave_data_len > MAX_FRAME_SIZE)
{
slave_data_len = 0;
}
if (sSpiTxIsReady)
{
// Go ahead and try to immediately send a frame if we have it queued up.
spi_header_set_data_len(sSpiTxFrameBuffer, sSpiTxPayloadSize);
if (sSpiTxPayloadSize > spi_xfer_bytes)
{
spi_xfer_bytes = sSpiTxPayloadSize;
}
}
if (sSpiRxPayloadSize == 0)
{
if (slave_data_len != 0)
{
// In a previous transaction the slave indicated
// it had something to send us. Make sure our
// transaction is large enough to handle it.
if (slave_data_len > spi_xfer_bytes)
{
spi_xfer_bytes = slave_data_len;
}
}
else
{
// Set up a minimum transfer size to allow small
// frames the slave wants to send us to be handled
// in a single transaction.
if (sSpiSmallPacketSize > spi_xfer_bytes)
{
spi_xfer_bytes = (uint16_t)sSpiSmallPacketSize;
}
}
spi_header_set_accept_len(sSpiTxFrameBuffer, spi_xfer_bytes);
}
// Perform the SPI transaction.
ret = do_spi_xfer(spi_xfer_bytes);
if (ret < 0)
{
perror("do_spi_xfer");
// Print out a helpful error message for
// a common error.
if ( (sSpiCsDelay != 0)
&& (errno == EINVAL)
) {
syslog(LOG_ERR, "SPI ioctl failed with EINVAL. Try adding `--spi-cs-delay=0` to command line arguments.");
}
goto bail;
}
// Account for misalignment (0xFF bytes at the start)
spiRxFrameBuffer = get_real_rx_frame_start();
debug_spi_header("push_pull", false);
slave_header = spi_header_get_flag_byte(spiRxFrameBuffer);
if ((slave_header == 0xFF) || (slave_header == 0x00))
{
if ( (slave_header == spiRxFrameBuffer[1])
&& (slave_header == spiRxFrameBuffer[2])
&& (slave_header == spiRxFrameBuffer[3])
&& (slave_header == spiRxFrameBuffer[4])
) {
// Device is off or in a bad state.
// In some cases may be induced by flow control.
syslog(slave_data_len == 0 ? LOG_DEBUG : LOG_WARNING, "Slave did not respond to frame. (Header was all 0x%02X)", slave_header);
sSpiUnresponsiveFrameCount++;
}
else
{
// Header is full of garbage
syslog(
LOG_WARNING,
"Garbage in header : %02X %02X %02X %02X %02X",
spiRxFrameBuffer[0],
spiRxFrameBuffer[1],
spiRxFrameBuffer[2],
spiRxFrameBuffer[3],
spiRxFrameBuffer[4]
);
sSpiGarbageFrameCount++;
if (sVerbose < LOG_DEBUG)
{
log_debug_buffer("SPI-TX", sSpiTxFrameBuffer, (int)spi_xfer_bytes + HEADER_LEN + sSpiRxAlignAllowance, true);
log_debug_buffer("SPI-RX", sSpiRxFrameBuffer, (int)spi_xfer_bytes + HEADER_LEN + sSpiRxAlignAllowance, true);
}
}
sSpiTxRefusedCount++;
goto bail;
}
slave_max_rx = spi_header_get_accept_len(spiRxFrameBuffer);
slave_data_len = spi_header_get_data_len(spiRxFrameBuffer);
if ( ((slave_header & SPI_HEADER_PATTERN_MASK) != SPI_HEADER_PATTERN_VALUE)
|| (slave_max_rx > MAX_FRAME_SIZE)
|| (slave_data_len > MAX_FRAME_SIZE)
)
{
sSpiGarbageFrameCount++;
sSpiTxRefusedCount++;
slave_data_len = 0;
syslog(
LOG_WARNING,
"Garbage in header : %02X %02X %02X %02X %02X",
spiRxFrameBuffer[0],
spiRxFrameBuffer[1],
spiRxFrameBuffer[2],
spiRxFrameBuffer[3],
spiRxFrameBuffer[4]
);
if (sVerbose < LOG_DEBUG)
{
log_debug_buffer("SPI-TX", sSpiTxFrameBuffer, (int)spi_xfer_bytes + HEADER_LEN + sSpiRxAlignAllowance, true);
log_debug_buffer("SPI-RX", sSpiRxFrameBuffer, (int)spi_xfer_bytes + HEADER_LEN + sSpiRxAlignAllowance, true);
}
goto bail;
}
sSpiValidFrameCount++;
if ( (slave_header & SPI_HEADER_RESET_FLAG) == SPI_HEADER_RESET_FLAG)
{
sSlaveResetCount++;
syslog(LOG_NOTICE, "Slave did reset (%llu resets so far)", (unsigned long long)sSlaveResetCount);
sSlaveDidReset = true;
sDumpStats = true;
}
// Handle received packet, if any.
if ( (sSpiRxPayloadSize == 0)
&& (slave_data_len != 0)
&& (slave_data_len <= spi_header_get_accept_len(sSpiTxFrameBuffer))
) {
// We have received a packet. Set sSpiRxPayloadSize so that
// the packet will eventually get queued up by push_hdlc().
