fix support for XON/XOFF flow control

[libftdi] / src / ftdi.c

diff --git a/src/ftdi.c b/src/ftdi.c
index 175befc..675f8ca 100644 (file)
--- a/src/ftdi.c
+++ b/src/ftdi.c
@@ -87,7 +87,7 @@ static void ftdi_usb_close_internal (struct ftdi_context *ftdi)
 */
 int ftdi_init(struct ftdi_context *ftdi)
 {
-    struct ftdi_eeprom* eeprom = (struct ftdi_eeprom *)malloc(sizeof(struct ftdi_eeprom));
+    struct ftdi_eeprom* eeprom;
     ftdi->usb_ctx = NULL;
     ftdi->usb_dev = NULL;
     ftdi->usb_read_timeout = 5000;
@@ -111,6 +111,7 @@ int ftdi_init(struct ftdi_context *ftdi)
     ftdi_set_interface(ftdi, INTERFACE_ANY);
     ftdi->bitbang_mode = 1; /* when bitbang is enabled this holds the number of the mode  */
 
+    eeprom = (struct ftdi_eeprom *)malloc(sizeof(struct ftdi_eeprom));
     if (eeprom == 0)
         ftdi_error_return(-2, "Can't malloc struct ftdi_eeprom");
     memset(eeprom, 0, sizeof(struct ftdi_eeprom));
@@ -2262,9 +2263,11 @@ int ftdi_poll_modem_status(struct ftdi_context *ftdi, unsigned short *status)
 /**
     Set flowcontrol for ftdi chip
 
+    Note: Do not use this function to enable XON/XOFF mode, use ftdi_setflowctrl_xonxoff() instead.
+
     \param ftdi pointer to ftdi_context
     \param flowctrl flow control to use. should be
-           SIO_DISABLE_FLOW_CTRL, SIO_RTS_CTS_HS, SIO_DTR_DSR_HS or SIO_XON_XOFF_HS
+           SIO_DISABLE_FLOW_CTRL, SIO_RTS_CTS_HS, SIO_DTR_DSR_HS
 
     \retval  0: all fine
     \retval -1: set flow control failed
@@ -2284,6 +2287,31 @@ int ftdi_setflowctrl(struct ftdi_context *ftdi, int flowctrl)
 }
 
 /**
+    Set XON/XOFF flowcontrol for ftdi chip
+
+    \param ftdi pointer to ftdi_context
+    \param xon character code used to resume transmission
+    \param xoff character code used to pause transmission
+
+    \retval  0: all fine
+    \retval -1: set flow control failed
+    \retval -2: USB device unavailable
+*/
+int ftdi_setflowctrl_xonxoff(struct ftdi_context *ftdi, unsigned char xon, unsigned char xoff)
+{
+    if (ftdi == NULL || ftdi->usb_dev == NULL)
+        ftdi_error_return(-2, "USB device unavailable");
+
+    uint16_t xonxoff = xon | (xoff << 8);
+    if (libusb_control_transfer(ftdi->usb_dev, FTDI_DEVICE_OUT_REQTYPE,
+                                SIO_SET_FLOW_CTRL_REQUEST, xonxoff, (SIO_XON_XOFF_HS | ftdi->index),
+                                NULL, 0, ftdi->usb_write_timeout) < 0)
+        ftdi_error_return(-1, "set flow control failed");
+
+    return 0;
+}
+
+/**
     Set dtr line
 
     \param ftdi pointer to ftdi_context