From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Date: Mon, 02 Sep 2019 09:42:11 +0000 Subject: Re: [PATCH v3 4/4] backlight: pwm_bl: Set scale type for brightness curves specified in the DT Message-Id: <20190902094211.GO32232@dell> List-Id: References: <20190709190007.91260-1-mka@chromium.org> <20190709190007.91260-5-mka@chromium.org> In-Reply-To: <20190709190007.91260-5-mka@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Matthias Kaehlcke Cc: Thierry Reding , Daniel Thompson , Jingoo Han , Bartlomiej Zolnierkiewicz , linux-pwm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Enric Balletbo i Serra , Douglas Anderson , Brian Norris , Pavel Machek , Jacek Anaszewski On Tue, 09 Jul 2019, Matthias Kaehlcke wrote: > Check if a brightness curve specified in the device tree is linear or > not and set the corresponding property accordingly. This makes the > scale type available to userspace via the 'scale' sysfs attribute. > > To determine if a curve is linear it is compared to a interpolated linear > curve between min and max brightness. The curve is considered linear if > no value deviates more than +/-5% of ${brightness_range} from their > interpolated value. > > Signed-off-by: Matthias Kaehlcke > Acked-by: Daniel Thompson > --- > Changes in v3: > - none > > Changes in v2: > - use 128 (power of two) instead of 100 as factor for the slope > - add comment about max quantization error > - added Daniel's 'Acked-by' tag > --- > drivers/video/backlight/pwm_bl.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) Applied, thanks. -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog