From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750910Ab3JREsi (ORCPT ); Fri, 18 Oct 2013 00:48:38 -0400 Received: from mail-pa0-f44.google.com ([209.85.220.44]:36083 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767Ab3JREsg (ORCPT ); Fri, 18 Oct 2013 00:48:36 -0400 Message-ID: <5260BD8C.7000200@gmail.com> Date: Fri, 18 Oct 2013 12:48:12 +0800 From: Mark Zhang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Thierry Reding CC: rpurdie@rpsys.net, jg1.han@samsung.com, Jean-Christophe PLAGNIOL-VILLARD , tomi.valkeinen@ti.com, linux-pwm@vger.kernel.org, "linux-fbdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: How to set fops in "struct platform_pwm_backlight_data"? References: <525F8895.5010806@gmail.com> <20131017071445.GA2502@ulmo.nvidia.com> In-Reply-To: <20131017071445.GA2502@ulmo.nvidia.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/17/2013 03:14 PM, Thierry Reding wrote: > On Thu, Oct 17, 2013 at 02:49:57PM +0800, Mark Zhang wrote: >> Hi, >> >> This is the first time I send mail to linux-pwm, I didn't read through >> the mails in this list, so if somebody already asked this question, I'm >> sorry about that. >> >> I wanna set some fops in "struct platform_pwm_backlight_data". But the >> currrent probe function in pwm_bl.c says: >> >> ------- >> if (!data) { >> ret = pwm_backlight_parse_dt(&pdev->dev, &defdata); >> if (ret < 0) { >> dev_err(&pdev->dev, "failed to find platform data\n"); >> return ret; >> } >> >> data = &defdata; >> } >> ------- >> >> This looks like if we set the platform data for pwm backlight device, >> "pwm_backlight_parse_dt" will never have a chance to be called, which >> means the stuffs I defined in backlight DT node will be ignored. >> >> If I don't set the platform data for pwm backlight device, according to >> the pwm_backlight_probe, I will never have a chance to set some fops >> which I need(like "notify", "check_fb"...). >> >> So, what I suppose to do now? Maybe there is a way to set function >> pointers in DT? > > Perhaps you could describe in more detail what you need the functions > for. > Okay, I just want to set the "notify" function pointer in "struct platform_pwm_backlight_data", because I want to tune the brightness value before the pwm-bl sets the brightness to hardware. I don't know how to do that, unless we define the platform data explicitly. Mark > Generally you're not supposed to mix DT and platform data. Without more > info that's about all I can say. > > Thierry >