From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Murphy Subject: Re: [PATCH v6 1/2] dt-bindings: leds: Add bindings for lm3697 driver Date: Tue, 11 Sep 2018 16:05:40 -0500 Message-ID: References: <20180906135005.6718-1-dmurphy@ti.com> <20180906211617.GB16899@amd> <20180907133228.GA16297@amd> <70f7506c-6a3d-3830-59a4-a246dc6163f7@ti.com> <226b8770-7041-39a4-5a06-6002a7c1225f@gmail.com> <20a814ce-a4c5-0649-6677-6b85a5fd2321@ti.com> <59561e0f-e3b9-7898-a300-90b198ad14e6@gmail.com> <20d9ea9e-bbb8-2240-97cc-615e3fbcef8c@ti.com> <20180911205504.GA31219@amd> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180911205504.GA31219@amd> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Pavel Machek Cc: Jacek Anaszewski , robh+dt@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org List-Id: devicetree@vger.kernel.org On 09/11/2018 03:55 PM, Pavel Machek wrote: > Hi! > >>>>>>>> And I think Jacek pointed out that the bindings references in this bindings >>>>>>>> don't even exist. >>>>>>>> >>>>>>>> I am thinking we need to deprecate this MFD driver and consolidate these drivers >>>>>>>> in the LED directory as we indicated before. I did not find any ti-lmu support >>>>>>>> code. >>>>>>>> >>>>>>>> ti-lmu common core code and then the LED children appending the feature differentiation. >>>>>>> >>>>>>>> Need some maintainer weigh in here. >>>>>>> >>>>>>> Hehe. I'm maintnainer. Fun. >>>>>> >>>>>> I know. I want to see if there was any other opinion. Especially for the LED driver. >>>>>> >>>>> [...] >>>>> >>>>> I have a question - is this lm3697 LED controller a cell of some MFD >>>>> device? Or is it a self-contained chip? >>>>> >>>> >>>> This is a self contained chip. And the LM3697 only function is a LED driver. >>>> It does not have any other special functions like the LM363X drivers for GPIO and Regulator support. >>> >>> This is an argument for merging it as a standalone LED class driver >>> then. It is even more justifiable, taking into account uncertainties >>> related to the proper way of adding the support for it to the existing >>> MFD driver, whereas the code reuse would be the only advantage of having >>> thus support in MFD subsystem. >> >> Does the argument carry over to the other devices? > > We really need something reasonable, that works for stand-alone LEDs, > and also works for LEDs that are part of MFD when the hardware is similar. I agree that LED drivers that have other functional blocks beyond driving a LED chain belongs in the MFD space. The amount of code that is similar is very small. And like I pointed out Droid 4 may be only one use case where it makes sense to combine all the LED code into a central place. But most customers will just want a LED specific driver to maintain. > >> Like the LM3632 (part of the ti-lmu) has flash and torch and no other special functions >> so it would look like the lm3601x family with different register mappings. >> >> The LM3631 seems to also be just a LED driver with no extra functionality >> >> I could go buy an EVM and put together a driver for that device as well using the lm3601x as >> reference. > > I do have hardware with lm3532. I can test patches, and I guess I can > port driver easily if it is obvious how to do that. I can get the LM3532 EVM. I wrote a similar driver for the original Droid 10 years ago. Upstreaming was not a priority for that company. Here is a reference to the LM3530 code from back in the day on Google OMAP kernel. https://android.googlesource.com/kernel/omap/+/android-omap-3.0/drivers/leds/leds-lm3530.c Otherwise I can create the LM3532 driver as well and look at the LM3530 Dan > > Pavel > -- ------------------ Dan Murphy