libsigrok/hardware/common/serial.c

880 lines
21 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
* Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <glob.h>
#include <termios.h>
#include <sys/ioctl.h>
#endif
#include <stdlib.h>
#include <errno.h>
#include <glib.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
/* Message logging helpers with driver-specific prefix string. */
#define DRIVER_LOG_DOMAIN "serial: "
#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
// FIXME: Must be moved, or rather passed as function argument.
#ifdef _WIN32
static HANDLE hdl;
#endif
/**
* Open the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param flags Flags to use when opening the serial port. Possible flags
* include SERIAL_RDWR, SERIAL_RDONLY, SERIAL_NONBLOCK.
*
* If the serial structure contains a serialcomm string, it will be
* passed to serial_set_paramstr() after the port is opened.
*
* @return SR_OK on success, SR_ERR on failure.
*/
SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags)
{
int flags_local = 0;
#ifdef _WIN32
DWORD desired_access = 0, flags_and_attributes = 0;
#endif
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
#ifdef _WIN32
/* Map 'flags' to the OS-specific settings. */
desired_access |= GENERIC_READ;
flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
if (flags & SERIAL_RDWR)
desired_access |= GENERIC_WRITE;
if (flags & SERIAL_NONBLOCK)
flags_and_attributes |= FILE_FLAG_OVERLAPPED;
hdl = CreateFile(serial->port, desired_access, 0, 0,
OPEN_EXISTING, flags_and_attributes, 0);
if (hdl == INVALID_HANDLE_VALUE) {
sr_err("Error opening serial port '%s'.", serial->port);
return SR_ERR;
}
#else
/* Map 'flags' to the OS-specific settings. */
if (flags & SERIAL_RDWR)
flags_local |= O_RDWR;
if (flags & SERIAL_RDONLY)
flags_local |= O_RDONLY;
if (flags & SERIAL_NONBLOCK)
flags_local |= O_NONBLOCK;
if ((serial->fd = open(serial->port, flags_local)) < 0) {
sr_err("Error opening serial port '%s': %s.", serial->port,
strerror(errno));
return SR_ERR;
}
sr_spew("Opened serial port '%s' (fd %d).", serial->port, serial->fd);
#endif
if (serial->serialcomm)
return serial_set_paramstr(serial, serial->serialcomm);
else
return SR_OK;
}
/**
* Close the specified serial port.
*
* @param serial Previously initialized serial port structure.
*
* @return SR_OK on success, SR_ERR on failure.
*/
SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
{
int ret;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (serial->fd == -1) {
sr_dbg("Cannot close unopened serial port %s (fd %d).",
serial->port, serial->fd);
return SR_ERR;
}
sr_spew("Closing serial port %s (fd %d).", serial->port, serial->fd);
ret = SR_OK;
#ifdef _WIN32
/* Returns non-zero upon success, 0 upon failure. */
if (CloseHandle(hdl) == 0)
ret = SR_ERR;
#else
/* Returns 0 upon success, -1 upon failure. */
if (close(serial->fd) < 0) {
sr_err("Error closing serial port: %s (fd %d).", strerror(errno),
serial->fd);
ret = SR_ERR;
}
#endif
serial->fd = -1;
return ret;
}
/**
* Flush serial port buffers.
*
* @param serial Previously initialized serial port structure.
*
* @return SR_OK on success, SR_ERR on failure.
*/
SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
{
int ret;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (serial->fd == -1) {
sr_dbg("Cannot flush unopened serial port %s (fd %d).",
serial->port, serial->fd);
return SR_ERR;
}
sr_spew("Flushing serial port %s (fd %d).", serial->port, serial->fd);
ret = SR_OK;
#ifdef _WIN32
/* Returns non-zero upon success, 0 upon failure. */
if (PurgeComm(hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0) {
sr_err("Error flushing serial port: %s.", strerror(errno));
ret = SR_ERR;
}
#else
/* Returns 0 upon success, -1 upon failure. */
if (tcflush(serial->fd, TCIOFLUSH) < 0) {
sr_err("Error flushing serial port: %s.", strerror(errno));
ret = SR_ERR;
}
return ret;
#endif
}
/**
* Write a number of bytes to the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param buf Buffer containing the bytes to write.
* @param count Number of bytes to write.
*
* @return The number of bytes written, or -1 upon failure.
