libsigrok/hardware/common/serial.c

659 lines
17 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 <stdlib.h>
#include <glib.h>
#include <libserialport.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
/* Message logging helpers with subsystem-specific prefix string. */
#define LOG_PREFIX "serial: "
#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
#define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
/**
* 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 ret;
char *error;
int sp_flags = 0;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
sp_get_port_by_name(serial->port, &serial->data);
if (flags & SERIAL_RDWR)
sp_flags = (SP_MODE_READ | SP_MODE_WRITE);
else if (flags & SERIAL_RDONLY)
sp_flags = SP_MODE_READ;
serial->nonblocking = (flags & SERIAL_NONBLOCK) ? 1 : 0;
ret = sp_open(serial->data, sp_flags);
switch (ret) {
case SP_ERR_ARG:
sr_err("Attempt to open serial port with invalid parameters.");
return SR_ERR_ARG;
case SP_ERR_FAIL:
error = sp_last_error_message();
sr_err("Error opening port: %s.", error);
sp_free_error_message(error);
return SR_ERR;
}
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;
char *error;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (!serial->data) {
sr_dbg("Cannot close unopened serial port %s.", serial->port);
return SR_ERR;
}
sr_spew("Closing serial port %s.", serial->port);
ret = sp_close(serial->data);
switch (ret) {
case SP_ERR_ARG:
sr_err("Attempt to close an invalid serial port.");
return SR_ERR_ARG;
case SP_ERR_FAIL:
error = sp_last_error_message();
sr_err("Error closing port: %s.", error);
sp_free_error_message(error);
return SR_ERR;
}
sp_free_port(serial->data);
serial->data = NULL;
return SR_OK;
}
/**
* 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;
char *error;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (!serial->data) {
sr_dbg("Cannot flush unopened serial port %s.", serial->port);
return SR_ERR;
}
sr_spew("Flushing serial port %s.", serial->port);
ret = sp_flush(serial->data, SP_BUF_BOTH);
switch (ret) {
case SP_ERR_ARG:
sr_err("Attempt to flush an invalid serial port.");
return SR_ERR_ARG;
case SP_ERR_FAIL:
error = sp_last_error_message();
sr_err("Error flushing port: %s.", error);
sp_free_error_message(error);
return SR_ERR;
}
return SR_OK;
}
/**
* 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 a negative error code upon failure.
*/
SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
const void *buf, size_t count)
{
ssize_t ret;
char *error;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (!serial->data) {
sr_dbg("Cannot use unopened serial port %s.", serial->port);
return SR_ERR;
}
if (serial->nonblocking)
ret = sp_nonblocking_write(serial->data, buf, count);
else
ret = sp_blocking_write(serial->data, buf, count, 0);
switch (ret) {
case SP_ERR_ARG:
sr_err("Attempted serial port write with invalid arguments.");
return SR_ERR_ARG;
case SP_ERR_FAIL:
error = sp_last_error_message();
sr_err("Write error: %s.", error);
sp_free_error_message(error);
return SR_ERR;
}
sr_spew("Wrote %d/%d bytes.", ret, count);
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 a negative error code upon failure.
*/
SR_PRIV int serial_read(struct sr_serial_dev_inst *serial, void *buf,
size_t count)
{
ssize_t ret;
char *error;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (!serial->data) {
sr_dbg("Cannot use unopened serial port %s.", serial->port);
return SR_ERR;
}
if (serial->nonblocking)
ret = sp_nonblocking_read(serial->data, buf, count);
else
ret = sp_blocking_read(serial->data, buf, count, 0);
switch (ret) {
case SP_ERR_ARG:
sr_err("Attempted serial port read with invalid arguments.");
return SR_ERR_ARG;
case SP_ERR_FAIL:
error = sp_last_error_message();
sr_err("Read error: %s.", error);
sp_free_error_message(error);
return SR_ERR;
}
if (ret > 0)
sr_spew("Read %d/%d bytes.", ret, count);
return ret;
}
/**
* Set serial parameters for the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param[in] baudrate The baudrate to set.
* @param[in] bits The number of data bits to use (5, 6, 7 or 8).
* @param[in] parity The parity setting to use (0 = none, 1 = even, 2 = odd).
* @param[in] stopbits The number of stop bits to use (1 or 2).
* @param[in] flowcontrol The flow control settings to use (0 = none,
* 1 = RTS/CTS, 2 = XON/XOFF).
* @param[in] rts Status of RTS line (0 or 1; required by some interfaces).
* @param[in] dtr Status of DTR line (0 or 1; required by some interfaces).
