From patchwork Tue Feb 20 13:39:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herve Codina X-Patchwork-Id: 774384 Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [217.70.183.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88FB36A346; Tue, 20 Feb 2024 13:40:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.200 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708436403; cv=none; b=VSK07IHiJvkG3EwkAOiKyYfWLJIU3oVXENnTrSuuqnGyvH8xb5CHKQV2yMg+C7WHAEHL9HK1r4hm7/xw0e0kK8Pidk663BGqZfid8RMN2c8k9BZlKCNdj2vn0AD3zxifk5M4RY0QcTEOZ7PNvjFKd0efZQMhq07JhOhbzYS4VA4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708436403; c=relaxed/simple; bh=G5QNoctspJ1RDquSBWI4re9ufm9ecSTNMxVtKdOzPC4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kTEdHGNLrci+3WCJtSAUntTpKKK1PhPzTSNaPyrDNdeM748XjCAIwAgRERnjjaS1xTDldCxkcAlREB0sawgy2Ft6DwahT4BeR9qX1hMMtrvdkzoKrWQ7UP/HFlVYmKcsXDjQPhrTO/3CEpFXpkelliZY92s2rXG9RZkFxvtt1W4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=dyt63mmK; arc=none smtp.client-ip=217.70.183.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="dyt63mmK" Received: by mail.gandi.net (Postfix) with ESMTPA id 8916820011; Tue, 20 Feb 2024 13:39:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1708436399; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=THtvQDT+qQLPub8vG8YsD0SpllI5xUKHDkxR4GFPKUc=; b=dyt63mmKnd2Z/+FblfX5f/mKstSpdWCixUiXcAjswnNreAWHDLHGYt1BaRFxvUsnHTUags LHksF5XcBusLoE7jcn/YsTyiDylHsblQwVWca+QnQqYxbYMtfMQ3iUVA/PaSOHoCnrblaY 9lEBlNzIBfv/IVHWRnmOhb/tkpg24xeTV6WQsBVXPzKWgCezLNisM5qWLkjFTkqlXuhSnr q+2beu/laXjyXqEpjbFcCKUQKdBZNiF44J1CtIARcJEjdlOx3ujuLa6/tDWpPjNJraWGPm s0n3u9GGXPLDdUFAggMkENlqWakT4Kz0Vl6RxV1KpId6CWR6CzDp5EeR3hak9A== From: Herve Codina To: Linus Walleij , Bartosz Golaszewski , Pavel Machek , Lee Jones Cc: Saravana Kannan , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, Luca Ceresoli , Thomas Petazzoni , Herve Codina Subject: [PATCH RESEND 2/2] leds: gpio: Add devlinks between the gpio consumed and the gpio leds device Date: Tue, 20 Feb 2024 14:39:49 +0100 Message-ID: <20240220133950.138452-3-herve.codina@bootlin.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240220133950.138452-1-herve.codina@bootlin.com> References: <20240220133950.138452-1-herve.codina@bootlin.com> Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-GND-Sasl: herve.codina@bootlin.com When a gpio is removed, the gpio leds consumer need to be removed first. This dependency consumer/supplier can be described by devlink links. In case of device-tree, even if some devlinks are created due to the presence of gpio phandles in the gpio leds children, these links do not help in removing the gpio leds device (i.e. the real consumer) before the consumed gpio. We can reach cases where the gpio are no more present and the gpio leds driver continue to have leds using these gpio. Further more, when the gpio come back, the gpio leds still use the old removed one. Indeed, the gpio are consumed by the parent of the consumer used in the devlink creation due to phandles. A link is missing between the gpio and the real gpio consumer, the gpio leds device itself. Use the newly introduced gpiod_device_add_link() to create this missing link between the gpio leds devices and the gpios. With that done, if a gpio is removed, the gpio leds is removed and the resources are correctly released. Signed-off-by: Herve Codina --- drivers/leds/leds-gpio.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c index 83fcd7b6afff..b3ec8ecbe5da 100644 --- a/drivers/leds/leds-gpio.c +++ b/drivers/leds/leds-gpio.c @@ -150,6 +150,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct device *dev) { struct fwnode_handle *child; struct gpio_leds_priv *priv; + struct device_link *link; int count, ret; count = device_get_child_node_count(dev); @@ -197,6 +198,20 @@ static struct gpio_leds_priv *gpio_leds_create(struct device *dev) /* Set gpiod label to match the corresponding LED name. */ gpiod_set_consumer_name(led_dat->gpiod, led_dat->cdev.dev->kobj.name); + + /* + * Create a link between the GPIO and the gpio-leds device. + * This allow to have a relationship between the gpio used and + * the gpio-leds device in order to automatically remove the + * gpio-leds device (consumer) when a GPIO (supplier) is removed. + */ + link = gpiod_device_add_link(dev, led_dat->gpiod, + DL_FLAG_AUTOREMOVE_CONSUMER); + if (IS_ERR(link)) { + fwnode_handle_put(child); + return ERR_CAST(link); + } + priv->num_leds++; }