From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [RFC 2.6.27 1/1] gpiolib: add support for batch set of pins Date: Mon, 29 Dec 2008 11:59:36 -0800 Message-ID: <200812291159.37449.david-b@pacbell.net> References: <12276535632759-git-send-email-jayakumar.lkml@gmail.com> <200812281346.56703.rgetz@blackfin.uclinux.org> <1230501634.16910.57.camel@linux-51e8.site> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1230501634.16910.57.camel@linux-51e8.site> Content-Disposition: inline Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Ben Nizette Cc: Robin Getz , Jaya Kumar , Eric Miao , Sam Ravnborg , Eric Miao , Haavard Skinnemoen , Philipp Zabel , Russell King , Ben Gardner , Greg KH , linux-arm-kernel@lists.arm.linux.org.uk, linux-fbdev-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org On Sunday 28 December 2008, Ben Nizette wrote: > > > gpio_set_batch(DB0, value, 0xFFFF, 16) > > > > > > which has the nice performance benefit of skipping all the bit > > > counting in the most common use case scenario. > > > > but has the requirement that the driver know exactly the board level > > impmentation details (something that doesn't sound generic). > > The original use case for these batch operations was in a fastpath - > setting data lines on a framebuffer. And the rationale for generalizing them was to let such fastpaths stop being board-specific hacks. :)