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

Axel Lin axel.lin at ingics.com
Wed Jun 19 15:44:13 CEST 2013


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;
 }





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