--- /dev/null
+Kernel driver i2c-parport
+
+Author: Jean Delvare <khali@linux-fr.org>
+
+This is a unified driver for several i2c-over-parallel-port adapters,
+such as the ones made by Philips, Velleman or ELV. This driver is
+meant as a replacement for the older, individual drivers:
+ * i2c-philips-par
+ * i2c-elv
+ * i2c-velleman
+ * video/i2c-parport (NOT the same as this one, dedicated to home brew
+ teletext adapters)
+
+It currently supports the following devices:
+ * Philips adapter
+ * home brew teletext adapter
+ * Velleman K8000 adapter
+ * ELV adapter
+ * Analog Devices evaluation boards (ADM1025, ADM1030, ADM1031, ADM1032)
+
+These devices use different pinout configurations, so you have to tell
+the driver what you have, using the type module parameter. There is no
+way to autodetect the devices. Support for different pinout configurations
+can be easily added when needed.
+
+
+Building your own adapter
+-------------------------
+
+If you want to build you own i2c-over-parallel-port adapter, here is
+a sample electronics schema (credits go to Sylvain Munaut):
+
+Device PC
+Side ___________________Vdd (+) Side
+ | | |
+ --- --- ---
+ | | | | | |
+ |R| |R| |R|
+ | | | | | |
+ --- --- ---
+ | | |
+ | | /| |
+SCL ----------x--------o |-----------x------------------- pin 2
+ | \| | |
+ | | |
+ | |\ | |
+SDA ----------x----x---| o---x--------------------------- pin 13
+ | |/ |
+ | |
+ | /| |
+ ---------o |----------------x-------------- pin 3
+ \| | |
+ | |
+ --- ---
+ | | | |
+ |R| |R|
+ | | | |
+ --- ---
+ | |
+ ### ###
+ GND GND
+
+Remarks:
+ - This is the exact pinout and electronics used on the Analog Devices
+ evaluation boards.
+ /|
+ - All inverters -o |- must be 74HC05, they must be open collector output.
+ \|
+ - All resitors are 10k.
+ - Pins 18-25 of the parallel port connected to GND.
+ - Pins 4-9 (D2-D7) could be used as VDD is the driver drives them high.
+ The ADM1032 evaluation board uses D4-D7. Beware that the amount of
+ current you can draw from the parallel port is limited. Also note that
+ all connected lines MUST BE driven at the same state, else you'll short
+ circuit the output buffers! So plugging the I2C adapter after loading
+ the i2c-parport module might be a good safety since data line state
+ prior to init may be unknown.
+ - This is 5V!
+ - Obviously you cannot read SCL (so it's not really standard-compliant).
+ Pretty easy to add, just copy the SDA part and use another input pin.
+ That would give (ELV compatible pinout):
+
+
+Device PC
+Side ______________________________Vdd (+) Side
+ | | | |
+ --- --- --- ---
+ | | | | | | | |
+ |R| |R| |R| |R|
+ | | | | | | | |
+ --- --- --- ---
+ | | | |
+ | | |\ | |
+SCL ----------x--------x--| o---x------------------------ pin 15
+ | | |/ |
+ | | |
+ | | /| |
+ | ---o |-------------x-------------- pin 2
+ | \| | |
+ | | |
+ | | |
+ | |\ | |
+SDA ---------------x---x--| o--------x------------------- pin 10
+ | |/ |
+ | |
+ | /| |
+ ---o |------------------x--------- pin 3
+ \| | |
+ | |
+ --- ---
+ | | | |
+ |R| |R|
+ | | | |
+ --- ---
+ | |
+ ### ###
+ GND GND
+
+
+If possible, you should use the same pinout configuration as existing
+adapters do, so you won't even have to change the code.
+
+
+Similar (but different) drivers
+-------------------------------
+
+This driver is NOT the same as the i2c-pport driver found in the i2c
+package. The i2c-pport driver makes use of modern parallel port features so
+that you don't need additional electronics. It has other restrictions
+however, and was not ported to Linux 2.6 (yet).
+
+This driver is also NOT the same as the i2c-pcf-epp driver found in the
+lm_sensors package. The i2c-pcf-epp driver doesn't use the parallel port as
+an I2C bus directly. Instead, it uses it to control an external I2C bus
+master. That driver was not ported to Linux 2.6 (yet) either.
+
+
+Legacy documentation for Velleman adapter
+-----------------------------------------
+
+Useful links:
+Velleman http://www.velleman.be/
+Velleman K8000 Howto http://howto.htlw16.ac.at/k8000-howto.html
+
+The project has lead to new libs for the Velleman K8000 and K8005:
+ LIBK8000 v1.99.1 and LIBK8005 v0.21
+With these libs, you can control the K8000 interface card and the K8005
+stepper motor card with the simple commands which are in the original
+Velleman software, like SetIOchannel, ReadADchannel, SendStepCCWFull and
+many more, using /dev/velleman.
+ http://home.wanadoo.nl/hihihi/libk8000.htm
+ http://home.wanadoo.nl/hihihi/libk8005.htm
+ http://struyve.mine.nu:8080/index.php?block=k8000
+ http://sourceforge.net/projects/libk8005/
git://git.onelab.eu / linux-2.6.git / blobdiff