[RFT][PATCH 1/2] gpio: bcm-kona: Return error if requesting an already taken gpio

From: Axel Lin <axel.lin@ingics.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Ray Jui <rjui@broadcom.com>, Alexandre Courbot <gnurou@gmail.com>,
	bcm-kernel-feedback-list@broadcom.com,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>
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	[thread overview]
Message-ID: <1428629325.5384.1.camel@phoenix> (raw)

If a gpio is already taken, .gpio_request should return error.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
 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