*/
SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
const void *buf, size_t count)
{
ssize_t ret;
if (!serial) {
sr_dbg("Invalid serial port.");
return -1;
}
if (serial->fd == -1) {
sr_dbg("Cannot use unopened serial port %s (fd %d).",
serial->port, serial->fd);
return -1;
}
#ifdef _WIN32
DWORD tmp = 0;
/* FIXME */
/* Returns non-zero upon success, 0 upon failure. */
WriteFile(hdl, buf, count, &tmp, NULL);
#else
/* Returns the number of bytes written, or -1 upon failure. */
ret = write(serial->fd, buf, count);
if (ret < 0)
sr_err("Write error: %s.", strerror(errno));
else
sr_spew("Wrote %d/%d bytes (fd %d).", ret, count, serial->fd);
#endif
return ret;
}
/**
* Read a number of bytes from the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param buf Buffer where to store the bytes that are read.
* @param count The number of bytes to read.
*
* @return The number of bytes read, or -1 upon failure.
*/
SR_PRIV int serial_read(struct sr_serial_dev_inst *serial, void *buf,
size_t count)
{
ssize_t ret;
if (!serial) {
sr_dbg("Invalid serial port.");
return -1;
}
if (serial->fd == -1) {
sr_dbg("Cannot use unopened serial port %s (fd %d).",
serial->port, serial->fd);
return -1;
}
#ifdef _WIN32
DWORD tmp = 0;
/* FIXME */
/* Returns non-zero upon success, 0 upon failure. */
return ReadFile(hdl, buf, count, &tmp, NULL);
#else
/* Returns the number of bytes read, or -1 upon failure. */
ret = read(serial->fd, buf, count);
#endif
return ret;
}
/**
* Set serial parameters for the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param baudrate The baudrate to set.
* @param bits The number of data bits to use.
* @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
* @param stopbits The number of stop bits to use (1 or 2).
* @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
* 2 = XON/XOFF).
*
* @return SR_OK upon success, SR_ERR upon failure.
*/
SR_PRIV int serial_set_params(struct sr_serial_dev_inst *serial, int baudrate,
int bits, int parity, int stopbits,
int flowcontrol, int rts, int dtr)
{
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (serial->fd == -1) {
sr_dbg("Cannot configure unopened serial port %s (fd %d).",
serial->port, serial->fd);
return SR_ERR;
}
sr_spew("Setting serial parameters on port %s (fd %d).", serial->port,
serial->fd);
#ifdef _WIN32
DCB dcb;
if (!GetCommState(hdl, &dcb)) {
sr_err("Failed to get comm state on port %s (fd %d): %d.",
serial->port, serial->fd, GetLastError());
return SR_ERR;
}
switch (baudrate) {
/*
* The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
* have documented CBR_* macros.
*/
case 110:
dcb.BaudRate = CBR_110;
break;
case 300:
dcb.BaudRate = CBR_300;
break;
case 600:
dcb.BaudRate = CBR_600;
break;
case 1200:
dcb.BaudRate = CBR_1200;
break;
case 2400:
dcb.BaudRate = CBR_2400;
break;
case 4800:
dcb.BaudRate = CBR_4800;
break;
case 9600:
dcb.BaudRate = CBR_9600;
break;
case 14400:
dcb.BaudRate = CBR_14400; /* Not available on Unix? */
break;
case 19200:
dcb.BaudRate = CBR_19200;
break;
case 38400:
dcb.BaudRate = CBR_38400;
break;
case 57600:
dcb.BaudRate = CBR_57600;
break;
case 115200:
dcb.BaudRate = CBR_115200;
break;
case 128000:
dcb.BaudRate = CBR_128000; /* Not available on Unix? */
break;
case 256000:
dcb.BaudRate = CBR_256000; /* Not available on Unix? */
break;
default:
sr_err("Unsupported baudrate: %d.", baudrate);
return SR_ERR;
}
sr_spew("Configuring baudrate to %d (%d).", baudrate, dcb.BaudRate);
sr_spew("Configuring %d data bits.", bits);
dcb.ByteSize = bits;
sr_spew("Configuring %d stop bits.", stopbits);
switch (stopbits) {
/* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
case 1:
dcb.StopBits = ONESTOPBIT;
