From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH 2/2] leds: lp5024: Add the LP5024/18 RGB LED driver Date: Fri, 4 Jan 2019 22:37:58 +0100 Message-ID: References: <8740cfd6-a6b5-ad27-313b-984a9febf18a@ti.com> <20181219201047.GA23448@amd> <54f28115-0a7d-8e9c-3bec-6e91fb3981ec@gmail.com> <986b5105-2fdb-bd25-7c8a-ca8fd1ade821@gmail.com> <7f205102-e854-f1cb-cc03-1307d1cddc87@gmail.com> <20190104201256.GA2931@amd> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190104201256.GA2931@amd> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Pavel Machek Cc: =?UTF-8?B?VmVzYSBKw6TDpHNrZWzDpGluZW4=?= , Dan Murphy , 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 1/4/19 9:12 PM, Pavel Machek wrote: > Hi! > >>> I suppose if one would just make it an array of values (separated by >>> space) and then one file with string array of color element names and on >>> file with maximum value array it could be within those words. >>> >>> The it would be something like: >>> >>> $ echo "23 54 32" > color >> >> Go ahead, but first convince Pavel, and then Greg :-) >> >> I'd personally would not have much against, especially that the >> list of values will not grow for that one like in case of old patch set >> [0] where Pavel and Greg thwarted my similar attempt. > > Oh, you can get this past Pavel (and probably Greg) -- if you have a > good reason. Performance is _not_ a good reason. You don't need to > change LED color 50000 times a second. We would need to do some profiling here to check if the problem exists. But, aside from that hypothetic issue, we need a solution for LEDn_BRIGHTNESS feature of lp5024, i.e. setting color intensity via a single register write. How would you propose to address that? > If you can demonstrate a reasonable design, where user selects color > from well-known RGB pallete and either kernel or library+kernel acts > to set that color on the LED, we can talk. > > When user asks for white, it has to be white. Exact color temperature > does not matter. When user asks for pink, it has to be pink. Again, > exact color does not matter; different monitors display slightly > different colors, too -- Best regards, Jacek Anaszewski