From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754897Ab1A2Uwm (ORCPT ); Sat, 29 Jan 2011 15:52:42 -0500 Received: from mailhost.informatik.uni-hamburg.de ([134.100.9.70]:54600 "EHLO mailhost.informatik.uni-hamburg.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751477Ab1A2Uwl (ORCPT ); Sat, 29 Jan 2011 15:52:41 -0500 Message-ID: <4D447E5E.6060007@metafoo.de> Date: Sat, 29 Jan 2011 21:53:50 +0100 From: Lars-Peter Clausen User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20101226 Icedove/3.0.11 MIME-Version: 1.0 To: Sascha Hauer CC: linux-kernel@vger.kernel.org, Eric Miao , Ben Dooks , Kukjin Kim , Hemanth V , Jean Delvare , linux-arm-kernel@lists.infradead.org, Uwe Kleine-Koenig , Shawn Guo , Arun Murthy , Bill Gatliff Subject: Re: [RFC] add pwmlib support References: <1296217283-14531-1-git-send-email-s.hauer@pengutronix.de> In-Reply-To: <1296217283-14531-1-git-send-email-s.hauer@pengutronix.de> X-Enigmail-Version: 1.0.1 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 01/28/2011 01:21 PM, Sascha Hauer wrote: > Hi all, > > While implementing just another pwm driver I thought it's time to implement > generic pwm support. The following series adds drivers/pwm/pwmlib.c and > a i.MX23/28 pwm driver which serves as a usage example for pwmlib. The > code is inspired by gpiolib support and tested using the backlight pwm > driver by Eric Miao. > > Currently the pwm_request, pwm_add, pwm_remove and pwm_free operations are > protected with a single mutex wherea the pwm_enable, pwm_disable and > pwm_config operations are unlocked. It is assumed that the owners of the > pwm handle the serialization of the pwm accesses. This may not be enough, so > i'd like to discuss the locking (and type of locking) here. > > I Cced the people working with PWMs in the kernel in the hope that they can > give input on what's missing / wrong in this implementation > > Sascha > Hi There have been two other proposals for a generic PWM api during the last year. You might want to take a look at them. https://lkml.org/lkml/2010/2/9/275 https://lkml.org/lkml/2010/9/28/107 I've added Bill Gatliff and Arun Murthy to Cc. - Lars