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
| ||
|
Date: Wed, 25 Oct 2017 00:36:04 +0200 From: Andrea Scian - DAVE Embedded Systems <andrea.scian@...e.eu> To: Cédric Le Goater <clg@...d.org> Cc: Bryan Wu <cooloney@...il.com>, Richard Purdie <rpurdie@...ys.net>, Jacek Anaszewski <j.anaszewski@...sung.com>, linux-leds@...r.kernel.org, linux-kernel <linux-kernel@...r.kernel.org>, Andrew Jeffery <andrew@...id.au> Subject: Re: about pca955x led driver gpio management Il 24/10/2017 07:51, Cédric Le Goater ha scritto: > On 10/17/2017 11:16 AM, Andrea Scian - DAVE Embedded Systems wrote: >> >>> On 10/17/2017 10:20 AM, Andrea Scian - DAVE Embedded Systems wrote: >>>> >>>> Il 17/10/2017 10:18, Cédric Le Goater ha scritto: >>>>> On 10/17/2017 09:36 AM, Andrea Scian - DAVE Embedded Systems wrote: >>>>>> Dear all, >>>>>> >>>>>> I'm working on an iMX6 based board with a PCA9555 which is used both to drive LEDs and manage some GPIOs. >>>>> The PCA9555 chip and the PCA955[0-3] chips have different control >>>>> registers. You need a different led driver for it. >>>> >>>> My typo sorry, as you can see in the device tree below, I'm using pca9551 >>> >>> ok. >>> >>> You might want to take a look at how we mixed gpios and leds on the witherspoon >>> system using pca9552 chips. we added a gpio-leds binding. >>> >>> https://github.com/openbmc/linux/blob/dev-4.10/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts >> >> understood: you configure all pins of PCA955x as GPIOs and the map the one you need as led with gpio-leds binding. > > Sorry I got distracted. > >> However to me this is a kind of workaround or, at least, there's nothing about this limitation into the devicetree binding (in fact, IMHO, the device tree binding example will just fail) > > euh ? what do you mean. There is a real system using this device tree. > I think we would know about it if it didn't work. Please explain > I mean that, for what I understand, your configuration is working because all pin of 9551 are configured as GPIOs (and the binded back as led) In my configuration I have some pins configured as led and some as GPIOs, and this is not working. >> I wrote the attached patch which should fix the issue and allow a more generic approach. WDYT? >> >> (in case it looks good, I'll send the patch in the correct way) > > Please send the patch to discuss, add Andrew Jeffery <andrew@...id.au> > in cc: > Sorry for the delay but I'm busy in Prague with OSSummit and ELCE. I'll send a proper patch and more comments, if needed, by the begin of next week. (BTW, if some of you are here, drop me a line and have a beer together! ;-) )
Powered by blists - more mailing lists