sSpiRxPayloadSize = slave_data_len;
slave_data_len = 0;
successful_exchanges++;
}
// Handle transmitted packet, if any.
if ( sSpiTxIsReady
&& (sSpiTxPayloadSize == spi_header_get_data_len(sSpiTxFrameBuffer))
) {
if (spi_header_get_data_len(sSpiTxFrameBuffer) <= slave_max_rx)
{
// Our outbound packet has been successfully transmitted. Clear
// sSpiTxPayloadSize and sSpiTxIsReady so that pull_hdlc() can
// pull another packet for us to send.
sSpiTxIsReady = false;
sSpiTxPayloadSize = 0;
sSpiTxRefusedCount = 0;
successful_exchanges++;
}
else
{
// The slave Wasn't ready for what we had to
// send them. Incrementing this counter will
// turn on rate limiting so that we
// don't waste a ton of CPU bombarding them
// with useless SPI transfers.
sSpiTxRefusedCount++;
}
}
if (!sSpiTxIsReady)
{
sSpiTxRefusedCount = 0;
}
if (successful_exchanges == 2)
{
sSpiDuplexFrameCount++;
}
bail:
return ret;
}
static bool check_and_clear_interrupt(void)
{
if (sIntGpioValueFd >= 0)
{
char value[5] = "";
ssize_t len;
lseek(sIntGpioValueFd, 0, SEEK_SET);
len = read(sIntGpioValueFd, value, sizeof(value)-1);
if (len < 0)
{
perror("check_and_clear_interrupt");
sRet = EXIT_FAILURE;
}
// The interrupt pin is active low.
return GPIO_INT_ASSERT_STATE == atoi(value);
}
return true;
}
/* ------------------------------------------------------------------------- */
/* MARK: HDLC Transfer Functions */
#define HDLC_BYTE_FLAG 0x7E
#define HDLC_BYTE_ESC 0x7D
#define HDLC_BYTE_XON 0x11
#define HDLC_BYTE_XOFF 0x13
#define HDLC_BYTE_SPECIAL 0xF8
#define HDLC_ESCAPE_XFORM 0x20
static uint16_t hdlc_crc16(uint16_t aFcs, uint8_t aByte)
{
#if 1
// CRC-16/CCITT, CRC-16/CCITT-TRUE, CRC-CCITT
// width=16 poly=0x1021 init=0x0000 refin=true refout=true xorout=0x0000 check=0x2189 name="KERMIT"
// http://reveng.sourceforge.net/crc-catalogue/16.htm#crc.cat.kermit
static const uint16_t sFcsTable[256] =
{
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};
return (aFcs >> 8) ^ sFcsTable[(aFcs ^ aByte) & 0xff];
#else
// CRC-16/CCITT-FALSE, same CRC as 802.15.4
// width=16 poly=0x1021 init=0xffff refin=false refout=false xorout=0x0000 check=0x29b1 name="CRC-16/CCITT-FALSE"
// http://reveng.sourceforge.net/crc-catalogue/16.htm#crc.cat.crc-16-ccitt-false
aFcs = (uint16_t)((aFcs >> 8) | (aFcs << 8));
aFcs ^= aByte;
aFcs ^= ((aFcs & 0xff) >> 4);
aFcs ^= (aFcs << 12);
aFcs ^= ((aFcs & 0xff) << 5);
return aFcs;
#endif
}
static bool hdlc_byte_needs_escape(uint8_t byte)
{
switch(byte)
{
case HDLC_BYTE_SPECIAL:
case HDLC_BYTE_ESC:
case HDLC_BYTE_FLAG:
case HDLC_BYTE_XOFF:
case HDLC_BYTE_XON:
return true;
default:
return false;
}
}
static int push_hdlc(void)
{
int ret = 0;
const uint8_t* spiRxFrameBuffer = get_real_rx_frame_start();
static uint8_t escaped_frame_buffer[MAX_FRAME_SIZE*2];
static uint16_t unescaped_frame_len;
static uint16_t escaped_frame_len;
static uint16_t escaped_frame_sent;
if (escaped_frame_len == 0)
{
if (sSlaveDidReset)
{
// Indicate an MCU reset.
memcpy(escaped_frame_buffer, kHdlcResetSignal, sizeof(kHdlcResetSignal));
escaped_frame_len = sizeof(kHdlcResetSignal);
sSlaveDidReset = false;
// Set this to zero, since this isn't a real frame.
unescaped_frame_len = 0;
}
else if (sSpiRxPayloadSize != 0)
{
// Escape the frame.
