On Sat, Aug 30, 2014 at 1:27 PM, Heiko Stübner <heiko@xxxxxxxxx> wrote: > Am Freitag, 29. August 2014, 21:51:46 schrieb Doug Anderson: >> On Thu, Aug 28, 2014 at 2:26 PM, Santosh Shilimkar >> >> <santosh.shilimkar@xxxxxx> wrote: >> > On Thursday 28 August 2014 03:36 PM, Doug Anderson wrote: >> >> These two patches add support for automatically configuring the IO >> >> voltage domains on rk3188 and rk3288 SoCs. The first patch adds some >> >> new notification types to the regulator code. It's used by the second >> >> patch which actually implements the IO voltage domain driver. >> >> >> >> These two patches were co-developed by Heiko Stübner and Doug Anderson >> >> (proof of concept patches were written by Heiko). They were tested in >> >> a private branch on an rk3288 board using rk808 instead of mainline >> >> since rk808 support isn't finalized in mainline yet. >> >> >> >> (sorry if you got this series twice; my mailer seems unhappy with me) >> >> >> >> Heiko Stübner (2): >> >> regulator: core: Add REGULATOR_EVENT_PRE_VOLTAGE_CHANGE (and ABORT) >> >> soc/rockchip: io-domain: add driver handling io domains >> > >> > Sorry to shot down but your IO domains are nothing but voltage domains >> > and you should really build something in the drivers/power/* >> >> If everyone agrees that this belongs in drivers/power that's totally >> OK. Neither Heiko nor I was confident that it should be in >> drivers/soc. I had even though that the code wouldn't be totally out >> of place in the Rockchip pinctrl driver (adding Linus W since I think >> some SoCs did add code to handle 3.3V vs. 1.8V in pinctrl). > > a bit of context for Linus ... > > This is essentially the continuation of the thread "io-domain voltages as > regulators?" from the beginning of august. After more discussions we found out > that the io voltage selection I asked about is not an independent supply, but > instead has to reflect the voltage of the real supplying regulator. > > And setting the io-voltage setting to 1.8V while the regulator is supplying > 3.3V for example may actually damage the chip. > > > So in our current approach here, we added a driver that tracks voltage changes > of the supplying regulator via a notifier and sets the register bits > accordingly. I feel I'm not smart enough for this. You need the PM people to look at this stuff, like Rafael Wysocki, Kevin Hilman and Ulf Hansson. Since it is also MMC/SD UHS-related, Ulf should know better than most what is needed, plus he's working on generic power domains right now. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
