On Fri, Jun 10, 2016 at 12:39:57PM -0700, Brian Norris wrote:

The LP8556 datasheet describes an EN/VDDIO input, which serves "both as
a chip enable and as a power supply reference for PWM, SDA, and SCL
inputs." The LP8556 that I'm testing doesn't respond properly if I try
to talk I2C to it too quickly after enabling VDDIO, and the LP8555
datasheet mentions a t_RESPONSE delay of up to 1 millisecond.

Support this EN/VDDIO by adding a regulator property to the binding;
enabling this regulator at probe time; and sleeping for 1 to 2ms, if the
EN/VDDIO regulator was provided.

Signed-off-by: Brian Norris <briannorris@chromium.org>
---
v2: s/TS8555/LP8555/ in comment (typo)

 .../devicetree/bindings/leds/backlight/lp855x.txt  |  2 ++

I would have picked 'vddio' as the name, but it's fine.

Acked-by: Rob Herring <robh@kernel.org>

 drivers/video/backlight/lp855x_bl.c                | 29 ++++++++++++++++++++++
 2 files changed, 31 insertions(+)