sifive-gpio.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* SiFive GPIO driver
*
* Copyright (C) 2019 SiFive, Inc.
*/
#include <common.h>
#include <dm.h>
#include <asm/arch/gpio.h>
#include <asm/io.h>
#include <errno.h>
#include <asm/gpio.h>
static int sifive_gpio_probe(struct udevice *dev)
{
struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
char name[18], *str;
sprintf(name, "gpio@%4lx_", (uintptr_t)plat->base);
str = strdup(name);
if (!str)
return -ENOMEM;
uc_priv->bank_name = str;
/*
* Use the gpio count mentioned in device tree,
* if not specified in dt, set NR_GPIOS as default
*/
uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios", NR_GPIOS);
return 0;
}
static void sifive_update_gpio_reg(void *bptr, u32 offset, bool value)
{
void __iomem *ptr = (void __iomem *)bptr;
u32 bit = BIT(offset);
u32 old = readl(ptr);
if (value)
writel(old | bit, ptr);
else
writel(old & ~bit, ptr);
}
static int sifive_gpio_direction_input(struct udevice *dev, u32 offset)
{
struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
if (offset > uc_priv->gpio_count)
return -EINVAL;
/* Configure gpio direction as input */
sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN, offset, true);
sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, false);
return 0;
}
static int sifive_gpio_direction_output(struct udevice *dev, u32 offset,
int value)
{
struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
if (offset > uc_priv->gpio_count)
return -EINVAL;
/* Configure gpio direction as output */
sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, true);
sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN, offset, false);
/* Set the output state of the pin */
sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
return 0;
}
static int sifive_gpio_get_value(struct udevice *dev, u32 offset)
{
struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
int val;
int dir;
if (offset > uc_priv->gpio_count)
return -EINVAL;
/* Get direction of the pin */
dir = !(readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset));
if (dir)
val = readl(plat->base + GPIO_INPUT_VAL) & BIT(offset);
else
val = readl(plat->base + GPIO_OUTPUT_VAL) & BIT(offset);
return val ? HIGH : LOW;
}
static int sifive_gpio_set_value(struct udevice *dev, u32 offset, int value)
{
struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
if (offset > uc_priv->gpio_count)
return -EINVAL;
sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
return 0;
}
static int sifive_gpio_get_function(struct udevice *dev, unsigned int offset)
{
struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
u32 outdir, indir, val;
struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
if (offset > uc_priv->gpio_count)
return -1;
/* Get direction of the pin */
outdir = readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset);
indir = readl(plat->base + GPIO_INPUT_EN) & BIT(offset);
if (outdir)
/* Pin at specified offset is configured as output */
val = GPIOF_OUTPUT;
else if (indir)
/* Pin at specified offset is configured as input */
val = GPIOF_INPUT;
else
/*The requested GPIO is not set as input or output */
val = GPIOF_UNUSED;
return val;
}
static const struct udevice_id sifive_gpio_match[] = {
{ .compatible = "sifive,gpio0" },
{ }
};
static const struct dm_gpio_ops sifive_gpio_ops = {
.direction_input = sifive_gpio_direction_input,
.direction_output = sifive_gpio_direction_output,
.get_value = sifive_gpio_get_value,
.set_value = sifive_gpio_set_value,
.get_function = sifive_gpio_get_function,
};
static int sifive_gpio_ofdata_to_platdata(struct udevice *dev)
{
struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
fdt_addr_t addr;
addr = devfdt_get_addr(dev);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
plat->base = (void *)addr;
return 0;
}
U_BOOT_DRIVER(gpio_sifive) = {
.name = "gpio_sifive",
.id = UCLASS_GPIO,
.of_match = sifive_gpio_match,
.ofdata_to_platdata = of_match_ptr(sifive_gpio_ofdata_to_platdata),
.platdata_auto_alloc_size = sizeof(struct sifive_gpio_platdata),
.ops = &sifive_gpio_ops,
.probe = sifive_gpio_probe,
};