patch #7165 Add support for bitbanging GPIO lines using the Linux sysf GPIO interface

* doc/avrdude.texi,avrdude.1: added doc for linuxgpio 
	* avrdude.conf.in: added template for linuxgpio programmer
	* config_gram.y: pin numbers restricted to [PIN_MIN, PIN_MAX]
	* pindefs.h: added PIN_MIN, PIN_MAX, removed unused LED_ON/OFF
	* configure.ac: configure option enable-linuxgpio, print of enabled options
	* linuxgpio.[ch]: new source for linuxgpio programmer
	* Makefile.am: added linuxgpio to sources list
	* pgm_type.c: added linuxgpio to programmer types list

git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@1132 81a1dc3b-b13d-400b-aceb-764788c761c2

ChangeLog

@@ -1,3 +1,15 @@
+2013-01-09  Rene Liebscher <R.Liebscher@gmx.de>
+
+	patch #7165 Add support for bitbanging GPIO lines using the Linux sysf GPIO interface
+	* doc/avrdude.texi,avrdude.1: added doc for linuxgpio 
+	* avrdude.conf.in: added template for linuxgpio programmer
+	* config_gram.y: pin numbers restricted to [PIN_MIN, PIN_MAX]
+	* pindefs.h: added PIN_MIN, PIN_MAX, removed unused LED_ON/OFF
+	* configure.ac: configure option enable-linuxgpio, print of enabled options
+	* linuxgpio.[ch]: new source for linuxgpio programmer
+	* Makefile.am: added linuxgpio to sources list
+	* pgm_type.c: added linuxgpio to programmer types list
+
 2013-01-08  Joerg Wunsch <j.gnu@uriah.heep.sax.de>
 
 	* jtagmkI.c (jtagmkI_prmsg): replace a putchar() by putc(...stderr)

Makefile.am

@@ -31,6 +31,7 @@ EXTRA_DIST   = \
 	ChangeLog-2009 \
 	ChangeLog-2010 \
 	ChangeLog-2011 \
+	ChangeLog-2012 \
 	avrdude.1 \
 	avrdude.spec \
 	bootstrap
@@ -123,6 +124,8 @@ libavrdude_a_SOURCES = \
 	jtag3.c \
 	jtag3.h \
 	jtag3_private.h \
+	linuxgpio.c \
+	linuxgpio.h \
 	linux_ppdev.h \
 	lists.c \
 	lists.h \

NEWS

@@ -14,6 +14,10 @@ Current:
     - ATmega256RFR2, ATmega128RFR2, ATmega64RFR2
 
   * New programmers supported:
+    - linuxgpio
+      + any (embedded) Linux system with 4 GPIOs available can be used
+        as a programmer with little or no additional hardware.
+
     - avrftdi
       + o-link (patch #7672 adding support for O-Link (FTDI based
         JTAG) as programmer)

avrdude.1

@@ -98,6 +98,18 @@ port.
 Connecting to a serial port emulated on top of USB is likely to not
 work at all, or to work abysmally slow.
 .Pp
+If you happen to have a Linux system with at least 4 hardware GPIOs 
+available (like almost all embedded Linux boards) you can do without 
+any additional hardware - just connect them to the MOSI, MISO, RESET 
+and SCK pins on the AVR and use the linuxgpio programmer type. It bitbangs
+the lines using the Linux sysfs GPIO interface. Of course, care should
+be taken about voltage level compatibility. Also, although not strictrly 
+required, it is strongly advisable to protect the GPIO pins from 
+overcurrent situations in some way. The simplest would be to just put
+some resistors in series or better yet use a 3-state buffer driver like
+the 74HC244. Have a look at http://kolev.info/avrdude-linuxgpio for a more
+detailed tutorial about using this programmer type.
+.Pp
 Atmel's STK500 programmer is also supported and connects to a serial
 port.
 Both, firmware versions 1.x and 2.x can be handled, but require a

