From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marek Vasut <marex@denx.de>
Date: Wed, 19 Jun 2013 15:49:01 +0200
Subject: [U-Boot] gpio: Question about gpio_set_value() implementation
	in spear_gpio.c
In-Reply-To: <1371649453.2126.2.camel@phoenix>
References: <1371649453.2126.2.camel@phoenix>
Message-ID: <201306191549.01906.marex@denx.de>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

Dear Axel Lin,

> Current code looks strange because no matter the value argument is 0 or 1
> it always calls
> 	writel(1 << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
> 
> And then gpio_get_value() always return 1.
> 
> I'm wondering if it needs to be fixed, something like below change:
> 
> diff --git a/drivers/gpio/spear_gpio.c b/drivers/gpio/spear_gpio.c
> index d3c728e..8878608 100644
> --- a/drivers/gpio/spear_gpio.c
> +++ b/drivers/gpio/spear_gpio.c
> @@ -52,7 +52,10 @@ int gpio_set_value(unsigned gpio, int value)
>  {
>  	struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
> 
> -	writel(1 << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
> +	if (value)
> +		writel(1 << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
> +	else
> +		writel(0, &regs->gpiodata[DATA_REG_ADDR(gpio)]);


You might want to use clrbits_le32() and setbits_le32() here, no?

>  	return 0;
>  }

Best regards,
Marek Vasut