]> sigrok.org Git - libserialport.git/commitdiff
Refactor port configuration code.
authorMartin Ling <redacted>
Mon, 18 Nov 2013 19:52:37 +0000 (19:52 +0000)
committerMartin Ling <redacted>
Mon, 18 Nov 2013 19:52:37 +0000 (19:52 +0000)
serialport.c

index 269992e83a6cc2efe7ad85883c970ce384d870a3..e86bd3e5684bb1e7ff1afa72082c0839653541b3 100644 (file)
@@ -52,10 +52,6 @@ struct sp_port_data {
 #else
        struct termios term;
        int controlbits;
-       int rts;
-       int cts;
-       int dtr;
-       int dsr;
 #endif
 };
 
@@ -96,17 +92,8 @@ const struct std_baudrate std_baudrates[] = {
 #define NUM_STD_BAUDRATES ARRAY_SIZE(std_baudrates)
 
 /* Helper functions for configuring ports. */
-static int start_config(struct sp_port *port, struct sp_port_data *data);
-static int set_baudrate(struct sp_port_data *data, int baudrate);
-static int set_bits(struct sp_port_data *data, int bits);
-static int set_parity(struct sp_port_data *data, int parity);
-static int set_stopbits(struct sp_port_data *data, int stopbits);
-static int set_rts(struct sp_port_data *data, int rts);
-static int set_cts(struct sp_port_data *data, int cts);
-static int set_dtr(struct sp_port_data *data, int dtr);
-static int set_dsr(struct sp_port_data *data, int dsr);
-static int set_xon_xoff(struct sp_port_data *data, int xon_xoff);
-static int apply_config(struct sp_port *port, struct sp_port_data *data);
+static int get_config(struct sp_port *port, struct sp_port_data *data, struct sp_port_config *config);
+static int set_config(struct sp_port *port, struct sp_port_data *data, struct sp_port_config *config);
 
 int sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
 {
@@ -450,6 +437,8 @@ int sp_open(struct sp_port *port, int flags)
 #else
        int flags_local = 0;
        struct sp_port_data data;
+       struct sp_port_config config;
+       int ret;
 
        /* Map 'flags' to the OS-specific settings. */
        if (flags & SP_MODE_RDWR)
@@ -462,7 +451,13 @@ int sp_open(struct sp_port *port, int flags)
        if ((port->fd = open(port->name, flags_local)) < 0)
                return SP_ERR_FAIL;
 
-       start_config(port, &data);
+       ret = get_config(port, &data, &config);
+
+       if (ret < 0)
+       {
+               sp_close(port);
+               return ret;
+       }
 
        /* Turn off all serial port cooking. */
        data.term.c_iflag &= ~(ISTRIP | INLCR | ICRNL);
@@ -476,7 +471,13 @@ int sp_open(struct sp_port *port, int flags)
        /* Ignore modem status lines; enable receiver */
        data.term.c_cflag |= (CLOCAL | CREAD);
 
-       apply_config(port, &data);
+       ret = set_config(port, &data, &config);
+
+       if (ret < 0)
+       {
+               sp_close(port);
+               return ret;
+       }
 #endif
 
        return SP_OK;
@@ -564,344 +565,16 @@ int sp_read(struct sp_port *port, void *buf, size_t count)
 #endif
 }
 
