On Mon, Nov 09, 2015 at 10:38:03AM +0100, Ulf Hansson wrote: > [...] > > >> > Is the regulator-gpio usage the right thing to do for vqmmc? In my case it is > >> > not really driven by a gpio but by a pio from the sdhci device. In the binding, > >> > >> What's a "pio"? > >> > >> What do you mean by the it's driven from the sdhci device? > >> > > > > Sorry I mean sdhci device from the SoC point of view, I should say > > controller. So yes the signal is driven by the controller. > > > >> Is it the internal HW logic of the sdhci controller that manages the > >> IO voltage? And this logic can be controlled via certain register bits > >> in the SDHCI controller? > >> > > > > Yes, it depends of the value of the '1.8V Signaling Enable' value in the > > host control 2 register. > > > >> > declaring the gpio is an option so I thought using this regulator fits my need. > >> > >> In quite many cases it makes sense to model this though a gpio > >> regulator. For example when you use a level shifter circuit. Those > >> normally have gpio pin routed to control the voltage level output for > >> the signals. For example switching between 1.8V and 2.9V. > >> > > > > I agree, my concern is to know if I can consider it as a 'general' pio > > since it is driven by the sdhci controller. > > This doesn't seems like a case where a gpio regulator should be used > and I am not sure what problem it would solve. Beside to suppress the > log warnings (actually those aren't warnings but informations). > > Isn't sdhci_do_start_signal_voltage_switch() doing what you need here? > It is. I am only wondering the best way to describe the hardware: - No regulator but I have the 'no vqmmc regulator not found' message which is a bit annoying and which can be interpreted as an issue for someone who has no knowledge about this stuff. - Describe the regulator since there is one on my board. But it is not a fixed regulator and even if it's close to a gpio one it is not. Regards Ludovic -- 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
