From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 439CAC43381 for ; Thu, 21 Mar 2019 10:25:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11B532190A for ; Thu, 21 Mar 2019 10:25:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="X4oF7pT9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728106AbfCUKZv (ORCPT ); Thu, 21 Mar 2019 06:25:51 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:47826 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727575AbfCUKZv (ORCPT ); Thu, 21 Mar 2019 06:25:51 -0400 Received: from pendragon.ideasonboard.com (30.net042126252.t-com.ne.jp [42.126.252.30]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id F08BF23A; Thu, 21 Mar 2019 11:25:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1553163948; bh=hortb+fLPxm48q4oN7adARz9wJcUzEYac3LLowmBhpY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=X4oF7pT9mGAzemS1c6b5XxA5CS7hSnRxS9etWNtB5QJn+9Xlz9NnBVIKAzWY4WKaY Diif70Nv2U1xjgRopqug256O3SodUUDvGF0D3n4gulf5yQiykr8X2Hi+UqzXiYGA+Q nOkri1XzI2ctJRUwzY922eOcAEb6+Qf6l8Tx/dpo= Date: Thu, 21 Mar 2019 12:25:37 +0200 From: Laurent Pinchart To: Geert Uytterhoeven Cc: Linus Walleij , Bartosz Golaszewski , "Rafael J . Wysocki" , Ulf Hansson , Kevin Hilman , linux-gpio@vger.kernel.org, linux-pm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC] gpio: pca953x: Configure wake-up path when wake-up is enabled Message-ID: <20190321102537.GR4615@pendragon.ideasonboard.com> References: <20190320103927.21227-1-geert+renesas@glider.be> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190320103927.21227-1-geert+renesas@glider.be> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Geert, Thank you for the patch. On Wed, Mar 20, 2019 at 11:39:27AM +0100, Geert Uytterhoeven wrote: > If a device is part of the wake-up path, it should indicate this by > setting its power.wakeup_path field. This allows the genpd core code to > keep the device enabled during system suspend when needed. > > As regulators powering devices are not handled by genpd, the driver > handles these itself, and thus must skip regulator control when the > device is part of the wake-up path. It would be nice for this to be handled automatically... > Signed-off-by: Geert Uytterhoeven > --- > Note that I don't really need this on the Renesas Ebisu-4D board, as > there is no regulator or PM Domain controlling power to the GPIO > expander on that board. I did want to have all wake-up path processing > implemented in the driver for completeness, and did test its behavior > with gpio-keys configured as a wake-up source. > > However, while this approach is known to work fine on other boards, with > other GPIO and interrupt controllers (gpio-rcar, irq-renesas-irqc, > irq-renesas-intc-irqpin), it wouldn't work on Ebisu-4D, due to different > device suspend ordering. > > The proper ordering is: > 1. When gpio-keys is suspended, its suspend handler calls > enable_irq_wake(), invoking pca953x_irq_set_wake(), and causing > pca953x_chip.wakeup_path to be incremented, > 2. When gpio-pca953x is suspended, it checks pca953x_chip.wakeup_path, > and marks the device to be part of the wake-up path. > > However, gpio-keys is suspended _after_ gpio-pca953x, breaking the > scheme :-( > > So depending on topology, this may work, or not... Could device links help there ? > --- > drivers/gpio/gpio-pca953x.c | 21 ++++++++++++++++----- > 1 file changed, 16 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c > index 88c94d155e218535..349d0ccb5285a6c4 100644 > --- a/drivers/gpio/gpio-pca953x.c > +++ b/drivers/gpio/gpio-pca953x.c > @@ -153,6 +153,7 @@ struct pca953x_chip { > u8 irq_trig_fall[MAX_BANK]; > struct irq_chip irq_chip; > #endif > + atomic_t wakeup_path; > > struct i2c_client *client; > struct gpio_chip gpio_chip; > @@ -581,6 +582,11 @@ static int pca953x_irq_set_wake(struct irq_data *d, unsigned int on) > struct gpio_chip *gc = irq_data_get_irq_chip_data(d); > struct pca953x_chip *chip = gpiochip_get_data(gc); > > + if (on) > + atomic_inc(&chip->wakeup_path); > + else > + atomic_dec(&chip->wakeup_path); > + > return irq_set_irq_wake(chip->client->irq, on); > } > > @@ -1100,7 +1106,10 @@ static int pca953x_suspend(struct device *dev) > > regcache_cache_only(chip->regmap, true); > > - regulator_disable(chip->regulator); > + if (atomic_read(&chip->wakeup_path)) > + device_set_wakeup_path(dev); > + else > + regulator_disable(chip->regulator); > > return 0; > } > @@ -1110,10 +1119,12 @@ static int pca953x_resume(struct device *dev) > struct pca953x_chip *chip = dev_get_drvdata(dev); > int ret; > > - ret = regulator_enable(chip->regulator); > - if (ret != 0) { > - dev_err(dev, "Failed to enable regulator: %d\n", ret); > - return 0; > + if (!atomic_read(&chip->wakeup_path)) { > + ret = regulator_enable(chip->regulator); > + if (ret != 0) { > + dev_err(dev, "Failed to enable regulator: %d\n", ret); > + return 0; > + } > } > > regcache_cache_only(chip->regmap, false); -- Regards, Laurent Pinchart