u-boot/drivers/led/led_gpio.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <led.h>
#include <asm/gpio.h>
#include <dm/lists.h>
#include <dm/uclass-internal.h>
struct led_gpio_priv {
struct gpio_desc gpio;
};
static int gpio_led_set_state(struct udevice *dev, enum led_state_t state)
{
struct led_gpio_priv *priv = dev_get_priv(dev);
int ret;
if (!dm_gpio_is_valid(&priv->gpio))
return -EREMOTEIO;
switch (state) {
case LEDST_OFF:
case LEDST_ON:
break;
case LEDST_TOGGLE:
ret = dm_gpio_get_value(&priv->gpio);
if (ret < 0)
return ret;
state = !ret;
break;
default:
return -ENOSYS;
}
return dm_gpio_set_value(&priv->gpio, state);
}
static enum led_state_t gpio_led_get_state(struct udevice *dev)
{
struct led_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 ? LEDST_ON : LEDST_OFF;
}
static int led_gpio_probe(struct udevice *dev)
{
struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
struct led_gpio_priv *priv = dev_get_priv(dev);
const char *default_state;
int ret;
/* Ignore the top-level LED node */
if (!uc_plat->label)
return 0;
ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
if (ret)
return ret;
default_state = dev_read_string(dev, "default-state");
if (default_state) {
if (!strncmp(default_state, "on", 2))
gpio_led_set_state(dev, LEDST_ON);
else if (!strncmp(default_state, "off", 3))
gpio_led_set_state(dev, LEDST_OFF);
}
return 0;
}
static int led_gpio_remove(struct udevice *dev)
{
/*
* The GPIO driver may have already been removed. We will need to
* address this more generally.
*/
#ifndef CONFIG_SANDBOX
struct led_gpio_priv *priv = dev_get_priv(dev);
if (dm_gpio_is_valid(&priv->gpio))
dm_gpio_free(dev, &priv->gpio);
#endif
return 0;
}
static int led_gpio_bind(struct udevice *parent)
{
struct udevice *dev;
ofnode node;
int ret;
dev_for_each_subnode(node, parent) {
struct led_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, "gpio_led",
ofnode_get_name(node),
node, &dev);
if (ret)
return ret;
uc_plat = dev_get_uclass_platdata(dev);
uc_plat->label = label;
if (ofnode_read_bool(node, "default-state")) {
struct udevice *devp;
ret = uclass_get_device_tail(dev, 0, &devp);
if (ret)
return ret;
}
}
return 0;
}
static const struct led_ops gpio_led_ops = {
.set_state = gpio_led_set_state,
.get_state = gpio_led_get_state,
};
static const struct udevice_id led_gpio_ids[] = {
{ .compatible = "gpio-leds" },
{ }
};
U_BOOT_DRIVER(led_gpio) = {
.name = "gpio_led",
.id = UCLASS_LED,
.of_match = led_gpio_ids,
.ops = &gpio_led_ops,
.priv_auto_alloc_size = sizeof(struct led_gpio_priv),
.bind = led_gpio_bind,
.probe = led_gpio_probe,
.remove = led_gpio_remove,
};