From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vipin Kumar Date: Thu, 20 Jun 2013 09:22:04 +0530 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: <51C27C64.3060306@st.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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,®s->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,®s->gpiodata[DATA_REG_ADDR(gpio)]); > + if (value) > + writel(1<< gpio,®s->gpiodata[DATA_REG_ADDR(gpio)]); > + else > + writel(0,®s->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; > } > > >