From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rhyland Klein Subject: Re: [PATCH 1/4] regulator: tps65910: update type for regmap Date: Wed, 18 Apr 2012 13:19:31 -0700 Message-ID: <1334780371.32315.66.camel@rklein-linux> References: <1334710829-22777-1-git-send-email-rklein@nvidia.com> <1334710829-22777-2-git-send-email-rklein@nvidia.com> <20120418092547.GE3021@opensource.wolfsonmicro.com> <1334779402.32315.63.camel@rklein-linux> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1334779402.32315.63.camel@rklein-linux> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Brown Cc: Samuel Ortiz , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Rob Herring , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Liam Girdwood List-Id: devicetree@vger.kernel.org On Wed, 2012-04-18 at 13:03 -0700, Rhyland Klein wrote: > On Wed, 2012-04-18 at 02:25 -0700, Mark Brown wrote: > > * PGP Signed by an unknown key > > > > On Tue, Apr 17, 2012 at 06:00:26PM -0700, Rhyland Klein wrote: > > > When accessing the regmap via the read/write functions, we need to use a > > > unsigned int * instead of a u8 * otherwise corruption will occur. > > > > > > Signed-off-by: Rhyland Klein > > > > > static inline int tps65910_read(struct tps65910_reg *pmic, u8 reg) > > > { > > > - u8 val; > > > + unsigned int val; > > > int err; > > > > > > err = pmic->mfd->read(pmic->mfd, reg, 1, &val); > > > > Ugh, this interface is just broken all round - there's absolutely no > > type safety here and all users of these functions will be broken (a > > similar issue applies on write). It's much better to fix this for 3.4 > > by converting the core code to use regmap_raw_ functions which take > > native formatted data for the device like the function driver API > > actually expects. > > Which interface are you saying is broken? The regmap interface or the > one internal to the tps65910 code? > > > > > Looking at the MFD code the fix for 3.5 should at the very least involve > > making the functions take typed pointers, though given the way they're > > implemented right now with direct references in the subdevices I'd also > > consider just having the subdevices uses regmap directly as the wrappers > > are just adding an opportunity for error (the bit operations could be > > converted into static inlines in the header too). > > > > So to be clear... Your recommendation is to change the tps65910 code to > remove the common read/write callbacks and to use regmap directly in > each component, and then when using regmap, do use the regmap raw > functions instead of the bulkread/write? Looking at the code, I would think it makes more sense use regmap_read which enforces types since the tps65910 code only ever seems to use regmap to access a single register at a time. Do you agree? -rhyland --- nvpublic