avrdude.conf.in

@@ -1142,7 +1142,28 @@ programmer
 
 @HAVE_PARPORT_END@
 
+#This programmer bitbangs GPIO lines using the Linux sysfs GPIO interface
 #
+#To enable it set the configuration below to match the GPIO lines connected to the
+#relevant ISP header pins and uncomment the entry definition. In case you don't
+#have the required permissions to edit this system wide config file put the
+#entry in a separate <your name>.conf file and use it with -C+<your name>.conf
+#on the command line.
+#
+#To check if your avrdude build has support for the linuxgpio programmer compiled in,
+#use -c?type on the command line and look for linuxgpio in the list. If it's not available
+#you need pass the --enable-linuxgpio=yes option to configure and recompile avrdude.
+#
+#programmer
+#  id    = "linuxgpio";
+#  desc  = "Use the Linux sysfs interface to bitbang GPIO lines";
+#  type  = "linuxgpio";
+#  reset = ?;
+#  sck   = ?;
+#  mosi  = ?;
+#  miso  = ?;
+#;
+
 # some ultra cheap programmers use bitbanging on the 
 # serialport.
 #

config_gram.y

@@ -1346,11 +1346,11 @@ static int assign_pin(int pinno, TOKEN * v, int invert)
   value = v->value.number;
   free_token(v);
 
-  if ((value <= 0) || (value >= 18)) {
+  if ((value < PIN_MIN) || (value > PIN_MAX)) {
     fprintf(stderr, 
             "%s: error at line %d of %s: pin must be in the "
-            "range 1-17\n",
+            "range %d-%d\n",
-            progname, lineno, infile);
+            progname, lineno, infile, PIN_MIN, PIN_MAX);
     exit(1);
   }
   if (invert)

configure.ac

@@ -271,6 +271,18 @@ AC_ARG_ENABLE(
 		*)   AC_MSG_ERROR(bad value ${enableval} for enable-parport option) ;;
 		esac],
 	[enabled_parport=yes])
+	
+AC_ARG_ENABLE(
+	[linuxgpio],
+	AC_HELP_STRING(
+		[--enable-linuxgpio],
+		[Enable the Linux sysfs GPIO interface programmer type]),
+	[case "${enableval}" in
+		yes) enabled_linuxgpio=yes ;;
+		no)  enabled_linuxgpio=no ;;
+		*)   AC_MSG_ERROR(bad value ${enableval} for enable-linuxgpio option) ;;
+		esac],
+	[enabled_linuxgpio=no])	
 
 DIST_SUBDIRS_AC='doc windows'
 
@@ -340,6 +352,15 @@ else
 	confsubst="-e /^@HAVE_PARPORT_BEGIN@/,/^@HAVE_PARPORT_END@/d"
 fi
 
+
+if test "$enabled_linuxgpio" = "yes"; then
+	AC_DEFINE(HAVE_LINUXGPIO, 1, [Linux sysfs GPIO support enabled])
+	confsubst="$confsubst -e /^@HAVE_LINUXGPIO_/d"
+else
+	confsubst="$confsubst -e /^@HAVE_LINUXGPIO_BEGIN@/,/^@HAVE_LINUXGPIO_END@/d"
+fi
+
+
 # If we are compiling with gcc, enable all warning and make warnings errors.
 if test "$GCC" = yes; then
     ENABLE_WARNINGS="-Wall"
@@ -479,3 +500,21 @@ else
    echo "DON'T HAVE pthread"
 fi
 
+if test x$enabled_doc = xyes; then
+   echo "ENABLED    doc"
+else
+   echo "DISABLED   doc"
+fi
+
+if test x$enabled_parport = xyes; then
+   echo "ENABLED    parport"
+else
+   echo "DISABLED   parport"
+fi
+
+if test x$enabled_linuxgpio = xyes; then
+   echo "ENABLED    linuxgpio"
+else
+   echo "DISABLED   linuxgpio"
+fi
+

doc/avrdude.texi

@@ -168,6 +168,18 @@ attached to a physical serial port.  Connecting to a serial port
 emulated on top of USB is likely to not work at all, or to work
 abysmally slow.
 
