From patchwork Fri Apr 10 01:28:45 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Axel Lin X-Patchwork-Id: 459876 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 908BF14012F for ; Fri, 10 Apr 2015 11:28:52 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751881AbbDJB2v (ORCPT ); Thu, 9 Apr 2015 21:28:51 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:36366 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751310AbbDJB2u (ORCPT ); Thu, 9 Apr 2015 21:28:50 -0400 Received: by pdea3 with SMTP id a3so5694295pde.3 for ; Thu, 09 Apr 2015 18:28:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:subject:from:to:cc:date:content-type :mime-version:content-transfer-encoding; bh=MIDI4UTaKbgmy3DOKpPhXUHjtlZU6gcAfpHq4xRQyEQ=; b=ZYOv6ao6QOLkG7mzxvCKxaxKyN+38kYNw5nYLl3/FKFHlyHvxiioQrZ85UIugF4EAM Ds6KUst3+8icn4+hoYxCxo7uZxYCDrIVCaiPHqHHntMcTllSi46oGz/kDA0qRwpBhtEl 010jllZNnxKZWsRbVvIG6PHPCqO78LBc5GDL5r0jgsu7aQR70MfuHI4OektXmOFSP4gQ rCzCtb7zuQXHm17IXt4lfH/dpiK+WbGsVkJcdamG5I6wzYZakCzyh9Zm1NzJVrBN8CXL fVEGEtknsAc0fkgz9LLOYJnMGuP+WkcTqgTHIrjldBlxWtvEveOPxZNH00LK5CKUgqQS JW7A== X-Gm-Message-State: ALoCoQleUZ5mtD1OSvIx7ADso6/pD4AZuS1BdTquAgSeETCkqnIqG1Sh+Lbqm5q5b/6c7ryg62hl X-Received: by 10.70.32.164 with SMTP id k4mr33919687pdi.138.1428629330318; Thu, 09 Apr 2015 18:28:50 -0700 (PDT) Received: from [192.168.0.104] (36-239-215-205.dynamic-ip.hinet.net. [36.239.215.205]) by mx.google.com with ESMTPSA id ot6sm298223pdb.28.2015.04.09.18.28.47 (version=TLSv1.2 cipher=AES128-GCM-SHA256 bits=128/128); Thu, 09 Apr 2015 18:28:49 -0700 (PDT) Message-ID: <1428629325.5384.1.camel@phoenix> Subject: [RFT][PATCH 1/2] gpio: bcm-kona: Return error if requesting an already taken gpio From: Axel Lin To: Linus Walleij Cc: Ray Jui , Alexandre Courbot , bcm-kernel-feedback-list@broadcom.com, "linux-gpio@vger.kernel.org" Date: Fri, 10 Apr 2015 09:28:45 +0800 X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org If a gpio is already taken, .gpio_request should return error. Signed-off-by: Axel Lin --- drivers/gpio/gpio-bcm-kona.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c index b164ce8..632352d 100644 --- a/drivers/gpio/gpio-bcm-kona.c +++ b/drivers/gpio/gpio-bcm-kona.c @@ -106,7 +106,7 @@ static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio, spin_unlock_irqrestore(&kona_gpio->lock, flags); } -static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, +static int bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, unsigned gpio) { u32 val; @@ -116,10 +116,17 @@ static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio, spin_lock_irqsave(&kona_gpio->lock, flags); val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id)); + if (!(val & BIT(gpio))) { + spin_unlock_irqrestore(&kona_gpio->lock, flags); + return -EBUSY; + } + val &= ~BIT(gpio); bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val); spin_unlock_irqrestore(&kona_gpio->lock, flags); + + return 0; } static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value) @@ -185,8 +192,7 @@ static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio) { struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip); - bcm_kona_gpio_unlock_gpio(kona_gpio, gpio); - return 0; + return bcm_kona_gpio_unlock_gpio(kona_gpio, gpio); } static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)