-static int start_config(struct sp_port *port, struct sp_port_data *data)
-{
-       CHECK_PORT();
-#ifdef _WIN32
-       if (!GetCommState(port->hdl, &data->dcb))
-               return SP_ERR_FAIL;
-#else
-       if (tcgetattr(port->fd, &data->term) < 0)
-               return SP_ERR_FAIL;
-
-       if (ioctl(port->fd, TIOCMGET, &data->controlbits) < 0)
-               return SP_ERR_FAIL;
-
-       if (data->term.c_cflag & CRTSCTS) {
-               data->rts = SP_RTS_FLOW_CONTROL;
-               data->cts = SP_CTS_FLOW_CONTROL;
-       } else {
-               data->rts = (data->controlbits & TIOCM_RTS) ? SP_RTS_ON : SP_RTS_OFF;
-               data->cts = SP_CTS_IGNORE;
-       }
-
-       data->dtr = (data->controlbits & TIOCM_DTR) ? SP_DTR_ON : SP_DTR_OFF;
-       data->dsr = SP_DSR_IGNORE;
-#endif
-       return SP_OK;
-}
-
-static int set_baudrate(struct sp_port_data *data, int baudrate)
+static int get_config(struct sp_port *port, struct sp_port_data *data, struct sp_port_config *config)
 {
        unsigned int i;
-       for (i = 0; i < NUM_STD_BAUDRATES; i++) {
-               if (baudrate == std_baudrates[i].value) {
-#ifdef _WIN32
-                       data->dcb.BaudRate = std_baudrates[i].index;
-#else
-                       if (cfsetospeed(&data->term, std_baudrates[i].index) < 0)
-                               return SP_ERR_FAIL;
-
-                       if (cfsetispeed(&data->term, std_baudrates[i].index) < 0)
-                               return SP_ERR_FAIL;
-#endif
-                       break;
-               }
-       }
-
-       if (i == NUM_STD_BAUDRATES)
-               return SP_ERR_ARG;
 
