u-boot/drivers/gpio/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 <dm.h>
#include <errno.h>
#include <asm/gpio.h>
#include <asm/io.h>
struct bcm2835_gpios {
struct bcm2835_gpio_regs *reg;
};
static int bcm2835_gpio_direction_input(struct udevice *dev, unsigned gpio)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
unsigned val;
val = readl(&gpios->reg->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, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
return 0;
}
static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned gpio,
int value)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
unsigned val;
gpio_set_value(gpio, value);
val = readl(&gpios->reg->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, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
return 0;
}
static bool bcm2835_gpio_is_output(const struct bcm2835_gpios *gpios, int gpio)
{
u32 val;
val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
val &= BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio);
return val ? true : false;
}
static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio)
{
unsigned val;
val = readl(&gpios->reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
}
static int bcm2835_gpio_get_value(struct udevice *dev, unsigned gpio)
{
const struct bcm2835_gpios *gpios = dev_get_priv(dev);
return bcm2835_get_value(gpios, gpio);
}
static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio,
int value)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
u32 *output_reg = value ? gpios->reg->gpset : gpios->reg->gpclr;
writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
&output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
return 0;
}
static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
/* GPIOF_FUNC is not implemented yet */
if (bcm2835_gpio_is_output(gpios, offset))
return GPIOF_OUTPUT;
else
return GPIOF_INPUT;
}
static const struct dm_gpio_ops gpio_bcm2835_ops = {
.direction_input = bcm2835_gpio_direction_input,
.direction_output = bcm2835_gpio_direction_output,
.get_value = bcm2835_gpio_get_value,
.set_value = bcm2835_gpio_set_value,
.get_function = bcm2835_gpio_get_function,
};
static int bcm2835_gpio_probe(struct udevice *dev)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
uc_priv->bank_name = "GPIO";
uc_priv->gpio_count = BCM2835_GPIO_COUNT;
gpios->reg = (struct bcm2835_gpio_regs *)plat->base;
return 0;
}
U_BOOT_DRIVER(gpio_bcm2835) = {
.name = "gpio_bcm2835",
.id = UCLASS_GPIO,
.ops = &gpio_bcm2835_ops,
.probe = bcm2835_gpio_probe,
.priv_auto_alloc_size = sizeof(struct bcm2835_gpios),
};