From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754658AbbCCC4G (ORCPT ); Mon, 2 Mar 2015 21:56:06 -0500 Received: from mailout3.samsung.com ([203.254.224.33]:63356 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753744AbbCCC4C (ORCPT ); Mon, 2 Mar 2015 21:56:02 -0500 MIME-version: 1.0 Content-type: text/plain; charset=utf-8 X-AuditID: cbfee691-f79b86d000004a5a-f9-54f522bfb897 Content-transfer-encoding: 8BIT Message-id: <54F522BE.6080708@samsung.com> Date: Tue, 03 Mar 2015 11:55:58 +0900 From: Ingi Kim User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 To: Sakari Ailus , Bryan Wu Cc: Jacek Anaszewski , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , "rpurdie@rpsys.net" , Thierry Reding , p.zabel@pengutronix.de, Andrew Lunn , Greg Kroah-Hartman , florian.vaussard@epfl.ch, arno@natisbad.org, kuninori.morimoto.gx@renesas.com, hytszk@gmail.com, antonynpavlov@gmail.com, "devicetree@vger.kernel.org" , lkml , Linux LED Subsystem , "sw0312.kim@samsung.com" , ideal.song@samsung.com Subject: Re: [PATCH 0/3] Add ktd2692 Flash LED driver References: <1424998891-25591-1-git-send-email-ingi2.kim@samsung.com> <54F02DF5.1000706@samsung.com> <54F40DDF.8070708@samsung.com> <20150302091530.GQ6539@valkosipuli.retiisi.org.uk> <20150302220315.GU6539@valkosipuli.retiisi.org.uk> In-reply-to: <20150302220315.GU6539@valkosipuli.retiisi.org.uk> X-Brightmail-Tracker: H4sIAAAAAAAAA02Se0iTURjGOd/37duFjNPyclplMNBC0qVudSJLCYNDf0RRRJlhyz60cro2 jSQsyyyaqVszDK9Ns3TNtJn3Ql0rgpZmFgk5pYuV1wwvFJG1uaD+ezjP8z7n/cEroMU3eRLB 0eRUTpOsTJKyIsbiLVcHd0hn96x70+mFe5w2GufMT/BwT6eDwo9bDRQut3fzsGM0D+D8cRMP Z1XWsdh6oRbgtl9DAHeP1gCc+/ozwKOP2gDuaythceP4XYCr3vRS2Dn4lMH6wloGZz+083F7 27CrqqOGxdeNIyx++3NxlB+xlFkA6cvLpcit7Ds0aS1y8knN7RmWPJo1McRqvsySjlILn7S2 TFOktPkDn+RmTbIk/9c6MucwMORB+XceybtvBmTa6r8TxogijnBJR09yGtmWQ6LEyuII9cSy 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On 2015년 03월 03일 07:03, Sakari Ailus wrote: > Hi Bryan, > > On Mon, Mar 02, 2015 at 12:07:42PM -0800, Bryan Wu wrote: >> On Mon, Mar 2, 2015 at 1:15 AM, Sakari Ailus wrote: >>> H Ingi, >>> >>> On Mon, Mar 02, 2015 at 04:14:39PM +0900, Ingi Kim wrote: >>>> Hi Jacek >>>> >>>> On 2015년 02월 27일 17:42, Jacek Anaszewski wrote: >>>>> Hi Ingi, >>>>> >>>>> On 02/27/2015 02:01 AM, Ingi Kim wrote: >>>>>> This patch supports KTD2692 flash LED driver >>>>>> >>>>>> Ingi Kim (3): >>>>>> of: Add vendor prefix for Kinetic technologies >>>>>> leds: ktd2692: add device tree bindings for ktd2692 >>>>>> leds: Add ktd2692 flash LED driver >>>>>> >>>>>> .../devicetree/bindings/leds/leds-ktd2692.txt | 19 ++ >>>>>> .../devicetree/bindings/vendor-prefixes.txt | 1 + >>>>>> drivers/leds/Kconfig | 8 + >>>>>> drivers/leds/Makefile | 1 + >>>>>> drivers/leds/leds-ktd2692.c | 245 ++++++++++++++++++++ >>>>>> 5 files changed, 274 insertions(+) >>>>>> create mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt >>>>>> create mode 100644 drivers/leds/leds-ktd2692.c >>>>>> >>>>> >>>>> In your device tree binding documentation there is torch-gpio mentioned, >>>>> but you seem not to use it in the driver. >>>>> >>>>> We have already LED Flash class (/drivers/leds/led-class-flash.c) for >>>>> this type of devices, which handles both torch and flash modes >>>>> (flash_strobe sysfs attribute is provided for strobing the flash). >>>>> >>>>> The reference drivers using LED Flash class are still pending [1], but I >>>>> think that at least leds-aat1290 driver is almost ready for merging. >>>>> It controls very similar device to yours. >>>>> >>>>> Another advantage of using LED Flash class is that it has been designed >>>>> to be compatible with Video for Linux 2 subsystem, which will allow for registering LED Flash class devices as a V4L2 sub-devices. >>>>> >>>>> Adding Sakari. >>>>> >>>> >>>> Ok, I'll check LED Flash class, and add torch-gpio >>> >>> Many LED flash chips include a hardware pin for torch control but few really >>> need it. If you don't, i.e. you can implement the torch using the control bus >>> instead, I think I'd probably drop it from the chip's DT bindings. >>> >> >> Ingi, please follow Jacek's advice to use LED Flash class interface. >> I'm reviewing those leds flash drivers and probably merge them soon. >> >> Jacek and Sakari thanks for the review. >> >> Sakari, so what's the control bus your mentioned here? > > I wasn't cc'd in the original patch so I didn't know whether it was I2C or > not. Doesn't appear to be. > Thanks for the review and I'll work to use LED Flash class interface and try adding torch-gpio(flash mode enable) line (I'll rename those gpio lines) Sakari, ktd2692 flash led device is controlled through Expresswire single-wire interface by using the strobe-gpio(control) pin. Adding pin information of the KTD2692. CTRL pin can control LED on/off and Movie/Flash mode current, Flash timeout, LVP(low voltage protection). AUX pin(torch-gpio) allows highest priority ON/OFF flash mode control.