-       return SP_OK;
-}
-
-static int set_bits(struct sp_port_data *data, int bits)
-{
 #ifdef _WIN32
-       data->dcb.ByteSize = bits;
-#else
-       data->term.c_cflag &= ~CSIZE;
-       switch (bits) {
-       case 8:
-               data->term.c_cflag |= CS8;
-               break;
-       case 7:
-               data->term.c_cflag |= CS7;
-               break;
-       case 6:
-               data->term.c_cflag |= CS6;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
-}
-
-static int set_parity(struct sp_port_data *data, int parity)
-{
-#ifdef _WIN32
-       switch (parity) {
-       /* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
-       case SP_PARITY_NONE:
-               data->dcb.Parity = NOPARITY;
-               break;
-       case SP_PARITY_EVEN:
-               data->dcb.Parity = EVENPARITY;
-               break;
-       case SP_PARITY_ODD:
-               data->dcb.Parity = ODDPARITY;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->term.c_iflag &= ~IGNPAR;
-       data->term.c_cflag &= ~(PARENB | PARODD);
-       switch (parity) {
-       case SP_PARITY_NONE:
-               data->term.c_iflag |= IGNPAR;
-               break;
-       case SP_PARITY_EVEN:
-               data->term.c_cflag |= PARENB;
-               break;
-       case SP_PARITY_ODD:
-               data->term.c_cflag |= PARENB | PARODD;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
-}
-
-static int set_stopbits(struct sp_port_data *data, int stopbits)
-{
-#ifdef _WIN32
-       switch (stopbits) {
-       /* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
-       case 1:
-               data->dcb.StopBits = ONESTOPBIT;
-               break;
-       case 2:
-               data->dcb.StopBits = TWOSTOPBITS;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->term.c_cflag &= ~CSTOPB;
-       switch (stopbits) {
-       case 1:
-               data->term.c_cflag &= ~CSTOPB;
-               break;
-       case 2:
-               data->term.c_cflag |= CSTOPB;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
-}
-
-static int set_rts(struct sp_port_data *data, int rts)
-{
-#ifdef _WIN32
-       switch (rts) {
-       case SP_RTS_OFF:
-               data->dcb.fRtsControl = RTS_CONTROL_DISABLE;
-               break;
-       case SP_RTS_ON:
-               data->dcb.fRtsControl = RTS_CONTROL_ENABLE;
-               break;
-       case SP_RTS_FLOW_CONTROL:
-               data->dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->rts = rts;
-#endif
-       return SP_OK;
-}
-
-static int set_cts(struct sp_port_data *data, int cts)
-{
-#ifdef _WIN32
-       switch (cts) {
-       case SP_CTS_IGNORE:
-               data->dcb.fOutxCtsFlow = FALSE;
-               break;
-       case SP_CTS_FLOW_CONTROL:
-               data->dcb.fOutxCtsFlow = TRUE;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->cts = cts;
-#endif
-       return SP_OK;
-}
-
-static int set_dtr(struct sp_port_data *data, int dtr)
-{
-#ifdef _WIN32
-       switch (dtr) {
-       case SP_DTR_OFF:
-               data->dcb.fDtrControl = DTR_CONTROL_DISABLE;
-               break;
-       case SP_DTR_ON:
-               data->dcb.fDtrControl = DTR_CONTROL_ENABLE;
-               break;
-       case SP_DTR_FLOW_CONTROL:
-               data->dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->dtr = dtr;
-#endif
-       return SP_OK;
-}
-
-static int set_dsr(struct sp_port_data *data, int dsr)
-{
-#ifdef _WIN32
-       switch (dsr) {
-       case SP_DSR_IGNORE:
-               data->dcb.fOutxDsrFlow = FALSE;
-               break;
-       case SP_DSR_FLOW_CONTROL:
-               data->dcb.fOutxDsrFlow = TRUE;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->dsr = dsr;
-#endif
-       return SP_OK;
-}
-
-static int set_xon_xoff(struct sp_port_data *data, int xon_xoff)
-{
-#ifdef _WIN32
-       switch (xon_xoff) {
-       case SP_XONXOFF_DISABLED:
-               data->dcb.fInX = FALSE;
-               data->dcb.fOutX = FALSE;
-               break;
-       case SP_XONXOFF_IN:
-               data->dcb.fInX = TRUE;
-               data->dcb.fOutX = FALSE;
-               break;
-       case SP_XONXOFF_OUT:
-               data->dcb.fInX = FALSE;
-               data->dcb.fOutX = TRUE;
-               break;
-       case SP_XONXOFF_INOUT:
-               data->dcb.fInX = TRUE;
-               data->dcb.fOutX = TRUE;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->term.c_iflag &= ~(IXON | IXOFF | IXANY);
-       switch (xon_xoff) {
-       case SP_XONXOFF_DISABLED:
-               break;
-       case SP_XONXOFF_IN:
-               data->term.c_iflag |= IXOFF;
-               break;
-       case SP_XONXOFF_OUT:
-               data->term.c_iflag |= IXON | IXANY;
-               break;
-       case SP_XONXOFF_INOUT:
-               data->term.c_iflag |= IXON | IXOFF | IXANY;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
-}
-
-static int apply_config(struct sp_port *port, struct sp_port_data *data)
-{
-#ifdef _WIN32
-       if (!SetCommState(port->hdl, &data->dcb))
-               return SP_ERR_FAIL;
-#else
-       int controlbits;
-
-       /* Asymmetric use of RTS/CTS not supported yet. */
-       if ((data->rts == SP_RTS_FLOW_CONTROL) != (data->cts == SP_CTS_FLOW_CONTROL))
-               return SP_ERR_ARG;
-
-       /* DTR/DSR flow control not supported yet. */
-       if (data->dtr == SP_DTR_FLOW_CONTROL || data->dsr == SP_DSR_FLOW_CONTROL)
-               return SP_ERR_ARG;
-
-       if (data->rts == SP_RTS_FLOW_CONTROL)
-               data->term.c_iflag |= CRTSCTS;
-       else
-       {
-               controlbits = TIOCM_RTS;
-               if (ioctl(port->fd, data->rts == SP_RTS_ON ? TIOCMBIS : TIOCMBIC,
-                               &controlbits) < 0)
-                       return SP_ERR_FAIL;
-       }
-
-       controlbits = TIOCM_DTR;
-       if (ioctl(port->fd, data->dtr == SP_DTR_ON ? TIOCMBIS : TIOCMBIC,
-                       &controlbits) < 0)
-               return SP_ERR_FAIL;
-
-       /* Write the configured settings. */
-       if (tcsetattr(port->fd, TCSADRAIN, &data->term) < 0)
+       if (!GetCommState(port->hdl, &data->dcb))
                return SP_ERR_FAIL;
-#endif
-       return SP_OK;
-}
-
-#define TRY(x) do { int ret = x; if (ret != SP_OK) return ret; } while (0)
-#define TRY_SET(x, y) do { if (y >= 0) TRY(set_##x(&data, y)); } while (0)
-#define TRY_SET_CONFIG(x) TRY_SET(x, config->x)
 
