Re: [PATCH v3 1/5] leds: lm3532: Fix brightness control for i2c mode

From: Dan Murphy
Date: Tue Aug 27 2019 - 09:02:11 EST


On 8/27/19 7:44 AM, Dan Murphy wrote:

On 8/27/19 7:18 AM, Pavel Machek wrote:
On Mon 2019-08-26 15:44:37, Tony Lindgren wrote:
* Pavel Machek <pavel@xxxxxx> [190826 22:14]:
On Mon 2019-08-26 14:58:22, Tony Lindgren wrote:

* Dan Murphy <dmurphy@xxxxxx> [190820 19:53]:
Fix the brightness control for I2C mode.  Instead of
changing the full scale current register update the ALS target
register for the appropriate banks.

In addition clean up some code errors and random misspellings found
during coding.

Tested on Droid4 as well as LM3532 EVM connected to a BeagleBoneBlack

Fixes: e37a7f8d77e1 ("leds: lm3532: Introduce the lm3532 LED driver")
Reported-by: Pavel Machek <pavel@xxxxxx>
Signed-off-by: Dan Murphy <dmurphy@xxxxxx>

v3 - Removed register define updates -
Looks like starting with this patch in Linux next the LCD on droid4
is so dim it's unreadable even with brightness set to 255. Setting
brightness to 0 does blank it completely though.

Did something maybe break with the various patch revisions or are
we now missing some dts patch?
Maybe missing dts patch. We should provide maximum current the LED can
Or i2c control is somehow broken and only als control now works?

With only setting CONFIG_LEDS_LM3532=m to the next branch I get full brightness with 255.

I also see half brightness at 128 with the ramp down working.

I am not able to reproduce this issue on my device.

Just to make sure my data was right I did a clean rebuild on commit 1dbb9fb4082ce2a2f1cf9596881ddece062d15d0

from the led-next branch.

Just adding the above config flag.  I still cannot reproduce the issue

See attached pic



Attachment: droid4.jpg
Description: JPEG image