From patchwork Wed Oct 1 21:08:30 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ryang X-Patchwork-Id: 395674 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id A1EE3140168 for ; Thu, 2 Oct 2014 07:09:10 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751484AbaJAVJI (ORCPT ); Wed, 1 Oct 2014 17:09:08 -0400 Received: from mail-ob0-f178.google.com ([209.85.214.178]:57129 "EHLO mail-ob0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208AbaJAVJI (ORCPT ); Wed, 1 Oct 2014 17:09:08 -0400 Received: by mail-ob0-f178.google.com with SMTP id wn1so1060146obc.37 for ; Wed, 01 Oct 2014 14:09:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=E2gx4RBOVLEbux57VdNXGkACUUvKX5lSrwnTxgIOKgA=; b=dFiUecp1wlXyXMyKNuKbC5TYKJ8/7i+NAJSa7eWWEUvzZz45X9ptQ9f0vHLG7m+K4H 34PeNw4RSxRTyYN02PvlYo9KCTUTo7191rRkeg24sK5yzS8JQihnLs7pUwCjvQ51MhMz jvb4YDX8xyE5OWAnrE5wAafy3JUdqCYnRTATU/DoIUEz5iJ8wVMJNR/2ITzWMFQglCUu Jx1AAXvjwxRtcbWD/ZFzjJsIKNkSiZJzY1Sr6NpUGVUxoZKUm5t/TxkTn1F/rBC76vQt Z5sDGrSTzl75bRA34EUlJPjpSaET7Q6yaR8FglBrhCQJ4uY36LO3QXjHc623bXITRk9H MGTg== X-Received: by 10.60.101.226 with SMTP id fj2mr24811400oeb.70.1412197746658; Wed, 01 Oct 2014 14:09:06 -0700 (PDT) Received: from ubuntu.hach.ewqg.com ([64.90.124.37]) by mx.google.com with ESMTPSA id jv9sm1133671oeb.8.2014.10.01.14.09.05 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 01 Oct 2014 14:09:06 -0700 (PDT) From: robert yang X-Google-Original-From: robert yang To: Thierry Reding , linux-pwm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, ryang Subject: [PATCH 1/1] Atmel-PWM: Fixed the PWM channel enable/disable issue which will cause the PWM output stop working after reenable. THe PWM channel status register is read to ensure the PWM channel is really enabled or disabled. Date: Wed, 1 Oct 2014 15:08:30 -0600 Message-Id: <1412197710-17731-1-git-send-email-ryang@hach.com> X-Mailer: git-send-email 1.9.1 Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org From: ryang Signed-off-by: ryang --- drivers/pwm/pwm-atmel.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index 6e700a5..bab933a 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -237,7 +237,10 @@ static int atmel_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) } atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm); - + while (!(atmel_pwm_readl(atmel_pwm, PWM_SR) & (1 << pwm->hwpwm))) { + atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm); + cpu_relax(); + } return 0; } @@ -246,7 +249,10 @@ static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm); - + while (atmel_pwm_readl(atmel_pwm, PWM_SR) & (1 << pwm->hwpwm)) { + atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm); + cpu_relax(); + } clk_disable(atmel_pwm->clk); }