-int sp_set_config(struct sp_port *port, struct sp_port_config *config)
-{
-       struct sp_port_data data;
-
-       TRY(start_config(port, &data));
-       TRY_SET_CONFIG(baudrate);
-       TRY_SET_CONFIG(bits);
-       TRY_SET_CONFIG(parity);
-       TRY_SET_CONFIG(stopbits);
-       TRY_SET_CONFIG(rts);
-       TRY_SET_CONFIG(cts);
-       TRY_SET_CONFIG(dtr);
-       TRY_SET_CONFIG(dsr);
-       TRY_SET_CONFIG(xon_xoff);
-       TRY(apply_config(port, &data));
-
-       return SP_OK;
-}
-
-int sp_get_config(struct sp_port *port, struct sp_port_config *config)
-{
-       struct sp_port_data data;
-       unsigned int i;
-
-       TRY(start_config(port, &data));
-
-#ifdef _WIN32
        for (i = 0; i < NUM_STD_BAUDRATES; i++) {
-               if (data.dcb.BaudRate == std_baudrates[i].index) {
+               if (data->dcb.BaudRate == std_baudrates[i].index) {
                        config->baudrate = std_baudrates[i].value;
                        break;
                }
@@ -909,12 +582,12 @@ int sp_get_config(struct sp_port *port, struct sp_port_config *config)
 
        if (i == NUM_STD_BAUDRATES)
                /* BaudRate field can be either an index or a custom baud rate. */
-               config->baudrate = data.dcb.BaudRate;
+               config->baudrate = data->dcb.BaudRate;
 
-       config->bits = data.dcb.ByteSize;
+       config->bits = data->dcb.ByteSize;
 
-       if (data.dcb.fParity)
-               switch (data.dcb.Parity) {
+       if (data->dcb.fParity)
+               switch (data->dcb.Parity) {
                case NOPARITY:
                        config->parity = SP_PARITY_NONE;
                        break;
@@ -930,7 +603,7 @@ int sp_get_config(struct sp_port *port, struct sp_port_config *config)
        else
                config->parity = SP_PARITY_NONE;
 
-       switch (data.dcb.StopBits) {
+       switch (data->dcb.StopBits) {
        case ONESTOPBIT:
                config->stopbits = 1;
                break;
@@ -941,7 +614,7 @@ int sp_get_config(struct sp_port *port, struct sp_port_config *config)
                config->stopbits = -1;
        }
 
-       switch (data.dcb.fRtsControl) {
+       switch (data->dcb.fRtsControl) {
                case RTS_CONTROL_DISABLE:
                        config->rts = SP_RTS_OFF;
                        break;
@@ -955,9 +628,9 @@ int sp_get_config(struct sp_port *port, struct sp_port_config *config)
                        config->rts = -1;
        }
 
-       config->cts = data.dcb.fOutxCtsFlow ? SP_CTS_FLOW_CONTROL : SP_CTS_IGNORE;
+       config->cts = data->dcb.fOutxCtsFlow ? SP_CTS_FLOW_CONTROL : SP_CTS_IGNORE;
 
-       switch (data.dcb.fDtrControl) {
+       switch (data->dcb.fDtrControl) {
                case DTR_CONTROL_DISABLE:
                        config->dtr = SP_DTR_OFF;
                        break;
@@ -971,10 +644,17 @@ int sp_get_config(struct sp_port *port, struct sp_port_config *config)
                        config->dtr = -1;
        }
 
