u-boot/drivers/gpio/spear_gpio.c
Axel Lin c0c374024d gpio: spear_gpio: Fix gpio_set_value() implementation
In current gpio_set_value() implementation, it always sets the gpio control bit
no matter the value argument is 0 or 1. Thus the GPIOs never set to low.
This patch fixes this bug.

The address bus is used as a mask on read/write operations, so that independent
software drivers can set their GPIO bits without affecting any other pins in a
single write operation. Thus we don't need a read-modify-write to update the
register.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Stefan Roese <sr@denx.de>
Reviewed-by: Vipin Kumar <vipin.kumar@st.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
2014-07-04 21:37:29 +02:00

90 lines
1.5 KiB
C

/*
* Copyright (C) 2012 Stefan Roese <sr@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Driver for SPEAr600 GPIO controller
*/
#include <common.h>
#include <asm/arch/hardware.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <errno.h>
static int gpio_direction(unsigned gpio,
enum gpio_direction direction)
{
struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
u32 val;
val = readl(&regs->gpiodir);
if (direction == GPIO_DIRECTION_OUT)
val |= 1 << gpio;
else
val &= ~(1 << gpio);
writel(val, &regs->gpiodir);
return 0;
}
int gpio_set_value(unsigned gpio, int value)
{
struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
if (value)
writel(1 << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
else
writel(0, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
return 0;
}
int gpio_get_value(unsigned gpio)
{
struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
u32 val;
val = readl(&regs->gpiodata[DATA_REG_ADDR(gpio)]);
return !!val;
}
int gpio_request(unsigned gpio, const char *label)
{
if (gpio >= SPEAR_GPIO_COUNT)
return -EINVAL;
return 0;
}
int gpio_free(unsigned gpio)
{
return 0;
}
void gpio_toggle_value(unsigned gpio)
{
gpio_set_value(gpio, !gpio_get_value(gpio));
}
int gpio_direction_input(unsigned gpio)
{
return gpio_direction(gpio, GPIO_DIRECTION_IN);
}
int gpio_direction_output(unsigned gpio, int value)
{
int ret = gpio_direction(gpio, GPIO_DIRECTION_OUT);
if (ret < 0)
return ret;
gpio_set_value(gpio, value);
return 0;
}