Hi Alexandru
On Tue, Oct 20, 2020 at 05:14:58PM -0500, Alexandru Gagniuc wrote:
On the SII9022, the IOVCC and CVCC12 supplies must reach the correct voltage before the reset sequence is initiated. On most boards, this assumption is true at boot-up, so initialization succeeds.
However, when we try to initialize the chip with incorrect supply voltages, it will not respond to I2C requests. sii902x_probe() fails with -ENXIO.
To resolve this, look for the "iovcc" and "cvcc12" regulators, and make sure they are enabled before starting the reset sequence. If these supplies are not available in devicetree, then they will default to dummy-regulator. In that case everything will work like before.
This was observed on a STM32MP157C-DK2 booting in u-boot falcon mode. On this board, the supplies would be set by the second stage bootloader, which does not run in falcon mode.
Signed-off-by: Alexandru Gagniuc mr.nuke.me@gmail.com
Thanks, applied series to drm-misc-next. I fixed two checkpatch --strict warnings while applying.
Sam