[PATCH v2 3/7] power: regulator-uclass: perform regulator setup inside uclass

[Svyatoslav Ryhel]

сб, 5 серп. 2023 р. о 15:49 Jonas Karlman <jonas at kwiboo.se> пише:
>
> Hi,
>
> On 2023-07-21 07:34, Svyatoslav Ryhel wrote:
> > чт, 20 лип. 2023 р. о 22:43 Simon Glass <sjg at chromium.org> пише:
> >>
> >> Hi Svyatoslav,
> >>
> >> On Thu, 20 Jul 2023 at 06:38, Svyatoslav Ryhel <clamor95 at gmail.com> wrote:
> >>>
> >>> Regulators initial setup was previously dependent on board call.
> >>> To move from this behaviour were introduced two steps. First is
> >>> that all individual regulators will be probed just after binding
> >>
> >> We must not probe devices automatically when bound. The i2c interface
> >> may not be available, etc. Do a probe afterwards.
> >>
> >> Perhaps I am misunderstanding this, iwc please reword this commit message.
> >
> > After bound. If the regulator is a self-sufficient i2c device then it
> > will be bound
> > after i2c is available by code design so i2c interface should be
> > available at that
> > moment. At least led and gpio uclasses perform this for initial setup
> > of devices.
> >
> > Platform regulators (aka fixed/gpio regulators) work perfectly fine. I
> > have no i2c
> > regulators to test deeply.
> >
> > As for now only one uclass is not compatible with this system - PMIC which has
> > strong dependency between regulator and main mfd. This is why probing after
> > bind for pmic regulators is disabled and pmic regulators are probed on pmic core
> > post_probe.
>
> This sounds more like a possible bug of some dependency not being
> probed in correct order or not leaving the device in a ready state
> after probe.
>
> If pmic regulators are bind in pmic bind with the pmic as parent, then
> at regulator probe the driver core ensure that pmic has probed before
> regulator use.

I have found why this occurs. With this patchset always/boot-on regulators
are probed immediately after bind, since pmic regulators are bound on pmics
bind it causes a situation when regulator is probed before pmic and pmics ops
are not available. Moving pmic children bind to pmics probe fixed this issue.

> This works perfect fine with the RK8xx I2C PMIC and its regulators.
> Wich a call to device_get_supply_regulator(dev, "test-supply", &reg)
> probe happens in i2c, pmic and regulator order.
>
> >
> >>> which ensures that regulator pdata is filled and second is setting
> >>> up regulator in post probe which enseres that correct regulator
> >>> state according to pdata is reached.
>
> I think that the approach in this patch is trying to change too much all
> at once.
>
> Have made some adjustments that I think should help with transition.
> - Added a flag to protect regulator_autoset from being called more then
>   once for each regulator, in a separate patch.
> - Changed to only probe-after-bind on regulators marked as
>   always-on/boot-on.
>
> And it works something like this:
>
> static int regulator_post_bind(struct udevice *dev)
> {
>         [...]
>
>         if (uc_pdata->always_on || uc_pdata->boot_on)
>                 dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND);
> }
>
> static int regulator_post_probe(struct udevice *dev)
> {
>         ret = regulator_autoset(dev);
> }
>
> With that any always-on/boot-on regulator would automatically probe and
> autoset after bind, remaining would only probe and autoset if they are
> used.
>
> This approach should also prevent having to change existing code that
> may call autoset, and cleanup can be done in follow-up patches/series.
>
> Probe-after-bind and call to autoset could also be protected with a new
> Kconfig to help with transition.
>
> See following for a working example using a new driver that depends
> on that regulators have been autoset prior to regulator_get_value.
> https://github.com/Kwiboo/u-boot-rockchip/compare/master...rk3568-io-domain
>
> Or the two commits separate:
>
> power: regulator: Only run autoset once for each regulator
> https://github.com/Kwiboo/u-boot-rockchip/commit/05db4dbcb8f908b417ed5cae8a7a325c82112d75
>
> power: regulator: Perform regulator setup inside uclass
> https://github.com/Kwiboo/u-boot-rockchip/commit/489bd5d2c1a2a33824eac4f2d54399ef5dff4fdf
>
> Regards,
> Jonas
>
> >>>
> >>> Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
> >>> ---
> >>>  drivers/power/regulator/regulator-uclass.c | 212 ++++++---------------
> >>>  include/power/regulator.h                  | 119 ------------
> >>>  2 files changed, 62 insertions(+), 269 deletions(-)
> >>
> >> Regards,
> >> SImon
>