X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=hardware%2Fcommon%2Fserial.c;h=ebc6979763100a2399a5d9678ed666c16caa81db;hb=50a9aba21b912b44559290ece466b46aaa8840cf;hp=cebca29e418dd833007c37572a747d2c84d85cbc;hpb=e006af1116adb76014e77db718bb8673137a8bf5;p=libsigrok.git diff --git a/hardware/common/serial.c b/hardware/common/serial.c index cebca29e..ebc69797 100644 --- a/hardware/common/serial.c +++ b/hardware/common/serial.c @@ -1,7 +1,9 @@ /* - * This file is part of the sigrok project. + * This file is part of the libsigrok project. * - * Copyright (C) 2010 Bert Vermeulen + * Copyright (C) 2010-2012 Bert Vermeulen + * Copyright (C) 2010-2012 Uwe Hermann + * Copyright (C) 2012 Alexandru Gagniuc * * 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 @@ -23,157 +25,467 @@ #include #include #ifdef _WIN32 -#include +#include #else -#include #include +#include #endif #include +#include #include -#include +#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) // FIXME: Must be moved, or rather passed as function argument. #ifdef _WIN32 -HANDLE hdl; +static HANDLE hdl; #endif -char *serial_port_glob[] = { - /* Linux */ - "/dev/ttyS*", - "/dev/ttyUSB*", - "/dev/ttyACM*", - /* MacOS X */ - "/dev/ttys*", - "/dev/tty.USB-*", - "/dev/tty.Modem-*", - NULL, -}; - -GSList *list_serial_ports(void) +/** + * 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 - /* TODO */ -#else - glob_t g; - GSList *ports; - unsigned int i, j; + DWORD desired_access = 0, flags_and_attributes = 0; +#endif - ports = NULL; - for (i = 0; serial_port_glob[i]; i++) { - if (glob(serial_port_glob[i], 0, NULL, &g)) - continue; - for (j = 0; j < g.gl_pathc; j++) - ports = g_slist_append(ports, strdup(g.gl_pathv[j])); - globfree(&g); + if (!serial) { + sr_dbg("Invalid serial port."); + return SR_ERR; } - return ports; -#endif -} + sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags); -int serial_open(const char *pathname, int flags) -{ #ifdef _WIN32 - /* FIXME: Don't hardcode COM1. */ - hdl = CreateFile("COM1", GENERIC_READ | GENERIC_WRITE, 0, 0, - OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0); + /* 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) { - /* TODO: Error handling. */ + sr_err("Error opening serial port '%s'.", serial->port); + return SR_ERR; } - return 0; #else - return open(pathname, flags); + /* 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; } -int serial_close(int fd) +/** + * 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 - CloseHandle(hdl); + /* Returns non-zero upon success, 0 upon failure. */ + if (CloseHandle(hdl) == 0) + ret = SR_ERR; #else - return close(fd); + /* 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 -} -int serial_flush(int fd) -{ + serial->fd = -1; - return tcflush(fd, TCIOFLUSH); + return ret; } -void *serial_backup_params(int fd) +/** + * 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 - /* TODO */ + /* 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 - struct termios *term; + /* 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; + } - term = malloc(sizeof(struct termios)); - tcgetattr(fd, term); +#ifdef _WIN32 + DWORD tmp = 0; - return term; + /* 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; } -void serial_restore_params(int fd, void *backup) +/** + * 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 - /* TODO */ + DWORD tmp = 0; + + /* FIXME */ + /* Returns non-zero upon success, 0 upon failure. */ + return ReadFile(hdl, buf, count, &tmp, NULL); #else - tcsetattr(fd, TCSADRAIN, (struct termios *)backup); + /* Returns the number of bytes read, or -1 upon failure. */ + ret = read(serial->fd, buf, count); #endif + + return ret; } -/* - * flowcontrol 1 = rts/cts 2 = xon/xoff - * parity 0 = none, 1 = even, 2 = odd +/** + * 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. */ -int serial_set_params(int fd, int speed, int bits, int parity, int stopbits, - int flowcontrol) +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)) { - /* TODO: Error handling. */ + sr_err("Failed to get comm state on port %s (fd %d): %d.", + serial->port, serial->fd, GetLastError()); + return SR_ERR; } - /* TODO: Rename 'speed' to 'baudrate'. */ - switch(speed) { - case 115200: - dcb.BaudRate = CBR_115200; + 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 57600: - dcb.BaudRate = CBR_57600; + case 300: + dcb.BaudRate = CBR_300; break; - case 38400: - dcb.BaudRate = CBR_38400; + case 600: + dcb.BaudRate = CBR_600; break; - case 19200: - dcb.BaudRate = CBR_19200; + 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; - default: - /* TODO: Error handling. */ + 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; - dcb.Parity = NOPARITY; /* TODO: Don't hardcode. */ - dcb.StopBits = ONESTOPBIT; /* TODO: Don't hardcode. */ + + 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)) { - /* TODO: Error handling. */ + 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 (speed) { + 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; @@ -183,18 +495,32 @@ int serial_set_params(int fd, int speed, int bits, int parity, int stopbits, case 115200: baud = B115200; break; + case 230400: + baud = B230400; + break; +#if !defined(__APPLE__) && !defined(__OpenBSD__) case 460800: baud = B460800; break; +#endif default: - return SIGROK_ERR; + sr_err("Unsupported baudrate: %d.", baudrate); + return SR_ERR; } - if (tcgetattr(fd, &term) < 0) - return SIGROK_ERR; - if (cfsetispeed(&term, baud) < 0) - return SIGROK_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: @@ -204,48 +530,354 @@ int serial_set_params(int fd, int speed, int bits, int parity, int stopbits, term.c_cflag |= CS7; break; default: - return SIGROK_ERR; + 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: - return SIGROK_ERR; + sr_err("Unsupported stopbits number %d.", stopbits); + return SR_ERR; } - term.c_cflag &= ~(IXON | IXOFF | CRTSCTS); + term.c_iflag &= ~(IXON | IXOFF | IXANY); + term.c_cflag &= ~CRTSCTS; switch (flowcontrol) { - case 2: - term.c_cflag |= IXON | IXOFF; + 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 | IXANY); + break; default: - return SIGROK_ERR; + sr_err("Unsupported flow control setting %d.", flowcontrol); + return SR_ERR; } - term.c_iflag &= ~(IGNPAR | PARODD | PARENB); + term.c_iflag &= ~IGNPAR; + term.c_cflag &= ~(PARENB | PARODD); switch (parity) { - case 0: + case SERIAL_PARITY_NONE: + sr_spew("Configuring no parity."); term.c_iflag |= IGNPAR; break; - case 1: - term.c_iflag |= PARENB; + case SERIAL_PARITY_EVEN: + sr_spew("Configuring even parity."); + term.c_cflag |= PARENB; break; - case 2: - term.c_iflag |= PARENB | PARODD; + case SERIAL_PARITY_ODD: + sr_spew("Configuring odd parity."); + term.c_cflag |= PARENB | PARODD; break; default: - return SIGROK_ERR; + 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 &= ~(OPOST | 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); + + /* Ignore modem status lines; enable receiver */ + term.c_cflag |= (CLOCAL | CREAD); + + /* 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; + } } - if (tcsetattr(fd, TCSADRAIN, &term) < 0) - return SIGROK_ERR; #endif - return SIGROK_OK; + 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 /, 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; + 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 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; + } + 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; }