+If you happen to have a Linux system with at least 4 hardware GPIOs 
+available (like almost all embedded Linux boards) you can do without 
+any additional hardware - just connect them to the MOSI, MISO, RESET 
+and SCK pins on the AVR and use the linuxgpio programmer type. It bitbangs
+the lines using the Linux sysfs GPIO interface. Of course, care should
+be taken about voltage level compatibility. Also, although not strictrly 
+required, it is strongly advisable to protect the GPIO pins from 
+overcurrent situations in some way. The simplest would be to just put
+some resistors in series or better yet use a 3-state buffer driver like
+the 74HC244. Have a look at http://kolev.info/avrdude-linuxgpio for a more
+detailed tutorial about using this programmer type.
+
 The STK500, JTAG ICE, avr910, and avr109/butterfly use the serial port to communicate with the PC.
 The STK600, JTAG ICE mkII, AVRISP mkII, USBasp, avrftdi (and derivitives), and USBtinyISP
 programmers communicate through the USB, using @code{libusb} as a

linuxgpio.c

@@ -0,0 +1,349 @@
+/*
+ * avrdude - A Downloader/Uploader for AVR device programmers
+ * Support for bitbanging GPIO pins using the /sys/class/gpio interface
+ * 
+ * Copyright (C) 2013 Radoslav Kolev <radoslav@kolev.info>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "ac_cfg.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "avrdude.h"
+#include "avr.h"
+#include "pindefs.h"
+#include "pgm.h"
+#include "bitbang.h"
+
+#if HAVE_LINUXGPIO
+
+/*
+ * GPIO user space helpers
+ *
+ * Copyright 2009 Analog Devices Inc.
+ * Michael Hennerich (hennerich@blackfin.uclinux.org)
+ *
+ * Licensed under the GPL-2 or later
+ */
+
+/*
+ * GPIO user space helpers
+ * The following functions are acting on an "unsigned gpio" argument, which corresponds to the 
+ * gpio numbering scheme in the kernel (starting from 0).  
+ * The higher level functions use "int pin" to specify the pins with an offset of 1:
+ * gpio = pin - 1;
+ */
+
+#define GPIO_DIR_IN	0
+#define GPIO_DIR_OUT	1
+
+static int linuxgpio_export(unsigned int gpio)
+{
+  int fd, len, r;
+  char buf[11];
+
+  fd = open("/sys/class/gpio/export", O_WRONLY);
+  if (fd < 0) {
+    perror("Can't open /sys/class/gpio/export");
+    return fd;
+  }
+
+  len = snprintf(buf, sizeof(buf), "%d", gpio);
+  r = write(fd, buf, len);
+  close(fd);
+
+  return r;
+}
+
+static int linuxgpio_unexport(unsigned int gpio)
+{
+  int fd, len, r;
+  char buf[11];
+
+  fd = open("/sys/class/gpio/unexport", O_WRONLY);
+  if (fd < 0) {
+    perror("Can't open /sys/class/gpio/unexport");
+    return fd;
+  }
+
+  len = snprintf(buf, sizeof(buf), "%d", gpio);
+  r = write(fd, buf, len);
+  close(fd);
+
+  return r;
+}
+
+static int linuxgpio_openfd(unsigned int gpio)
+{
+  char filepath[60];
+
+  snprintf(filepath, sizeof(filepath), "/sys/class/gpio/gpio%d/value", gpio);
+  return (open(filepath, O_RDWR));
+}
+
+static int linuxgpio_dir(unsigned int gpio, unsigned int dir)
+{
+  int fd, r;
+  char buf[60];
+
+  snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/direction", gpio);
+
+  fd = open(buf, O_WRONLY);
+  if (fd < 0) {
+    perror("Can't open gpioX/direction");
+    return fd;
+  }
+
+  if (dir == GPIO_DIR_OUT)
+    r = write(fd, "out", 4);
+  else
+    r = write(fd, "in", 3);
+
+  close(fd);
+
+  return r;
+}
+
+static int linuxgpio_dir_out(unsigned int gpio)
+{
+  return linuxgpio_dir(gpio, GPIO_DIR_OUT);
+}
+
+static int linuxgpio_dir_in(unsigned int gpio)
+{
+  return linuxgpio_dir(gpio, GPIO_DIR_IN);
+}
+
+/*
+ * End of GPIO user space helpers
+ */
+
+#define N_GPIO (PIN_MAX + 1)
+
+/*
+* an array which holds open FDs to /sys/class/gpio/gpioXX/value for all needed pins
+*/
+static int linuxgpio_fds[N_GPIO] ;
+
+
+static int linuxgpio_setpin(PROGRAMMER * pgm, int pin, int value)
+{
+  int r;
+
+  if (pin & PIN_INVERSE)
+  {
+    value  = !value;
+    pin   &= PIN_MASK;
+  }
+
+  if ( linuxgpio_fds[pin] < 0 )
+    return -1;
+
+  if (value)
+    r = write(linuxgpio_fds[pin], "1", 1);
+  else
+    r = write(linuxgpio_fds[pin], "0", 1);
+
+  if (r!=1) return -1;
+
+  if (pgm->ispdelay > 1)
+    bitbang_delay(pgm->ispdelay);
+
+  return 0;
+}
+
