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
This commit is contained in:
rliebscher
2013-01-09 19:23:30 +00:00
parent 1b8fc9897d
commit 8d6f310736
12 changed files with 495 additions and 6 deletions

View File

@@ -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