uint8_t c;
uint16_t fcs = kHdlcCrcResetValue;
uint16_t i;
unescaped_frame_len = sSpiRxPayloadSize;
for (i = 0; i < sSpiRxPayloadSize; i++)
{
c = spiRxFrameBuffer[i + HEADER_LEN];
fcs = hdlc_crc16(fcs, c);
if (hdlc_byte_needs_escape(c))
{
escaped_frame_buffer[escaped_frame_len++] = HDLC_BYTE_ESC;
escaped_frame_buffer[escaped_frame_len++] = c ^ HDLC_ESCAPE_XFORM;
}
else
{
escaped_frame_buffer[escaped_frame_len++] = c;
}
}
fcs ^= 0xFFFF;
c = fcs & 0xFF;
if (hdlc_byte_needs_escape(c))
{
escaped_frame_buffer[escaped_frame_len++] = HDLC_BYTE_ESC;
escaped_frame_buffer[escaped_frame_len++] = c ^ HDLC_ESCAPE_XFORM;
}
else
{
escaped_frame_buffer[escaped_frame_len++] = c;
}
c = (fcs >> 8) & 0xFF;
if (hdlc_byte_needs_escape(c))
{
escaped_frame_buffer[escaped_frame_len++] = HDLC_BYTE_ESC;
escaped_frame_buffer[escaped_frame_len++] = c ^ HDLC_ESCAPE_XFORM;
}
else
{
escaped_frame_buffer[escaped_frame_len++] = c;
}
escaped_frame_buffer[escaped_frame_len++] = HDLC_BYTE_FLAG;
escaped_frame_sent = 0;
sSpiRxPayloadSize = 0;
}
else
{
// Nothing to do.
goto bail;
}
}
ret = (int)write(
sHdlcOutputFd,
escaped_frame_buffer + escaped_frame_sent,
escaped_frame_len - escaped_frame_sent
);
if (ret < 0)
{
if (errno == EAGAIN)
{
ret = 0;
}
else
{
perror("push_hdlc:write");
syslog(LOG_ERR, "push_hdlc:write: errno=%d (%s)", errno, strerror(errno));
}
goto bail;
}
escaped_frame_sent += ret;
// Reset state once we have sent the entire frame.
if (escaped_frame_len == escaped_frame_sent)
{
escaped_frame_len = escaped_frame_sent = 0;
// Increment counter for statistics
sHdlcTxFrameCount++;
sHdlcTxFrameByteCount += unescaped_frame_len;
}
ret = 0;
bail:
return ret;
}
static int pull_hdlc(void)
{
int ret = 0;
static uint16_t fcs;
static bool unescape_next_byte = false;
if (!sSpiTxIsReady)
{
uint8_t byte;
while ((ret = (int)read(sHdlcInputFd, &byte, 1)) == 1)
{
if (sSpiTxPayloadSize >= (MAX_FRAME_SIZE - HEADER_LEN))
{
syslog(LOG_WARNING, "HDLC frame was too big");
unescape_next_byte = false;
sSpiTxPayloadSize = 0;
fcs = kHdlcCrcResetValue;
}
else if (byte == HDLC_BYTE_FLAG)
{
if (sSpiTxPayloadSize <= 2)
{
unescape_next_byte = false;
sSpiTxPayloadSize = 0;
fcs = kHdlcCrcResetValue;
continue;
}
else if (fcs != kHdlcCrcCheckValue)
{
syslog(LOG_WARNING, "HDLC frame with bad CRC (LEN:%d, FCS:0x%04X)", sSpiTxPayloadSize, fcs);
sHdlcRxBadCrcCount++;
unescape_next_byte = false;
sSpiTxPayloadSize = 0;
fcs = kHdlcCrcResetValue;
continue;
}
// Clip off the CRC
sSpiTxPayloadSize -= 2;
// Indicate that a frame is ready to go out
sSpiTxIsReady = true;
// Increment counters for statistics
sHdlcRxFrameCount++;
sHdlcRxFrameByteCount += sSpiTxPayloadSize;
// Clean up for the next frame
unescape_next_byte = false;
fcs = kHdlcCrcResetValue;
break;
}
else if (byte == HDLC_BYTE_ESC)
{
unescape_next_byte = true;
continue;
}
else if (hdlc_byte_needs_escape(byte))
{
// Skip all other control codes.
continue;
}
else if (unescape_next_byte)
{
byte = byte ^ HDLC_ESCAPE_XFORM;
unescape_next_byte = false;
}
fcs = hdlc_crc16(fcs, byte);
sSpiTxFrameBuffer[HEADER_LEN + sSpiTxPayloadSize++] = byte;
}
}
if (ret < 0)
{
if (errno == EAGAIN)
{
ret = 0;
}
else
{
perror("pull_hdlc:read");
syslog(LOG_ERR, "pull_hdlc:read: errno=%d (%s)", errno, strerror(errno));
}
}
return ret < 0
? ret
: 0;
}
/* ------------------------------------------------------------------------- */
/* MARK: Raw Transfer Functions */
static int push_raw(void)
{
int ret = 0;
const uint8_t* spiRxFrameBuffer = get_real_rx_frame_start();
static uint8_t raw_frame_buffer[MAX_FRAME_SIZE];
static uint16_t raw_frame_len;
static uint16_t raw_frame_sent;
if (raw_frame_len == 0)
{
if (sSlaveDidReset)
{
// Indicates an MCU reset.