break;
case 2:
dcb.StopBits = TWOSTOPBITS;
break;
default:
sr_err("Unsupported stopbits number: %d.", stopbits);
return SR_ERR;
}
switch (parity) {
/* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
case SERIAL_PARITY_NONE:
sr_spew("Configuring no parity.");
dcb.Parity = NOPARITY;
break;
case SERIAL_PARITY_EVEN:
sr_spew("Configuring even parity.");
dcb.Parity = EVENPARITY;
break;
case SERIAL_PARITY_ODD:
sr_spew("Configuring odd parity.");
dcb.Parity = ODDPARITY;
break;
default:
sr_err("Unsupported parity setting: %d.", parity);
return SR_ERR;
}
if (rts != -1) {
sr_spew("Setting RTS %s.", rts ? "high" : "low");
if (rts)
dcb.fRtsControl = RTS_CONTROL_ENABLE;
else
dcb.fRtsControl = RTS_CONTROL_DISABLE;
}
if (dtr != -1) {
sr_spew("Setting DTR %s.", dtr ? "high" : "low");
if (dtr)
dcb.fDtrControl = DTR_CONTROL_ENABLE;
else
dcb.fDtrControl = DTR_CONTROL_DISABLE;
}
if (!SetCommState(hdl, &dcb)) {
sr_err("Failed to set comm state on port %s (fd %d): %d.",
serial->port, serial->fd, GetLastError());
return SR_ERR;
}
#else
struct termios term;
speed_t baud;
int ret, controlbits;
if (tcgetattr(serial->fd, &term) < 0) {
sr_err("tcgetattr() error on port %s (fd %d): %s.",
serial->port, serial->fd, strerror(errno));
return SR_ERR;
}
switch (baudrate) {
case 50:
baud = B50;
break;
case 75:
baud = B75;
break;
case 110:
baud = B110;
break;
case 134:
baud = B134;
break;
case 150:
baud = B150;
break;
case 200:
baud = B200;
break;
case 300:
baud = B300;
break;
case 600:
baud = B600;
break;
case 1200:
baud = B1200;
break;
case 1800:
baud = B1800;
break;
case 2400:
baud = B2400;
break;
case 4800:
baud = B4800;
break;
case 9600:
baud = B9600;
break;
case 19200:
baud = B19200;
break;
case 38400:
baud = B38400;
break;
case 57600:
baud = B57600;
break;
case 115200:
baud = B115200;
break;
case 230400:
baud = B230400;
break;
#if !defined(__APPLE__) && !defined(__OpenBSD__)
case 460800:
baud = B460800;
break;
#endif
default:
sr_err("Unsupported baudrate: %d.", baudrate);
return SR_ERR;
}
sr_spew("Configuring output baudrate to %d (%d).", baudrate, baud);
if (cfsetospeed(&term, baud) < 0) {
sr_err("cfsetospeed() error: %s.", strerror(errno));
return SR_ERR;
}
sr_spew("Configuring input baudrate to %d (%d).", baudrate, baud);
if (cfsetispeed(&term, baud) < 0) {
sr_err("cfsetispeed() error: %s.", strerror(errno));
return SR_ERR;
}
sr_spew("Configuring %d data bits.", bits);
term.c_cflag &= ~CSIZE;
switch (bits) {
case 8:
term.c_cflag |= CS8;
break;
case 7:
term.c_cflag |= CS7;
break;
default:
sr_err("Unsupported data bits number %d.", bits);
return SR_ERR;
}
sr_spew("Configuring %d stop bits.", stopbits);
term.c_cflag &= ~CSTOPB;
switch (stopbits) {
case 1:
term.c_cflag &= ~CSTOPB;
break;
case 2:
term.c_cflag |= CSTOPB;
break;
default:
sr_err("Unsupported stopbits number %d.", stopbits);
return SR_ERR;
}
term.c_iflag &= ~(IXON | IXOFF);
term.c_cflag &= ~CRTSCTS;
switch (flowcontrol) {
case 0:
/* No flow control. */
sr_spew("Configuring no flow control.");
break;
case 1:
sr_spew("Configuring RTS/CTS flow control.");
term.c_cflag |= CRTSCTS;
break;
case 2:
sr_spew("Configuring XON/XOFF flow control.");
term.c_iflag |= IXON | IXOFF;
break;
default:
sr_err("Unsupported flow control setting %d.", flowcontrol);
return SR_ERR;
}
term.c_iflag &= ~IGNPAR;
term.c_cflag &= ~(PARODD | PARENB);
switch (parity) {
case SERIAL_PARITY_NONE:
sr_spew("Configuring no parity.");
term.c_iflag |= IGNPAR;
break;
case SERIAL_PARITY_EVEN:
sr_spew("Configuring even parity.");
term.c_cflag |= PARENB;
break;
case SERIAL_PARITY_ODD:
sr_spew("Configuring odd parity.");
term.c_cflag |= PARENB | PARODD;
break;
default:
