[avrdude-dev] Fix linuxgpio bug and add TPI support

[David Mosberger]

With the attached patch (relative to GIT repository), I'm able to program
an ATtiny9 via TPI using a Raspberry PI.
Example command:

 $ avrdude -i100 -C./avrdude.conf -pt9 -clinuxgpio

​-i option is only needed if the data clock needs to be slowed down for
some reason (shouldn't be needed, normally).

The bugfix is to mask the pin number against PIN_MASK before checking it
against PIN_AVR_RESET etc.  Without that,
I get errors because the code then tries to export GPIO 0 multiple times.

  --david​

-- 
eGauge Systems LLC, http://egauge.net/, 1.877-EGAUGE1, fax 720.545.9768

diff --git a/avrdude/linuxgpio.c b/avrdude/linuxgpio.c
index e6452e2..77abf60 100644
--- a/avrdude/linuxgpio.c
+++ b/avrdude/linuxgpio.c
@@ -258,12 +258,12 @@ static int linuxgpio_open(PROGRAMMER *pgm, char *port)
   //mostry LED status, can't be set to GPIO0. It can be fixed when a better
   //solution exists.
   for (i=0; i<N_PINS; i++) {
-    if ( pgm->pinno[i] != 0 ||
+    pin = pgm->pinno[i] & PIN_MASK;
+    if ( pin != 0) ||
          i == PIN_AVR_RESET ||
          i == PIN_AVR_SCK   ||
          i == PIN_AVR_MOSI  ||
          i == PIN_AVR_MISO ) {
-        pin = pgm->pinno[i] & PIN_MASK;
         if ((r=linuxgpio_export(pin)) < 0) {
             fprintf(stderr, "Can't export GPIO %d, already exported/busy?:
%s",
                     pin, strerror(errno));
@@ -327,6 +327,7 @@ void linuxgpio_initpgm(PROGRAMMER *pgm)
   pgm->program_enable = bitbang_program_enable;
   pgm->chip_erase     = bitbang_chip_erase;
   pgm->cmd            = bitbang_cmd;
+  pgm->cmd_tpi        = bitbang_cmd_tpi;
   pgm->open           = linuxgpio_open;
   pgm->close          = linuxgpio_close;
   pgm->setpin         = linuxgpio_setpin;