From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750910AbcFDG0O (ORCPT ); Sat, 4 Jun 2016 02:26:14 -0400 Received: from down.free-electrons.com ([37.187.137.238]:45669 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750748AbcFDG0M (ORCPT ); Sat, 4 Jun 2016 02:26:12 -0400 Date: Sat, 4 Jun 2016 08:26:08 +0200 From: Boris Brezillon To: Brian Norris Cc: Thierry Reding , linux-pwm@vger.kernel.org, Mark Brown , Liam Girdwood , Heiko Stuebner , linux-rockchip@lists.infradead.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim , Doug Anderson , Caesar Wang , Stephen Barber , Ajit Pal Singh , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com Subject: Re: [PATCH 05/14] pwm: rockchip: Avoid glitches on already running PWMs Message-ID: <20160604082608.041925a7@bbrezillon> In-Reply-To: <20160603202859.GD124478@google.com> References: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> <1464942192-25967-6-git-send-email-boris.brezillon@free-electrons.com> <20160603202859.GD124478@google.com> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 3 Jun 2016 13:28:59 -0700 Brian Norris wrote: > Hi, > > Just noticed a few things: > > On Fri, Jun 03, 2016 at 10:23:03AM +0200, Boris Brezillon wrote: > > The current logic will disable the PWM clk even if the PWM was left > > enabled by the bootloader (because it's controlling a critical device > > like a regulator for example). > > Keep the PWM clk enabled if the PWM is enabled to avoid any glitches. > > > > Signed-off-by: Boris Brezillon > > --- > > drivers/pwm/pwm-rockchip.c | 24 +++++++++++++++++++++++- > > 1 file changed, 23 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c > > index dfacf7d..798a787 100644 > > --- a/drivers/pwm/pwm-rockchip.c > > +++ b/drivers/pwm/pwm-rockchip.c > > @@ -299,6 +299,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev) > > { > > const struct of_device_id *id; > > struct rockchip_pwm_chip *pc; > > + struct pwm_state state; > > struct resource *r; > > int ret; > > > > @@ -319,7 +320,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev) > > if (IS_ERR(pc->clk)) > > return PTR_ERR(pc->clk); > > > > - ret = clk_prepare(pc->clk); > > + ret = clk_prepare_enable(pc->clk); > > if (ret) > > return ret; > > > > @@ -342,12 +343,33 @@ static int rockchip_pwm_probe(struct platform_device *pdev) > > dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); > > } > > > > + /* Keep the PWM clk enabled if the PWM appears to be up and running. */ > > + pwm_get_state(pc->chip.pwms, &state); > > + if (!state.enabled) > > Why not just if (!pwm_is_enabled())? It's a leftover from a previous version where I was deprecating pwm_enable(). I'll switch back to pwm_enable(). Thanks, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Sat, 4 Jun 2016 08:26:08 +0200 Subject: [PATCH 05/14] pwm: rockchip: Avoid glitches on already running PWMs In-Reply-To: <20160603202859.GD124478@google.com> References: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> <1464942192-25967-6-git-send-email-boris.brezillon@free-electrons.com> <20160603202859.GD124478@google.com> Message-ID: <20160604082608.041925a7@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 3 Jun 2016 13:28:59 -0700 Brian Norris wrote: > Hi, > > Just noticed a few things: > > On Fri, Jun 03, 2016 at 10:23:03AM +0200, Boris Brezillon wrote: > > The current logic will disable the PWM clk even if the PWM was left > > enabled by the bootloader (because it's controlling a critical device > > like a regulator for example). > > Keep the PWM clk enabled if the PWM is enabled to avoid any glitches. > > > > Signed-off-by: Boris Brezillon > > --- > > drivers/pwm/pwm-rockchip.c | 24 +++++++++++++++++++++++- > > 1 file changed, 23 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c > > index dfacf7d..798a787 100644 > > --- a/drivers/pwm/pwm-rockchip.c > > +++ b/drivers/pwm/pwm-rockchip.c > > @@ -299,6 +299,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev) > > { > > const struct of_device_id *id; > > struct rockchip_pwm_chip *pc; > > + struct pwm_state state; > > struct resource *r; > > int ret; > > > > @@ -319,7 +320,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev) > > if (IS_ERR(pc->clk)) > > return PTR_ERR(pc->clk); > > > > - ret = clk_prepare(pc->clk); > > + ret = clk_prepare_enable(pc->clk); > > if (ret) > > return ret; > > > > @@ -342,12 +343,33 @@ static int rockchip_pwm_probe(struct platform_device *pdev) > > dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); > > } > > > > + /* Keep the PWM clk enabled if the PWM appears to be up and running. */ > > + pwm_get_state(pc->chip.pwms, &state); > > + if (!state.enabled) > > Why not just if (!pwm_is_enabled())? It's a leftover from a previous version where I was deprecating pwm_enable(). I'll switch back to pwm_enable(). Thanks, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com