// We don't have anything to do here because
// raw mode doesn't have any way to signal
// resets out-of-band.
sSlaveDidReset = false;
}
else if (sSpiRxPayloadSize > 0)
{
// Read the frame into raw_frame_buffer
assert(sSpiRxPayloadSize <= sizeof(raw_frame_buffer));
memcpy(raw_frame_buffer, &spiRxFrameBuffer[HEADER_LEN], sSpiRxPayloadSize);
raw_frame_len = sSpiRxPayloadSize;
raw_frame_sent = 0;
sSpiRxPayloadSize = 0;
}
else
{
// Nothing to do.
goto bail;
}
}
ret = (int)write(
sHdlcOutputFd,
raw_frame_buffer + raw_frame_sent,
raw_frame_len - raw_frame_sent
);
if (ret < 0)
{
if (errno == EAGAIN)
{
ret = 0;
}
else
{
perror("push_raw:write");
syslog(LOG_ERR, "push_raw:write: errno=%d (%s)", errno, strerror(errno));
}
goto bail;
}
raw_frame_sent += ret;
// Reset state once we have sent the entire frame.
if (raw_frame_len == raw_frame_sent)
{
// Increment counter for statistics
sHdlcTxFrameCount++;
sHdlcTxFrameByteCount += raw_frame_len;
raw_frame_len = raw_frame_sent = 0;
}
ret = 0;
bail:
return ret;
}
static int pull_raw(void)
{
int ret = 0;
if (!sSpiTxIsReady)
{
ret = (int)read(sHdlcInputFd, &sSpiTxFrameBuffer[HEADER_LEN], (size_t)sMTU);
if (ret < 0)
{
if (errno == EAGAIN)
{
ret = 0;
}
else
{
perror("pull_raw:read");
syslog(LOG_ERR, "pull_raw:read: errno=%d (%s)", errno, strerror(errno));
}
}
else if (ret > 0)
{
sSpiTxPayloadSize = (uint16_t)ret;
sSpiTxIsReady = true;
// Increment counters for statistics
sHdlcRxFrameCount++;
sHdlcRxFrameByteCount += sSpiTxPayloadSize;
}
}
return ret < 0
? ret
: 0;
}
/* ------------------------------------------------------------------------- */
/* MARK: Setup Functions */
static bool update_spi_mode(int x)
{
sSpiMode = (uint8_t)x;
if ( (sSpiDevFd >= 0)
&& (ioctl(sSpiDevFd, SPI_IOC_WR_MODE, &sSpiMode) < 0)
)
{
perror("ioctl(SPI_IOC_WR_MODE)");
return false;
}
return true;
}
static bool update_spi_speed(int x)
{
sSpiSpeed = x;
if ( (sSpiDevFd >= 0)
&& (ioctl(sSpiDevFd, SPI_IOC_WR_MAX_SPEED_HZ, &sSpiSpeed) < 0)
)
{
perror("ioctl(SPI_IOC_WR_MAX_SPEED_HZ)");
return false;
}
return true;
}
static bool setup_spi_dev(const char* path)
{
int fd = -1;
const uint8_t spi_word_bits = 8;
int ret;
sSpiDevPath = path;
fd = open(path, O_RDWR);
if (fd < 0)
{
perror("open");
goto bail;
}
// Set the SPI mode.
ret = ioctl(fd, SPI_IOC_WR_MODE, &sSpiMode);
if (ret < 0)
{
perror("ioctl(SPI_IOC_WR_MODE)");
goto bail;
}
// Set the SPI clock speed.
ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &sSpiSpeed);
if (ret < 0)
{
perror("ioctl(SPI_IOC_WR_MAX_SPEED_HZ)");
goto bail;
}
// Set the SPI word size.
ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &spi_word_bits);
if (ret < 0)
{
perror("ioctl(SPI_IOC_WR_BITS_PER_WORD)");
goto bail;
}
// Lock the file descriptor
if (flock(fd, LOCK_EX | LOCK_NB) < 0)
{
perror("flock");
goto bail;
}
sSpiDevFd = fd;
fd = -1;
bail:
if (fd >= 0)
{
close(fd);
}
return sSpiDevFd >= 0;
}
static bool setup_res_gpio(const char* path)
{
int setup_fd = -1;
char* dir_path = NULL;
char* value_path = NULL;
int len;
sResGpioDevPath = path;
len = asprintf(&dir_path, "%s/direction", path);
if (len < 0)
{
perror("asprintf");
goto bail;
}
len = asprintf(&value_path, "%s/value", path);
if (len < 0)
{
perror("asprintf");
goto bail;
}
setup_fd = open(dir_path, O_WRONLY);
if (setup_fd >= 0)
{
if (-1 == write(setup_fd, "high\n", 5))
{
perror("set_res_direction");
goto bail;
}
}
sResGpioValueFd = open(value_path, O_WRONLY);
bail:
if (setup_fd >= 0)
{
close(setup_fd);
}
if (dir_path)
{
free(dir_path);
}
if (value_path)
{
free(value_path);
}
return sResGpioValueFd >= 0;
}
static void trigger_reset(void)
{
if (sResGpioValueFd >= 0)
{
char str[] = { '0' + GPIO_RES_ASSERT_STATE, '\n' };
lseek(sResGpioValueFd, 0, SEEK_SET);
if (write(sResGpioValueFd, str, sizeof(str)) == -1)
{
syslog(LOG_ERR, "trigger_reset(): error on write: %d (%s)", errno, strerror(errno));
}
usleep(10 * USEC_PER_MSEC);
// Set the string to switch to the not-asserted state.
