On 5 June 2015 at 10:10, Lu Y.B. <yangbo.lu@xxxxxxxxxxxxx> wrote: >> >> On 2 June 2015 at 09:09, Yangbo Lu <yangbo.lu@xxxxxxxxxxxxx> wrote: >> >> > This quirk is used for controllers that can only support 1.8V >> >> > voltage but the peripheral hardware circuit has capability to >> >> > support 3.3V voltage. >> >> >> >> Which voltage are you referring to? The I/O voltage or the power to >> >> the card? VCC or VCCQ? >> >> >> >> Kind regards >> >> Uffe >> > >> > The voltage here means I/O voltage. >> > Although the controller only supports 1.8v, the hardware circuit has a >> level translator for supporting 3.3v. >> >> Thanks for clarifying. > > Sorry, it should be power voltage... > This quirk is used to set capability register "Voltage Support 3.3V" bit since the controller self doesn’t support but circuit supports. > Okay. So then please tell me, exactly, how is the power being controlled when using this "hardware circuit"? This patchset only tries to change the content of the ocr_mask, but there is no logic added to support changing voltage levels by using the "external circuit". At least to my understanding. Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
