From mboxrd@z Thu Jan 1 00:00:00 1970 From: Axel Lin Subject: [RFT][PATCH 1/2] gpio: bcm-kona: Return error if requesting an already taken gpio Date: Fri, 10 Apr 2015 09:28:45 +0800 Message-ID: <1428629325.5384.1.camel@phoenix> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: 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) Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: Linus Walleij Cc: Ray Jui , Alexandre Courbot , bcm-kernel-feedback-list@broadcom.com, "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) -- 1.9.1