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