u-boot-brain/drivers/led/led_gpio.c
Simon Glass 8f4b612333 dm: led: Add support for getting the state of an LED
It is useful to be able to read the LED as well as write it. Add this to
the uclass and update the GPIO 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

130 lines
2.7 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);
if (!dm_gpio_is_valid(&priv->gpio))
return -EREMOTEIO;
switch (state) {
case LEDST_OFF:
case LEDST_ON:
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,
};