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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>
#define GPIO_NAME_SIZE 20
struct bcm2835_gpios {
char label[BCM2835_GPIO_COUNT][GPIO_NAME_SIZE];
struct bcm2835_gpio_regs *reg;
};
/**
* gpio_is_requested() - check if a GPIO has been requested
*
* @bank: Bank to check
* @offset: GPIO offset within bank to check
* @return true if marked as requested, false if not
*/
static inline bool gpio_is_requested(struct bcm2835_gpios *gpios, int offset)
{
return *gpios->label[offset] != '\0';
}
static int check_requested(struct udevice *dev, unsigned offset,
const char *func)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
if (!gpio_is_requested(gpios, offset)) {
printf("omap_gpio: %s: error: gpio %s%d not requested\n",
func, uc_priv->bank_name, offset);
return -EPERM;
}
return 0;
}
static int bcm2835_gpio_request(struct udevice *dev, unsigned offset,
const char *label)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
if (gpio_is_requested(gpios, offset))
return -EBUSY;
strncpy(gpios->label[offset], label, GPIO_NAME_SIZE);
gpios->label[offset][GPIO_NAME_SIZE - 1] = '\0';
return 0;
}
static int bcm2835_gpio_free(struct udevice *dev, unsigned offset)
{
struct bcm2835_gpios *gpios = dev_get_priv(dev);
int ret;
ret = check_requested(dev, offset, __func__);
if (ret)
return ret;
gpios->label[offset][0] = '\0';
return 0;
}
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);
if (!gpio_is_requested(gpios, offset))
return GPIOF_UNUSED;
/* GPIOF_FUNC is not implemented yet */
if (bcm2835_gpio_is_output(gpios, offset))
return GPIOF_OUTPUT;
else
return GPIOF_INPUT;
}
static int bcm2835_gpio_get_state(struct udevice *dev, unsigned int offset,
char *buf, int bufsize)
{
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
struct bcm2835_gpios *gpios = dev_get_priv(dev);
const char *label;
bool requested;
bool is_output;
int size;
label = gpios->label[offset];
is_output = bcm2835_gpio_is_output(gpios, offset);
size = snprintf(buf, bufsize, "%s%d: ",
uc_priv->bank_name ? uc_priv->bank_name : "", offset);
buf += size;
bufsize -= size;
requested = gpio_is_requested(gpios, offset);
snprintf(buf, bufsize, "%s: %d [%c]%s%s",
is_output ? "out" : " in",
bcm2835_get_value(gpios, offset),
requested ? 'x' : ' ',
requested ? " " : "",
label);
return 0;
}
static const struct dm_gpio_ops gpio_bcm2835_ops = {
.request = bcm2835_gpio_request,
.free = bcm2835_gpio_free,
.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,
.get_state = bcm2835_gpio_get_state,
};
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),
};
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