*
* @retval SR_OK Success
* @retval SR_ERR 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)
{
int ret;
char *error;
struct sp_port_config *config;
if (!serial) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (!serial->data) {
sr_dbg("Cannot configure unopened serial port %s.", serial->port);
return SR_ERR;
}
sr_spew("Setting serial parameters on port %s.", serial->port);
sp_new_config(&config);
sp_set_config_baudrate(config, baudrate);
sp_set_config_bits(config, bits);
switch (parity) {
case 0:
sp_set_config_parity(config, SP_PARITY_NONE);
break;
case 1:
sp_set_config_parity(config, SP_PARITY_EVEN);
break;
case 2:
sp_set_config_parity(config, SP_PARITY_ODD);
break;
default:
return SR_ERR_ARG;
}
sp_set_config_stopbits(config, stopbits);
sp_set_config_rts(config, flowcontrol == 1 ? SP_RTS_FLOW_CONTROL : rts);
sp_set_config_cts(config, flowcontrol == 1 ? SP_CTS_FLOW_CONTROL : SP_CTS_IGNORE);
sp_set_config_dtr(config, dtr);
sp_set_config_dsr(config, SP_DSR_IGNORE);
sp_set_config_xon_xoff(config, flowcontrol == 2 ? SP_XONXOFF_INOUT : SP_XONXOFF_DISABLED);
ret = sp_set_config(serial->data, config);
sp_free_config(config);
switch (ret) {
case SP_ERR_ARG:
sr_err("Invalid arguments for setting serial port parameters.");
return SR_ERR_ARG;
case SP_ERR_FAIL:
error = sp_last_error_message();
sr_err("Error setting serial port parameters: %s.", error);
sp_free_error_message(error);
return SR_ERR;
}
return SR_OK;
}
/**
* Set serial parameters for the specified serial port.
*
* @param serial Previously initialized serial port structure.
* @param[in] 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.
*
* @retval SR_OK Success.
* @retval SR_ERR Failure.
*/
#define SERIAL_COMM_SPEC "^(\\d+)/([5678])([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[in] 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.
*
* @retval SR_OK Success.
* @retval SR_ERR 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) {
sr_dbg("Invalid serial port.");
return SR_ERR;
}
if (!serial->data) {
sr_dbg("Cannot use unopened serial port %s.", serial->port);
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;
if (len < 1)
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 buflen Size of the buffer.
* @param[in] packet_size Size, in bytes, of a valid packet.
* @param is_valid Callback that assesses whether the packet is valid or not.
* @param[in] timeout_ms The timeout after which, if no packet is detected, to
* abort scanning.
* @param[in] baudrate The baudrate of the serial port. This parameter is not
* critical, but it helps fine tune the serial port polling
* delay.
*
* @retval SR_OK Valid packet was found within the given timeout
* @retval SR_ERR 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 %s (timeout = %" PRIu64
"ms, baudrate = %d).", serial->port, 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;
}
if (len < 1)
g_usleep(byte_delay_us);
}
*buflen = ibuf;
sr_err("Didn't find a valid packet (read %d bytes).", *buflen);
return SR_ERR;
}
/**
* Extract the serial device and options from the options linked list.
*
* @param options List of options passed from the command line.
* @param serial_device Pointer where to store the exctracted serial device.
* @param serial_options Pointer where to store the optional extracted serial
* options.
*
* @return SR_OK if a serial_device is found, SR_ERR if no device is found. The
* returned string should not be freed by the caller.
*/
SR_PRIV int sr_serial_extract_options(GSList *options, const char **serial_device,
const char **serial_options)
{
GSList *l;
struct sr_config *src;
*serial_device = NULL;
for (l = options; l; l = l->next) {
src = l->data;
switch (src->key) {
case SR_CONF_CONN:
*serial_device = g_variant_get_string(src->data, NULL);
sr_dbg("Parsed serial device: %s", *serial_device);
break;
case SR_CONF_SERIALCOMM:
*serial_options = g_variant_get_string(src->data, NULL);
sr_dbg("Parsed serial options: %s", *serial_options);
break;
}
}
if (!*serial_device) {
sr_dbg("No serial device specified");
return SR_ERR;
}
return SR_OK;
}
SR_PRIV int serial_source_add(struct sr_serial_dev_inst *serial, int events,
int timeout, sr_receive_data_callback_t cb, void *cb_data)
{
#ifdef _WIN32
return SR_ERR;
#else
int fd;
sp_get_port_handle(serial->data, &fd);
return sr_source_add(fd, events, timeout, cb, cb_data);
#endif
}
SR_PRIV int serial_source_remove(struct sr_serial_dev_inst *serial)
{
#ifdef _WIN32
return SR_ERR;
#else
int fd;
sp_get_port_handle(serial->data, &fd);
return sr_source_remove(fd);
#endif
}