From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751197AbdJDTJd (ORCPT ); Wed, 4 Oct 2017 15:09:33 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:51482 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750787AbdJDTJb (ORCPT ); Wed, 4 Oct 2017 15:09:31 -0400 X-Google-Smtp-Source: AOwi7QAmBt8lNJWH8w+KHJZiS0rsOyh/sVWMvKEs5DqCo1+7pc69Pb4ybj7BhosbpcWdtmZckFEkaQ== Subject: Re: [PATCH for 4.15] leds: pca955x: Fix configuration on GPIO request for input To: Andrew Jeffery , linux-leds@vger.kernel.org References: <20171004072701.25782-1-andrew@aj.id.au> Cc: pavel@ucw.cz, linux-kernel@vger.kernel.org, =?UTF-8?Q?C=c3=a9dric_Le_Goater?= , Joel Stanley From: Jacek Anaszewski X-Enigmail-Draft-Status: N1110 Message-ID: <80a419c1-9ccc-c477-fe48-641a527baaa5@gmail.com> Date: Wed, 4 Oct 2017 21:08:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20171004072701.25782-1-andrew@aj.id.au> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andrew, Thanks for the fix. On 10/04/2017 09:27 AM, Andrew Jeffery wrote: > The prior patch which fixed the problem with output inversion failed to > account for a necessary change to requesting a pin for input, which is > affected by the open-drain nature of the hardware. > > Previously pca955x_gpio_direction_input() called through > pca955x_set_value() to configure the direction, however continuing down > this route lead to a brain-hemorrhaging level of necessary inversions. > Instead, remove one layer by calling directly into pca955x_led_set(), > and define PCA955X_GPIO_INPUT to paper over the rest of the confusion. > > Cc: Cédric Le Goater > Cc: Joel Stanley > Signed-off-by: Andrew Jeffery > Tested-by: Matt Spinler > --- > Jacek: > > The prior patch called out above is "eae1693fb026 leds: pca955x: Don't > invert requested value in pca955x_gpio_set_value()" (at the time of sending). I > think I've seen the leds tree be rebased in the past, so feel free to squash > this change in if desired. Squashed this patch into the original fix on the for-next branch. Thanks, Jacek Anaszewski > drivers/leds/leds-pca955x.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c > index 6dcd2d7cc6a4..78183f90820e 100644 > --- a/drivers/leds/leds-pca955x.c > +++ b/drivers/leds/leds-pca955x.c > @@ -61,6 +61,7 @@ > #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */ > #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */ > > +#define PCA955X_GPIO_INPUT LED_OFF > #define PCA955X_GPIO_HIGH LED_OFF > #define PCA955X_GPIO_LOW LED_FULL > > @@ -358,8 +359,11 @@ static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) > static int pca955x_gpio_direction_input(struct gpio_chip *gc, > unsigned int offset) > { > - /* To use as input ensure pin is not driven */ > - return pca955x_set_value(gc, offset, 0); > + struct pca955x *pca955x = gpiochip_get_data(gc); > + struct pca955x_led *led = &pca955x->leds[offset]; > + > + /* To use as input ensure pin is not driven. */ > + return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); > } > > static int pca955x_gpio_direction_output(struct gpio_chip *gc, >