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

[Vipin Kumar]

On 6/19/2013 7:14 PM, Axel Lin 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)]);


Yes, this is the right way. It was a blunder. I am wondering no one ever 
tried to set a ZERO on any GPIO..

Thanks for pointing out

Regards
Vipin

        return 0;
  }




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