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From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: "Vokáč Michal" <Michal.Vokac@ysoft.com>
Cc: "Thierry Reding" <thierry.reding@gmail.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Mark Rutland" <mark.rutland@arm.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-pwm@vger.kernel.org" <linux-pwm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Lukasz Majewski" <l.majewski@majess.pl>,
	"Fabio Estevam" <fabio.estevam@nxp.com>,
	"Lothar Waßmann" <LW@karo-electronics.de>,
	kernel@pengutronix.de
Subject: Re: [RCF PATCH,v2,2/2] pwm: imx: Configure output to GPIO in disabled state
Date: Wed, 7 Nov 2018 10:33:55 +0100	[thread overview]
Message-ID: <20181107093355.e4n3irrnkybqsjvc@pengutronix.de> (raw)
In-Reply-To: <e4289ee5-3fc1-2848-1cae-77d29b5ed93c@ysoft.com>

Hello Michal,

just to state it more explicitly, I think the following patch (not even
compile tested) is much preferable over your approach:

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 1d5242c9cde0..af88644b5efb 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -216,7 +216,14 @@ static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
 			cr |= MX3_PWMCR_POUTC;
 
 		writel(cr, imx->mmio_base + MX3_PWMCR);
-	} else if (cstate.enabled) {
+	} else if (cstate.enabled && state->polarity == PWM_POLARITY_NORMAL) {
+		/*
+		 * When disabled in hardware the output pin goes to 0
+		 * independant of the polarity setting. The expectation of some
+		 * people however is that after disabling the pin goes to the
+		 * inactive level which isn't given for an inversed pwm, so
+		 * only disable for normal polarity.
+		 */
 		writel(0, imx->mmio_base + MX3_PWMCR);
 
 		clk_disable_unprepare(imx->clk_per);

I think it solves most if not all problems you want to address with the
pinctrl stuff.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

  reply	other threads:[~2018-11-07  9:34 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-10  9:33 [RCF PATCH v2 0/2] pwm: imx: Configure output to GPIO in disabled state Vokáč Michal
2018-10-10  9:33 ` [RCF PATCH v2 1/2] dt-bindings: pwm: imx: Allow switching PWM output between PWM and GPIO Vokáč Michal
2018-10-10 13:39   ` Thierry Reding
2018-10-29 15:52     ` Vokáč Michal
2018-10-10  9:33 ` [RCF PATCH v2 2/2] pwm: imx: Configure output to GPIO in disabled state Vokáč Michal
2018-10-12  8:57   ` [RCF PATCH,v2,2/2] " Uwe Kleine-König
2018-10-12 15:04     ` Vokáč Michal
2018-10-12 15:54       ` Thierry Reding
2018-10-12 16:08       ` Uwe Kleine-König
2018-10-14 20:24         ` Uwe Kleine-König
2018-10-15  8:45           ` Thierry Reding
2018-10-29 15:55             ` Vokáč Michal
2018-10-29 15:54         ` Vokáč Michal
2018-11-07  9:33           ` Uwe Kleine-König [this message]
2018-11-07 13:32             ` Vokáč Michal
2018-11-07 15:01               ` Uwe Kleine-König
2018-11-08 15:21                 ` Vokáč Michal
2018-11-08 19:18                   ` Uwe Kleine-König
2018-11-09 14:24                     ` Vokáč Michal
2018-11-09 16:55                       ` Uwe Kleine-König
2018-11-14  9:09                         ` Uwe Kleine-König
2018-11-14 11:34                         ` Thierry Reding
2018-11-14 21:51                           ` Uwe Kleine-König
2018-11-15 15:25                             ` Thierry Reding
2018-11-15 20:37                               ` Uwe Kleine-König
2018-11-16  7:34                                 ` Lothar Waßmann
2018-11-16  8:25                                   ` Uwe Kleine-König
2018-11-22 15:42                                     ` Vokáč Michal
2018-11-22 16:23                                       ` Uwe Kleine-König
2018-11-22 16:46                                         ` Vokáč Michal
2018-11-22 19:03                                           ` Uwe Kleine-König
2018-11-23 15:15                                             ` Vokáč Michal
2018-11-25 20:56                                               ` Uwe Kleine-König
2018-11-26  9:11                                                 ` Lothar Waßmann
2018-11-26  9:18                                                   ` Uwe Kleine-König
2018-11-26 10:03                                                     ` Lothar Waßmann
2018-11-26 11:51                                               ` Thierry Reding
2018-11-26 12:23                                                 ` Lothar Waßmann
2018-11-26 13:34                                                   ` Thierry Reding
2018-11-26 15:50                                                     ` Vokáč Michal
2018-11-16  9:51                                 ` Thierry Reding
2018-11-16 10:39                                   ` Uwe Kleine-König
2018-11-16 11:56                                     ` Lothar Waßmann
2018-11-18 11:30                                       ` Uwe Kleine-König
2018-11-16 12:24                                     ` Thierry Reding
2018-11-18 20:08                                       ` Uwe Kleine-König
2018-11-19  8:48                                         ` Uwe Kleine-König
2018-11-22 15:03                                         ` Thierry Reding
2018-11-22 16:17                                           ` Uwe Kleine-König
2018-11-20 13:14                                   ` Vokáč Michal
2018-11-20 16:54                                     ` Uwe Kleine-König
2018-11-22 14:23                                       ` Vokáč Michal
2018-11-19  7:44                             ` Linus Walleij
2018-11-19  8:32                               ` Uwe Kleine-König
2018-11-20  8:35                                 ` Linus Walleij
2018-11-20  9:16                                   ` Viresh Kumar
2018-11-20  9:53                                   ` Uwe Kleine-König
2018-11-14 11:14                   ` Thierry Reding
2018-10-12 16:00   ` [RCF PATCH v2 2/2] " Thierry Reding
2018-10-29 15:53     ` Vokáč Michal

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