Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753929AbbGXNKZ (ORCPT ); Fri, 24 Jul 2015 09:10:25 -0400 Received: from mail-yk0-f182.google.com ([209.85.160.182]:36211 "EHLO mail-yk0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752550AbbGXNKW (ORCPT ); Fri, 24 Jul 2015 09:10:22 -0400 MIME-Version: 1.0 In-Reply-To: <1437681127-15760-1-git-send-email-bjorn.andersson@sonymobile.com> References: <1437681127-15760-1-git-send-email-bjorn.andersson@sonymobile.com> Date: Fri, 24 Jul 2015 09:10:21 -0400 Message-ID: Subject: Re: [PATCH] backlight: pm8941-wled: Add default-brightness property From: Rob Clark To: Bjorn Andersson Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Jingoo Han , Lee Jones , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , "devicetree@vger.kernel.org" , Linux Kernel Mailing List , Linux Fbdev development list , linux-arm-msm Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3150 Lines: 74 On Thu, Jul 23, 2015 at 3:52 PM, Bjorn Andersson wrote: > Add the possibility of specifying the default brightness in DT. > > Signed-off-by: Bjorn Andersson > --- > > This depends on the patch moving pm8941-wled to backlight [1]. The dt property > is used by several other backlight drivers, so I considered this to be a > "common" property and it's hence not prefixed with "qcom,". > > [1] https://lkml.org/lkml/2015/7/21/906 > > Documentation/devicetree/bindings/video/backlight/pm8941-wled.txt | 1 + > drivers/video/backlight/pm8941-wled.c | 4 ++++ > 2 files changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/video/backlight/pm8941-wled.txt b/Documentation/devicetree/bindings/video/backlight/pm8941-wled.txt > index 424f8444a6cd..37503f8c3620 100644 > --- a/Documentation/devicetree/bindings/video/backlight/pm8941-wled.txt > +++ b/Documentation/devicetree/bindings/video/backlight/pm8941-wled.txt > @@ -5,6 +5,7 @@ Required properties: > - reg: slave address > > Optional properties: > +- default-brightness: value from: 0-4095 > - label: The name of the backlight device > - qcom,cs-out: bool; enable current sink output > - qcom,cabc: bool; enable content adaptive backlight control > diff --git a/drivers/video/backlight/pm8941-wled.c b/drivers/video/backlight/pm8941-wled.c > index c704c3236034..b875e58df0fc 100644 > --- a/drivers/video/backlight/pm8941-wled.c > +++ b/drivers/video/backlight/pm8941-wled.c > @@ -373,6 +373,7 @@ static int pm8941_wled_probe(struct platform_device *pdev) > struct backlight_device *bl; > struct pm8941_wled *wled; > struct regmap *regmap; > + u32 val = 0; > int rc; as discussed on IRC, it would be better if the default read back the current settings (so-as to inherit bootloader splash smoothly.. drm/msm supports a memory-region phandle, for example, so it can take over the bootloader splash-screen as stolen-mem) and it would I think be useful to have a comment in the bindings file explaining that you *should* use the default-brightness property to set a sane default if bootloader isn't putting up a splash, and you should *not* use the property if it is.. BR, -R > regmap = dev_get_regmap(pdev->dev.parent, NULL); > @@ -395,8 +396,11 @@ static int pm8941_wled_probe(struct platform_device *pdev) > if (rc) > return rc; > > + of_property_read_u32(pdev->dev.of_node, "default-brightness", &val); > + > memset(&props, 0, sizeof(struct backlight_properties)); > props.type = BACKLIGHT_RAW; > + props.brightness = val; > props.max_brightness = PM8941_WLED_REG_VAL_MAX; > bl = devm_backlight_device_register(&pdev->dev, wled->name, > &pdev->dev, wled, > -- > 1.8.2.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/