-       config->dsr = data.dcb.fOutxDsrFlow ? SP_DSR_FLOW_CONTROL : SP_DSR_IGNORE;
-#else
+       config->dsr = data->dcb.fOutxDsrFlow ? SP_DSR_FLOW_CONTROL : SP_DSR_IGNORE;
+
+#else // !_WIN32
+
+       if (tcgetattr(port->fd, &data->term) < 0)
+               return SP_ERR_FAIL;
+
+       if (ioctl(port->fd, TIOCMGET, &data->controlbits) < 0)
+               return SP_ERR_FAIL;
        for (i = 0; i < NUM_STD_BAUDRATES; i++) {
-               if (cfgetispeed(&data.term) == std_baudrates[i].index) {
+               if (cfgetispeed(&data->term) == std_baudrates[i].index) {
                        config->baudrate = std_baudrates[i].value;
                        break;
                }
@@ -983,7 +663,7 @@ int sp_get_config(struct sp_port *port, struct sp_port_config *config)
        if (i == NUM_STD_BAUDRATES)
                config->baudrate = -1;
 
-       switch (data.term.c_cflag & CSIZE) {
+       switch (data->term.c_cflag & CSIZE) {
        case CS8:
                config->bits = 8;
                break;
@@ -1000,67 +680,326 @@ int sp_get_config(struct sp_port *port, struct sp_port_config *config)
                config->bits = -1;
        }
 
-       if (!(data.term.c_cflag & PARENB) && (data.term.c_iflag & IGNPAR))
+       if (!(data->term.c_cflag & PARENB) && (data->term.c_iflag & IGNPAR))
                config->parity = SP_PARITY_NONE;
-       else if (!(data.term.c_cflag & PARENB) || (data.term.c_iflag & IGNPAR))
+       else if (!(data->term.c_cflag & PARENB) || (data->term.c_iflag & IGNPAR))
                config->parity = -1;
        else
-               config->parity = (data.term.c_cflag & PARODD) ? SP_PARITY_ODD : SP_PARITY_EVEN;
+               config->parity = (data->term.c_cflag & PARODD) ? SP_PARITY_ODD : SP_PARITY_EVEN;
 
-       config->stopbits = (data.term.c_cflag & CSTOPB) ? 2 : 1;
+       config->stopbits = (data->term.c_cflag & CSTOPB) ? 2 : 1;
 
-       if (data.term.c_cflag & CRTSCTS) {
+       if (data->term.c_cflag & CRTSCTS) {
                config->rts = SP_RTS_FLOW_CONTROL;
                config->cts = SP_CTS_FLOW_CONTROL;
        } else {
-               config->rts = (data.controlbits & TIOCM_RTS) ? SP_RTS_ON : SP_RTS_OFF;
+               config->rts = (data->controlbits & TIOCM_RTS) ? SP_RTS_ON : SP_RTS_OFF;
                config->cts = SP_CTS_IGNORE;
        }
 
-       config->dtr = (data.controlbits & TIOCM_DTR) ? SP_DTR_ON : SP_DTR_OFF;
+       config->dtr = (data->controlbits & TIOCM_DTR) ? SP_DTR_ON : SP_DTR_OFF;
        config->dsr = SP_DSR_IGNORE;
 #endif
 
        return SP_OK;
 }
 
-int sp_set_flowcontrol(struct sp_port *port, int flowcontrol)
+static int set_config(struct sp_port *port, struct sp_port_data *data, struct sp_port_config *config)
 {
-       struct sp_port_data data;
+       unsigned int i;
 
-       TRY(start_config(port, &data));
+#ifdef _WIN32
+       if (config->baudrate >= 0)
+       {
+               for (i = 0; i < NUM_STD_BAUDRATES; i++) {
+                       if (config->baudrate == std_baudrates[i].value) {
+                               data->dcb.BaudRate = std_baudrates[i].index;
+                               break;
+                       }
+               }
 
-       if (flowcontrol == SP_FLOWCONTROL_XONXOFF)
-               TRY_SET(xon_xoff, SP_XONXOFF_INOUT);
-       else
-               TRY_SET(xon_xoff, SP_XONXOFF_DISABLED);
+               if (i == NUM_STD_BAUDRATES)
+                       data->dcb.BaudRate = config->baudrate;
+       }
 
-       if (flowcontrol == SP_FLOWCONTROL_RTSCTS) {
-               TRY_SET(rts, SP_RTS_FLOW_CONTROL);
-               TRY_SET(cts, SP_CTS_FLOW_CONTROL);
-       } else {
-               TRY_SET(rts, SP_RTS_ON);
-               TRY_SET(cts, SP_CTS_IGNORE);
+       if (config->bits >= 0)
+               data->dcb.ByteSize = config->bits;
+
+       if (config->parity >= 0) {
+               switch (config->parity) {
+               /* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
+               case SP_PARITY_NONE:
+                       data->dcb.Parity = NOPARITY;
+                       break;
+               case SP_PARITY_EVEN:
+                       data->dcb.Parity = EVENPARITY;
+                       break;
+               case SP_PARITY_ODD:
+                       data->dcb.Parity = ODDPARITY;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
        }
 
-       if (flowcontrol == SP_FLOWCONTROL_DTRDSR) {
-               TRY_SET(dtr, SP_DTR_FLOW_CONTROL);
-               TRY_SET(dsr, SP_DSR_FLOW_CONTROL);
-       } else {
-               TRY_SET(dtr, SP_DTR_ON);
-               TRY_SET(dsr, SP_DSR_IGNORE);
+       if (config->stopbits >= 0) {
+               switch (config->stopbits) {
+               /* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
+               case 1:
+                       data->dcb.StopBits = ONESTOPBIT;
+                       break;
+               case 2:
+                       data->dcb.StopBits = TWOSTOPBITS;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (config->rts >= 0) {
+               switch (config->rts) {
+               case SP_RTS_OFF:
+                       data->dcb.fRtsControl = RTS_CONTROL_DISABLE;
+                       break;
+               case SP_RTS_ON:
+                       data->dcb.fRtsControl = RTS_CONTROL_ENABLE;
+                       break;
+               case SP_RTS_FLOW_CONTROL:
+                       data->dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (config->cts >= 0) {
+               switch (config->cts) {
+               case SP_CTS_IGNORE:
+                       data->dcb.fOutxCtsFlow = FALSE;
+                       break;
+               case SP_CTS_FLOW_CONTROL:
+                       data->dcb.fOutxCtsFlow = TRUE;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (config->dtr >= 0) {
+               switch (config->dtr) {
+               case SP_DTR_OFF:
+                       data->dcb.fDtrControl = DTR_CONTROL_DISABLE;
+                       break;
+               case SP_DTR_ON:
+                       data->dcb.fDtrControl = DTR_CONTROL_ENABLE;
+                       break;
+               case SP_DTR_FLOW_CONTROL:
+                       data->dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (config->dsr >= 0) {
+               switch (config->dsr) {
+               case SP_DSR_IGNORE:
+                       data->dcb.fOutxDsrFlow = FALSE;
+                       break;
+               case SP_DSR_FLOW_CONTROL:
+                       data->dcb.fOutxDsrFlow = TRUE;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
        }
 
