bcm2835_gpio.c
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/*
* Copyright (C) 2012 Vikram Narayananan
* <vikram186@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/gpio.h>
#include <asm/io.h>
inline int gpio_is_valid(unsigned gpio)
{
return (gpio < BCM2835_GPIO_COUNT);
}
int gpio_request(unsigned gpio, const char *label)
{
return !gpio_is_valid(gpio);
}
int gpio_free(unsigned gpio)
{
return 0;
}
int gpio_direction_input(unsigned gpio)
{
struct bcm2835_gpio_regs *reg =
(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
unsigned val;
val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
return 0;
}
int gpio_direction_output(unsigned gpio, int value)
{
struct bcm2835_gpio_regs *reg =
(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
unsigned val;
gpio_set_value(gpio, value);
val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
return 0;
}
int gpio_get_value(unsigned gpio)
{
struct bcm2835_gpio_regs *reg =
(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
unsigned val;
val = readl(®->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
}
int gpio_set_value(unsigned gpio, int value)
{
struct bcm2835_gpio_regs *reg =
(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
u32 *output_reg = value ? reg->gpset : reg->gpclr;
writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
&output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
return 0;
}