From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingi Kim Subject: Re: [PATCH 0/3] Add ktd2692 Flash LED driver Date: Tue, 03 Mar 2015 11:55:58 +0900 Message-ID: <54F522BE.6080708@samsung.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-reply-to: <20150302220315.GU6539@valkosipuli.retiisi.org.uk> Sender: linux-leds-owner@vger.kernel.org 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 List-Id: devicetree@vger.kernel.org Hi On 2015=EB=85=84 03=EC=9B=94 03=EC=9D=BC 07:03, Sakari Ailus wrote: > Hi Bryan, >=20 > On Mon, Mar 02, 2015 at 12:07:42PM -0800, Bryan Wu wrote: >> On Mon, Mar 2, 2015 at 1:15 AM, Sakari Ailus w= rote: >>> H Ingi, >>> >>> On Mon, Mar 02, 2015 at 04:14:39PM +0900, Ingi Kim wrote: >>>> Hi Jacek >>>> >>>> On 2015=EB=85=84 02=EC=9B=94 27=EC=9D=BC 17:42, Jacek Anaszewski w= rote: >>>>> 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 men= tioned, >>>>> 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)= =2E >>>>> >>>>> The reference drivers using LED Flash class are still pending [1]= , but I >>>>> think that at least leds-aat1290 driver is almost ready for mergi= ng. >>>>> It controls very similar device to yours. >>>>> >>>>> Another advantage of using LED Flash class is that it has been de= signed >>>>> to be compatible with Video for Linux 2 subsystem, which will all= ow 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 f= ew really >>> need it. If you don't, i.e. you can implement the torch using the c= ontrol 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? >=20 > I wasn't cc'd in the original patch so I didn't know whether it was I= 2C or > not. Doesn't appear to be. >=20 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 gp= io lines) Sakari, ktd2692 flash led device is controlled through Expresswire single-wire = interface by using the strobe-gpio(control) pin.=20 Adding pin information of the KTD2692. CTRL pin can control LED on/off and Movie/Flash mode current, =46lash timeout, LVP(low voltage protection). AUX pin(torch-gpio) allows highest priority ON/OFF flash mode control.