sr_err("Unsupported parity setting %d.", parity);
return SR_ERR;
}
/* Turn off all serial port cooking. */
term.c_iflag &= ~(ISTRIP | INLCR | ICRNL);
term.c_oflag &= ~(ONLCR | OCRNL | ONOCR);
#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
term.c_oflag &= ~OFILL;
#endif
/* Disable canonical mode, and don't echo input characters. */
term.c_lflag &= ~(ICANON | ECHO);
/* Write the configured settings. */
if (tcsetattr(serial->fd, TCSADRAIN, &term) < 0) {
sr_err("tcsetattr() error: %s.", strerror(errno));
return SR_ERR;
}
if (rts != -1) {
sr_spew("Setting RTS %s.", rts ? "high" : "low");
controlbits = TIOCM_RTS;
if ((ret = ioctl(serial->fd, rts ? TIOCMBIS : TIOCMBIC,
&controlbits)) < 0) {
sr_err("Error setting RTS: %s.", strerror(errno));
return SR_ERR;
}
}
if (dtr != -1) {
sr_spew("Setting DTR %s.", dtr ? "high" : "low");
controlbits = TIOCM_DTR;
if ((ret = ioctl(serial->fd, dtr ? TIOCMBIS : TIOCMBIC,
&controlbits)) < 0) {
sr_err("Error setting DTR: %s.", strerror(errno));
return SR_ERR;
}
}
#endif
return SR_OK;
}
/**
* Set serial parameters for the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param paramstr A serial communication parameters string, in the form
* of <speed>/<data bits><parity><stopbits><flow>, for example "9600/8n1" or
* "600/7o2" or "460800/8n1/flow=2" where flow is 0 for none, 1 for rts/cts and 2 for xon/xoff.
*
* @return SR_OK upon success, SR_ERR upon failure.
*/
#define SERIAL_COMM_SPEC "^(\\d+)/([78])([neo])([12])(.*)$"
SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
const char *paramstr)
{
GRegex *reg;
GMatchInfo *match;
int speed, databits, parity, stopbits, flow, rts, dtr, i;
char *mstr, **opts, **kv;
speed = databits = parity = stopbits = flow = 0;
rts = dtr = -1;
sr_spew("Parsing parameters from \"%s\".", paramstr);
reg = g_regex_new(SERIAL_COMM_SPEC, 0, 0, NULL);
if (g_regex_match(reg, paramstr, 0, &match)) {
if ((mstr = g_match_info_fetch(match, 1)))
speed = strtoul(mstr, NULL, 10);
g_free(mstr);
if ((mstr = g_match_info_fetch(match, 2)))
databits = strtoul(mstr, NULL, 10);
g_free(mstr);
if ((mstr = g_match_info_fetch(match, 3))) {
switch (mstr[0]) {
case 'n':
parity = SERIAL_PARITY_NONE;
break;
case 'e':
parity = SERIAL_PARITY_EVEN;
break;
case 'o':
parity = SERIAL_PARITY_ODD;
break;
}
}
g_free(mstr);
if ((mstr = g_match_info_fetch(match, 4)))
stopbits = strtoul(mstr, NULL, 10);
g_free(mstr);
if ((mstr = g_match_info_fetch(match, 5)) && mstr[0] != '\0') {
if (mstr[0] != '/') {
sr_dbg("missing separator before extra options");
speed = 0;
} else {
/* A set of "key=value" options separated by / */
opts = g_strsplit(mstr + 1, "/", 0);
for (i = 0; opts[i]; i++) {
kv = g_strsplit(opts[i], "=", 2);
if (!strncmp(kv[0], "rts", 3)) {
if (kv[1][0] == '1')
rts = 1;
else if (kv[1][0] == '0')
rts = 0;
else {
sr_dbg("invalid value for rts: %c", kv[1][0]);
speed = 0;
}
} else if (!strncmp(kv[0], "dtr", 3)) {
if (kv[1][0] == '1')
dtr = 1;
else if (kv[1][0] == '0')
dtr = 0;
else {
sr_dbg("invalid value for dtr: %c", kv[1][0]);
speed = 0;
}
} else if (!strncmp(kv[0], "flow", 4)) {
if (kv[1][0] == '0')
flow = 0;
else if (kv[1][0] == '1')
flow = 1;
else if (kv[1][0] == '2')
flow = 2;
else {
sr_dbg("invalid value for flow: %c", kv[1][0]);
speed = 0;
}
}
g_strfreev(kv);
}
g_strfreev(opts);
}
}
g_free(mstr);
}
g_match_info_unref(match);
g_regex_unref(reg);
if (speed) {
return serial_set_params(serial, speed, databits, parity,
stopbits, flow, rts, dtr);
} else {
sr_dbg("Could not infer speed from parameter string.");
return SR_ERR_ARG;
}
}
/**
* Read a line from the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param buf Buffer where to store the bytes that are read.