-       TRY(apply_config(port, &data));
+       if (config->xon_xoff >= 0) {
+               switch (config->xon_xoff) {
+               case SP_XONXOFF_DISABLED:
+                       data->dcb.fInX = FALSE;
+                       data->dcb.fOutX = FALSE;
+                       break;
+               case SP_XONXOFF_IN:
+                       data->dcb.fInX = TRUE;
+                       data->dcb.fOutX = FALSE;
+                       break;
+               case SP_XONXOFF_OUT:
+                       data->dcb.fInX = FALSE;
+                       data->dcb.fOutX = TRUE;
+                       break;
+               case SP_XONXOFF_INOUT:
+                       data->dcb.fInX = TRUE;
+                       data->dcb.fOutX = TRUE;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (!SetCommState(port->hdl, &data->dcb))
+               return SP_ERR_FAIL;
+
+#else // !_WIN32
+
+       if (config->baudrate >= 0)
+       {
+               for (i = 0; i < NUM_STD_BAUDRATES; i++) {
+                       if (config->baudrate == std_baudrates[i].value) {
+                               if (cfsetospeed(&data->term, std_baudrates[i].index) < 0)
+                                       return SP_ERR_FAIL;
+
+                               if (cfsetispeed(&data->term, std_baudrates[i].index) < 0)
+                                       return SP_ERR_FAIL;
+                               break;
+                       }
+               }
+
+               if (i == NUM_STD_BAUDRATES)
+                       return SP_ERR_ARG;
+       }
+
+       if (config->bits >= 0) {
+               data->term.c_cflag &= ~CSIZE;
+               switch (config->bits) {
+               case 8:
+                       data->term.c_cflag |= CS8;
+                       break;
+               case 7:
+                       data->term.c_cflag |= CS7;
+                       break;
+               case 6:
+                       data->term.c_cflag |= CS6;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (config->parity >= 0) {
+               data->term.c_iflag &= ~IGNPAR;
+               data->term.c_cflag &= ~(PARENB | PARODD);
+               switch (config->parity) {
+               case SP_PARITY_NONE:
+                       data->term.c_iflag |= IGNPAR;
+                       break;
+               case SP_PARITY_EVEN:
+                       data->term.c_cflag |= PARENB;
+                       break;
+               case SP_PARITY_ODD:
+                       data->term.c_cflag |= PARENB | PARODD;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (config->stopbits >= 0) {
+               data->term.c_cflag &= ~CSTOPB;
+               switch (config->stopbits) {
+               case 1:
+                       data->term.c_cflag &= ~CSTOPB;
+                       break;
+               case 2:
+                       data->term.c_cflag |= CSTOPB;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (config->rts >= 0 || config->cts >= 0)
+       {
+               /* Asymmetric use of RTS/CTS not supported yet. */
+
+               if (data->term.c_iflag & CRTSCTS) {
+                       /* Flow control can only be disabled for both RTS & CTS together. */
+                       if (config->rts >= 0 && config->rts != SP_RTS_FLOW_CONTROL) {
+                               if (config->cts != SP_CTS_IGNORE)
+                                       return SP_ERR_ARG;
+                       }
+                       if (config->cts >= 0 && config->cts != SP_CTS_FLOW_CONTROL) {
+                               if (config->rts <= 0 || config->rts == SP_RTS_FLOW_CONTROL)
+                                       return SP_ERR_ARG;
+                       }
+               } else {
+                       /* Flow control can only be enabled for both RTS & CTS together. */
+                       if (((config->rts == SP_RTS_FLOW_CONTROL) && (config->cts != SP_CTS_FLOW_CONTROL)) ||
+                               ((config->cts == SP_CTS_FLOW_CONTROL) && (config->rts != SP_RTS_FLOW_CONTROL)))
+                               return SP_ERR_ARG;
+               }
+
+               if (config->rts >= 0) {
+                       if (config->rts == SP_RTS_FLOW_CONTROL) {
+                               data->term.c_iflag |= CRTSCTS;
+                       } else {
+                               int controlbits = TIOCM_RTS;
+                               if (ioctl(port->fd, config->rts == SP_RTS_ON ? TIOCMBIS : TIOCMBIC,
+                                               &controlbits) < 0)
+                                       return SP_ERR_FAIL;
+                       }
+               }
+       }
+
+       if (config->dtr >= 0 || config->dsr >= 0)
+       {
+               /* DTR/DSR flow control not supported yet. */
+               if (config->dtr == SP_DTR_FLOW_CONTROL || config->dsr == SP_DSR_FLOW_CONTROL)
+                       return SP_ERR_ARG;
+
+               if (config->dtr >= 0) {
+                       int controlbits = TIOCM_DTR;
+                       if (ioctl(port->fd, config->dtr == SP_DTR_ON ? TIOCMBIS : TIOCMBIC,
+                                       &controlbits) < 0)
+                               return SP_ERR_FAIL;
+               }
+       }
+
+       if (config->xon_xoff >= 0) {
+               data->term.c_iflag &= ~(IXON | IXOFF | IXANY);
+               switch (config->xon_xoff) {
+               case SP_XONXOFF_DISABLED:
+                       break;
+               case SP_XONXOFF_IN:
+                       data->term.c_iflag |= IXOFF;
+                       break;
+               case SP_XONXOFF_OUT:
+                       data->term.c_iflag |= IXON | IXANY;
+                       break;
+               case SP_XONXOFF_INOUT:
+                       data->term.c_iflag |= IXON | IXOFF | IXANY;
+                       break;
+               default:
+                       return SP_ERR_ARG;
+               }
+       }
+
+       if (tcsetattr(port->fd, TCSADRAIN, &data->term) < 0)
+               return SP_ERR_FAIL;
+#endif
+
+       return SP_OK;
+}
+
+#define TRY(x) do { int ret = x; if (ret != SP_OK) return ret; } while (0)
+
+int sp_set_config(struct sp_port *port, struct sp_port_config *config)
+{
+       struct sp_port_data data;
+       struct sp_port_config prev_config;
+
+       TRY(get_config(port, &data, &prev_config));
+       TRY(set_config(port, &data, config));
 
