Messages in this thread | | | Date | Mon, 9 Nov 2015 10:38:03 +0100 | Subject | Re: [PATCH 0/2] mmc: sdhci: potentially bad behavior when using vmmc supply | From | Ulf Hansson <> |
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>> > 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?
Kind regards Uffe
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