On 12/17/2012 06:37 PM, Wolfgang Grandegger wrote: > /* Do synchronous data output with a single write access */ > __raw_writel(~mask, pio + PIO_OWDR); > __raw_writel(mask, pio + PIO_OWER); > __raw_writel(val, pio + PIO_ODSR); > > For caching we would need a storage. Not sure if it's worth compared to > a context switch into the kernel.
Block GPIO is not only for you in userspace. ;-) You can also implement efficient n-bit bus I/O in kernel drivers, n-bit-banging. :-) So not always context switches involved. Roland -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/