On Tue, 2015-05-05 at 10:47 +0200, Ulf Hansson wrote: > On 5 May 2015 at 10:35, Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> wrote: > > On 05/05/15 10:56, Ulf Hansson wrote: > >> On 30 April 2015 at 14:32, Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> wrote: > >>> Implement voltage switch, supporting modes up to SDR-50. > >>> > >>> Based on work by Shinobu Uehara, Rob Taylor, William Towle and Ian Molton. > >>> > >>> This uses two voltage regulators, one external and one on the pfc. > >> > >> Why two? If there is a parent child relation ship, that should be > >> handled through the regulator tree, right!? Please elaborate. > > > > The card main power is separate from the IO line voltages. > > > > To get to the high-speed, card power is left at 3.3V and the IO > > voltage is changed to 1.8V. > > > > In the systems we have the power gate is separate from the controls > > for the IO but not integrated into the MMC controller itself. In this case, there are *three* regulators: 1. External regulator for card power (VDD pin): "vmmc" 2. External regulator for pull-up voltage for the data pins: "vqmmc" 3. Internal regulator for input(?) level on the data pins: "vqmmc_ref" (I'm open to suggestions of a better name) > Okay, that's what I was expecting and hoping for :-) > > Then you need to rework $subject patch according to below. > > 1) Use mmc_regulator_get_supply() to fetch both the I/O voltage > regulator (vqmmc) and the main power regulator (vmmc). We already do that. > Your "vqmmc_ref" regulator should thus be renamed to "vmmc". No, we have one of those already. > 2) The vmmc regulator should not be handled from the > ->start_signal_voltage_switch() callback, since it's only vqmmc > voltage levels that should be changed from there. It isn't. > 3) The voltage levels changes for vmmc shall be handled via the > ->set_ios() callback. We don't support UHS-II so we never change the voltage of this regulator. Ben. > I suggest you go and have a look in drivers/mmc/host/mmci.c, that > should provide you with a good inspiration. > > Kind regards > Uffe -- 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
