From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Andersson Subject: Re: [PATCH V4 5/8] backlight: qcom-wled: Restructure the driver for WLED3 Date: Mon, 6 Aug 2018 22:37:05 -0700 Message-ID: <20180807053705.GB23866@tuxbook-pro> References: <1531131741-19971-1-git-send-email-kgunda@codeaurora.org> <1531131741-19971-6-git-send-email-kgunda@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1531131741-19971-6-git-send-email-kgunda@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Kiran Gunda Cc: jingoohan1@gmail.com, lee.jones@linaro.org, b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, daniel.thompson@linaro.org, jacek.anaszewski@gmail.com, pavel@ucw.cz, robh+dt@kernel.org, mark.rutland@arm.com, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-arm-msm@vger.kernel.org List-Id: devicetree@vger.kernel.org On Mon 09 Jul 03:22 PDT 2018, Kiran Gunda wrote: > diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c [..] > @@ -365,6 +434,15 @@ static int wled_configure(struct wled *wled, struct device *dev) > > cfg->num_strings = cfg->num_strings + 1; > > + string_len = of_property_count_elems_of_size(dev->of_node, > + "qcom,enabled-strings", > + sizeof(u32)); > + if (string_len > 0) > + rc = of_property_read_u32_array(dev->of_node, > + "qcom,enabled-strings", > + wled->cfg.enabled_strings, qcom,enabled-strings is listed as optional, but without it we will end up with qcom,num-strings zeros in an array. Initialize wled->cfg.enabled_strings to 0,1,2,3 and the driver will be backwards compatible. I also think that if you do qcom,enabled-strings = <0, 1, 2>; there's no need to also specify qcom,num-strings = <3>; and we can just use string_len for num_strings. > + sizeof(u32)); > + > return 0; > } Regards, Bjorn