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"Das U-Boot" Source Tree
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2018 Xilinx, Inc. - Michal Simek
4 */
5
6#include <dm.h>
7#include <errno.h>
8#include <log.h>
9#include <sysreset.h>
10#include <asm/gpio.h>
11
12struct gpio_reboot_priv {
13 struct gpio_desc gpio;
14};
15
16static int gpio_reboot_request(struct udevice *dev, enum sysreset_t type)
17{
18 struct gpio_reboot_priv *priv = dev_get_priv(dev);
19 int ret;
20
21 /*
22 * When debug log is enabled please make sure that chars won't end up
23 * in output fifo. Or you can append udelay(); to get enough time
24 * to HW to emit output fifo.
25 */
26 debug("GPIO reset\n");
27
28 /* Writing 1 respects polarity (active high/low) based on gpio->flags */
29 ret = dm_gpio_set_value(&priv->gpio, 1);
30 if (ret < 0)
31 return ret;
32
33 return -EINPROGRESS;
34}
35
36static struct sysreset_ops gpio_reboot_ops = {
37 .request = gpio_reboot_request,
38};
39
40static int gpio_reboot_probe(struct udevice *dev)
41{
42 struct gpio_reboot_priv *priv = dev_get_priv(dev);
43
44 /*
45 * Linux kernel DT binding contain others optional properties
46 * which are not supported now
47 */
48
49 return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
50}
51
52static const struct udevice_id led_gpio_ids[] = {
53 { .compatible = "gpio-restart" },
54 { }
55};
56
57U_BOOT_DRIVER(gpio_reboot) = {
58 .id = UCLASS_SYSRESET,
59 .name = "gpio_restart",
60 .of_match = led_gpio_ids,
61 .ops = &gpio_reboot_ops,
62 .priv_auto = sizeof(struct gpio_reboot_priv),
63 .probe = gpio_reboot_probe,
64};