u-boot/drivers/gpio/gpio-uclass.c

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/*
* Copyright (c) 2013 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <asm/gpio.h>
/**
* gpio_to_device() - Convert global GPIO number to device, number
* gpio: The numeric representation of the GPIO
*
* Convert the GPIO number to an entry in the list of GPIOs
* or GPIO blocks registered with the GPIO controller. Returns
* entry on success, NULL on error.
*/
static int gpio_to_device(unsigned int gpio, struct udevice **devp,
unsigned int *offset)
{
struct gpio_dev_priv *uc_priv;
struct udevice *dev;
int ret;
for (ret = uclass_first_device(UCLASS_GPIO, &dev);
dev;
ret = uclass_next_device(&dev)) {
uc_priv = dev->uclass_priv;
if (gpio >= uc_priv->gpio_base &&
gpio < uc_priv->gpio_base + uc_priv->gpio_count) {
*devp = dev;
*offset = gpio - uc_priv->gpio_base;
return 0;
}
}
/* No such GPIO */
return ret ? ret : -EINVAL;
}
int gpio_lookup_name(const char *name, struct udevice **devp,
unsigned int *offsetp, unsigned int *gpiop)
{
struct gpio_dev_priv *uc_priv;
struct udevice *dev;
int ret;
if (devp)
*devp = NULL;
for (ret = uclass_first_device(UCLASS_GPIO, &dev);
dev;
ret = uclass_next_device(&dev)) {
ulong offset;
int len;
uc_priv = dev->uclass_priv;
len = uc_priv->bank_name ? strlen(uc_priv->bank_name) : 0;
if (!strncmp(name, uc_priv->bank_name, len)) {
if (strict_strtoul(name + len, 10, &offset))
continue;
if (devp)
*devp = dev;
if (offsetp)
*offsetp = offset;
if (gpiop)
*gpiop = uc_priv->gpio_base + offset;
return 0;
}
}
return ret ? ret : -EINVAL;
}
/**
* gpio_request() - [COMPAT] Request GPIO
* gpio: GPIO number
* label: Name for the requested GPIO
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_request(unsigned gpio, const char *label)
{
unsigned int offset;
struct udevice *dev;
int ret;
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
if (!gpio_get_ops(dev)->request)
return 0;
return gpio_get_ops(dev)->request(dev, offset, label);
}
/**
* gpio_free() - [COMPAT] Relinquish GPIO
* gpio: GPIO number
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_free(unsigned gpio)
{
unsigned int offset;
struct udevice *dev;
int ret;
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
if (!gpio_get_ops(dev)->free)
return 0;
return gpio_get_ops(dev)->free(dev, offset);
}
/**
* gpio_direction_input() - [COMPAT] Set GPIO direction to input
* gpio: GPIO number
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_direction_input(unsigned gpio)
{
unsigned int offset;
struct udevice *dev;
int ret;
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
return gpio_get_ops(dev)->direction_input(dev, offset);
}
/**
* gpio_direction_output() - [COMPAT] Set GPIO direction to output and set value
* gpio: GPIO number
* value: Logical value to be set on the GPIO pin
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_direction_output(unsigned gpio, int value)
{
unsigned int offset;
struct udevice *dev;
int ret;
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
return gpio_get_ops(dev)->direction_output(dev, offset, value);
}
/**
* gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
* gpio: GPIO number
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns the value of the GPIO pin, or negative value
* on error.
*/
int gpio_get_value(unsigned gpio)
{
unsigned int offset;
struct udevice *dev;
int ret;
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
return gpio_get_ops(dev)->get_value(dev, offset);
}
/**
* gpio_set_value() - [COMPAT] Configure logical value on GPIO pin
* gpio: GPIO number
* value: Logical value to be set on the GPIO pin.
*
* This function implements the API that's compatible with current
* GPIO API used in U-Boot. The request is forwarded to particular
* GPIO driver. Returns 0 on success, negative value on error.
*/
int gpio_set_value(unsigned gpio, int value)
{
unsigned int offset;
struct udevice *dev;
int ret;
ret = gpio_to_device(gpio, &dev, &offset);
if (ret)
return ret;
return gpio_get_ops(dev)->set_value(dev, offset, value);
}
const char *gpio_get_bank_info(struct udevice *dev, int *bit_count)
{
struct gpio_dev_priv *priv;
/* Must be called on an active device */
priv = dev->uclass_priv;
assert(priv);
*bit_count = priv->gpio_count;
return priv->bank_name;
}
/* We need to renumber the GPIOs when any driver is probed/removed */
static int gpio_renumber(void)
{
struct gpio_dev_priv *uc_priv;
struct udevice *dev;
struct uclass *uc;
unsigned base;
int ret;
ret = uclass_get(UCLASS_GPIO, &uc);
if (ret)
return ret;
/* Ensure that we have a base for each bank */
base = 0;
uclass_foreach_dev(dev, uc) {
if (device_active(dev)) {
uc_priv = dev->uclass_priv;
uc_priv->gpio_base = base;
base += uc_priv->gpio_count;
}
}
return 0;
}
static int gpio_post_probe(struct udevice *dev)
{
return gpio_renumber();
}
static int gpio_pre_remove(struct udevice *dev)
{
return gpio_renumber();
}
UCLASS_DRIVER(gpio) = {
.id = UCLASS_GPIO,
.name = "gpio",
.post_probe = gpio_post_probe,
.pre_remove = gpio_pre_remove,
.per_device_auto_alloc_size = sizeof(struct gpio_dev_priv),
};