Added missing RTS/DTR management feature to serialupdi programmer

src/avrdude.1

@@ -1186,6 +1186,17 @@ line, and the XBee DIN pin (pin 3) must be connected to the MCU's
 .Ql TXD
 line.
 .El
+.It Ar serialupdi
+Extended parameters:
+.Bl -tag -offset indent -width indent
+.It Ar rtsdtr=low|high
+Forces RTS/DTR lines to assume low or high state during the whole
+programming session. Some programmers might use this signal to
+indicate UPDI programming state, but this is strictly hardware
+specific.
+.Pp
+When not provided, driver/OS default value will be used.
+.El
 .El
 .Sh FILES
 .Bl -tag -offset indent -width /dev/ppi0XXX

src/doc/avrdude.texi

@@ -1067,6 +1067,18 @@ The remaining two necessary XBee-to-MCU connections are not selectable
 the MCU's ‘TXD’ line.
 @end table
 
+@item serialupdi
+Extended parameters:
+@table @code
+@item @samp{rtsdtr=low|high}
+Forces RTS/DTR lines to assume low or high state during the whole
+programming session. Some programmers might use this signal to
+indicate UPDI programming state, but this is strictly hardware
+specific.
+
+When not provided, driver/OS default value will be used.
+@end table
+
 @end table
 
 @page

src/serialupdi.c

@@ -55,6 +55,7 @@ static void serialupdi_setup(PROGRAMMER * pgm)
     exit(1);
   }
   memset(pgm->cookie, 0, sizeof(updi_state));
+  updi_set_rts_mode(pgm, RTS_MODE_DEFAULT);
   updi_set_datalink_mode(pgm, UPDI_LINK_MODE_16BIT);
 }
 
@@ -184,6 +185,10 @@ static void serialupdi_close(PROGRAMMER * pgm)
   if (serialupdi_leave_progmode(pgm) < 0) {
     avrdude_message(MSG_INFO, "%s: Unable to leave NVM programming mode\n", progname);
   }
+  if (updi_get_rts_mode(pgm) != RTS_MODE_DEFAULT) {
+    avrdude_message(MSG_INFO, "%s: Releasing DTR/RTS handshake lines\n", progname);
+  }
+
   updi_link_close(pgm);
 }
 
@@ -582,6 +587,10 @@ static int serialupdi_initialize(PROGRAMMER * pgm, AVRPART * p)
   }
   avrdude_message(MSG_INFO, "%s: UPDI link initialization OK\n", progname);
 
+  if (updi_get_rts_mode(pgm) != RTS_MODE_DEFAULT) {
+    avrdude_message(MSG_INFO, "%s: Forcing serial DTR/RTS handshake lines %s\n", progname, updi_get_rts_mode(pgm) == RTS_MODE_LOW ? "LOW" : "HIGH");
+  }
+
   if (updi_read_cs(pgm, UPDI_ASI_SYS_STATUS, &value)<0) {
 
     /* let's try reset the connection */
@@ -926,6 +935,35 @@ static int serialupdi_read_sib(PROGRAMMER * pgm, AVRPART *p, char *sib) {
   return 0;
 }
 
+static int serialupdi_parseextparms(PROGRAMMER * pgm, LISTID extparms)
+{
+  LNODEID ln;
+  const char *extended_param;
+  char rts_mode[5];
+  int rv = 0;
+
+  for (ln = lfirst(extparms); ln; ln = lnext(ln)) {
+    extended_param = ldata(ln);
+
+    if (sscanf(extended_param, "rtsdtr=%4s", rts_mode) == 1) {
+      if (strcasecmp(rts_mode, "low") == 0) {
+        updi_set_rts_mode(pgm, RTS_MODE_LOW);
+      } else if (strcasecmp(rts_mode, "high") == 0) {
+        updi_set_rts_mode(pgm, RTS_MODE_HIGH);
+      } else {
+        avrdude_message(MSG_INFO, "%s: RTS/DTR mode must be LOW or HIGH\n", progname);
+        return -1;
+      }
+      continue;
+    }
+
+    avrdude_message(MSG_INFO, "%s: serialupdi_parseextparms(): invalid extended parameter '%s'\n",
+                    progname, extended_param);
+    rv = -1;
+  }
+
+  return rv;
+}
 
 void serialupdi_initpgm(PROGRAMMER * pgm)
 {
@@ -936,6 +974,7 @@ void serialupdi_initpgm(PROGRAMMER * pgm)
    */
 
   pgm->initialize     = serialupdi_initialize;
+  pgm->parseextparams = serialupdi_parseextparms;
   pgm->display        = serialupdi_display;
   pgm->enable         = serialupdi_enable;
   pgm->disable        = serialupdi_disable;

src/updi_link.c

@@ -39,9 +39,16 @@
 #include "updi_constants.h"
 #include "updi_state.h"
 
