On Thu, Dec 14, 2006 at 10:56:03AM +0100, Hans-Jürgen Koch wrote: > A small German manufacturer produces high-end AD converter cards. He sells > 100 pieces per year, only in Germany and only with Windows drivers. He would > now like to make his cards work with Linux. He has two driver programmers > with little experience in writing Linux kernel drivers. What do you tell him? > Write a large kernel module from scratch? Completely rewrite his code > because it uses floating point arithmetics?
Write a small kernel module which: - create a device node per-card - read the data from the A/D as fast as possible and buffer it in main memory without touching it - implements a read interface to read data from the buffer - implement ioctls for whatever controls you need And that's it. All the rest can be done in userspace, safely, with floating point, C++ and everything. If the driver programmers are worth their pay, their driver is probably already split logically at where the userspace-kernel interface would be. And small means small, like 200 lines or so, more if you want to have fun with sysfs, poll, aio and their ilk, but that's not a necessity. OG. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