+static int linuxgpio_getpin(PROGRAMMER * pgm, int pin)
+{
+  unsigned char invert=0;
+  char c;
+
+  if (pin & PIN_INVERSE)
+  {
+    invert = 1;
+    pin   &= PIN_MASK;
+  }
+
+  if ( linuxgpio_fds[pin] < 0 )
+    return -1;
+
+  if (lseek(linuxgpio_fds[pin], 0, SEEK_SET)<0)
+    return -1;
+
+  if (read(linuxgpio_fds[pin], &c, 1)!=1)
+    return -1;
+
+  if (c=='0')
+    return 0+invert;
+  else if (c=='1')
+    return 1-invert;
+  else
+    return -1;
+
+}
+
+static int linuxgpio_highpulsepin(PROGRAMMER * pgm, int pin)
+{
+
+  if ( linuxgpio_fds[pin & PIN_MASK] < 0 )
+    return -1;
+
+  linuxgpio_setpin(pgm, pin, 1);
+  linuxgpio_setpin(pgm, pin, 0);
+
+  return 0;
+}
+
+
+
+static void linuxgpio_display(PROGRAMMER *pgm, const char *p)
+{
+  /* MAYBE */
+}
+
+static void linuxgpio_enable(PROGRAMMER *pgm)
+{
+  /* nothing */
+}
+
+static void linuxgpio_disable(PROGRAMMER *pgm)
+{
+  /* nothing */
+}
+
+static void linuxgpio_powerup(PROGRAMMER *pgm)
+{
+  /* nothing */
+}
+
+static void linuxgpio_powerdown(PROGRAMMER *pgm)
+{
+  /* nothing */
+}
+
+static int linuxgpio_open(PROGRAMMER *pgm, char *port)
+{
+  int r, i, pin;
+
+  bitbang_check_prerequisites(pgm);
+
+
+  for (i=0; i<N_GPIO; i++)
+    linuxgpio_fds[i] = -1;
+  //Avrdude assumes that if a pin number is 0 it means not used/available
+  //this causes a problem because 0 is a valid GPIO number in Linux sysfs.
+  //To avoid annoying off by one pin numbering we assume SCK, MOSI, MISO 
+  //and RESET pins are always defined in avrdude.conf, even as 0. If they're
+  //not programming will not work anyway. The drawbacks of this approach are
+  //that unwanted toggling of GPIO0 can occur and that other optional pins
+  //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 ||
+         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));
+            return r;
+        }
+        if (i == PIN_AVR_MISO)
+            r=linuxgpio_dir_in(pin);
+        else
+            r=linuxgpio_dir_out(pin);
+
+        if (r < 0)
+            return r;
+
+        if ((linuxgpio_fds[pin]=linuxgpio_openfd(pin)) < 0)
+            return linuxgpio_fds[pin];
+    }
+  }
+
+ return(0);
+}
+
+static void linuxgpio_close(PROGRAMMER *pgm)
+{
+  int i, reset_pin;
+
+  reset_pin = pgm->pinno[PIN_AVR_RESET] & PIN_MASK;
+
+  //first configure all pins as input, except RESET
+  //this should avoid possible conflicts when AVR firmware starts
+  for (i=0; i<N_GPIO; i++) {
+    if (linuxgpio_fds[i] >= 0 && i != reset_pin) {
+       close(linuxgpio_fds[i]);
+       linuxgpio_dir_in(i);
+       linuxgpio_unexport(i);
+    }
+  }
+  //configure RESET as input, if there's external pull up it will go high
+  if (linuxgpio_fds[reset_pin] >= 0) {
+    close(linuxgpio_fds[reset_pin]);
+    linuxgpio_dir_in(reset_pin);
+    linuxgpio_unexport(reset_pin);
+  }
+}
+
+void linuxgpio_initpgm(PROGRAMMER *pgm)
+{
+  strcpy(pgm->type, "linuxgpio");
+
+  pgm->rdy_led        = bitbang_rdy_led;
+  pgm->err_led        = bitbang_err_led;
+  pgm->pgm_led        = bitbang_pgm_led;
+  pgm->vfy_led        = bitbang_vfy_led;
+  pgm->initialize     = bitbang_initialize;
+  pgm->display        = linuxgpio_display;
+  pgm->enable         = linuxgpio_enable;
+  pgm->disable        = linuxgpio_disable;
+  pgm->powerup        = linuxgpio_powerup;
+  pgm->powerdown      = linuxgpio_powerdown;
+  pgm->program_enable = bitbang_program_enable;
+  pgm->chip_erase     = bitbang_chip_erase;
+  pgm->cmd            = bitbang_cmd;
+  pgm->open           = linuxgpio_open;
+  pgm->close          = linuxgpio_close;
+  pgm->setpin         = linuxgpio_setpin;
+  pgm->getpin         = linuxgpio_getpin;
+  pgm->highpulsepin   = linuxgpio_highpulsepin;
+  pgm->read_byte      = avr_read_byte_default;
+  pgm->write_byte     = avr_write_byte_default;
+}
+
+const char linuxgpio_desc[] = "GPIO bitbanging using the Linux sysfs interface";
+
+#else  /* !HAVE_LINUXGPIO */
+
+void linuxgpio_initpgm(PROGRAMMER * pgm)
+{
+  fprintf(stderr,
+	  "%s: Linux sysfs GPIO support not available in this configuration\n",
+	  progname);
+}
+
+const char linuxgpio_desc[] = "GPIO bitbanging using the Linux sysfs interface (not available)";
+
+#endif /* HAVE_LINUXGPIO */