-static void msleep(int tms)
+static void updi_set_rtsdtr_mode(PROGRAMMER* pgm)
 {
-    usleep(tms * 1000);
+  updi_rts_mode rts_mode = updi_get_rts_mode(pgm);
+
+  if (rts_mode == RTS_MODE_DEFAULT) {
+    return;
+  }
+
+  serial_set_dtr_rts(&pgm->fd, 0);
+  serial_set_dtr_rts(&pgm->fd, rts_mode == RTS_MODE_LOW ? 1 : 0);
 }
 
 static int updi_physical_open(PROGRAMMER* pgm, int baudrate, unsigned long cflags)
@@ -65,11 +72,17 @@ static int updi_physical_open(PROGRAMMER* pgm, int baudrate, unsigned long cflag
    */
   serial_drain(&pgm->fd, 0);
 
+  /*
+   * set RTS/DTR mode if needed
+   */
+  updi_set_rtsdtr_mode(pgm);
+
   return 0;
 }
 
 static void updi_physical_close(PROGRAMMER* pgm)
 {
+  serial_set_dtr_rts(&pgm->fd, 0);
   serial_close(&pgm->fd);
   pgm->fd.ifd = -1;
 }
@@ -124,28 +137,31 @@ static int updi_physical_send_double_break(PROGRAMMER * pgm)
 
   avrdude_message(MSG_DEBUG, "%s: Sending double break\n", progname);
 
-  updi_physical_close(pgm);
-
-  if (updi_physical_open(pgm, 300, SERIAL_8E1)==-1) {
-
+  if (serial_setparams(&pgm->fd, 300, SERIAL_8E1) < 0) {
     return -1;
   }
 
+  updi_set_rtsdtr_mode(pgm);
+
   buffer[0] = UPDI_BREAK;
 
   serial_send(&pgm->fd, buffer, 1);
   serial_recv(&pgm->fd, buffer, 1);
 
-  msleep(100);
+  usleep(100*1000);
 
   buffer[0] = UPDI_BREAK;
 
   serial_send(&pgm->fd, buffer, 1);
   serial_recv(&pgm->fd, buffer, 1);
 
-  updi_physical_close(pgm);
+  if (serial_setparams(&pgm->fd, pgm->baudrate? pgm->baudrate: 115200, SERIAL_8E2) < 0) {
+    return -1;
+  }
+
+  updi_set_rtsdtr_mode(pgm);
 
-  return updi_physical_open(pgm, pgm->baudrate? pgm->baudrate: 115200, SERIAL_8E2);
+  return 0;
 }
 
 int updi_physical_sib(PROGRAMMER * pgm, unsigned char * buffer, uint8_t size)

src/updi_state.c

@@ -53,3 +53,13 @@ void updi_set_nvm_mode(PROGRAMMER * pgm, updi_nvm_mode mode)
 {
   ((updi_state *)(pgm->cookie))->nvm_mode = mode;
 }
+
+updi_rts_mode updi_get_rts_mode(PROGRAMMER * pgm)
+{
+  return ((updi_state *)(pgm->cookie))->rts_mode;
+}
+
+void updi_set_rts_mode(PROGRAMMER * pgm, updi_rts_mode mode)
+{
+  ((updi_state *)(pgm->cookie))->rts_mode = mode;
+}

src/updi_state.h

@@ -61,11 +61,19 @@ typedef struct
   char debug_version;
 } updi_sib_info;
 
+typedef enum
+{
+  RTS_MODE_DEFAULT,
+  RTS_MODE_LOW,
+  RTS_MODE_HIGH
+} updi_rts_mode;
+
 typedef struct
 {
   updi_sib_info sib_info;
   updi_datalink_mode datalink_mode;
   updi_nvm_mode nvm_mode;
+  updi_rts_mode rts_mode;
 } updi_state;
 
 #ifdef __cplusplus
@@ -77,6 +85,8 @@ updi_datalink_mode updi_get_datalink_mode(PROGRAMMER * pgm);
 void updi_set_datalink_mode(PROGRAMMER * pgm, updi_datalink_mode mode);
 updi_nvm_mode updi_get_nvm_mode(PROGRAMMER * pgm);
 void updi_set_nvm_mode(PROGRAMMER * pgm, updi_nvm_mode mode);
+updi_rts_mode updi_get_rts_mode(PROGRAMMER * pgm);
+void updi_set_rts_mode(PROGRAMMER * pgm, updi_rts_mode mode);
 
 #ifdef __cplusplus
 }