This patch set addresses a structural problem in the handling of regulators for VDDIO, VDDA, and VDDD in the SGTL5000 driver.
The first two of these power rails must be powered on prior to any I2C communication, and yet the regulators were tied to the codec, which is instantiated only after a fair amount of I2C communication takes place.
In other words, these regulators could never have function, and we can surmise that no user of this driver has switched power supply rails connected to them.
The third power rail (VDDD) can be derived internally (by using I2C registers) though the data sheet says that if an external VDDD is used, it should be enabled before MCLK is started and I2C activity begins.
[I rebased Eric's patches from Feb 2015, fixed a few warnings, URLs, etc. and squashed two patches into one. - Clemens]
Clemens Gruber (1): ASoC: sgtl5000: Remove misleading comment
Eric Nelson (5): ASoC: sgtl5000: Fix regulator support ASoC: sgtl5000: Write all default registers ASoC: sgtl5000: Initialize CHIP_ANA_POWER to power-on defaults ASoC: sgtl5000: Disable internal PLL early ASoC: sgtl5000: Do not disable regulators in SND_SOC_BIAS_OFF
sound/soc/codecs/sgtl5000.c | 421 +++++++++++--------------------------------- sound/soc/codecs/sgtl5000.h | 2 + 2 files changed, 102 insertions(+), 321 deletions(-)