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SGTL5000: external VDDD with linux codec driver

Question asked by Alexander Stein on Apr 16, 2015
Latest reply on Mar 7, 2017 by Stefan Agner

The datasheet and the errata say the SGTL5000 should be connected to an external VDDD supply.

The linux driver (both mainline and the one in the QorIQ-SDK 1.7) try to use it. But with codec revision >= 0x11 it falls back to internal LDO.

It seems that the sgtl5000 driver did this from the first version integrated into linux mainline. But I could not find any documentation why this should be done (starting from this specific revision).

This topic seems to be referred by others too: e.g. Re: SGTL5000 hangs I2C bus after reset


So my questions:

  • For which reason the internal LDO instead of external VDDD should be used on revisions >=0x11?
  • What is the correct codec configuration regarding VDDD?
  • Are there any driver patches available? Especially regarding QorIQ-SDK. Maybe I can also backport them from mainline.



Alexander Stein