[PATCH 6/9] rtc: stmp3xxx: add sysfs entries for persistent regs

[s.trumtrar@pengutronix.de (Steffen Trumtrar)]

Hi Grant!

On Mon, Mar 04, 2013 at 11:14:54PM +0800, Grant Likely wrote:
> On Mon, Mar 4, 2013 at 10:05 PM, Steffen Trumtrar
> <s.trumtrar@pengutronix.de> wrote:
> > The persistent registers 1-5 are completely software defined. To have access
> > from userspace, export them via sysfs.
> >
> > Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> 
> Hi Steffen,
> 
> A few comments on this. First and foremost, any additions to the
> kernel sysfs interface must be accompanied with documentation in
> Documentation/ABI/. Second, adding attributes to an existing device

Okay. I forgot that and will add it in the next version.

> that has already been registered is almost guaranteed to be wrong. The
> attributes need to be added all at the same time so they are available
> immediately when the new device uevent is issued by the kernel.
> 
> Instead, the correct thing to do is add an attribute_group to the
> child device before the device gets registered. See the 'attributes'
> section of Documentation/driver-model/device.txt to see how to do
> this.
> 
> (I also see that the rtc core code is doing the wrong thing here also.
> rtc_sysfs_add_device(), rtc_sysfs_add_device() should also be replaced
> with an attribute group so that the sysfs files get added
> automatically; but that is outside the scope of this patch)
> 

Hm, I modeled it after other rtcs and the rtc_sysfs. Seems that I have to
rework this.

Thanks,
Steffen

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