Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758185Ab3DAHcI (ORCPT ); Mon, 1 Apr 2013 03:32:08 -0400 Received: from mail-pb0-f50.google.com ([209.85.160.50]:64650 "EHLO mail-pb0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758168Ab3DAHcG (ORCPT ); Mon, 1 Apr 2013 03:32:06 -0400 MIME-Version: 1.0 X-Originating-IP: [114.39.109.172] In-Reply-To: References: <1364741987.3834.2.camel@phoenix> <1364742271.3834.7.camel@phoenix> Date: Mon, 1 Apr 2013 15:32:05 +0800 Message-ID: Subject: Re: [PATCH 3/3] pwm: pxa: Remove clk_enabled field from struct pxa_pwm_chip From: Axel Lin To: Eric Miao Cc: Thierry Reding , linux-kernel Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1564 Lines: 44 2013/4/1 Eric Miao : > On Sun, Mar 31, 2013 at 11:04 PM, Axel Lin wrote: >> clk_enable/clk_disable maintain an enable_count, clk_prepare and clk_unprepare >> also maintain a prepare_count. These APIs will do prepare/enable when the first >> user calling these APIs, and do disable/unprepare when the corresponding counter >> reach 0. Thus We don't need to maintain a clk_enabled counter here. > > The original intention is to keep a paired clk enable counter no matter > how the user calls pwm_enable()/pwm_disable() in pair or not, if that's > no longer the case. We don't need to worry that case: In pwm core, both pwm_enable() and pwm_disable() will always check PWMF_ENABLED flag. /** * pwm_enable() - start a PWM output toggling * @pwm: PWM device */ int pwm_enable(struct pwm_device *pwm) { if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) return pwm->chip->ops->enable(pwm->chip, pwm); return pwm ? 0 : -EINVAL; } EXPORT_SYMBOL_GPL(pwm_enable); /** * pwm_disable() - stop a PWM output toggling * @pwm: PWM device */ void pwm_disable(struct pwm_device *pwm) { if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) pwm->chip->ops->disable(pwm->chip, pwm); } EXPORT_SYMBOL_GPL(pwm_disable); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/