From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756782AbaH0L1U (ORCPT ); Wed, 27 Aug 2014 07:27:20 -0400 Received: from mail-qa0-f47.google.com ([209.85.216.47]:64984 "EHLO mail-qa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755814AbaH0L1S (ORCPT ); Wed, 27 Aug 2014 07:27:18 -0400 Date: Wed, 27 Aug 2014 12:27:09 +0100 From: Lee Jones To: Dmitry Torokhov Cc: Chris Zhong , robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, sameo@linux.intel.com, lgirdwood@gmail.com, broonie@kernel.org, a.zummo@towertech.it, mturquette@linaro.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, grant.likely@linaro.org, hl@rock-chips.com, huangtao@rock-chips.com, cf@rock-chips.com, zhangqing@rock-chips.com, xxx@rock-chips.com, dianders@chromium.org, heiko@sntech.de, olof@lixom.net, sonnyrao@chromium.org, dtor@chromium.org, javier.martinez@collabora.co.uk, kever.yang@rock-chips.com Subject: Re: [PATCH v2 2/5] MFD: RK808: Add new mfd driver for RK808 Message-ID: <20140827112709.GB6364@lee--X1> References: <1408505461-24200-1-git-send-email-zyw@rock-chips.com> <20140820092117.GI4266@lee--X1> <53FA9D1E.8040202@rock-chips.com> <20140826092205.GG9574@lee--X1> <20140826162831.GA22842@core.coreip.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140826162831.GA22842@core.coreip.homeip.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 26 Aug 2014, Dmitry Torokhov wrote: > On Tue, Aug 26, 2014 at 10:22:05AM +0100, Lee Jones wrote: > > On Mon, 25 Aug 2014, Chris Zhong wrote: > > > On 08/20/2014 05:21 PM, Lee Jones wrote: > > > >On Wed, 20 Aug 2014, Chris Zhong wrote: > > > > > > > >>The RK808 chip is a power management IC for multimedia and handheld > > > >>devices. It contains the following components: > > > >> > > > >>- Regulators > > > >>- RTC > > > >> > > > >>The rk808 core driver is registered as a platform driver and provides > > > >>communication through I2C with the host device for the different > > > >>components. > > > >> > > > >>Signed-off-by: Chris Zhong > > > >>--- > > > > [...] > > > > > >>+ rk808->pdata = pdata; > > > >Remove pdata from 'struct rk808'. You can obtain it from dev. > > > > > > Can I keep this pdata in rk808, because it is used in the regulator driver. > > > The one obtain from dev maybe empty. > > > > If the one in dev is empty, you should populate that instead. > > No, drivers should not populate platform data in devices - they do not > own it (unlike drvdata). Platform data should be read-only so that if > one would unbind and then try to re-bind the driver we'd end up in > exactly same state as before. Right. I guess this point is moot now, as my other point about pdata not actually being required has been accecpted. But, when I say "you can obtain it from dev" I meant via dev_get_platdata(dev), rather than dev_get_platdata(dev->parent). So if this 'pdata' has to go somewhere, rather than sticking it in the MFD's (parent) platform_data, the .platform_data attribute in 'struct mfd_cell' should be used. > For DT systems we should be allocating platform data separately and make > sure we clean up after ourselves. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog