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