        return SP_OK;
 }
 
 #define CREATE_SETTER(x) int sp_set_##x(struct sp_port *port, int x) { \
        struct sp_port_data data; \
-       TRY(start_config(port, &data)); \
-       TRY(set_##x(&data, x)); \
-       TRY(apply_config(port, &data)); \
+       struct sp_port_config config; \
+       TRY(get_config(port, &data, &config)); \
+       config.x = x; \
+       TRY(set_config(port, &data, &config)); \
        return SP_OK; \
 }
 
@@ -1074,6 +1013,41 @@ CREATE_SETTER(dtr)
 CREATE_SETTER(dsr)
 CREATE_SETTER(xon_xoff)
 
+int sp_set_flowcontrol(struct sp_port *port, int flowcontrol)
+{
+       struct sp_port_data data;
+       struct sp_port_config config;
+
+       TRY(get_config(port, &data, &config));
+
+       if (flowcontrol == SP_FLOWCONTROL_XONXOFF)
+               config.xon_xoff = SP_XONXOFF_INOUT;
+       else
+               config.xon_xoff = SP_XONXOFF_DISABLED;
+
+       if (flowcontrol == SP_FLOWCONTROL_RTSCTS) {
+               config.rts = SP_RTS_FLOW_CONTROL;
+               config.cts = SP_CTS_FLOW_CONTROL;
+       } else {
+               if (config.rts == SP_RTS_FLOW_CONTROL)
+                       config.rts = SP_RTS_ON;
+               config.cts = SP_CTS_IGNORE;
+       }
+
+       if (flowcontrol == SP_FLOWCONTROL_DTRDSR) {
+               config.dtr = SP_DTR_FLOW_CONTROL;
+               config.dsr = SP_DSR_FLOW_CONTROL;
+       } else {
+               if (config.dtr == SP_DTR_FLOW_CONTROL)
+                       config.dtr = SP_DTR_ON;
+               config.dsr = SP_DSR_IGNORE;
+       }
+
+       TRY(set_config(port, &data, &config));
+
+       return SP_OK;
+}
+
 int sp_last_error_code(void)
 {
 #ifdef _WIN32