Please do not answer to this series, it contains a wrong address for the linux-arm-kernel list. I just resent this with the correct addres. Sorry for the noise.
Sascha On Wed, Sep 30, 2015 at 03:57:48PM +0200, Sascha Hauer wrote: > Until now changing the voltage of a regulator only ever effected the > regulator itself, but never its supplies. It's a common pattern though > to put LDO regulators behind switching regulators. The switching > regulators efficiently drop the input voltage but have a high ripple on > their output. The output is then cleaned up by the LDOs. For higher > energy efficiency the voltage drop at the LDOs should be minimized. This > patch adds support for such a scenario. > > A new min_dropout_uv field is added to struct regulator_desc. Regulators > can specify the minimun dropout voltage they need for proper function > here. Now when the voltage is changed on a regulator the regulator core > makes sure that > a) before increasing the voltage on the current regulator the supply > provides at least the desired voltage plus the minimum dropout > b) after decreasing the voltage on the current regulator the supply > is optimized to the minimum required voltage within the needs of > the consumers of the supply. > > Calculating the optimum voltage for the supply regulator is a bit tricky > since the simple approach of just adding the desired minimum voltage and > the minimum dropout is not enough. It may happen that the current > regulator does not support the desired minimum voltage, but only a > higher one. This means we have to figure out the lowest voltage > supported by the regulator that is higher than the minimum desired > voltage. The regulator_get_voltage_floor introduced with this series > does > exactly that. > > This is a first RFC for this series which probably has some rough edges, > but it was already tested successfully on a Phytec PFLA02 i.MX6 board. > > Please review, any input welcome. > > Sascha > > > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
