On 29.06.2013 09:11, Matthias Klein wrote: > What is the right way to access these registers for e.g > setting a single bit of such a register to avoid > read/modify/write problems ? > Do I have to use some locking / atomic operations ? If the hardware does not support you here with bit-banding (some Cortex processors export single GPIO bits as separate bytes but I don't think the i.MX537 does), yes, you have to lock. I'd say implement a general GPIO driver and use its function for access. https://www.kernel.org/doc/Documentation/gpio.txt http://lxr.free-electrons.com/source/include/asm-generic/gpio.h#L52 http://lxr.free-electrons.com/source/drivers/gpio/gpio-cs5535.c#L93 Generally (several different modules accessing something that does not have a single driver to implement it) I think the only sane way is to implement the shared part in arch/arm/.../mach-* and have all users depend on it. -- Stano -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