linuxgpio.h

@@ -0,0 +1,36 @@
+/*
+ * avrdude - A Downloader/Uploader for AVR device programmers
+ * Copyright (C) 2013 Radoslav Kolev <radoslav@kolev.info>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/* $Id: par.h 722 2007-01-24 22:43:46Z joerg_wunsch $ */
+
+#ifndef linuxgpio_h
+#define linuxgpio_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const char linuxgpio_desc[];
+void linuxgpio_initpgm        (PROGRAMMER * pgm);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

pgm_type.c

@@ -38,6 +38,7 @@
 #include "jtagmkI.h"
 #include "jtagmkII.h"
 #include "jtag3.h"
+#include "linuxgpio.h"
 #include "par.h"
 #include "pickit2.h"
 #include "ppi.h"
@@ -74,6 +75,7 @@ const PROGRAMMER_TYPE const programmers_types[] = {
         {"jtagice3_pdi", jtag3_pdi_initpgm, jtag3_pdi_desc},
         {"jtagice3_dw", jtag3_dw_initpgm, jtag3_dw_desc},
         {"jtagice3_isp", stk500v2_jtag3_initpgm, stk500v2_jtag3_desc},
+        {"linuxgpio", linuxgpio_initpgm, linuxgpio_desc},
         {"par", par_initpgm, par_desc},
         {"pickit2", pickit2_initpgm, pickit2_desc},
         {"serbb", serbb_initpgm, serbb_desc},

pindefs.h

@@ -38,8 +38,7 @@ enum {
 };
 #define PIN_MASK    (UINT_MAX>>1)
 #define PIN_INVERSE (~(PIN_MASK))	/* flag for inverted pin in serbb */
-
+#define PIN_MIN     1   /* smallest allowed pin number */
-#define LED_ON(fd,pin)  ppi_setpin(fd,pin,0)
+#define PIN_MAX     255 /* largest allowed pin number */
-#define LED_OFF(fd,pin) ppi_setpin(fd,pin,1)
 
 #endif