str[0] = '0' + !GPIO_RES_ASSERT_STATE;
lseek(sResGpioValueFd, 0, SEEK_SET);
if (write(sResGpioValueFd, str, sizeof(str)) == -1)
{
syslog(LOG_ERR, "trigger_reset(): error on write: %d (%s)", errno, strerror(errno));
}
syslog(LOG_NOTICE, "Triggered hardware reset");
}
}
static bool setup_int_gpio(const char* path)
{
char* edge_path = NULL;
char* dir_path = NULL;
char* value_path = NULL;
ssize_t len;
int setup_fd = -1;
sIntGpioValueFd = -1;
sIntGpioDevPath = path;
len = asprintf(&dir_path, "%s/direction", path);
if (len < 0)
{
perror("asprintf");
goto bail;
}
len = asprintf(&edge_path, "%s/edge", path);
if (len < 0)
{
perror("asprintf");
goto bail;
}
len = asprintf(&value_path, "%s/value", path);
if (len < 0)
{
perror("asprintf");
goto bail;
}
setup_fd = open(dir_path, O_WRONLY);
if (setup_fd >= 0)
{
len = write(setup_fd, "in", 2);
if (len < 0)
{
perror("write");
goto bail;
}
close(setup_fd);
}
setup_fd = open(edge_path, O_WRONLY);
if (setup_fd >= 0)
{
len = write(setup_fd, "falling", 7);
if (len < 0)
{
perror("write");
goto bail;
}
close(setup_fd);
setup_fd = -1;
}
sIntGpioValueFd = open(value_path, O_RDONLY);
bail:
if (setup_fd >= 0)
{
close(setup_fd);
}
if (edge_path)
{
free(edge_path);
}
if (dir_path)
{
free(dir_path);
}
if (value_path)
{
free(value_path);
}
return sIntGpioValueFd >= 0;
}
/* ------------------------------------------------------------------------- */
/* MARK: Help */
static void print_version(void)
{
printf("spi-hdlc-adapter " SPI_HDLC_VERSION " (" __TIME__ " " __DATE__ ")\n");
printf("Copyright (c) 2017 The OpenThread Authors, All Rights Reserved\n");
}
static void print_help(void)
{
print_version();
const char* help =
"\n"
"Syntax:\n"
"\n"
" spi-hdlc [options] <spi-device-path>\n"
"\n"
"Options:\n"
"\n"
" --stdio ...................... Use `stdin` and `stdout` for HDLC input and\n"
" output. Useful when directly started by the\n"
" program that will be using it.\n"
#if HAVE_OPENPTY
" --pty ........................ Create a pseudoterminal for HDLC input and\n"
" output. The path of the newly-created PTY\n"
" will be written to `stdout`, followed by a\n"
" newline.\n"
#endif // HAVE_OPENPTY
" --raw ........................ Do not encode/decode packets using HDLC.\n"
" Instead, write whole, raw frames to the\n"
" specified input and output FDs. This is useful\n"
" for emulating a serial port, or when datagram-\n"
" based sockets are supplied for stdin and\n"
" stdout` (when used with --stdio).\n"
" --mtu=[MTU] .................. Specify the MTU. Currently only used in raw mode.\n"
" Default and maximum value is 2043.\n"
" -i/--gpio-int[=gpio-path] .... Specify a path to the Linux sysfs-exported\n"
" GPIO directory for the `I̅N̅T̅` pin. If not\n"
" specified, `spi-hdlc` will fall back to\n"
" polling, which is inefficient.\n"
" -r/--gpio-reset[=gpio-path] .. Specify a path to the Linux sysfs-exported\n"
" GPIO directory for the `R̅E̅S̅` pin.\n"
" --spi-mode[=mode] ............ Specify the SPI mode to use (0-3).\n"
" --spi-speed[=hertz] .......... Specify the SPI speed in hertz.\n"
" --spi-cs-delay[=usec] ........ Specify the delay after C̅S̅ assertion, in µsec\n"
" --spi-align-allowance[=n] .... Specify the the maximum number of FF bytes to\n"
" clip from start of MISO frame. Max value is 3.\n"
" --spi-small-packet=[n] ....... Specify the smallest packet we can receive\n"
" in a single transaction(larger packets will\n"
" require two transactions). Default value is 32.\n"
" -v/--verbose ................. Increase debug verbosity. (Repeatable)\n"
" -h/-?/--help ................. Print out usage information and exit.\n"
"\n";
printf("%s", help);
}
/* ------------------------------------------------------------------------- */
/* MARK: Main Loop */
int main(int argc, char *argv[])
{
int i = 0;
char prog[32];
static fd_set read_set;
static fd_set write_set;
static fd_set error_set;
struct timeval timeout;
