On Tue 2017-01-31 18:46:58, Thierry Reding wrote:
> On Mon, Jan 30, 2017 at 10:53:01PM +0100, Pavel Machek wrote:
> > Hi!
> >
> >
> > > +struct system_power_chip;
> > > +
> > > +struct system_power_ops {
> > > + int (*restart)(struct system_power_chip *chip, enum reboot_mode mode,
> > > + char *cmd);
> > > + int (*power_off_prepare)(struct system_power_chip *chip);
> > > + int (*power_off)(struct system_power_chip *chip);
> > > +};
> > > +
> > > +struct system_power_chip {
> > > + const struct system_power_ops *ops;
> > > + struct list_head list;
> > > + struct device *dev;
> > > +};
> >
> > Is it useful to have two structures? AFAICT one would do.
>
> Yeah, one structure works fine. I was drawing inspiration from other
> subsystems that have a separate structure for these. I've merged the
> operations into the struct system_power_chip now because that gives
> us some more flexiblity, for example in cases where a chip can be a
> power controller and a reset controller, but sometimes we may want
> it to be only one of them.
>
> > Do we always have struct device * to work with? IMO we have nothing
> > suitable for example in the ACPI case. Would void * be more suitable?
>
> The struct device * was meant to be purely optional, but working with
> the code some more today and doing some more conversions, I've resorted
> to adding a separate field (const char *name) that takes precedence. So
> if a chip specifies both a .dev and .name field, then .name will be the
> user visible string, otherwise dev_name(.dev) will be used in
> messages.Thanks! > > Could you convert someting (acpi?) to the new framework as > > demonstration? > > I had originally only converted architecture code to call into system > power instead of the notifier chain and added a driver for a chip that > I want to get this to work on. I've now converted a couple of other > drivers from drivers/power/reset as well as ACPI. I've also added a > very rudimentary prioritization mechanism that I've validated on the > specific setup that I'm working on. > > On the Jetson TX1 that I'm testing this on, the SoC has a way of > resetting itself. This has the advantage that some of the registers are > kept intact over the reset, and this in turn is used to control early > boot, so that specific recovery modes can be used. However, the board > has to be powered off using the PMIC (via I2C). The patches achieve this > by splitting up restart and power off into two steps, prepare and > restart/power-off, as well as levels to prioritize. On Jetson TX1 the > PMIC will be higher priority than the SoC (determined by the level) and > therefore be able to override the SoC restart mechanism if we want to. > If we don't we simply instruct the MAX77620 driver not to register the > restart callback, in which case the SoC implementation will be used. > > I've uploaded all of it to a branch on github: > > https://github.com/thierryreding/linux/tree/system-power > > It's rather lengthy, so I'm not sure if it makes sense to send to the > lists right away. It is easier to review on lists, but no reasons to do it now. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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