On 30/04/2021 11:02:06+0200, Maxime Ripard wrote: > Hi, > > On Sun, Apr 18, 2021 at 08:45:49PM -0500, Samuel Holland wrote: > > The sun6i RTC provides 32 bytes of general-purpose data registers. > > They can be used to save data in the always-on RTC power domain. > > The registers are writable via 32-bit MMIO accesses only. > > > > Expose the region as a NVMEM provider so it can be used by userspace and > > other drivers. > > > > Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx> > > As far as I understood, you want to use those registers to implement > super-standby? If so, while it makes sense for the kernel to be able to > be able to write to those registers, I guess it would be a bit unwise to > allow the userspace to access it? I would think nvmem is still the proper subsystem. I guess maybe we should have a version of __nvmem_device_get that would ensure exclusive access to a cell, thus preventing userspace accessing it as long a the kernel is using it. -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
