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

Dear Otavio Salvador,

On Wed, Jun 19, 2013 at 10:44 AM, Axel Lin axel.lin@ingics.com wrote:

...

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)]);
  
    return 0;
  
  

}

writel(value << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);

Should do no? This would avoid the if block.

No, you need clrbits_le32() to unset the GPIO

Best regards, Marek Vasut