From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932351AbcFCI1x (ORCPT ); Fri, 3 Jun 2016 04:27:53 -0400 Received: from down.free-electrons.com ([37.187.137.238]:45871 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752385AbcFCIX0 (ORCPT ); Fri, 3 Jun 2016 04:23:26 -0400 From: Boris Brezillon To: Thierry Reding , linux-pwm@vger.kernel.org, Mark Brown , Liam Girdwood Cc: 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 , Brian Norris , Ajit Pal Singh , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com, Boris Brezillon Subject: [PATCH 05/14] pwm: rockchip: Avoid glitches on already running PWMs Date: Fri, 3 Jun 2016 10:23:03 +0200 Message-Id: <1464942192-25967-6-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> References: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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) + clk_disable(pc->clk); + return ret; } static int rockchip_pwm_remove(struct platform_device *pdev) { struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev); + struct pwm_state state; + + /* + * Disable the PWM clk before unpreparing it if the PWM device is still + * running. This should only happen when the last PWM user left it + * enabled, or when nobody requested a PWM that was previously enabled + * by the bootloader. + * + * FIXME: Maybe the core should disable all PWM devices in + * pwmchip_remove(). In this case we'd only have to call + * clk_unprepare() after pwmchip_remove(). + * + */ + pwm_get_state(pc->chip.pwms, &state); + if (state.enabled) + clk_disable(pc->clk); clk_unprepare(pc->clk); -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: [PATCH 05/14] pwm: rockchip: Avoid glitches on already running PWMs Date: Fri, 3 Jun 2016 10:23:03 +0200 Message-ID: <1464942192-25967-6-git-send-email-boris.brezillon@free-electrons.com> References: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1464942192-25967-1-git-send-email-boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+glpar-linux-rockchip=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Thierry Reding , linux-pwm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mark Brown , Liam Girdwood Cc: Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Heiko Stuebner , Pawel Moll , Ian Campbell , Srinivas Kandagatla , Brian Norris , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Patrice Chotard , Doug Anderson , Milo Kim , linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Rob Herring , kernel-F5mvAk5X5gdBDgjK7y7TUQ@public.gmane.org, Boris Brezillon , Kumar Gala , Maxime Coquelin , Stephen Barber , Ajit Pal Singh , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Caesar Wang List-Id: devicetree@vger.kernel.org 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) + clk_disable(pc->clk); + return ret; } static int rockchip_pwm_remove(struct platform_device *pdev) { struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev); + struct pwm_state state; + + /* + * Disable the PWM clk before unpreparing it if the PWM device is still + * running. This should only happen when the last PWM user left it + * enabled, or when nobody requested a PWM that was previously enabled + * by the bootloader. + * + * FIXME: Maybe the core should disable all PWM devices in + * pwmchip_remove(). In this case we'd only have to call + * clk_unprepare() after pwmchip_remove(). + * + */ + pwm_get_state(pc->chip.pwms, &state); + if (state.enabled) + clk_disable(pc->clk); clk_unprepare(pc->clk); -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Fri, 3 Jun 2016 10:23:03 +0200 Subject: [PATCH 05/14] pwm: rockchip: Avoid glitches on already running PWMs In-Reply-To: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> References: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <1464942192-25967-6-git-send-email-boris.brezillon@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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) + clk_disable(pc->clk); + return ret; } static int rockchip_pwm_remove(struct platform_device *pdev) { struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev); + struct pwm_state state; + + /* + * Disable the PWM clk before unpreparing it if the PWM device is still + * running. This should only happen when the last PWM user left it + * enabled, or when nobody requested a PWM that was previously enabled + * by the bootloader. + * + * FIXME: Maybe the core should disable all PWM devices in + * pwmchip_remove(). In this case we'd only have to call + * clk_unprepare() after pwmchip_remove(). + * + */ + pwm_get_state(pc->chip.pwms, &state); + if (state.enabled) + clk_disable(pc->clk); clk_unprepare(pc->clk); -- 2.7.4