Messages in this thread | | | Subject | Re: [PATCH 10/18] staging: typec: fusb302: Add support for fcs,vbus-regulator-name device-property | From | Hans de Goede <> | Date | Mon, 7 Aug 2017 21:20:05 +0200 |
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Hi,
On 07-08-17 17:41, Mark Brown wrote: > On Mon, Aug 07, 2017 at 04:41:18PM +0200, Hans de Goede wrote: >> On 07-08-17 13:10, Mark Brown wrote: > >> Problem 1) > >> The regulator in question is part of the bq24292i charger-IC attached to >> a private i2c bus between the PMIC and the charger. The driver for the i2c >> controller inside the PMIC which drivers this bus currently also instantiates >> the i2c-client for the charger: > > ... > >> Note that the bq24190 driver is a generic driver, so to pass the >> board specific regulator_init_data to it I would need to somehow >> pass it here, but I don't see how, except by storing a pointer to >> it in an u64 device-property which seems like a bad idea > > I2C has a perfectly good platform_data pointer in the board info for > this stuff.
True, so you are suggesting that I define a bq24190_platform_data struct with a regulator_init_data pointer in there I guess?
At least I would not want to just claim that pointer for just regulator_init_data and more-over assuming that what is in there will be regulator_init_data feels wrong.
I don't think the power-supply maintainers will be enthusiastic about this (hi Sebastian). But that does make sense and is actually a good idea for tackling the problem of regulator_init_data.
>> Problem 2) > >> Even if I could add the mapping through regulator_init_data >> then it may well be too late, if the regulator_get happens >> before the bq24190 driver registers its regulator (and thus >> the mapping) the regulator_get for it may have already >> happened and returned a dummy-regulator, or another regulator >> with the rather generic vbus name. > > If you don't have control over the instantiation ordering
It is not just device-instantiation ordering, it is also driver loading order, the event around which ordering needs to happen is the registration of the regulator (as things are now).
> but you have a firmware which claims to provide a complete description of regulators > then you'd need to add an interface that allows mappings to be > registered separately to regulator registration.
So the pwm subsys has this pwm_add_table thing which can add lookup entries indepdentent of pwm_registration and which uses supply/device_name matching to find the entry for the caller of pwm_get which is the same as the current lookup code in the regulator-core, but since it is independent of the registration the lookup-table does not contain direct pointers to pwmchip-s instead it uses a string which gets matches against the pwm (parent) dev's dev_name().
Would extending the struct regulator_map with a const char *provider_name:
struct regulator_map { struct list_head list; const char *dev_name; /* The dev_name() for the consumer */ const char *supply; struct regulator_dev *regulator; const char *provider; /* The dev_name() for the regulator parent-dev */ };
And having a regulator_add_lookup function which adds an entry to the regulator_map_list which sets provider_name instead of regulator be acceptable ?
lookup of such entries would look for regulators where supply matches the regulator-name and provider matches the regulators parent-dev-name.
Alternatively the entry could additionally contain a provider_supply_name so that we can make arbitrary consumer-dev-name + consumer-supply-name provider-dev-name + provider-supply-name matches. That would probably be more flexible then requiring the supply name to match.
So would something like this (including returning -EPROBE_DEFER if there is a pwm_map_list entry and no matching regulator can be found) acceptable ?
> Whatever you're doing the answer isn't to try to specify the name of the > supply through some firmware binding, that's just obviously not sensible > both in terms of a firmware abstraction and in terms of how the > abstractions in Linux work.
Ok.
Regards,
Hans
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