* @param buflen Size of the buffer.
* @param timeout_ms How long to wait for a line to come in.
*
* Reading stops when CR of LR is found, which is stripped from the buffer.
*
* @return SR_OK on success, SR_ERR on failure.
*/
SR_PRIV int serial_readline(struct sr_serial_dev_inst *serial, char **buf,
int *buflen, gint64 timeout_ms)
{
gint64 start;
int maxlen, len;
if (!serial || serial->fd == -1) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (serial->fd == -1) {
sr_dbg("Cannot use unopened serial port %s (fd %d).",
serial->port, serial->fd);
return -1;
}
timeout_ms *= 1000;
start = g_get_monotonic_time();
maxlen = *buflen;
*buflen = len = 0;
while(1) {
len = maxlen - *buflen - 1;
if (len < 1)
break;
len = serial_read(serial, *buf + *buflen, 1);
if (len > 0) {
*buflen += len;
*(*buf + *buflen) = '\0';
if (*buflen > 0 && (*(*buf + *buflen - 1) == '\r'
|| *(*buf + *buflen - 1) == '\n')) {
/* Strip CR/LF and terminate. */
*(*buf + --*buflen) = '\0';
break;
}
}
if (g_get_monotonic_time() - start > timeout_ms)
/* Timeout */
break;
g_usleep(2000);
}
if (*buflen)
sr_dbg("Received %d: '%s'.", *buflen, *buf);
return SR_OK;
}
/**
* Try to find a valid packet in a serial data stream.
*
* @param serial Previously initialized serial port structure.
* @param buf Buffer containing the bytes to write.
* @param count Size of the buffer.
* @param packet_size Size, in bytes, of a valid packet.
* @param is_valid Callback that assesses whether the packet is valid or not.
* @param timeout_ms The timeout after which, if no packet is detected, to
* abort scanning.
* @param baudrate The baudrate of the serial port. This parameter is not
* critical, but it helps fine tune the serial port polling
* delay.
*
* @return SR_OK if a valid packet is found within the given timeout,
* SR_ERR upon failure.
*/
SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
uint8_t *buf, size_t *buflen,
size_t packet_size, packet_valid_t is_valid,
uint64_t timeout_ms, int baudrate)
{
uint64_t start, time, byte_delay_us;
size_t ibuf, i, maxlen;
int len;
maxlen = *buflen;
sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
"ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
if (maxlen < (packet_size / 2) ) {
sr_err("Buffer size must be at least twice the packet size.");
return SR_ERR;
}
/* Assume 8n1 transmission. That is 10 bits for every byte. */
byte_delay_us = 10 * (1000000 / baudrate);
start = g_get_monotonic_time();
i = ibuf = len = 0;
while (ibuf < maxlen) {
len = serial_read(serial, &buf[ibuf], 1);
if (len > 0) {
ibuf += len;
} else if (len == 0) {
/* No logging, already done in serial_read(). */
} else {
/* Error reading byte, but continuing anyway. */
}
time = g_get_monotonic_time() - start;
time /= 1000;
if ((ibuf - i) >= packet_size) {
/* We have at least a packet's worth of data. */
if (is_valid(&buf[i])) {
sr_spew("Found valid %d-byte packet after "
"%" PRIu64 "ms.", (ibuf - i), time);
*buflen = ibuf;
return SR_OK;
} else {
sr_spew("Got %d bytes, but not a valid "
"packet.", (ibuf - i));
}
/* Not a valid packet. Continue searching. */
i++;
}
if (time >= timeout_ms) {
/* Timeout */
sr_dbg("Detection timed out after %dms.", time);
break;
}
g_usleep(byte_delay_us);
}
*buflen = ibuf;
sr_err("Didn't find a valid packet (read %d bytes).", *buflen);
return SR_ERR;
}