From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <44906584.60503@domain.hid> Date: Wed, 14 Jun 2006 13:37:40 -0600 From: Jim Cromie MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Xenomai-core] GPIO and RTDM List-Id: "Xenomai life and development \(bug reports, patches, discussions\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai-core , Jan Kiszka hi Jan, everyone, Ive worked up a patchset to add a GPIO driver for the chip on my mobo. I adapted an existing one, drivers/char/scx200_gpio, and created drivers/char/pc8736x_gpio When doing this, I _oversimplified_ my problem by disregarding RTDM, and Im hoping I can just _retrofit_ as needed. the chip is on an ISA bus, a user-space C program can read the pins at (this) rate: Wed Jun 14 13:24:13 MDT 2006 Linux soekris 2.6.17-rc6-gpio-sk #4 Sun Jun 11 20:43:10 MDT 2006 i586 GNU/Linux opened /dev/gpio-17, for 1 loops, 1000000 samples read 1000000 samples in 7.8434 sec, rate: 127494.9460 samples/sec opened /dev/led, for 1 loops, 1000000 samples read 1000000 samples in 5.4116 sec, rate: 184788.5056 samples/sec (obviously speed isnt latency, but theres some correlation ..) I dont actually have a Real Question, to I'll throw out a placeholder - What are the top 3-5 things to do or look at in order to check the compatibility of my patches with RTDM ? Separately.. In this GPIO work, I concluded that I needed to add a sysfs interface to my driver, in order to better fit with LKML expectations. What I did so far works, and seems to hang together coherently, but insofar as it is the 1st time (to my knowledge) that a uniform treatment has been tried, I might have painted myself / all-of-us into a corner. Hopefully not, but you folks have a keener perception of these things. Ill send shortly. tia jimc