From: Dan Murphy <dmurphy@ti.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: <robh+dt@kernel.org>, <jacek.anaszewski@gmail.com>,
<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-leds@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] dt: bindings: lm3697: Add bindings for lm3697 driver
Date: Wed, 8 Aug 2018 16:50:59 -0500 [thread overview]
Message-ID: <65e927b4-8bd2-1f34-3422-36ce21f674c3@ti.com> (raw)
In-Reply-To: <20180808214527.GE15831@amd>
Pavel
On 08/08/2018 04:45 PM, Pavel Machek wrote:
> On Wed 2018-08-08 16:41:16, Dan Murphy wrote:
>> On 08/08/2018 04:09 PM, Pavel Machek wrote:
>>> On Wed 2018-08-08 16:04:43, Dan Murphy wrote:
>>>> On 08/08/2018 04:02 PM, Pavel Machek wrote:
>>>>> Hi!
>>>>>
>>>>>>>> + - #size-cells : 0
>>>>>>>> + - control-bank-cfg - : Indicates which sink is connected to which control bank
>>>>>>>> + 0 - All HVLED outputs are controlled by bank A
>>>>>>>> + 1 - HVLED1 is controlled bank B, HVLED2/3 are controlled by bank A
>>>>>>>> + 2 - HVLED2 is controlled bank B, HVLED1/3 are controlled by bank A
>>>>>>>> + 3 - HVLED1/2 are controlled by bank B, HVLED3 is controlled by bank A
>>>>>>>> + 4 - HVLED3 is controlled by bank B, HVLED1/2 are controlled by bank A
>>>>>>>> + 5 - HVLED1/3 is controlled by bank B, HVLED2 is controlled by bank A
>>>>>>>> + 6 - (default) HVLED1 is controlled by bank A, HVLED2/3 are controlled by bank B
>>>>>>>> + 7 - All HVLED outputs are controlled by bank B
>>>>>>>
>>>>>>> This is quite long way to describe a bitmask, no? Could we make
>>>>>>> it so that control-bank-cfg is not needed?
>>>>>>
>>>>>> The problem we have here is there is a potential to control
>>>>>> 3 different LED string but only 2 sinks. So control bank A can control 2 LED strings and control
>>>>>> bank b can control 1 LED string.
>>>>>>
>>>>>
>>>>> Can we forget about the LED strings, and just expose the sinks as
>>>>> Linux LED devices?
>>>>
>>>> 2 sinks 3 LED strings. How do you know which LED string is which and what bank it belongs
>>>> to when setting the brightness. Each Bank has a separate register for brightness control.
>>>
>>> Yes, and LED strings are statically assigned to banks, right?
>>>
>>> So why not simply forget about LED strings for sake of hw
>>> abstractions, and work just with banks?
>>
>> How would you set the control bank register for the correct LED string configuration?
>
> Have property at each LED saying which which HVLEDs it controls?
Isn't that what I have already using the reg property?
Then we would have to aggregate the configuration and make a determination in the driver.
But that does not follow the LED child node ideology.
Each output of the LED driver should have a child node.
In this case the outputs are the sinks(inputs) and there are only 2 sinks so having 3 LED child nodes would be confusing
and there are required properties for each child like label.
Each child node would then need to present 1 LED node to the user space to control the LED string. Which would
be technically incorrect because you would have 2 LED nodes controlling the same control bank sink.
>
> Pavel
>
--
------------------
Dan Murphy
next prev parent reply other threads:[~2018-08-08 21:51 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-07 16:04 [PATCH v2 1/2] dt: bindings: lm3697: Add bindings for lm3697 driver Dan Murphy
2018-08-07 16:04 ` [PATCH v2 2/2] leds: lm3697: Introduce the " Dan Murphy
2018-08-08 19:59 ` Pavel Machek
2018-08-14 13:54 ` Dan Murphy
2018-08-08 7:56 ` [PATCH v2 1/2] dt: bindings: lm3697: Add bindings for " Michal Vokáč
2018-08-08 9:52 ` Jacek Anaszewski
2018-08-08 19:59 ` Pavel Machek
2018-08-08 20:42 ` Dan Murphy
2018-08-08 21:02 ` Pavel Machek
2018-08-08 21:04 ` Dan Murphy
2018-08-08 21:09 ` Pavel Machek
2018-08-08 21:41 ` Dan Murphy
2018-08-08 21:45 ` Pavel Machek
2018-08-08 21:50 ` Dan Murphy [this message]
2018-08-08 21:58 ` Pavel Machek
2018-08-08 21:09 ` Jacek Anaszewski
2018-08-08 21:45 ` Dan Murphy
2018-08-09 12:09 ` Jacek Anaszewski
2018-08-09 13:24 ` Pavel Machek
2018-08-09 13:30 ` Dan Murphy
2018-08-09 14:48 ` Jacek Anaszewski
2018-08-09 15:01 ` Dan Murphy
2018-08-09 21:59 ` Pavel Machek
2018-08-08 22:00 ` Pavel Machek
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=65e927b4-8bd2-1f34-3422-36ce21f674c3@ti.com \
--to=dmurphy@ti.com \
--cc=devicetree@vger.kernel.org \
--cc=jacek.anaszewski@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-leds@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).