u-boot/drivers/led/led_gpio.c
Simon Glass 9413ad4f0d dm: led: Support toggling LEDs
Add support for toggling an LED into the uclass interface. This can be
efficiently implemented by the driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ziping Chen <techping.chan@gmail.com>
2017-04-14 19:38:57 -06:00

136 lines
2.8 KiB
C

/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <led.h>
#include <asm/gpio.h>
#include <dm/lists.h>
DECLARE_GLOBAL_DATA_PTR;
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);
/* Ignore the top-level LED node */
if (!uc_plat->label)
return 0;
return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
}
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)
{
const void *blob = gd->fdt_blob;
struct udevice *dev;
int node;
int ret;
for (node = fdt_first_subnode(blob, dev_of_offset(parent));
node > 0;
node = fdt_next_subnode(blob, node)) {
struct led_uc_plat *uc_plat;
const char *label;
label = fdt_getprop(blob, node, "label", NULL);
if (!label) {
debug("%s: node %s has no label\n", __func__,
fdt_get_name(blob, node, NULL));
return -EINVAL;
}
ret = device_bind_driver_to_node(parent, "gpio_led",
fdt_get_name(blob, node, NULL),
node, &dev);
if (ret)
return ret;
uc_plat = dev_get_uclass_platdata(dev);
uc_plat->label = label;
}
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,
};