int max_fd = -1;
bool did_print_rate_limit_log = false;
#if AUTO_PRINT_BACKTRACE
struct sigaction sigact;
#endif // if AUTO_PRINT_BACKTRACE
enum {
ARG_SPI_MODE = 1001,
ARG_SPI_SPEED = 1002,
ARG_VERBOSE = 1003,
ARG_SPI_CS_DELAY = 1004,
ARG_SPI_ALIGN_ALLOWANCE = 1005,
ARG_RAW = 1006,
ARG_MTU = 1007,
ARG_SPI_SMALL_PACKET = 1008,
};
static struct option options[] = {
{ "stdio", no_argument, &sMode, MODE_STDIO },
{ "pty", no_argument, &sMode, MODE_PTY },
{ "gpio-int", required_argument, NULL, 'i' },
{ "gpio-res", required_argument, NULL, 'r' },
{ "verbose", optional_argument, NULL, ARG_VERBOSE },
{ "version", no_argument, NULL, 'V' },
{ "raw", no_argument, NULL, ARG_RAW },
{ "mtu", required_argument, NULL, ARG_MTU },
{ "help", no_argument, NULL, 'h' },
{ "spi-mode", required_argument, NULL, ARG_SPI_MODE },
{ "spi-speed", required_argument, NULL, ARG_SPI_SPEED },
{ "spi-cs-delay",required_argument,NULL, ARG_SPI_CS_DELAY },
{ "spi-align-allowance", required_argument, NULL, ARG_SPI_ALIGN_ALLOWANCE },
{ "spi-small-packet", required_argument, NULL, ARG_SPI_SMALL_PACKET },
{ NULL, 0, NULL, 0 },
};
strncpy(prog, argv[0], sizeof(prog) - 1);
prog[sizeof(prog) - 1] = 0;
if (argc < 2)
{
print_help();
exit(EXIT_FAILURE);
}
// ========================================================================
// INITIALIZATION
sPreviousHandlerForSIGINT = signal(SIGINT, &signal_SIGINT);
sPreviousHandlerForSIGTERM = signal(SIGTERM, &signal_SIGTERM);
signal(SIGHUP, &signal_SIGHUP);
signal(SIGUSR1, &signal_dumpstats);
signal(SIGUSR2, &signal_clearstats);
#if AUTO_PRINT_BACKTRACE
sigact.sa_sigaction = &signal_critical;
sigact.sa_flags = SA_RESTART | SA_SIGINFO | SA_NOCLDWAIT;
sigaction(SIGSEGV, &sigact, (struct sigaction *)NULL);
sigaction(SIGBUS, &sigact, (struct sigaction *)NULL);
sigaction(SIGILL, &sigact, (struct sigaction *)NULL);
sigaction(SIGABRT, &sigact, (struct sigaction *)NULL);
#endif // if AUTO_PRINT_BACKTRACE
// ========================================================================
// ARGUMENT PARSING
openlog(basename(prog), LOG_PERROR | LOG_PID | LOG_CONS, LOG_DAEMON);
setlogmask(LOG_UPTO(sVerbose));
while (1)
{
int c = getopt_long(argc, argv, "i:r:vVh?", options, NULL);
if (c == -1)
{
break;
}
else
{
switch (c)
{
case 'i':
if (!setup_int_gpio(optarg))
{
syslog(LOG_ERR, "Unable to setup INT GPIO \"%s\", %s", optarg, strerror(errno));
exit(EXIT_FAILURE);
}
break;
case ARG_SPI_ALIGN_ALLOWANCE:
errno = 0;
sSpiRxAlignAllowance = atoi(optarg);
if (errno != 0 || (sSpiRxAlignAllowance < 0))
{
syslog(LOG_ERR, "Invalid SPI RX Align Allowance \"%s\"", optarg);
exit(EXIT_FAILURE);
}
if (sSpiRxAlignAllowance > SPI_RX_ALIGN_ALLOWANCE_MAX)
{
syslog(LOG_WARNING, "Reducing SPI RX Align Allowance from %s to %d", optarg, SPI_RX_ALIGN_ALLOWANCE_MAX);
sSpiRxAlignAllowance = SPI_RX_ALIGN_ALLOWANCE_MAX;
}
break;
case ARG_SPI_MODE:
if (!update_spi_mode(atoi(optarg)))
{
syslog(LOG_ERR, "Unable to set SPI mode to \"%s\", %s", optarg, strerror(errno));
exit(EXIT_FAILURE);
}
break;
case ARG_SPI_SPEED:
if (!update_spi_speed(atoi(optarg)))
{
syslog(LOG_ERR, "Unable to set SPI speed to \"%s\", %s", optarg, strerror(errno));
exit(EXIT_FAILURE);
}
break;
case ARG_SPI_SMALL_PACKET:
sSpiSmallPacketSize = atoi(optarg);
if (sSpiSmallPacketSize > MAX_FRAME_SIZE - HEADER_LEN)
{
syslog(LOG_WARNING, "Reducing SPI small-packet size from %s to %d", optarg, MAX_FRAME_SIZE - HEADER_LEN);
sSpiSmallPacketSize = MAX_FRAME_SIZE - HEADER_LEN;
}
if (sSpiSmallPacketSize < 0)
{
syslog(LOG_ERR, "The argument to --spi-small-packet cannot be negative. (Given: \"%s\")", optarg);
exit(EXIT_FAILURE);
}
syslog(LOG_NOTICE, "SPI small-packet size set to %d bytes.", sSpiSmallPacketSize);
break;
case ARG_SPI_CS_DELAY:
sSpiCsDelay = atoi(optarg);
if (sSpiCsDelay < 0)
{
syslog(LOG_ERR, "Negative values (%d) for --spi-cs-delay are invalid.", sSpiCsDelay);
exit(EXIT_FAILURE);
}
