linux-kernel - Re: [PATCH v2 2/2] leds: lp50xx: Add the LP50XX family of the RGB LED driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8def5414-9170-7034-34f9-70e6c71f8161@ti.com>
Date:   Thu, 17 Jan 2019 07:27:00 -0600
From:   Dan Murphy <dmurphy@...com>
To:     Pavel Machek <pavel@....cz>
CC:     Jacek Anaszewski <jacek.anaszewski@...il.com>,
        <linux-leds@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <devicetree@...r.kernel.org>, <dachaac@...il.com>,
        <robh+dt@...nel.org>
Subject: Re: [PATCH v2 2/2] leds: lp50xx: Add the LP50XX family of the RGB LED
 driver

Hello

On 1/17/19 4:06 AM, Pavel Machek wrote:
> Hi!
> 
>>>>> You know what? First, submit driver with similar functionality to
>>>>> existing RGB drivers, using same interface existing drivers are
>>>>> using. When that is accepted, we can talk about extending
>>>>> kernel<->user interfaces.
>>>>>
>>>>
>>>> I could do that but then there is no way for users to have any other color but "white" with this driver.
>>>> That defeats the purpose of the device itself.
>>>
>>> No, that is not what I meant.
>>>
>>> We do have RGB drivers in tree, they just present three separate LEDs
>>> -- red, green and blue. I ask you to do the same for initial
>>> submission.
>>>
>>
>> For clarification you are asking me to register a LED class per
>> output pin?
> 
> Yes.
> 

OK I can do that but I would like to get Jacek to align with this as he
suggested creating the code as I submitted based on the review of the
devices data sheet.

LED class registration per LED module or for the single Banked output.

>> As explained before the Master brightness register has absolute control over the output current
>> to the LED outputs regardless of the color control setting.
>>
> 
> Yes, just set master brightness to 255 and you can ignore it.

OK Sounds fine.  Will just need to do an init that sets the color
register to 0 and brightness to 0 so we don't have a flash.

> 
>>> You'll still be able to set brightness independently on the
>>> red/green/blue LEDs...
>>>
>>
>> But which one would control the overall brightness of the cluster?
> 
> You would not have that control in initial version of the patch.
> 

See above on alignment

Dan

> 								Pavel
> 


-- 
------------------
Dan Murphy