[U-Boot] gpio: Question about gpio_set_value() implementation in spear_gpio.c

Marek Vasut marex at denx.de
Wed Jun 19 15:49:01 CEST 2013


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


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