syslog(LOG_NOTICE, "SPI CS Delay set to %d usec", sSpiCsDelay);
break;
case ARG_RAW:
sUseRawFrames = true;
syslog(LOG_NOTICE, "HDLC encoding/decoding disabled. Will use raw frames for input/output.");
break;
case ARG_MTU:
sMTU = atoi(optarg);
if (sMTU > MAX_FRAME_SIZE - HEADER_LEN)
{
syslog(LOG_ERR, "Specified MTU of %d is too large, maximum is %d bytes.", sMTU, MAX_FRAME_SIZE - HEADER_LEN);
exit(EXIT_FAILURE);
}
if (sMTU < 1)
{
syslog(LOG_ERR, "Specified MTU of %d is too small, minimum is 1 byte.", sMTU);
exit(EXIT_FAILURE);
}
syslog(LOG_NOTICE, "MTU set to %d bytes", sMTU);
break;
case 'r':
if (!setup_res_gpio(optarg))
{
syslog(LOG_ERR, "Unable to setup RES GPIO \"%s\", %s", optarg, strerror(errno));
exit(EXIT_FAILURE);
}
break;
case 'v':
case ARG_VERBOSE:
if (sVerbose < LOG_DEBUG)
{
if (optarg)
{
sVerbose += atoi(optarg);
}
else
{
sVerbose++;
}
setlogmask(setlogmask(0) | LOG_UPTO(sVerbose));
syslog(sVerbose, "Verbosity set to level %d", sVerbose);
}
break;
case 'V':
print_version();
exit(EXIT_SUCCESS);
break;
case 'h':
case '?':
print_help();
exit(EXIT_SUCCESS);
break;
}
}
}
syslog(LOG_NOTICE,"spi-hdlc-adapter " SPI_HDLC_VERSION " (" __TIME__ " " __DATE__ ")\n");
argc -= optind;
argv += optind;
if (argc >= 1)
{
if (!setup_spi_dev(argv[0]))
{
char spi_path[64];
strncpy(spi_path, argv[0], sizeof(spi_path) - 1);
spi_path[sizeof(spi_path) - 1] = 0;
syslog(LOG_ERR, "%s: Unable to open SPI device \"%s\", %s", prog, spi_path, strerror(errno));
exit(EXIT_FAILURE);
}
argc--;
argv++;
}
if (argc >= 1)
{
fprintf(stderr, "%s: Unexpected argument \"%s\"\n", prog, argv[0]);
exit(EXIT_FAILURE);
}
if (sSpiDevPath == NULL)
{
fprintf(stderr, "%s: Missing SPI device path\n", prog);
exit(EXIT_FAILURE);
}
if (sMode == MODE_STDIO)
{
sHdlcInputFd = dup(STDIN_FILENO);
sHdlcOutputFd = dup(STDOUT_FILENO);
close(STDIN_FILENO);
close(STDOUT_FILENO);
}
else if (sMode == MODE_PTY)
{
#if HAVE_OPENPTY
static int pty_slave_fd = -1;
char pty_name[1024];
sRet = openpty(&sHdlcInputFd, &pty_slave_fd, pty_name, NULL, NULL);
if (sRet != 0)
{
perror("openpty");
goto bail;
}
sHdlcOutputFd = dup(sHdlcInputFd);
printf("%s\n", pty_name);
close(STDOUT_FILENO);
#else // if HAVE_OPENPTY
syslog(LOG_ERR, "Not built with support for `--pty`.");
sRet = EXIT_FAILURE;
goto bail;
#endif // else HAVE_OPENPTY
}
else
{
sRet = EXIT_FAILURE;
goto bail;
}
if ((sHdlcInputFd < 0) || (sHdlcOutputFd < 0))
{
sRet = EXIT_FAILURE;
goto bail;
}
// Set up sHdlcInputFd for non-blocking I/O
if (-1 == (i = fcntl(sHdlcInputFd, F_GETFL, 0)))
{
i = 0;
}
IGNORE_RETURN_VALUE(fcntl(sHdlcInputFd, F_SETFL, i | O_NONBLOCK));
// Since there are so few file descriptors in
// this program, we calculate `max_fd` once
// instead of trying to optimize its value
// at every iteration.
max_fd = sHdlcInputFd;
if (max_fd < sHdlcOutputFd)
{
max_fd = sHdlcOutputFd;
}
if (max_fd < sIntGpioValueFd)
{
max_fd = sIntGpioValueFd;
}
if (sIntGpioValueFd < 0)
{
syslog(LOG_WARNING, "Interrupt pin was not set, must poll SPI. Performance will suffer.");
}
trigger_reset();
// ========================================================================
// MAIN LOOP
while (sRet == 0)
{
int timeout_ms = MSEC_PER_SEC * 60 * 60 * 24; // 24 hours
FD_ZERO(&read_set);
FD_ZERO(&write_set);
FD_ZERO(&error_set);
if (!sSpiTxIsReady)
{
FD_SET(sHdlcInputFd, &read_set);
}
else
{
// We have data to send to the slave.
timeout_ms = 0;
}
if (sSpiRxPayloadSize != 0)
{
// We have data that we are waiting to send out
// of the HDLC descriptor, so we need to wait
// for that to clear out before we can do anything
// else.
FD_SET(sHdlcOutputFd, &write_set);
}
else if (sIntGpioValueFd >= 0)
{
if (check_and_clear_interrupt())
{
// Interrupt pin is asserted,
// set the timeout to be 0.
timeout_ms = 0;
syslog(LOG_DEBUG, "Interrupt.");
}
else
{
// The interrupt pin was not asserted,
// so we wait for the interrupt pin to
// be asserted by adding it to the error
// set.
