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

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Philippe Reynes <philippe.reynes@softathome.com>
*/
#include <common.h>
#include <button.h>
#include <dm.h>
#include <dm/lists.h>
#include <dm/uclass-internal.h>
#include <log.h>
#include <asm/gpio.h>
struct button_gpio_priv {
struct gpio_desc gpio;
int linux_code;
};
static enum button_state_t button_gpio_get_state(struct udevice *dev)
{
struct button_gpio_priv *priv = dev_get_priv(dev);
int ret;
if (!dm_gpio_is_valid(&priv->gpio))
return -EREMOTEIO;
ret = dm_gpio_get_value(&priv->gpio);
if (ret < 0)
return ret;
return ret ? BUTTON_ON : BUTTON_OFF;
}
static int button_gpio_get_code(struct udevice *dev)
{
struct button_gpio_priv *priv = dev_get_priv(dev);
int code = priv->linux_code;
if (!code)
return -ENODATA;
return code;
}
static int button_gpio_probe(struct udevice *dev)
{
struct button_uc_plat *uc_plat = dev_get_uclass_plat(dev);
struct button_gpio_priv *priv = dev_get_priv(dev);
int ret;
/* Ignore the top-level button node */
if (!uc_plat->label)
return 0;
ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_IN);
if (ret)
return ret;
ret = dev_read_u32(dev, "linux,code", &priv->linux_code);
return ret;
}
static int button_gpio_remove(struct udevice *dev)
{
/*
* The GPIO driver may have already been removed. We will need to
* address this more generally.
*/
if (!IS_ENABLED(CONFIG_SANDBOX)) {
struct button_gpio_priv *priv = dev_get_priv(dev);
if (dm_gpio_is_valid(&priv->gpio))
dm_gpio_free(dev, &priv->gpio);
}
return 0;
}
static int button_gpio_bind(struct udevice *parent)
{
struct udevice *dev;
ofnode node;
int ret;
dev_for_each_subnode(node, parent) {
struct button_uc_plat *uc_plat;
const char *label;
label = ofnode_read_string(node, "label");
if (!label) {
debug("%s: node %s has no label\n", __func__,
ofnode_get_name(node));
return -EINVAL;
}
ret = device_bind_driver_to_node(parent, "button_gpio",
ofnode_get_name(node),
node, &dev);
if (ret)
return ret;
uc_plat = dev_get_uclass_plat(dev);
uc_plat->label = label;
}
return 0;
}
static const struct button_ops button_gpio_ops = {
.get_state = button_gpio_get_state,
.get_code = button_gpio_get_code,
};
static const struct udevice_id button_gpio_ids[] = {
{ .compatible = "gpio-keys" },
{ .compatible = "gpio-keys-polled" },
{ }
};
U_BOOT_DRIVER(button_gpio) = {
.name = "button_gpio",
.id = UCLASS_BUTTON,
.of_match = button_gpio_ids,
.ops = &button_gpio_ops,
.priv_auto = sizeof(struct button_gpio_priv),
.bind = button_gpio_bind,
.probe = button_gpio_probe,
.remove = button_gpio_remove,
};