Hi Oliver, On Sun, May 26, 2013 at 09:01:53PM +0200, Oliver Schinagl wrote: > On 05/26/13 15:21, Maxime Ripard wrote: > >For the iowrite* vs write*, there's no consensus, and as such no > >preferred way. write* functions are doing an MMIO only access, > >while iowrite functions can do MMIO and port I/O accesses. > > > >Note that it doesn't change anything on ARM, since there's no port IO on > >ARM. > Ah I see, missinformation on my end. Sorry. > > But why write 32 bits? The register is only 8 wide, with the rest > being 'reserved'. Then again, the register IS 32 bits wide and > probably will haev 32 bits written to it? Correct? Yes, the register is 32 bits wide. However, and I didn't noticed it at first, that all the registers have the 3 upper bytes reserved. But you'll end up writing a 32 bits value to a 32 bit register register anyway, even if the relevant information is contained in the 8 first bits. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
