Re: [RFC PATCH] regulator: core: allow consumers to request tocloses step voltage

From: Mark Brown
Date: Wed Jun 19 2013 - 18:38:38 EST


On Wed, Jun 19, 2013 at 02:17:54PM -0500, Nishanth Menon wrote:

> Account for step size accuracy when exact voltage requests are send for
> step based regulators.

If the consumer can tolerate a different voltage why not just request
the range that can be tolerated? Your problem here is specifying an
exact voltage.

> The specific example I faced was using cpufreq-cpu0 driver with voltages
> for OPPs for MPU rail and attempting the common definitions against voltages
> that are non-exact multiples of stepsize of PMIC.

> The alternative would be implement custom set_voltage (as againsta simpler
> set_voltage_sel and using linear map/list functions) for the regulator which
> will account for the same.

> Yet another alternative might be to introduce yet another custom function similar
> to regulator_set_voltage_tol which accounts for this. something like:
> regulator_set_voltage_floor(regulator, voltage, tol) or something to that effect.

Or as I keep telling you guys the consumer can just do that directly
using the existing API; the whole point in specifying the voltage as a
range is to allow the consumer to cope with arbatrary regulators by
giving a range of voltages that it can accept.

The API is deliberately very conservative in these matters since there
is a danger of physical damage if things really go wrong in some
applications, it makes sure that both the drivers and the system
integration are involved.

Attachment: signature.asc
Description: Digital signature