Merge pull request #1468 from stefanrueger/stk500

Fix probing of the generic -c stk500 programmer

src/avrdude.conf.in

@@ -1418,7 +1418,7 @@ programmer
 
 programmer
     id                     = "stk500";
-    desc                   = "Atmel STK500";
+    desc                   = "Atmel STK500 (probes STK500v2 first then STK500v1)";
     type                   = "stk500generic";
     prog_modes             = PM_ISP;
     extra_features         = HAS_VTARG_ADJ | HAS_VTARG_READ | HAS_FOSC_ADJ | HAS_VAREF_ADJ;

src/stk500.c

@@ -1454,6 +1454,7 @@ static void stk500_setup(PROGRAMMER * pgm)
 static void stk500_teardown(PROGRAMMER * pgm)
 {
   free(pgm->cookie);
+  pgm->cookie = NULL;
 }
 
 const char stk500_desc[] = "Atmel STK500 Version 1.x firmware";

src/stk500generic.c

@@ -24,12 +24,15 @@
  * This is a wrapper around the STK500[v1] and STK500v2 programmers.
  * Try to select the programmer type that actually responds, and
  * divert to the actual programmer implementation if successful.
+ * Using -c stk500 instead of the appropriate -c stk500v1 or -c stk500v2
+ * misses out on the extended -x options of the successful programmer.
  */
 
 #include "ac_cfg.h"
 
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 
 #include "avrdude.h"
 #include "libavrdude.h"
@@ -38,40 +41,39 @@
 #include "stk500.h"
 #include "stk500v2.h"
 
-static int stk500generic_open(PROGRAMMER *pgm, const char *port) {
-  stk500_initpgm(pgm);
-  if (pgm->open(pgm, port) >= 0)
-    {
-      pmsg_info("successfully opened stk500v1 device -- please use -c stk500v1\n");
-      return 0;
-    }
-
-  pgm->close(pgm);
-
-  stk500v2_initpgm(pgm);
-  if (pgm->open(pgm, port) >= 0)
-    {
-      pmsg_info("successfully opened stk500v2 device -- please use -c stk500v2\n");
-      return 0;
-    }
-
-  pmsg_error("cannot open either stk500v1 or stk500v2 programmer\n");
-  return -1;
+static PROGRAMMER *stk500vn;
+static void stk500vn_exithook(void) {
+  if(stk500vn && stk500vn->teardown)
+    stk500vn->teardown(stk500vn);
 }
 
-static void stk500generic_setup(PROGRAMMER * pgm)
-{
-  /*
-   * Only STK500v2 needs setup/teardown.
-   */
+static int stk500generic_open(PROGRAMMER *pgm, const char *port) {
   stk500v2_initpgm(pgm);
-  pgm->setup(pgm);
-}
+  if(pgm->setup)
+    pgm->setup(pgm);
+  if(pgm->open(pgm, port) >= 0) {
+    stk500vn = pgm;
+    atexit(stk500vn_exithook);
+    pmsg_info("successfully opened stk500v2 device; please use -c stk500v2\n");
+    return 0;
+  }
+  if(pgm->teardown)
+    pgm->teardown(pgm);
 
-static void stk500generic_teardown(PROGRAMMER * pgm)
-{
-  stk500v2_initpgm(pgm);
-  pgm->teardown(pgm);
+  stk500_initpgm(pgm);
+  if(pgm->setup)
+    pgm->setup(pgm);
+  if(pgm->open(pgm, port) >= 0) {
+    stk500vn = pgm;
+    atexit(stk500vn_exithook);
+    pmsg_info("successfully opened stk500v1 device; please use -c stk500v1\n");
+    return 0;
+  }
+  if(pgm->teardown)
+    pgm->teardown(pgm);
+
+  pmsg_error("probing stk500v2 failed, as did stk500v1; perhaps try -c stk500v1\n");
+  return -1;
 }
 
 const char stk500generic_desc[] = "Atmel STK500, autodetect firmware version";
@@ -80,6 +82,4 @@ void stk500generic_initpgm(PROGRAMMER *pgm) {
   strcpy(pgm->type, "STK500GENERIC");
 
   pgm->open           = stk500generic_open;
-  pgm->setup          = stk500generic_setup;
-  pgm->teardown       = stk500generic_teardown;
 }

src/stk500v2.c

@@ -339,6 +339,7 @@ static void stk500v2_jtag3_setup(PROGRAMMER * pgm)
 void stk500v2_teardown(PROGRAMMER * pgm)
 {
   free(pgm->cookie);
+  pgm->cookie = NULL;
 }
 
 static void stk500v2_jtagmkII_teardown(PROGRAMMER * pgm)
@@ -2123,14 +2124,9 @@ static int stk500v2_open(PROGRAMMER *pgm, const char *port) {
   if (serdev && serdev->usbsn)
     pgm->usbsn = serdev->usbsn;
 
-  /*
-   * drain any extraneous input
-   */
-  stk500v2_drain(pgm, 0);
-
-  stk500v2_getsync(pgm);
-
-  stk500v2_drain(pgm, 0);
+  // Drain any extraneous input, synchronise and drain again
+  if(stk500v2_drain(pgm, 0) < 0 || stk500v2_getsync(pgm) < 0 || stk500v2_drain(pgm, 0) < 0)
+    return -1;
 
   if (pgm->bitclock != 0.0) {
     if (pgm->set_sck_period(pgm, pgm->bitclock) != 0)
@@ -2180,14 +2176,9 @@ static int stk600_open(PROGRAMMER *pgm, const char *port) {
     return -1;
   }
 
-  /*
-   * drain any extraneous input
-   */
-  stk500v2_drain(pgm, 0);
-
-  stk500v2_getsync(pgm);
-
-  stk500v2_drain(pgm, 0);
+  // Drain any extraneous input, synchronise and drain again
+  if(stk500v2_drain(pgm, 0) < 0 || stk500v2_getsync(pgm) < 0 || stk500v2_drain(pgm, 0) < 0)
+    return -1;
 
   if (pgm->bitclock != 0.0) {
     if (pgm->set_sck_period(pgm, pgm->bitclock) != 0)