FD_SET(sIntGpioValueFd, &error_set);
}
}
else if (timeout_ms > SPI_POLL_PERIOD_MSEC)
{
// In this case we don't have an interrupt, so
// we revert to SPI polling.
timeout_ms = SPI_POLL_PERIOD_MSEC;
}
if (sDumpStats)
{
timeout_ms = 0;
}
if (sSpiTxRefusedCount)
{
// We are being rate-limited by the slave. This is
// fairly normal behavior. We poll because we
// won't get an interrupt unless the slave happens
// to be trying to send us something.
if (timeout_ms < SPI_POLL_PERIOD_MSEC)
{
timeout_ms = SPI_POLL_PERIOD_MSEC;
}
if ( sSpiTxIsReady
&& !did_print_rate_limit_log
&& (sSpiTxRefusedCount > 1)
) {
// To avoid printing out this message over and over,
// we only print it out once the refused count is at
// two or higher when we actually have something to
// send the slave. And then, we only print it once.
syslog(LOG_INFO, "Slave is rate limiting transactions");
did_print_rate_limit_log = true;
}
if (sSpiTxRefusedCount == 30)
{
// Ua-oh. The slave hasn't given us a chance to send
// it anything for over thirty frames. If this ever
// happens, print out a warning to the logs.
syslog(LOG_WARNING, "Slave seems stuck.");
}
if (sSpiTxRefusedCount == 100)
{
// Double ua-oh. The slave hasn't given us a chance
// to send it anything for over a hundred frames.
// This almost certainly means that the slave has
// locked up or gotten into an unrecoverable state.
// It is not spi-hdlc-adapter's job to identify and
// reset misbehaving devices (that is handled at a
// higher level), but we go ahead and log the condition
// for debugging purposes.
syslog(LOG_ERR, "Slave seems REALLY stuck.");
}
}
else
{
did_print_rate_limit_log = false;
}
// Calculate the timeout value.
timeout.tv_sec = timeout_ms / MSEC_PER_SEC;
timeout.tv_usec = (timeout_ms % MSEC_PER_SEC) * USEC_PER_MSEC;
// Wait for something to happen.
IGNORE_RETURN_VALUE(select(max_fd + 1, &read_set, &write_set, &error_set, &timeout));
if (sDumpStats || sRet != 0)
{
sDumpStats = false;
syslog(LOG_NOTICE, "INFO: sSlaveResetCount=%llu", (unsigned long long)sSlaveResetCount);
syslog(LOG_NOTICE, "INFO: sSpiFrameCount=%llu", (unsigned long long)sSpiFrameCount);
syslog(LOG_NOTICE, "INFO: sSpiValidFrameCount=%llu", (unsigned long long)sSpiValidFrameCount);
syslog(LOG_NOTICE, "INFO: sSpiDuplexFrameCount=%llu", (unsigned long long)sSpiDuplexFrameCount);
syslog(LOG_NOTICE, "INFO: sSpiUnresponsiveFrameCount=%llu", (unsigned long long)sSpiUnresponsiveFrameCount);
syslog(LOG_NOTICE, "INFO: sSpiGarbageFrameCount=%llu", (unsigned long long)sSpiGarbageFrameCount);
syslog(LOG_NOTICE, "INFO: sHdlcTxFrameCount=%llu", (unsigned long long)sHdlcTxFrameCount);
syslog(LOG_NOTICE, "INFO: sHdlcTxFrameByteCount=%llu", (unsigned long long)sHdlcTxFrameByteCount);
syslog(LOG_NOTICE, "INFO: sHdlcRxFrameCount=%llu", (unsigned long long)sHdlcRxFrameCount);
syslog(LOG_NOTICE, "INFO: sHdlcRxFrameByteCount=%llu", (unsigned long long)sHdlcRxFrameByteCount);
syslog(LOG_NOTICE, "INFO: sHdlcRxBadCrcCount=%llu", (unsigned long long)sHdlcRxBadCrcCount);
}
// Handle serial input.
if (FD_ISSET(sHdlcInputFd, &read_set))
{
// Read in the data.
if ((sUseRawFrames ? pull_raw() : pull_hdlc()) < 0)
{
sRet = EXIT_FAILURE;
break;
}
}
// Handle serial output.
if (FD_ISSET(sHdlcOutputFd, &write_set))
{
// Write out the data.
if ((sUseRawFrames ? push_raw() : push_hdlc()) < 0)
{
sRet = EXIT_FAILURE;
break;
}
continue;
}
// Service the SPI port if we can receive
// a packet or we have a packet to be sent.
if ( (sSpiRxPayloadSize == 0)
&& (sSpiTxIsReady || check_and_clear_interrupt())
) {
// We guard this with the above check because we don't
// want to overwrite any previously received (but not
// yet pushed out) frames.
if (push_pull_spi() < 0)
{
sRet = EXIT_FAILURE;
}
}
}
// ========================================================================
// SHUTDOWN
bail:
syslog(LOG_NOTICE, "Shutdown. (sRet = %d)", sRet);
if (sRet == EXIT_QUIT)
{
sRet = EXIT_SUCCESS;
}
else if (sRet == -1)
{
sRet = EXIT_FAILURE;
}
return sRet;
}